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					REMEDIAL ACTION CONTRACT
United States Environmental Protection Agency Region 6

              Contract No. EP-W-06-021


                                    Draft-Final Feasibility Study Report

                                         Tar Creek Superfund Site
                                              Operable Unit 4
                                         Ottawa County, Oklahoma

                                Remedial Action Contract No. EP-W-06-021
                                    Task Order No. 0011-RICO-06JW

                                                   July 2007




                        In Association With:
                        Weston Solutions, Inc.
                        Geo-Marine, Inc.
                        E2 Consulting Engineers, Inc.
                        Arrowhead Contracting, Inc.
             DRAFT FINAL
            Feasibility Study


       Tar Creek Superfund Site
          Operable Unit No. 4
       Ottawa County, Oklahoma


Remedial Action Contract No. EP-W-06-021
    Task Order No. 0011-RICO-06JW
            DCN 0011-02011


              Prepared for:
  U.S. Environmental Protection Agency



         Revision Prepared by:




               July 2007
                                                                                     TAR CREEK SUPERFUND SITE
                                                                                            OPERABLE UNIT NO. 4
                                                                                   DRAFT-FINAL FEASIBILITY STUDY




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Acknowledgement

This report is a revision to the original report prepared by AATA International, Inc. (AATA), titled
Draft: Feasibility Study (FS) Report Tar Creek OU4 RI/FS Program, dated December 2005. This
report revision uses the original data presented in the report. Figures presented used aerial
photography provided by AATA. The report revision was prepared under EPA Contract No. EP-W-
06-021, Task Order No. 0011-RICO-06JW.




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Table of Contents

1.0     Introduction ...............................................................................................................................1-1
        1.1      Mining History.................................................................................................................1-1
        1.2      Regulatory Framework ....................................................................................................1-2
        1.3      Report Organization.........................................................................................................1-3
2.0     Remedial Investigation Summary..............................................................................................2-1
        2.1      Investigations ...................................................................................................................2-1
                 2.1.1 Remedial Investigation Reports..........................................................................2-1
                 2.1.2 Human Health Risk Assessment.........................................................................2-1
                 2.1.3 Ecological Risk Assessment ...............................................................................2-2
                 2.1.4 Other Investigations and Studies ........................................................................2-2
        2.2      Physical Setting................................................................................................................2-3
        2.3      Source Materials ..............................................................................................................2-5
                 2.3.1 Chat Piles ............................................................................................................2-5
                 2.3.2 Chat Bases ..........................................................................................................2-6
                 2.3.3 Fine Tailings .......................................................................................................2-6
                 2.3.4 Smelter Wastes ...................................................................................................2-7
        2.4      Affected Media ................................................................................................................2-8
                 2.4.1 Soils ....................................................................................................................2-8
                         2.4.1.1 Transition Zone Soils ..........................................................................2-8
                         2.4.1.2 Smelter-Waste Affected Soils .............................................................2-8
                         2.4.1.3 Rural Residence Yard Soils.................................................................2-9
                 2.4.2 Ground Water .....................................................................................................2-9
                 2.4.3 Surface Water ...................................................................................................2-10
                 2.4.4 Biota..................................................................................................................2-10
3.0     Remedial Action Objectives ......................................................................................................3-1
        3.1      RAO Guidance.................................................................................................................3-1
                 3.1.1 Contaminants of Potential Concern ....................................................................3-1
                 3.1.2 Exposure Routes and Receptors .........................................................................3-1
                        3.1.2.1 Possible Human Exposure Routes and Receptors ...............................3-1
                        3.1.2.2 Possible Ecological Exposure Route and Receptors ...........................3-3
                 3.1.3 Site Clean-up Standards......................................................................................3-3
                        3.1.3.1 Source Materials and Affected Soils ...................................................3-3
                        3.1.3.2 Surface Water and Sediments..............................................................3-5
                        3.1.3.3 Use of Shallow Ground Water.............................................................3-6
                        3.1.3.4 Air........................................................................................................3-6
        3.2      Media-Specific RAOs......................................................................................................3-6
                 3.2.1 Source Material RAOs........................................................................................3-6
                 3.2.2 Affected Soils RAOs ..........................................................................................3-7
                 3.2.3 Use of Shallow Ground Water RAOs.................................................................3-8
4.0     Identification and Screening of Remedial Technologies...........................................................4-1
        4.1      Identification of General Response Actions and Remedial Technologies.......................4-2
                 4.1.1 Presumptive Remedies........................................................................................4-2
                 4.1.2 Source Materials and Affected Soils Technologies ............................................4-4

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                4.1.3 Surface-Water Technologies...............................................................................4-7
                4.1.4 Ground Water Technologies .............................................................................4-10
        4.2     Initial Technology Screening.........................................................................................4-12
                4.2.1 Initial Screening of Source Material and Affected Soils Technologies............4-13
                4.2.2 Initial Screening of Surface Water Technologies .............................................4-14
                4.2.3 Initial Screening of Ground Water Technologies .............................................4-15
        4.3     Final Screening of Potentially Applicable Technologies...............................................4-16
                4.3.1 Final Screening of Source Material and Affected Soils Technologies .............4-16
                4.3.2 Final Screening of Surface Water Technologies ..............................................4-18
                4.3.3 Final Screening of Ground Water Technologies ..............................................4-19
        4.4     Framework for Institutional Controls ............................................................................4-19
                4.4.1 Source Material and Affected Soils Institutional Controls ...............................4-20
                         4.4.1.1 Land Use Restriction to Protect Engineered Components ................4-20
                         4.4.1.2 Land Use Restriction, Zoning Regulations, and Health
                                  Ordinances to Enhance the Remedy’s Protectiveness of Human
                                  Health. ..............................................................................................4-21
                4.4.2 Ground Water Institutional Controls ................................................................4-21
5.0     Development and Screening of Candidate Remedial Alternatives............................................5-1
        5.1     Development of Candidate Remedial Alternatives..........................................................5-2
                5.1.1 Defining Source Material and Affected Media Categories.................................5-2
                5.1.2 Development of Candidate Alternatives.............................................................5-5
        5.2     Initial Screening of Candidate Remedial Alternatives.....................................................5-6
                5.2.1 Summary of Initial Screening .............................................................................5-7
6.0     Detailed Description of Remedial Alternatives .........................................................................6-1
        6.1     Key Assumptions Applicable to all Alternatives.............................................................6-3
                6.1.1 Commercial Chat Processing..............................................................................6-3
                6.1.2 Watershed Management ....................................................................................6-5
        6.2     Detailed Description of Alternative 1: No Further Action ..............................................6-6
                6.2.1 Alternative 1 Rationale .......................................................................................6-6
                6.2.2 Detailed Description of Alternative 1 .................................................................6-7
                        6.2.2.1 Chat Processing ...................................................................................6-7
                        6.2.2.2 Other Site Source Materials and Affected Media................................6-8
                        6.2.2.3 Residential Yard Soil...........................................................................6-8
                        6.2.2.4 Oklahoma Plan ....................................................................................6-8
                        6.2.2.5 Pilot and Treatability Studies ..............................................................6-9
                        6.2.2.6 Ongoing Monitoring............................................................................6-9
                        6.2.2.7 2005 State Buyout ...............................................................................6-9
        6.3     Detailed Description of Alternative 4: Phased Consolidation, On-site Disposal
                and Institutional Controls.................................................................................................6-9
                6.3.1 Alternative 4 Rationale .....................................................................................6-10
                6.3.2 Detailed Description of Alternative 4 ...............................................................6-11
                6.3.3 Phase 1 Elements ..............................................................................................6-11
                        6.3.3.1 Remedial Actions in Distal Areas .....................................................6-11
                        6.3.3.2 Smelter Waste Remedial Actions ......................................................6-12
                        6.3.3.3 Fine Tailings Remedial Actions ........................................................6-13
                        6.3.3.4 Hydrogeologic Study.........................................................................6-13
                        6.3.3.5 Remedial Actions Addressing Source Materials Present in Site
                                   Creeks ...............................................................................................6-14



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                        6.3.3.6 Remedial Actions Addressing Rural Residential Wells ....................6-14
                        6.3.3.7 Remedial Actions Addressing Rural Residential Yard Soil ..............6-14
                        6.3.3.8 Construction of an On-site Repository ..............................................6-15
                        6.3.3.9 Five Year Reviews ............................................................................6-15
                6.3.4 Phase 2 Elements ..............................................................................................6-15
                        6.3.4.1 Remedial Actions Addressing Non-Marketable Chat .......................6-15
                6.3.5 Other Planned Actions Common to Both Phases .............................................6-17
        6.4     Detailed Description of Alternative 5: Voluntary Relocation, Phased
                Consolidation, On-site Disposal and Institutional Controls...........................................6-18
                6.4.1 Alternative 5 Rationale .....................................................................................6-18
                6.4.2 Voluntary Relocation........................................................................................6-18
                6.4.3 Remedial Actions..............................................................................................6-20
                6.4.4 Detailed Description of Alternative 5 ...............................................................6-20
                        6.4.4.1 Voluntary Relocation.........................................................................6-20
                        6.4.4.2 Remedial Actions ..............................................................................6-21
        6.5     Detailed Description of Alternative 8: Total Source Consolidation, On-site
                Disposal, and Institutional Controls...............................................................................6-22
                6.5.1 Alternative 8 Rationale .....................................................................................6-22
                6.5.2 Detailed Description of Alternative 8 ...............................................................6-22
                        6.5.2.1 Chat Remedial Actions......................................................................6-22
                        6.5.2.2 Fine Tailings Remedial Actions ........................................................6-23
                        6.5.2.3 Smelter Waste and Affected Soils Remedial Actions .......................6-24
                        6.5.2.4 Site Affected Soils.............................................................................6-24
                        6.5.2.5 Remedial Actions Addressing Rural Residential Yard Soil ..............6-24
                        6.5.2.6 Remedial Actions Addressing Rural Residential Wells ....................6-24
7.0     Detailed Analysis of Alternatives..............................................................................................7-1
        7.1     Detailed Analysis Process................................................................................................7-1
                7.1.1 Threshold Criteria ...............................................................................................7-2
                        7.1.1.1 Overall Protection of Human Health and the Environment.................7-3
                        7.1.1.2 Compliance with ARARs ....................................................................7-3
                        7.1.1.3 Surface Water ARARs ........................................................................7-4
                        7.1.1.4 Ground Water ARARs ........................................................................7-4
                        7.1.1.5 Source Materials..................................................................................7-4
                        7.1.1.6 Relocation............................................................................................7-5
                7.1.2 Primary Balancing Criteria .................................................................................7-5
                        7.1.2.1 Long-Term Effectiveness and Permanence .........................................7-6
                        7.1.2.2 Adequacy and Reliability of Controls .................................................7-7
                        7.1.2.3 Short-Term Effectiveness ....................................................................7-9
                        7.1.2.4 Reduction of Toxicity, Mobility, or Volume.......................................7-9
                        7.1.2.5 Implementability................................................................................7-10
                        7.1.2.6 Cost....................................................................................................7-11
                7.1.3 Modifying Criteria ............................................................................................7-11
        7.2     Detailed Analysis of Alternative 1: No Further Action .................................................7-12
                7.2.1 Alternative 1: Threshold Criteria Evaluations ..................................................7-12
                        7.2.1.1 Overall Protectiveness of Human Health and the Environment ........7-12
                        7.2.1.2 Compliance with ARARs ..................................................................7-13
                7.2.2 Alternative 1: Primary Balancing Criteria Evaluations ....................................7-14
                        7.2.2.1 Long-Term Effectiveness and Permanence .......................................7-14
                        7.2.2.2 Short-Term Effectiveness ..................................................................7-15
                        7.2.2.3 Reduction of Toxicity, Mobility, or Volume through Treatment ......7-16

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                         7.2.2.4 Implementability................................................................................7-16
                         7.2.2.5 Cost....................................................................................................7-16
                7.2.3 Alternative 1: Modifying Criteria Evaluations .................................................7-16
                         7.2.3.1 State Acceptance ...............................................................................7-16
                         7.2.3.2 Public Acceptance .............................................................................7-16
        7.3     Detailed Analysis of Alternative 4: Phased Consolidation, On-site Disposal and
                Institutional Controls .....................................................................................................7-16
                7.3.1 Alternative 4: Threshold Criteria Evaluations ..................................................7-17
                         7.3.1.1 Overall Protectiveness of Human Health and the Environment ........7-17
                         7.3.1.2 Compliance with ARARs ..................................................................7-17
                7.3.2 Alternative 4: Primary Balancing Criteria Evaluations ....................................7-18
                         7.3.2.1 Long-Term Effectiveness and Permanence .......................................7-18
                         7.3.2.2 Short-Term Effectiveness ..................................................................7-21
                         7.3.2.3 Reduction of Toxicity, Mobility, or Volume through Treatment ......7-23
                         7.3.2.4 Implementability................................................................................7-23
                         7.3.2.5 Cost....................................................................................................7-25
                7.3.3 Alternative 4: Modifying Criteria Evaluations .................................................7-25
                         7.3.3.1 State Acceptance ...............................................................................7-25
                         7.3.3.2 Public Acceptance .............................................................................7-25
        7.4     Detailed Analysis of Alternative 5: Voluntary Relocation, On-site Disposal, and
                Institutional Controls .....................................................................................................7-26
                7.4.1 Alternative 5: Threshold Criteria Evaluations ..................................................7-26
                         7.4.1.1 Overall Protectiveness of Human Health and the Environment ........7-26
                         7.4.1.2 Compliance with ARARs ..................................................................7-26
                7.4.2 Alternative 5: Primary Balancing Criteria Evaluations ....................................7-27
                         7.4.2.1 Long-Term Effectiveness and Permanence .......................................7-27
                         7.4.2.2 Short-Term Effectiveness ..................................................................7-28
                         7.4.2.3 Reduction of Toxicity, Mobility, or Volume through Treatment ......7-28
                         7.4.2.4 Implementability................................................................................7-28
                         7.4.2.5 Cost....................................................................................................7-29
                7.4.3 Alternative 5: Modifying Criteria Evaluations .................................................7-29
                         7.4.3.1 State Acceptance ...............................................................................7-29
                         7.4.3.2 Public Acceptance .............................................................................7-30
        7.5     Detailed Analysis of Alternative 8: Total Source Consolidation, Stabilization,
                and Institutional Controls...............................................................................................7-30
                7.5.1 Alternative 8: Threshold Criteria Evaluations ..................................................7-30
                         7.5.1.1 Overall Protectiveness of Human Health and the Environment ........7-30
                         7.5.1.2 Compliance with ARARs ..................................................................7-30
                7.5.2 Alternative 8: Primary Balancing Criteria Evaluations ....................................7-31
                         7.5.2.1 Long-Term Effectiveness and Permanence .......................................7-31
                         7.5.2.2 Short-Term Effectiveness ..................................................................7-33
                         7.5.2.3 Reduction of Toxicity, Mobility, or Volume through Treatment ......7-35
                         7.5.2.4 Implementability................................................................................7-35
                         7.5.2.5 Cost....................................................................................................7-36
                7.5.3 Alternative 8: Modifying Criteria Evaluations .................................................7-37
                         7.5.3.1 State Acceptance ...............................................................................7-37
                         7.5.3.2 Public Acceptance .............................................................................7-37
8.0     Comparative Analysis of Alternatives.......................................................................................8-1
        8.1     Comparative Analysis of Remedial Alternatives with Respect to the Threshold
                Criteria .............................................................................................................................8-1

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                 8.1.1  Overall Protection of Human Health ..................................................................8-1
                 8.1.2  Overall Protection of the Environment ...............................................................8-1
                 8.1.3  Compliance with ARARs ...................................................................................8-2
                        8.1.3.1 Chemical-Specific ARARs..................................................................8-2
                        8.1.3.2 Action-Specific ARARs ......................................................................8-2
                        8.1.3.3 Location-Specific ARARs...................................................................8-2
        8.2      Comparative Analysis of Remedial Alternatives with Respect to the Primary
                 Balancing Criteria ............................................................................................................8-2
                 8.2.1 Long-Term Effectiveness and Permanence ........................................................8-2
                        8.2.1.1 Magnitude of Residual Risks...............................................................8-3
                        8.2.1.2 Adequacy and Reliability of Controls .................................................8-3
                 8.2.2 Short-Term Effectiveness ...................................................................................8-4
                        8.2.2.1 Risks to the Local Communities..........................................................8-4
                        8.2.2.2 Potential Risks to Workers ..................................................................8-5
                        8.2.2.3 Potential Environmental Impacts.........................................................8-5
                        8.2.2.4 Time Until RAOs Are Achieved .........................................................8-6
                 8.2.3 Reduction of Toxicity, Mobility, or Volume Through Treatment ......................8-6
                 8.2.4 Implementability.................................................................................................8-6
                        8.2.4.1 Technical Feasibility ...........................................................................8-6
                        8.2.4.2 Administrative Implementability.........................................................8-7
                 8.2.5 Cost .....................................................................................................................8-7
9.0     References .................................................................................................................................9-1


List of Tables

Table 2-1              Mine and Mill Waste within the Site Boundary
Table 3-1              Remedial Action Objective Summary for Tar Creek Operable Unit 4
Table 4-1              Results of the Initial Screening of Source Material Technologies
Table 4-2              Results of the Initial Screening of Surface Water Technologies
Table 4-3              Results of the Initial Screening of Ground Water Technologies
Table 4-4              Final Screening of Candidate Technologies for Source Materials and Affected Soils
Table 4-5              Final Screening of Candidate Technologies for Surface Water
Table 4-6              Final Screening of Candidate Technologies for Ground Water
Table 5-1              Source Material and Affected Media Categories for Tar Creek OU4
Table 5-2              Candidate Remedial Alternative Summary
Table 5-3              Candidate Remedial Alternatives - Initial Screening Summary
Table 6-1              Alternative 1 Remedial Action Summary
Table 6-2              Source Material and Affected Media Categories for Tar Creek OU4
                       Alternatives 4 and 5
Table 6-3              Alternative 4 and 5 Remedial Action Summary
Table 6-4              Alternative 8 Remedial Action Summary
Table 7-1              Potential Federal and State Chemical-Specific ARARs and Guidance to be
                       Considered
Table 7-2              Potential Federal and State Action-Specific ARARs and Guidance to be Considered
Table 7-3              Potential Federal and State Local-Specific ARARs and Guidance to be Considered
Table 7-4              Long-Term Effectiveness and Permanence under Alternative 1
Table 7-5              Long-Term Effectiveness and Permanence under Alternative 4
Table 7-6              Alternative 4 Estimated Costs
Table 7-7              Long-Term Effectiveness and Permanence under Alternative 5

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Table 7-8            Alternative 5 Estimated Costs
Table 7-9            Long-Term Effectiveness and Permanence under Alternative 8
Table 7-10           Alternative 8 Estimated Costs
Table 8-1            Comparative Analysis of Remedial Alternatives with Respect to Overall Protection
                     of Human Health and the Environment
Table 8-2            Comparative Analysis of Remedial Alternatives with Respect to Compliance with
                     ARARs
Table 8-3            Comparative Analysis of Remedial Alternatives with Respect to Long-Term
                     Effectiveness and Permanence
Table 8-4            Comparative Analysis of Remedial Alternatives with Respect to Short-Term
                     Effectiveness
Table 8-5            Comparative Analysis of Remedial Alternatives with Respect to Reduction of
                     Toxicity, Mobility, or Volume through Treatment
Table 8-6            Comparative Analysis of Remedial Alternatives with Respect to Implementability
Table 8-7            Comparative Analysis of Remedial Alternatives with Respect to Cost
Table 8-8            Comparative Analysis Results


List of Figures

Figure 1-1           Site Boundary Map
Figure 6-1           Alternative 4 and 5 - Chat Piles, Chat Base, and Fine Tailings Locations
Figure 6-2           Alternative 4 and 5 Source Material Summary Graph
Figure 6-3           Alternative 4 and 5 - Distal Zone Areas
Figure 6-4           Chat Disposal Decision Diagram
Figure 6-5           Fine Tailings Disposal Decision Diagram
Figure 6-6           Alternative 4 and 5 – Fine Tailings Locations and Proposed Disposition
Figure 6-7           Estimated Source and Seepage Control Locations
Figure 6-8           Relocation Assistance Zone


List of Appendices

Appendix A           EPA Region 6 Ecological Risk Memorandum
Appendix B           Graphical Summary of the Alternatives
Appendix C           Alternative Cost Estimates
Appendix D           Unit Cost Development
Appendix E           Chat Sales Cost Estimate




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Acronyms and Abbreviations

AATA                 AATA International, Inc.
AOC                  Administrative Order of Consent
ARARS                applicable or relevant and appropriate requirements
BIA                  Bureau of Indian Affairs
BMP                  Best Management Practices
BRA                  Baseline risk assessment
CAMU                 Corrective Action Management Units
CERCLA               Comprehensive Environmental Response Compensation and Liability Act
CFR                  Code of Federal Regulations
COPCs                Chemicals of Principal Concern
District             Tri-State Mining District
DOI                  Department of the Interior
EPA                  Environmental Protection Agency
ERA                  Ecological Risk Assessment
FEMA                 Federal Emergency Management Agency
FS                   Feasibility Study
GRA                  General Response Actions
HDS                  high-density sludge
HHRA                 Human Health Risk Assessment
HLAC                 Habitat-Limited Aquatic Community
MCL                  Maximum contaminant levels
mg/L                 milligrams per liter
NCP                  National Contingency Plan
NPL                  National Priorities List
O&M                  Operation and Maintenance
OCC                  Oklahoma Conservation Commission
ODEQ                 Oklahoma Department of Environmental Quality
OSHA                 Occupational Safety and Health Administration
OU4                  Operable Unit 4
OWRB                 Oklahoma Water Resources Board
PRG                  Preliminary Remediation Goal
RAA                  Remedial action alternatives
RAOs                 Remedial Action Objectives
RBC                  rotating biological contractor
RCRA                 Resource Conservation and Recovery Act
RI                   Remedial Investigation
ROD                  Record of Decision
SAP                  Sampling and Analysis Plan
SDS                  Spatial data standard
SOW                  Statement of Work
Site                 Tar Creek Superfund Site
SLERA                screening-level ecological risk assessment
SWPPP                Stormwater Pollution Prevention Plan
TBC                  To be considered
TCL                  Target Compound List
TMV                  Toxicity, Mobility, or Volume

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TZ                   Transition Zone
µg/dL                Micrograms per Deciliter
UIC                  Underground Injection Control
USFWS                U.S. Fish and Wildlife Service
USGS                 United States Geological Survey
yd3                  cubic yards
WP                   Work Plan




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1.0 Introduction

This Feasibility Study (FS) for Operable Unit 4 (OU4) of the Tar Creek Superfund Site (Site) is
submitted as part of the Remedial Investigation/Feasibility Study (RI/FS) characterizing Site
conditions and providing remedial alternatives for the Tar Creek Site.

The Site is located in northeast Oklahoma in Ottawa County and comprises approximately 40 square
miles (Figure 1-1). The Site is part of the Tri-State Mining District (the District) that also includes
southeastern Kansas and southwestern Missouri. The mining and milling of lead and zinc ores since
the late 1800s has generated mining and milling wastes that contain elevated concentrations of lead,
cadmium, and zinc. These wastes present a potential risk of exposure to human health and the
environment. The smelting of lead at the Site generated smelter waste that poses a potential risk of
exposure. Mining ceased in the region by 1970, and in 1983, the Site was placed on the National
Priority List (NPL). The investigation of the Site under OU4 includes characterization and evaluation
of both the source media (mine, mill, and smelter waste) and the affected media.


1.1 Mining History
The first ore discoveries and earliest mining operations in Ottawa County, Oklahoma, occurred in the
vicinity of Peoria (6 miles east and 1 mile south of Lincolnville) in 1891 (Weidman, 1932). The next
major ore discoveries occurred 1.5 miles northeast of Lincolnville near Quapaw in 1902, followed by
discoveries in 1905 near Commerce. The real expansion of zinc and lead mining at the Site occurred
after a major ore discovery in 1914 near the current site of Picher, Oklahoma. Following this
discovery, there was a major expansion of mining in what became known as the Picher Mining Field
(Picher Field) of Oklahoma and Kansas. By 1918, the Oklahoma section of the Picher Field was well
defined by producing mines, with 230 mills built or under construction (Luza, 1986).

A marked decline in annual production after 1946, and depressed metal-market prices forced a
cessation of most mining activities in 1958 (Brichta, 1960). The last record of significant production
from Ottawa County occurred in 1970 (McKnight and Fischer, 1970).

With few exceptions, all the crude ore produced at the Site was mined using underground mining
methods. Based on production records maintained by the U.S. Department of Interior, Bureau of
Mines, a total of 181,048,872 tons of crude ore was produced from the Oklahoma portion of the
District. Milling of this ore produced 8,884,898 tons of zinc concentrates and 1,686,713 tons of lead

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concentrates. With the exception of a limited amount of lead concentrates treated at the Ontario
Smelter, all the concentrates produced from the Site were transported off-site for the conversion of
the concentrates to metal by smelting. It has been estimated that approximately 3,670 acres of land at
the Site currently are or were once overlain by mine and mill waste (AATA, 2005a).


1.2 Regulatory Framework
EPA has defined four operable units for the Tar Creek Site, as follows:

•    OU1, Ground Water and Surface Water – OU1 was the original unit established in the 1980s to
     address the issues related to acid mine drainage. It is currently in After Action Monitoring.

•    OU2, Residential and High Access Areas – OU2 was established to address contaminated soil in
     residential areas of the Site.

•    OU3, Eagle Picher Industrial Facility – OU3 was established to address laboratory contamination
     at the Eagle Picher Industrial facility at Cardin, Oklahoma.

•    OU4, Mine, Mill, and Smelter Waste – OU4 was established to address mining-related source
     materials and the transport of cadmium, lead, and zinc—chemicals of principal concern
     (COPCs)—to surrounding media within the historically mined areas of the Site. The following
     areas were investigated as part of the OU4 RI/FS:

          1. Mine and mill wastes and smelter wastes (chat, fine tailings, and slag)

          2. Soil (background, transition zone (TZ), rural residential, and smelter-affected)

          3. Dust (rural residences with yard lead concentrations exceeding 400 mg/kg)

          4. Biota from flooded mill waste ponds

          5. Surface water runoff and seepage from mill wastes

          6. Shallow ground water from wells in the Boone Aquifer used for domestic purposes

•    OU5, Sediments – OU5 was established to address sediments in Site creeks and is in the early
     characterization phase.

OU4 was established to gather sufficient information to make informed risk management decisions
for addressing the risks to human health and the environment associated with the mine, mill, and
smelter waste deposited on the Site by former mining-related operations.


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The remedial alternatives developed and evaluated in this FS report for OU4 are intended to address
the potential exposure routes specifically identified in the Statement of Work (SOW) (EPA, 2003a),
including the following:

•    Possible human exposure to COPCs in surficial deposits of mine, mill, and smelter wastes

•    Rural residential yard soils not addressed under the remedial actions conducted under OU2

•    Affected soils, such as transition-zone and smelter-affected soils, and affected shallow aquifer
     well water

Specifically excluded from consideration under OU4 are potential human health and environmental
risks associated with the following possible exposure media:

•    Deep (Roubidoux) aquifer well water, which was addressed under OU1

•    Surface water and sediments in Site streams addressed through OU1 and OU5, respectively

•    Fugitive dust emissions from unpaved chat roads within the Site

•    Waters emanating from underground mine workings that are currently flowing into Site streams


1.3 Report Organization
The FS for OU4 is developed to be consistent with the National Contingency Plan (NCP) (EPA,
1990a) and EPA Guidance for Conducting RI/FS under the Comprehensive Environmental Response
Compensation and Liability Act (CERCLA) (EPA, 1988). The FS develops and evaluates alternatives
that address the potential OU-specific risks to human and ecological receptors. The alternative
development process consists of assembling combinations of technologies into comprehensive Site-
wide alternatives that address the identified OU-specific risks and meet the remedial action objectives
(RAOs) established for the Site. Steps in the alternative development process include the following:

•    Developing RAOs designed to address all identified potential risks associated with Site source
     materials and affected media

•    Identifying and evaluating general response actions (GRA), technology types, and process
     options that are potentially applicable for meeting the RAOs

•    Estimating the volumes and areas of source materials and affected media requiring remedial
     actions


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•    Assembling the potentially applicable technologies into a set of comprehensive Site-wide
     candidate remedial action alternatives (RAAs)

•    Screening the initial set of candidate alternatives and retaining only the most cost-effective and
     implementable alternatives for detailed analysis

•    Conducting the detailed analysis of the retained alternatives for selecting the most cost-effective
     remedy that protects human health and the environment, complies with all applicable regulatory
     requirements, and meets the established RAOs

This OU4 FS report is organized into nine sections. Section 1 consists of the introduction and
provides information on the background, history, and regulatory framework for the Site.

Section 2 of the FS summarizes the results of RI and baseline risk assessments (BRA) with emphasis
on the results specifically pertaining to OU4, and briefly describes the investigation activities
conducted at the Site, the physical setting, source materials, contaminant transport mechanisms,
affected media, and potential ecological risks.

Section 3 presents the OU-specific RAOs and describes the rationale for developing the RAOs.
RAOs for addressing the potential human health and ecological risks associated with OU4 are
presented for source materials, affected soils, surface water, and ground water.

Section 4 summarizes the process of identifying and screening GRAs and potentially applicable
technology types and process options for use in the development and screening of alternatives.

Section 5 documents the approach to developing and screening the candidate remedial alternatives for
OU4. Candidate alternatives for the various categories of source materials and affected media in
combination with their physical locations within the Site are developed and screened with respect to
their effectiveness, implementability, and cost. The purpose of this screening step is to refine the set
of alternatives carried forward to develop Site-wide comprehensive alternatives. This screening step
serves to focus and streamline the subsequent detailed analysis process.

Section 6 provides detailed descriptions of the six comprehensive, Site-wide, thematic alternatives
that are carried forward from the screening step described in Section 5. This section contains
engineering details and other information needed to evaluate and cost the candidate alternatives.

Section 7 describes the detailed analysis of the six candidate alternatives with respect to the nine
evaluation criteria prescribed in the NCP and EPA Guidance.



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Section 8 evaluates the relative performance of each alternative by comparing the results of the
detailed analysis presented in Section 7.

Section 9 lists the references used in preparing the FS report.




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2.0 Remedial Investigation Summary

The RI was designed to characterize the nature and extent of mining-related contamination at the Site
in order to provide data to evaluate risks to humans and the environment and to provide information
to develop and evaluate alternatives in the FS. This section describes the physical and chemical
characterization of the Site, as described in the RI report, as well as transport mechanisms for all
contaminated media and potential risks to human health and the environment.


2.1 Investigations
This section summarizes findings of investigations and reports that have been prepared as part of the
Tar Creek OU4 RI/FS. Included are summaries of the Tar Creek OU4 RI report (AATA, 2005b), the
Ecological Risk Assessment (ERA [EPA, 2005a]), and the Human Health Risk Assessment (HHRA)
(CH2M HILL, 2006).


2.1.1 Remedial Investigation Reports
A comprehensive summary of all available information on the Site was compiled in the Data Gap
Analysis (AATA, 2004a). The goals and objectives for the RI/FS were outlined and presented in a
Work Plan (WP) (AATA, 2004b). The Sampling and Analysis Plan (SAP) (AATA, 2005c) was then
prepared to describe the proposed procedures for sample collection and data analysis. A Site
reconnaissance was conducted during March and April of 2005, which included mapping of the
existing mine, mill, and smelter waste accumulations; physical characterization of chat and fine
tailings; and selection of potential sampling locations. The findings from this reconnaissance were
documented in a Site Reconnaissance Memorandum (AATA, 2005a). Between May 16 and October
22, 2005, field investigations were conducted that characterized affected media, including chat piles,
chat bases, fine tailings, flooded fine tailings ponds, soil, indoor dust, surface water, and ground
water. The final RI report was completed in December 2005 (AATA, 2005b).


2.1.2 Human Health Risk Assessment
CH2M HILL was contracted by EPA to complete the HHRA for OU4 under Contract No. 68-W6-
0025. The HHRA evaluated the COPCs and potential current and future residential and recreational
exposures. The assessment was conducted using Site-specific data. Based upon the exposure models
used and employing conservative assumptions, the HHRA concluded that the potential risks to

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residents are dependent on their proximity to source materials and due to direct and indirect contact.
The HHRA also concluded that Tribal ways of life might increase exposure due to increased contact
with soils, plants, and animals that have accumulated COPCs.


2.1.3 Ecological Risk Assessment
EPA Region 6 conducted a screening-level ecological risk assessment (SLERA) for Tar Creek OU4
during the autumn of 2005 (EPA, 2005a). The ERA follows EPA guidance for conducting a two-
tiered approach for evaluating potential risks to terrestrial species caused by exposure to COPCs in
environmental media at the Site. The SLERA did not address possible risks to aquatic species, but did
evaluate riparian exposure routes as possible sources of risk to terrestrial receptors. The initial step in
the two-tiered assessment evaluated risks from direct contact with inorganic media with respect to the
soil, plant, mammalian, and avian communities. The second tier SLERA refined the initial risk
characterization for the terrestrial and riparian endpoints but was unable to refine the assessment of
the soil and plant communities further without additional Site-specific analyses.

The SLERAs concluded that most assessment endpoints showed risks from exposure to the Site-
specific COPCs through food chain effects and possibly through incidental ingestion of abiotic media.
However, the SLERAs are recognized as highly conservative for remedial decision-making.


2.1.4 Other Investigations and Studies
In addition to the RI, HHRA, and ERA conducted under OU4, this FS report considered ongoing and
previously completed treatability studies conducted for as part of OU4, the RI/FS conducted for other
sites in the District, and the Oklahoma Plan. Some of the studies considered in this FS report include
the following:

•    The Chat Sales Treatability Study for the Sale of Indian-Owned Chat within the Tar Creek
     Superfund Site (EPA Region 6 and BIA, 2005)

•    The Interim Data Report for Chat Placement Pilot Study (EPA, 2005b) and the Chat and Chat
     Fines Placement Pilot Studies (EPA, 2006a) summarizing the results of pilot-scale treatability
     studies investigating in-mine disposal of mill waste.

•    Reports by the Oklahoma Conservation Commission (OCC) and the Oklahoma Department of
     Environmental Quality (ODEQ) updating and summarizing remedial actions already completed
     as part of the Oklahoma Plan. These reports contain cost and engineering information considered
     in the preparation of the FS report


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•    Investigations of subaqueous disposal of mill waste conducted for OU1 of the Jasper County,
     Missouri, Superfund Site, including the white paper on subaqueous disposal contained in
     Appendix B of the Jasper County OU1 FS report (NewFields, 2003), and the summary of the
     pilot-scale demonstration of subaqueous disposal at the Waco Subsite in the Jasper County,
     Missouri, Site (Hinrichs et al, 2003)


2.2 Physical Setting
The Site is situated within the Osage Plains section of the Central Lowland Province in northeastern
Oklahoma. The Osage Plains are generally characterized by a low relief, rolling treeless prairie
(Luza, 1986). According to the U.S. Census Bureau, the population of Ottawa County in 2000 was
33,194. About one third of the population lives in the rural area. The Site is characterized by a humid,
continental climate with moderate winters and hot summers. The average annual precipitation is
approximately 42 inches. Surface waters that drain from the Site flow into two principal regional
watersheds: the Neosho River and Spring River basins. Streams that drain the central and western
portions of the Site include Tar, Lytle, Quapaw, Garrett, and Elm Creeks, and associated tributary
drainages (Figure 1-1). These streams flow south and drain into the Neosho River, about 1 mile
southeast of Miami, Oklahoma. These streams are typically underlain by Pennsylvania shale and as
such are subject to rapid runoff, flooding, and intermittent flow. Surface drainages in the eastern
portion of the Site flow into the Spring River. The surface geology of these drainages typically is
Mississippian limestone, especially for drainages east of Highway 66. These small streams have
intermittent flows and include Hockerville, Ontario, and Beaver Creeks, and associated unnamed
drainages in the eastern portion of the Site. Historical mining activities have altered the drainage
pattern of Tar Creek and its tributaries (Spruill, 1984; Luza, 1986). Tar Creek supplied water to the
mills, received water pumped from mines, and was channelized and directed to keep water from
flowing into mine workings.

Tar Creek drains the most intensively mined areas of the Site and is therefore most susceptible to
contamination due to runoff and seepage from mill waste (Figure 1-1). The mining areas of the
Picher Field, including the Treece, Kansas subsite, and the Oklahoma mining areas at Picher, Cardin,
Hockerville, Century-Douthat, and Commerce all occur within the Tar Creek watershed. Water
quality in the Tar Creek watershed is regulated by the State of Oklahoma for various beneficial uses,
including a habitat-limited aquatic community (HLAC) and secondary body contact recreation.




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There are two principal aquifers in the region: the Boone (Mississippian) and Roubidoux (Cambro-
Ordovician) aquifers. The Boone Formation is primarily characterized as Mississippian limestone
layered with lead-zinc ores, and is the source of the shallow ground water. The Roubidoux Formation
consists largely of cherty dolomite and sandstone, and is the source of deeper ground water in the
area. A sequence of limestone, shale, and dolomite strata, along with the upper portion of the
Roubidoux formation, form a semi-confining unit, or aquitard separating the Boone aquifer from the
Roubidoux aquifer. Many private wells tap these aquifers for domestic use. After the cessation of
mining and dewatering activities, ground water recharge and subsequent flooding of underground
abandoned mines has led to contamination of ground water in the shallow aquifer (Playton, et al.,
1980). As a result, some of the shallow wells at the Site are contaminated with cadmium, lead, and zinc.

The surficial formations at the Site consist of Mississippian and Pennsylvanian units having a
regional southwestward dip. The lower to middle Mississippian Boone Formation is the host rock for
the lead and zinc ore deposits in the District. It consists primarily of limestone (sometimes oolitic),
dolomite, and chert, along with lesser quantities of sandstone and shale. The soils present within the
Site area are derived from the underlying Pennsylvanian sedimentary and Mississippian cherty
carbonate rock formations, along with admixed Pleistocene and Holocene wind-deposited materials.
Most of these soils are silty loams, which are comprised primarily of silt, with lesser quantities of
sand and clay. Chert and other rock fragments may also be present in significant quantities. The
Taloka silt loam is the most common soil series present at the Site. Other locally prevalent soil series
present include Dennis, Parsons, Choteau, Craig, Bates, and Newtonia. Background soil samples
collected at the Site had average concentrations of cadmium, lead, and zinc of 0.73 mg/kg, 31.25
mg/kg, and 83.25 mg/kg, respectively (AATA, 2005b).

Maps of mines, mineshafts, and old mills are included in Luza (1986). U.S. Geological Survey (USGS)
7.5 minute topographic quadrangle maps covering the Site include Miami NW, Pitcher, and Peoria.

Much of the land at the Site remains undeveloped. Land use at the Site is dominated by agriculture, with
approximately 68 percent of the Site characterized as either crop farming or pasture grazing. The
remaining land uses include residential, industrial, commercial, and mine-related activities. Floodplain
areas near creeks and tributaries are often characterized by undeveloped deciduous woodlands.

Mill waste deposits are scattered throughout the Site, but are most concentrated in the western half
(west of S. 590 Rd.; Figure 1-1). Types of source material, estimated volumes, and acreages were
estimated in the RI report and are summarized in Table 2-1. Chat bases cover the largest area (2,079
acres), but chat piles contain the largest volume of the source materials (31 million cubic yards [yd3]).


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2.3 Source Materials

2.3.1 Chat Piles
Chat is a type of waste tailings that is produced by the gravity separation milling process that was once
used in the Tri-State Mining District. Chat consists of mainly fine gravel to coarse sand sized rock
fragments plus minor amounts of smaller intermingled material, such as medium-to-fine sands, silt, and
clay. Chat is primarily made up of chert, limestone / dolomite fragments of less than 3/8 inch to plus 40
mesh (i.e., greater than 0.02 inch). A total of 83 chat piles covering about 767 acres and having a
volume of approximately 31 million yd3 was identified at the Site. These piles are up to 200 feet high.

Field measurements of chat pH (41 samples) were in the range of 6.7 to 9.0, with all but two samples
having a slightly basic pH (greater than 7.0). Dry bulk density of the chat sampled from 37 major
piles at the Site ranged from 70 to 98 pounds per cubic foot. A total of 168 chat samples (collected at
1-foot depth) from 20 major chat piles at the Site were collected for chemical analysis. The
concentration of cadmium in the chat ranged from 43.1 mg/kg to 199.0 mg/kg with an average of 94.0
mg/kg; lead ranged from 210 mg/kg to 4,980 mg/kg with an average of 1,461 mg/kg; and zinc ranged
from 10,200 mg/kg to 40,300 mg/kg with an average of 23,790 mg/kg. The highest concentrations of
lead in chat are generally found in the fine material.

In addition, 14 samples were collected from the surface (0-1 inch) of selected piles. These surface
chat samples were screened and only the less than 60 mesh portion was analyzed for use in the risk
assessment. Most metals except aluminum, magnesium, and manganese in surface chat consistently
showed narrower concentration ranges and lower average and median values than bulk chat collected
at 1-foot depth.

The average concentrations of cadmium, lead, and zinc in the chat samples collected as part of OU4
were consistently higher than those reported for the Cherokee County, Kansas, and the Jasper County,
Missouri, Sites in the District (Dames & Moore, 1993a and 1995). This observation could be
because of differences in the grade of ore, with the Picher Field reported to have had higher grade ore;
the type of ore, with the Picher Field containing both free-milling and disseminated types of ore; the
reprocessing history of the chat, with a greater percentage of the chat having been remilled and
processed for aggregate in the Oklahoma portion of the District; and/or differences in sampling and
analysis of samples between the three RIs.




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2.3.2 Chat Bases
Chat base is the area that was once occupied by a chat pile. Chat bases can be either vegetated or non-
vegetated, and generally have little or no relief (compared to chat piles, which are typically
mounded).

There are 243 identified chat bases at the Site with a total area about 2,079 acres and a total volume of
approximately 6.7 million yd3. The average thickness of all chat bases is estimated to be
approximately 2 feet. Chat base showed similar particle size distribution as bulk chat. Nearly
85 percent of the chat bases at the Site were partially or totally revegetated / reclaimed.

A total of 22 samples from six chat bases were collected for chemical analysis. These samples were
crushed and ground so that all material passed through a #100-mesh sieve prior to analysis. The
concentration of cadmium in the chat base ranged from 51.0 mg/kg to 151.0 mg/kg with an average of
96.2 mg/kg; lead ranged from 650 mg/kg to 3,020 mg/kg with an average of 1,863 mg/kg; and zinc
ranged from 9,520 mg/kg to 40,300 mg/kg with an average of 33,600 mg/kg.

Cadmium, lead, and zinc concentrations from the chat base samples were all well within the ranges
defined by the chat samples from the Site and the mean concentrations of these two data sets are also
very similar.

Chat is also found on-site in historic railroad grades and haul roads but was not sampled as part of the
Remedial Investigation. The railroad grades and haul roads were mapped using aerial photographs.
This information was used to determine an assumed area of 551 acres, assuming an average width of
20 feet and a total network distance of 213 miles of historic railroad grades and haul roads.


2.3.3 Fine Tailings
Two types of fine tailings waste were recognized at the Site: washed fines generated as a waste during
washing of chat for aggregate sale, and flotation tailings generated during the metal extraction process
or milling. A total of 63 fine tailings ponds covering a total area of 820 acres were defined at the Site.
Based on field drilling and mapping, it was estimated there were 7.2 million yd3 of washed fines and
1.9 million yd3 of flotation tailings at the Site.

A total of 101 washed fines samples and 55 flotation tailings samples were collected for chemical
analysis from ten major fine tailings ponds. The samples were composited over their respective depth
interval (depth-integrated sample) and were not sieved prior to analysis. The concentration of
cadmium in the washed fines ranged from 10.0 mg/kg to 320.0 mg/kg with an average of 79.7 mg/kg;
lead ranged from 220 mg/kg to 26,600 mg/kg with an average of 3,658 mg/kg; and zinc ranged from

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1,730 mg/kg to 70,000 mg/kg with an average of 15,964 mg/kg. The concentration of cadmium in the
flotation tailings ranged from 26.3 mg/kg to 450.0 mg/kg with an average of 133.0 mg/kg; lead
ranged from 1,130 mg/kg to 17,800 mg/kg with an average of 5,694 mg/kg; and zinc ranged from
4,690 mg/kg to 103,000 mg/kg with an average of 29,842 mg/kg. With few exceptions, flotation
tailings contain higher cadmium, lead, and zinc concentrations than washed fines.

Ten surface (0-1 inch) fine tailings samples were collected from the Site and analyzed for use in the
risk assessment. Metal concentrations in the surface fine tailings are in the same range as reported
from the depth integrated washed fines samples.

Compared with the fine tailings from the Cherokee County, Kansas, and the Jasper County, Missouri,
Sites, the fine tailings from Tar Creek OU4 showed similar or narrower ranges in the concentrations
of cadmium, lead, and zinc. The average metal concentrations from the washed fine samples collected
as part of OU4 were very similar to those reported for the Cherokee County, Kansas, and the Jasper
County, Missouri, Sites (Dames & Moore, 1993a and 1995); while the flotation tailings from Tar
Creek showed consistently higher cadmium, lead, and zinc concentrations.


2.3.4 Smelter Wastes
One small accumulation of smelter wastes was identified near the former Ottawa smelter in the
northeastern portion of the Site. Results from field mapping indicated that the smelter wastes (mostly
slag with minor amount of clinker) covered approximately 2 acres of land with an average thickness
of 6 inches and thus an estimated volume of 1,846 yd3.

Five grab samples of smelter wastes were collected for chemical analysis. Cadmium and zinc
concentrations in the smelter wastes were found to be comparable to those in the mill wastes at the
Site. The concentration of lead in the smelter waste (2,800 to 80,000 mg/kg) was found to be
considerably higher than that in the mill waste at the Site. This is consistent with the fact that the
former smelter was a lead smelter.




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2.4 Affected Media

2.4.1 Soils
2.4.1.1     Transition Zone Soils
TZ soils are soils located adjacent to mill wastes that have elevated COPCs when compared to natural
background concentrations due primarily to mechanical redistribution of mill wastes and to a lesser
extent, water, and wind dispersion.

A total of 360 TZ soil samples were collected from the vicinity of five isolated mill waste
accumulations. TZ soil samples (at depth levels of 0-1 inch, 6 inch, 12 inch, and 24 inch) were
collected at 0, 5, 10, 20, 40, 70, 120, 200, and 300 foot intervals outward along the transects from the
selected accumulations. Evaluation of the laboratory analytical results indicated there is no clear trend
in the average concentration of cadmium, lead, or zinc in surface soils in relation to distance from
mill waste accumulations. However, in some instances, the concentrations of metals appear to
decrease with distance and depth. Source material was occasionally encountered in instances where
this was not the case. The observed variation of metals concentrations in TZ soils is believed to be
caused mainly by the extensive processing, transport, and use of chat throughout the Site.

For the purpose of the FS, an estimate of the areal extent and volume of affected soils that exceed the
human health risk-based volume of 500 mg/kg lead was made, which included the soils within a
50-foot wide buffer zone plus those from historical chat haul roads and chat-contaminated non-
operating railroads. The actual distance and depth will have to be determined in the remedial design.
There is an estimated total of 1,162 acres of land containing a soil lead concentration greater than 500
mg/kg with a volume of 1,360,000 yd3. To make this calculation, the TZ was assumed to extend 50
feet beyond the known edge of chat piles, chat bases, and fine tailings.

2.4.1.2     Smelter-Waste Affected Soils
Smelter-waste affected soils are soils in the immediate vicinity of the former Ottawa smelter near
Hockerville that have elevated COPCs when compared to background soils.

Thirty-five surface (0-1 inch) soils samples were collected from locations surrounding the former
Ottawa lead smelter. Soil lead concentration was significantly elevated near the former smelter, with
concentrations within 200 feet of the former smelter ranging from 1,560 mg/kg to 16,800 mg/kg. Soil
lead concentrations decreased to below 500 mg/kg just south of the area affected by smelter wastes
and rapidly approached background levels further south.



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Based on the human health risk-based values for lead (500 mg/kg), a 500-foot radius (centered with
the former smelter location) and 6-inch depth were selected to estimate the areal extent and volume of
smelter-waste affected soils. Therefore, the area of smelter-waste affected soils was estimated at
18 acres and the volume, 14,537 yd3.

2.4.1.3     Rural Residence Yard Soils
As part of the remedial investigation, yard soils from all rural residences at the Site that were not
investigated as part of OU2 were to be sampled as part of OU4. Seventy-seven rural residences were
identified that were not sampled as part of OU2. Access to 47 of these rural residences was obtained
and a total of 366 yard soil samples were collected from these residences. Soil cadmium
concentrations at the residential properties sampled ranged from less than 0.5 mg/kg to 53.8 mg/kg,
with an overall average of 4.4 mg/kg. Soil lead concentrations at the residential properties sampled
ranged from less than 0.05 mg/kg to 14,400 mg/kg, with an overall average of 201 mg/kg. Soil zinc
concentrations at the residential properties sampled ranged from less than 1 mg/kg to 10,700 mg/kg,
with an overall average of 692 mg/kg. Within an individual residential yard, metal concentrations
may vary widely.

Five rural residences investigated had one or more samples in which concentrations exceeded
acceptable human risk-based values for lead (500 mg/kg). Indoor dust was sampled from four of the
five residences with elevated soil lead concentrations and analyzed for lead. The concentration of lead
in the house dust samples collected ranged from less than the detection limit of the instruments used
to 360 mg/kg, with the concentration being below the analytical detection limit at two of the four
residences sampled. Yard soils in the remaining rural residences investigated showed a similar range
of metal concentrations as the background soils at the Site.

It should be noted that EPA, under OU2, remediated one of the five residential properties with
significantly elevated lead results in November 2005.


2.4.2 Ground Water
Thirteen rural residences that were using ground water from the shallow aquifer for domestic
purposes were identified and their wells sampled. Two samples, one first flush (minimum of 8 hours
of no flow time) and one flushed (sampled after 3 minutes of continuous flow) were collected from
each well. Water from all the wells investigated was neutral to slightly alkaline (pH 7.11 to 7.79) with
moderate mineralization (Total Dissolved Solids 160 to 480 mg/L). Eleven of the thirteen wells met
the federal health based standard for lead in drinking water (0.015 mg/L), while two wells exceeded
the standard. No other federal standards were exceeded in any of the wells sampled.

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2.4.3 Surface Water
To understand the effects of Site contamination on surface water, in August 2005, USGS investigated
the effects of chat pile seepage on the water in Tar Creek. USGS performed the study to update a chat
pile seepage study done by the Oklahoma Water Resources Board (OWRB) in 1982. The USGS study
characterized flow, water quality, and metal loading from seepage from the Western (John Beaver)
chat pile and from the Admiralty chat pile after a rainfall event.

Metal loading estimates varied substantially between the two piles based in part on pile size. The
larger chat piles retain more water from precipitation events and release it over a longer period than
the smaller chat piles. Total cadmium, iron, lead, and zinc loads from seepage from the Western chat
pile were negligible. Average total metal loads from the Admiralty pile for zinc, iron, cadmium, and
lead were 26.02, 0.46, 0.10, and 0.014 lbs/day, respectively. The Admiralty pile contains
2,542,600 yd3 of chat and is over 15 times the size of the Western pile.

The USGS estimated the mean total metal loading in lbs/day from chat seepage in the Tar Creek
Watershed within the Site during the study was 101.81 for zinc, 1.47 for iron, 0.12 for cadmium, and
0.00 for lead. In contrast, OWRB (1983) estimated an average total metal loading in lbs/day from chat
seepage within the entire Site at 27.5 for zinc, 4.05 for iron, 0.153 for cadmium, and 0.04 for lead.

These differences in loading estimates may be attributable to differences in methodologies between
the two studies. The USGS study determined metal loading from seepage from the Admiralty chat
pile indirectly by subtracting metal loads in Tar and Lytle Creeks immediately upstream of the
Admiralty pile from the metal loads in Tar Creek just downstream of the Admiralty pile. The OWRB
study determined metal loading estimates directly from seepage/runoff off the Admiralty pile’s
western bank, a few hundred feet above the Douthat Bridge. Other factors contributing to differences
in metal loading estimates include differences in chat pile volumes, variability in leachate flow and
chemical constituents between piles.


2.4.4 Biota
Investigations of biota from three flooded fine tailings ponds were conducted as part of the Tar Creek
OU4 remedial investigation. Selected ponds were sampled for surface water, pond sediment, aquatic
macrophytes, and benthic macroinvertebrates. The surface water in the ponds investigated had a pH
in the range of 7.78 to 8.52, dissolved cadmium in the range of <0.0001 to 0.0005 mg/L, dissolved
lead in the range of 0.0020 to 0.0129 mg/L, and dissolved zinc in the range of 0.07 to 0.19 mg/L.




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Pond sediments showed similar cadmium, lead, and zinc concentrations as the fine tailings at the Site.
The flooded fine tailings ponds at the Site displayed very low densities of aquatic organisms.

Observations of wildlife including mammals, birds, amphibians, reptiles, and fishes were made in
their native habitats at all the sampling areas. In addition, transects along the east-west and north-
south directions across the entire Tar Creek Site were conducted in the early morning, daytime, and
sunset periods on several occasions using existing roads and trails. A list of observed species is
provided in the RI report.




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3.0 Remedial Action Objectives

RAOs for OU4 of the Tar Creek Site are defined in this section. RAOs are quantitative, medium-
specific, and OU-specific goals for protecting human health and the environment. RAOs specific to
source materials, soils, surface water, ground water, and air are presented separately in this section.

The discussion provided in this section updates preliminary RAOs that were presented in the WP for
Tar Creek OU4 RI/FS Program (AATA, 2004b) approved in 2004 before the completion of the RI.
The medium-specific RAOs provided in the following subsections are modified from those presented
in the WP to reflect the findings of the RI field investigations, the human health and ERAs conducted
specifically for OU4, and EPA’s risk management decisions.


3.1 RAO Guidance
EPA guidance states that RAOs should be expressions of medium-specific risk prevention goals and
must specify the following:

•    The COPCs

•    Exposure routes and receptors

•    Acceptable contaminant levels or clean-up standards for each identified exposure route


3.1.1 Contaminants of Potential Concern
As specified in the AOC and SOW (EPA, 2003a), the list of COPCs for OU4 is limited to cadmium,
lead, and zinc.


3.1.2 Exposure Routes and Receptors
As reflected in the AOC and SOW (EPA, 2003a), the Record of Decision (ROD) for OU4 will
consider both human health and ecological risks identified in the risk assessments.

3.1.2.1     Possible Human Exposure Routes and Receptors
The extensive body of work conducted at the Site, including the OU4 HHRA, identified the following
possible human exposure routes and receptors:




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•    Human receptors, especially children, may be exposed to unacceptable levels of COPCs by
     ingestion and inhalation of source materials and affected soils through normal human activities,
     such as playing, walking, and working outdoors in areas containing or affected by source material
     deposits. In accordance with the SOW, human exposure due to ingestion of COPCs in residential
     yard soils shall be addressed under OU4 only in rural areas of the Site that were not previously
     addressed under EPA’s ROD for OU2. However, OU4 will address any identified human health
     risks associated with source material deposits.

•    Future residents may be exposed to unacceptable levels of COPCs by moving into previously
     undeveloped areas of the Site containing source material deposits or affected soils whose metal
     concentrations exceed risk-based criteria.

•    Native American peoples within the Site may be subjected to unacceptable risks through
     exposure routes that are unique to the Tar Creek Site. Some Native Americans, particularly
     members of the Quapaw Tribe, still engage in traditional ceremonial, medicinal, subsistence, and
     artistic practices. Some of these practices may involve foraging for native herbs, foodstuffs, and
     fibers that grow on source materials, such as chat bases, on affected soils or in Site surface
     waters. Concern exists that by practicing their traditional lifestyles within the Site, Native
     Americans may ingest COPCs in quantities that result in unacceptable risks.

•    Human receptors may be exposed to unacceptable levels of COPCs through direct and indirect
     ingestion of affected drinking water supplies. In OU4, this exposure route would be limited to
     rural residents who rely on shallow aquifer wells for their domestic water supplies. As determined
     during the RI and described in Section 2.4.2 of this FS report, a small number of residents living
     in rural areas of the Site outside the boundaries of municipal or rural water supply districts could
     be subject to unacceptable risks by consuming affected shallow ground water from private wells.

•    Inhalation of COPCs in ambient air by human receptors may be a potential exposure route within
     the Site, although no exceedances of ambient air quality standards for the COPCs have been
     identified in site-specific air-quality monitoring data. In addition, the results of the HHRA found
     no unacceptable risks associated with the ambient air exposure pathway.

Traditionally, the FS process evaluates remedial technologies that reduce toxicity, mobility, or
volume of contaminated media by treatment methods to prevent or eliminate the possible risks
associated with exposure routes and affected populations. In addition to this process, a voluntary
relocation component will be developed and evaluated as a remedial alternative as a way to address
possible human exposure routes and receptors.

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3.1.2.2     Possible Ecological Exposure Route and Receptors
As described in detail in Section 2.1.3 of this FS Report, ecological exposure routes and receptors
identified in the OU4 ERA include the following:

•    Ecological receptors may be exposed to unacceptable risks through direct contact with or direct or
     indirect ingestion, inhalation, or dermal contact of COPCs in source materials and affected abiotic
     media and food items.

•    Aquatic biota may be exposed to COPCs above risk-based criteria in perennial streams, riparian
     corridors, and ponds. COPCs are transported to surface water via two pathways—runoff and
     seepage from surficial source material deposits and ground water discharge from
     mined/mineralized portions of the shallow aquifer. COPCs are contributed via these pathways
     under all flow conditions, but the largest loads are contributed during seasonal wet periods and
     rainfall events. EPA’s ROD for OU1 addressed the COPC loads contributed by ground water
     discharges. Pursuant to the SOW, the ground water contribution to surface water will not be
     addressed further in this OU4 FS Report.

•    Aquatic biota may be exposed to COPCs above risk-based criteria due to out-washed source
     materials that are mobilized during rainfall events and deposited in Site surface water bodies.
     These out-washed source materials can also inundate streambeds and wetland areas, thereby
     physically affecting otherwise suitable aquatic habitats.


3.1.3 Site Clean-up Standards
This subsection describes the clean-up standards or action triggers used throughout this FS to set
remediation goals and evaluate candidate remedial alternatives. Clean-up standards or action triggers
are discussed for source materials and affected soils, surface water and sediment, ground water, and
air. Clean-up standards are established based upon EPA’s Risk Management Decision for OU4 (EPA,
2006b) in conjunction with ecological Preliminary Remediation Goals (PRGs) developed by EPA
Region 7 (EPA, 2006c) and adopted by EPA Region 6 for OU4.

3.1.3.1     Source Materials and Affected Soils
The HHRA found that exposure to source materials for a current or future recreator poses
unacceptable risks due to the levels of lead present in the materials. No other chemicals were
identified presenting unacceptable risks. The RI found that the residual lead contamination in all the
source materials evaluated would pose unacceptable risks.



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In order to address this exposure pathway, remedial strategies need to be developed for all of the
source materials identified at the Site. For residential yard soils, results from the OU4 HHRA indicate
that the PRG for lead of 500 mg/kg established for OU2 is protective of resident children and adults
under general residential yard-soil exposure scenarios. The field investigations conducted during the
RI did not specifically identify residents engaged in subsistence agriculture.

Results of the OU4 SLERA indicate the potential for unacceptable ecological risk and found the
primary risk drivers to be cadmium, lead, and zinc. To conserve resources, in lieu of conducting a
Baseline Ecological Risk Assessment for OU4, the Ecological PRGs developed by EPA for the
Cherokee County, Kansas, site were considered (EPA, 2006c). The Cherokee County Superfund Site
and Tar Creek are both part of the same Tri-State Mining District (Kansas, Missouri and Oklahoma).
The two sites are also in the same ecological subregion and province – the Osage Plains section of the
Central Lowland Province. Mining operations at both of these Sites used the ore deposits of the
Picher Mining Field for the production of lead and zinc and were separated only by the political
boundary - the Kansas-Oklahoma state line which has no effect on ecosystems. Mining operations of
the Picher field ore deposits resulted in cadmium, lead and zinc being the primary risk driver for both
sites and the background concentrations of these metals are comparable between both of the Cherokee
County Superfund Site and the Tar Creek OU4 Superfund Site. There are other similarities between
the sites including climate, topography, flora and fauna which make our use of the Region 7 study
appropriate. The Region 7 analysis recommended a range of values for cadmium, lead and zinc in
soil that would be protective for exposed terrestrial wildlife. The recommended soil PRGs were
given as a range:

•    Cadmium: 1.0 – 10.0 mg/kg

•    Lead: 377 – 1,175 mg/kg

•    Zinc: 156 – 1,076 mg/kg

EPA Region 7 used this analysis in its selection of the remediation goals for the Cherokee County,
Kansas, Site in the Amended Record of Decision dated September 29, 2006 (EPA, 2006d). The
specific goals selected for the Cherokee County Site were 10.0 mg/kg cadmium, 400 mg/kg lead, and
1,100 mg/kg zinc. Based on similarities between Cherokee County Site and the Tar Creek Site, EPA
proposes to use 10.0 mg/kg cadmium, 500 mg/kg lead, and 1,100 mg/kg zinc as the PRGs in soil to
address ecological risks at the Site. The PRG for lead is higher at Tar Creek than Cherokee County;
however, it is still on the lower end of the recommended range. The PRG of 500 mg/kg lead was
selected in order to be consistent with the remediation goal established in the OU2 ROD for Tar

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Creek Residential Areas for the protection of human health. EPA selected the lower end of the range
for lead developed at the Cherokee County site due to concerns with future sediment recontamination.
However, EPA proposes to implement erosion controls to limit future sediment transport at Tar Creek
OU4, and therefore has selected 500 mg/kg. This soil PRG is also applicable to source materials at
the Tar Creek Site, which is a source of contamination to the soil. EPA Region 6 documented this
approach as being acceptable in a memorandum, which is included in Appendix A.

In addition, the removal of source material located near streams and creeks at the Tar Creek Site.
Removal of source material will prevent all discharge of lead-, cadmium-, and zinc-contaminated
source materials to surface water and thereby remove the ingestion pathway of these chemicals to
riparian biota. Furthermore, the remedial strategies applied to source materials are expected to
achieve a large reduction of risk to the ecological receptors. The risk management decision also
recommends that a 50-foot buffer zone around all source materials be included in the remedial
strategies for each chat pile, chat base, or tailings pond to provide further reduction in ecological risk.

Site-wide sampling of soils have indicated that soils outside of the source material areas that would
remain upon completion of the remedial actions are expected to contain very low levels of lead.
Therefore, by addressing the source materials and the immediately adjacent soils the resulting risk
levels will be protective for all populations considered in OU4.

3.1.3.2     Surface Water and Sediments
Although surface water and sediments as a media of concern are not directly addressed in OU4, the
pathway from source materials to surface water is within scope. Data collected by the USGS indicates
that significant loading is occurring from the source materials to the surface water. Loading to
surrounding surface soils was not measured, but the results of the surface water study indicate that
this pathway is complete and that chemicals of concern would be moving into the soils through runoff
from the source materials.

The receiving streams of runoff from the source materials are already impacted well above Water
Quality Standards (EPA, 2004a) and do not have the capacity to absorb any additional loading. The
goal for the pathway is to reduce the loading to the stream from the source materials to zero. This
goal can be addressed in the interim through the use of stormwater controls and best management
practices (BMPs), as required in 40 Code of Federal Regulations (CFR) 122.44(k), and removal of
source materials in direct contact with the surface waters. It is likely that the interim controls will not
achieve zero discharge, but that the implementation of the remedial strategies to address the source
materials directly would be expected to approach the goal of zero discharge.


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3.1.3.3     Use of Shallow Ground Water
The ground water medium for OU4 is limited to the water drawn from the existing rural, shallow
domestic wells at residences located within the site boundary. The aquifer that the shallow domestic
wells are completed in is outside the scope of OU4. Of the 13 residential wells sampled, two slightly
exceed the tap water remediation goal for lead (i.e., the maximum detected concentration was 0.028
mg/L versus 0.015 mg/L).

Consistent with the NCP, the clean-up standards for ground water that is used as drinking water at the
Tar Creek Site consist of the maximum contaminant levels (MCLs) or remediation goals promulgated
under the National and Primary and Secondary Drinking Water Standards (40 CFR Parts 141 and
143). The Oklahoma MCLs and remediation goal are the same as the Federal MCLs because
Oklahoma adopted the Federal standards for their drinking water regulations.

Ground water samples were collected from 13 residential wells during the RI. The results from two
wells slightly exceeded the tap water remediation goal for lead of 0.015 milligrams per liter (mg/L).
EPA’s risk management decision defines ground water media for OU4 as limited to the existing rural,
shallow domestic wells from residences located within the Site boundary and establishes the National
Primary Drinking Water Standard of 0.015 mg/L as the PRG for lead (EPA, 2006a). Based upon this,
a remedial strategy will be required for two wells based upon the sampling completed during the RI.

3.1.3.4     Air
The HHRA identified no risks related to inhalation of ambient air at the Site. Therefore, no
remediation goals or RAOs are established for air under OU4 (EPA, 2006b).


3.2 Media-Specific RAOs
The media-specific RAOs identified for the Site are described in this section. In general, the large
volumes and geographical extent of materials present at the site limit achieving the objectives in a
short timeframe and therefore longer timeframes are expected. Longer timeframes to meet the
objectives may potentially reduce the cost of remedial implementation but could result in extended
exposure to Site contaminants found in source materials. Table 3-1 presents a tabulated summary of
the RAOs.


3.2.1 Source Material RAOs
The source material and smelter waste RAOs are stated as follows:



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•    Prevent adolescents from coming in direct contact, through the ingestion and inhalation exposure
     pathways, with lead-contaminated source material and smelter waste where lead concentrations
     exceed 500 ppm. The purpose of this objective is to reduce the central estimate of blood lead
     concentration in adults (i.e., the mature adolescents in question) that have been exposed to Site
     source materials to a level that ensures that the 95th percentile fetal blood lead concentration in
     their offspring does not exceed 10 micrograms per deciliter (µg/dL). This objective will also be
     protective for children who live on the site in the event they come in direct contact with the
     source material through the ingestion and inhalation exposure pathways.

•    Prevent the terrestrial fauna from coming into direct (or indirect through plant ingestion) contact,
     through the ingestion exposure pathway, with cadmium-, lead-, and zinc-contaminated source
     materials and smelter waste where cadmium, lead, and zinc concentrations exceed their respective
     remediation goals.

•    Prevent riparian biota including waterfowl from coming into contact, through the ingestion
     exposure pathway, with dangerous concentrations of cadmium, lead, and zinc in surface water
     and sediment by eliminating all discharge of cadmium, lead, and zinc from source materials to
     surface water. Discharge elimination is defined as attaining discharge concentration levels that
     would be consistent with the concentration levels that would be expected from soil that has
     background concentrations of these chemicals.


3.2.2 Affected Soils RAOs
The RAOs for affected soils under OU4 of the Tar Creek Site include the following:

•    Prevent children from coming in direct contact, through the ingestion and inhalation exposure
     pathways, with lead contaminated soil where soil concentrations exceed 500 ppm. The purpose of
     this objective is to limit exposure to soil lead levels such that a typical (a hypothetical) child or
     group of similarly exposed children living on site would have an estimated risk of no more than 5
     percent exceeding 10 µg/dl blood lead level.

•    Prevent the terrestrial fauna from coming into direct (or indirect through plant ingestion) contact,
     through the ingestion exposure pathway, with cadmium-, lead-, and zinc-contaminated source
     materials and smelter waste where cadmium, lead, and zinc concentrations exceed their respective
     remediation goals.




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3.2.3 Use of Shallow Ground Water RAOs
The RAO for OU4 ground water is as follows:

•    Prevent Site residents from the ingestion of water drawn from private wells that contain lead in
     concentrations exceeding the National Primary Drinking Water Standards.




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4.0 Identification and Screening of Remedial
  Technologies

The identification of GRA and screening of remedial technologies for OU4 are presented in this
section. This discussion updates and adds to the identification and screening of technologies
presented in several prior feasibility studies and other documents describing potentially applicable
remedial technologies for the Tar Creek Site, as well as other sites within the District.

The first step in the identification and screening process consists of identifying GRAs that address the
source materials and affected media covered under OU4. GRAs are defined as broad groupings of
remedial technologies or technology types that share common elements for addressing the RAOs
identified in Section 3 of this FS report. Technology types are subdivisions within the GRAs that
describe families of related process options. Process options consist of specific remedial actions that fall
within a general technology type. This terminology is consistent with EPA Guidance (EPA, 1988).

The GRAs for OU4 and the general technology types and process options that comprise them are
initially identified in Section 4.1. This identification of GRAs and related technologies is based on an
understanding of Site conditions, RI data, engineering judgment, prior experience in the District, and
knowledge of the applicability of the technology under Site-specific conditions. Separate sets of
GRAs, technology types, and process options are identified for source materials and the affected
media, including residential yard soils, TZ soils, surface water, and shallow aquifer well water. The
ground water technology evaluation contained in this section is limited to addressing shallow aquifer
well water in accordance with the scope of OU4 defined in the SOW (EPA, 2003a). All other ground
water issues are outside the scope of OU4.

Section 4.2 describes the results of the initial screening of remedial technologies. In this initial
screening process, the individual technologies and specific process options are evaluated with respect
to their general applicability and technical feasibility for addressing the RAOs. This screening step
relies on qualitative judgments and experience to eliminate technologies that clearly have no
relevance in achieving the RAOs. The purpose of this initial screening step is to narrow the set of
technologies for the final screening and the development of alternatives. The final screening of
remedial technologies is presented in Section 4.3.




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Section 4.4 describes the potential use of institutional controls for addressing the RAOs. According to
the NCP and EPA Guidance (EPA 1988), institutional controls are considered supplemental to the
selected remedial technologies, and are not represented in the technology hierarchy as GRAs,
technology types, or process options, and are not subjected to the technology screening process.
Section 4.4 describes the potential applicability of institutional controls to supplement OU4
engineering controls.


4.1 Identification of General Response Actions and Remedial
        Technologies
This section documents the identification of GRAs, technology types, and process options for source
materials and affected media addressed under OU4. The following subsections describe the GRAs,
technology types, and process options identified for source materials and the broad category of
affected media, including residential yard soils, TZ soils, smelter-affected soils, surface water, and
ground water. Recently developed innovative technologies are in bolded fonts.


4.1.1 Presumptive Remedies
Under the EPA guidance entitled Presumptive Remedy for Metals-in-Soil Sites (EPA, 1999a), the
suggested presumptive remedy, in the appropriate circumstances, for low-level threat metals-in-soil
waste that is not targeted for treatment is containment in place [see 9355.0-72FS at pp. 2 and E-4].
Based on the circumstances at OU4 and based on NCP criteria, however, EPA decided, in the remedy
screening phase, that it is not practicable or appropriate to pursue the presumptive remedy process at
this mining site. The primary reasons and circumstances for not pursuing the suggested presumptive
remedy at the Site are the low degree of support for containment in place by the parties interested in
OU4 (i.e., the State and the Quapaw Tribe and the local community), the low effectiveness of
containment over such a large area, and the difficulties associated with implementing such a remedy.
These issues are further discussed in the following paragraphs.

Unlike most Superfund sites, which are measured in acres, Tar Creek OU4 is measured in square
miles. It includes six municipalities and vast areas of land that was once used for farming, especially
hay production. In order to address contaminant source material (e.g., tailings ponds, chat bases, and
chat piles), approximately 4,220 acres, would be covered in place if the presumptive remedy were
implemented. This is equivalent to 6.6 square miles of surface area that would require institutional
controls, future land use restrictions, and long-term operation and maintenance. In addition, this
6.6 square mile “footprint” of covered source material is not a unified piece of land. The 6.6 square

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miles that would be covered is scattered throughout the Site, intermingled with land that otherwise
would be useful, unrestricted land, whose use may be limited or interrupted due to its proximity to the
covered land.

The State, the Quapaw Tribe of Oklahoma, and the local citizens have made it clear to EPA that they
consider a large covered source material footprint untenable. In particular, the Quapaw Tribe has
explained that the land under its jurisdiction is the place where “Quapaw can be Quapaw.”
Consequently, leaving behind a large footprint of covered contamination would be a blow to the
Tribe’s identity and sense of place. Local community members and the Quapaw Tribe have told EPA
that they want chat sales to continue since it is an important source of income in this otherwise
depressed county, but if the chat is covered as suggested by the presumptive remedy, it cannot
reasonably be sold. The State of Oklahoma has essentially said that covering in place is not a remedy
it is eager to support. In particular, the dependence upon institutional controls and the long-term
operation and maintenance associated with the presumptive remedy is a significant State concern.
The operation and maintenance, logistics, and administration are expected to be burdensome and
costly to implement since source materials that would be covered are distributed widely throughout
the Site. In addition, the State has expressed concern over the huge borrow soil requirements
necessary to cover the source material under the presumptive remedy, and the State has expressed
concern over the effects that removing so much soil may have on the locations where the borrow
source material is excavated. Under CERCLA, the degree of support for a remedial action by parties
interested in the site is an important factor. In addition, under the NCP criteria, State and Tribal
acceptance and community acceptance of a remedy are factors to be considered. As far as OU4 is
concerned, these factors weigh heavily against covering in place.

Additionally, EPA has concerns about the effectiveness of covering in place over such a large area.
Specifically, the placement of cover soils by design minimizes infiltration and thereby may increase
runoff of surface water into Site water bodies. With increased runoff, the potential exists for
increased localized flooding and erosion.

Implementability is another problem. Covering contamination in place on such a large scale would
require an almost prohibitively large amount of borrow soil. The State of Oklahoma has expressed
concern over the borrow soil requirements necessary to implement the presumptive remedy. The
State has also expressed concern that removing so much soil may have detrimental environmental
effects on the locations where the borrow source material is excavated. Moreover, policing such a
large cap to ensure that its integrity is maintained would be extremely difficult and costly. The
operation and maintenance, logistics, and administration are expected to be burdensome and costly to
implement since source materials that would be covered are distributed widely throughout the Site.


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In short, under the NCP criteria regarding effectiveness and implementability, and the CERCLA and
NCP criteria regarding State, Tribal, and community acceptance, the suggested presumptive remedy
fails as a viable alternative. Accordingly, containment in place was eliminated from further
consideration as the overall remedy for source material at OU4. Targeted containment (e.g., capping
of small isolated mining and milling waste deposits may be used as part of the remedy selected.

4.1.2 Source Materials and Affected Soils Technologies
Source materials within the Tar Creek Site consist of chat, fine tailings, mixtures of chat and fine
tailings with overburden and development rock, and a small amount of smelter wastes. Chat occurs in
piles and in the footprint of former piles referred to as chat bases. Fine tailings include flotation
tailings from the ore milling process and washed fines resulting from the processing of chat for sale as
aggregate.

For purposes of this FS report, the discussion of source material technologies is combined with the
discussion of residential yard soils, TZ soils, and smelter-affected soils (affected media). Combining
the source materials and soils technology evaluations is appropriate because both source materials and
soils are granular media that share similar physical and geotechnical characteristics. For this reason
and based on prior experience, the potentially applicable remedial technologies identified for soils are
almost identical to those for source materials. In addition, physical connections exist between soils
and the various source materials within the Site; and the boundaries between soils and source material
deposits are often gradual and indistinct, especially in terms of metal concentrations. Hence, soils
may be viewed as either source materials or affected media; and combining them with source
materials is an appropriate simplification of the technology identification process.

The following GRAs are identified as being applicable for addressing the site-specific risks, source
materials and soils RAOs, and potential transport mechanisms by which some categories of source
materials affect other media. It is emphasized, however, that some GRAs may only be applicable to
certain categories of source materials or soils based on their locations within specific physical
settings.

•    No Action – Evaluation of the no action GRA is required by the NCP
     [40 CFR Part 300.430 (e) 6].

•    Containment and Stabilization – The containment and stabilization GRA includes actions, such
     as capping, covering, armoring, or habitat modification. These actions are designed to reduce
     direct exposure and contaminant mobility and toxicity by physically containing or stabilizing the
     source materials. Reducing the opportunities for direct exposure to contaminants by humans and

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     terrestrial biota and preventing human health and ecological risks are key considerations in
     identifying containment and stabilization response actions.

•    Surficial Source Removal – Source removal actions refer to excavating, transporting,
     consolidating, or disposing of materials for the purpose of reducing their availability as exposure
     media and their susceptibility to mobilization. This GRA focuses strictly on aboveground
     (surficial) contaminant sources and excludes underground sources. Removal of underground
     source materials is outside the scope of OU4.

•    Treatment – Treatment includes physical and/or chemical methods of reducing volume,
     mobility, and toxicity of source materials. This GRA includes recycling, reprocessing of materials
     for resource recovery, sizing or grading for segregation of the more mobile or toxic fractions,
     leaching or re-milling to reduce metal concentrations, and various treatments to reduce volume
     and/ or surface area. Identification of treatment technologies in this FS report takes into
     consideration the general lack of viable opportunities for volume reduction at mining sites due to
     the presence of high-volume, low-grade materials, such as chat. For example, most of the chat
     within the Tar Creek Site was previously re-milled at least once, thereby reducing its metal
     concentrations. This prior treatment leaves recycling for use as aggregate for road base, asphalt,
     or concrete as the only demonstrated volume reduction treatment technology identified for chat
     within the District.

•    Drainage and Erosion Controls – The discussion of drainage and erosion control technology
     types and process options is included in Section 4.1.2 under Surface Water Technologies. The
     technologies identified under this GRA, which address the interactions between surface water and
     source materials, could be discussed under either medium. For the sake of simplification, the
     evaluations of these technologies are included only once in Section 4.1.2.

The following list of potentially applicable technologies for each of the source material/affected soils
GRAs is provided for further evaluation during the screening process discussed below. The items
listed under the bulleted GRAs consist of the representative technology types and process options
identified for each general category of response actions.

No Action
•    Environmental Monitoring

Containment and Stabilization
•    Capping and Physical Reconfiguration


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     •    Direct Revegetation
     •    Habitat Modification
     •    Surface Armoring
     •    Soil or Clay Covering Systems
     •    Synthetic Membrane Cover Systems
     •    Geotextile Cover Systems
     •    Asphaltic Concrete Cover Systems
     •    Composite Cover Systems
     •    Wet or Submerged Covering (Inundation of metal sulfide materials)
     •    Oxygen-consuming Covers
     •    Slope Stabilization
     •    Grading and Slope Reduction
     •    Terracing
     •    Deep Tilling
     •    In Place Stabilization or Fixation
     •    Stabilization with Phosphate, Hydroxy-Apatite or high-phosphate biosolids
     •    Lime Stabilization of Mine or Mill Waste Deposits
     •    Fly Ash Stabilization of Mine or Mill Waste Deposits
     •    Pozzolanic Stabilization
     •    In Situ Vitrification
     •    Grout Injection
     •    Pyrokiln Thermal Encapsulation
Surficial Source Removal
•    Excavation and Disposal

     •    Excavation with On-site Consolidation without Capping
     •    Excavation with On-site Consolidation and Capping with a Soil Cover
     •    Excavation with On-site Consolidation in an Engineered Repository
     •    Excavation with On-site Disposal or Placement in Mine Shafts or Subsidence Pits
     •    Excavation with Injection into Underground Mine Workings
     •    Excavation with Off-site Disposal
Treatment
•    On-site or Off-site Reprocessing, Reuse or Recycling


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     •    Chat Reprocessing for Sand and Gravel Recovery
     •    Direct Reuse or Recycling as Construction Fill or Concrete and Asphalt Aggregate
     •    Direct Recycling of Some Smelter Wastes
     •    Hydrometallurgical Reprocessing for Metals Recovery
     •    Pyrometallurgical Reprocessing for Metals Recovery
•    Physical/Chemical Treatment

     •    In Situ Leaching
     •    Soil Washing
     •    Chemical Extraction
     •    Fluidized Bed Incineration
     •    Batch Leaching
     •    Size Grading or Screening for Toxicity, Mobility, or Volume (TMV) Reduction
     •    Electro-Kinetic Remediation
     •    In Situ or Ex Situ Metal Reduction
     •    In Situ Metal Precipitation
•    Biological Treatment

     •    Phyto-remediation or Phyto-extraction
     •    Organic Matter or Biosolids Addition
     •    In Situ Biological Remineralization

4.1.3 Surface-Water Technologies
This section presents the applicable GRAs for addressing surface water RAOs presented in
Section 3.2.3 of this FS report. The GRAs identified in this subsection are aimed at reducing metal
loadings to classified perennial streams and their major tributaries due to the various interactions
possible between surface waters and source materials. NOT included in this section are technologies
aimed at addressing discharges from underground mine workings because the metal contributions
from these discharges to surface water are specifically excluded from consideration in OU4 (SOW,
EPA, 2003a). The identified surface water GRAs include groups of technologies designed to control,
prevent, or treat metal loadings to classified perennial streams caused by the many possible
interactions between surface waters and source material deposits. Surface water and source material
interactions may include the following:

•    Point source discharges of runoff and seepage from source material deposits


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•    Non-point runoff and seepage from source material deposits

•    Mobilization and bulk transport of source materials during rainfall runoff events followed by the
     deposition of out-washed source materials in streams and wetland areas

•    Erosion and mobilization of source materials from deposits located in or adjacent to Site streams
     or ponds

The surface water GRAs include the following:

•    No Action - Evaluation of the no action GRA is required by the NCP [40 CFR Part 300.430 (e)
     6].

•    Containment and Stabilization – Although containment and stabilization technologies address
     the surface water RAOs, they also address ecological and human health risks due to exposure to
     source materials. In order to streamline the evaluation of these technologies, the discussion of the
     Containment and Stabilization GRA is presented in Section 4.1.1 under Source Materials and
     Affected Soils Technologies and is not repeated in this section.

•    Source Removal – Source removal actions refer to the excavation and disposal of surficial source
     materials for the purpose of reducing their availability for surface water transport. The discussion
     of the Source Removal GRA is presented in Section 4.1.1 under Source Materials and Affected
     Soils Technologies and is not repeated in this section.

•    Drainage and Erosion Controls – Actions contained in this GRA include diversion, runoff
     detention, stream channelization, and bank stabilization technologies designed to reduce
     contaminant transport by controlling or preventing the mobilization, erosion, and bulk transport
     of source materials by storm runoff during rainfall events.

•    Surface Water Treatment – This GRA includes actions designed to reduce the mobility,
     concentration, or toxicity of contaminants in point source discharges through physical, chemical,
     or biological means. Numerous specific treatment processes are considered under the broad
     category of physical/chemical treatment and biological treatment.

The following list of potentially applicable technologies for each surface-water GRA is provided for
further analysis during the initial screening described in Section 4.2. Potential remedial technologies
and potential process options for each GRA include the following:




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No Action
•    Surface-Water Monitoring.

Containment and Stabilization (Refer to Section 4.1.1 of this FS report)
Source Removal (Refer to Section 4.1.1 of this FS report)
Drainage and Erosion Controls
•    Embankment and Channel Stabilization

     •    Gabion Walls, Berms, Check Dams, Revetment, Rip-Rap
     •    Channel Liners or Channelization
     •    Detention and Sedimentation Basins
     •    Grade Control Structures
•    Stream Diversions

     •    Open Channel Diversion or Ditches
     •    Storage in Subsidence Pits
     •    Seep Collection Impoundments
     •    Runoff Impoundments or Retention Basins
     •    Closed Channel Storm Drains
Surface-Water Treatment
•    Physical and Chemical Treatment Processes

     •    Conventional Chemical Precipitation
     •    Anoxic Limestone Drains
     •    Passive Chemical Addition Systems
     •    Flotation
     •    Activated Carbon Treatment
     •    Molecular Sieves
     •    Reverse Osmosis
     •    Ultra-filtration or Nano-filtration
     •    Electrodialysis
     •    Distillation
     •    Spray, Mechanical or Solar Evaporation
     •    Freeze Crystallization
     •    Liquid-Liquid Extraction


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     •    Ion Exchange
     •    Land Application
     •    Electrowinning
     •    Zeolite Sorption/ Ion Exchange
•    Biological Treatment

     •    Activated Sludge Process
     •    Rotating Biological Contactors (RBCs)
     •    Biosulfate Process (active biological sulfate reduction and metals removal)
     •    Passive Anaerobic Treatment Systems
     •    Passive Aerobic Wetland Treatment
     •    Immobilized Biomass or Bio-Sorption
     •    Enzyme Treatment Systems
     •    Rhyzo-Filtration.

4.1.4 Ground Water Technologies
The identification and evaluation of ground water technologies in this FS report is limited based on
the definition of OU4 presented in the SOW (EPA, 2003a). The SOW states the following with
regard to the scope of ground water response actions to be considered (TBC) under OU4:

•    The purpose of the OU4 FS is not to address surface water degradation due to the discharge of
     acid mine water from underground mine workings or to address the threat of contamination of the
     Roubidoux aquifer due to downward migration of mine water from the shallow Boone aquifer.

•    The contribution of metals from mine and mill wastes to ground water is outside the scope of
     OU4.

•    The Respondents responsible for conducting the RI/FS should limit their investigations of ground
     water to identifying and characterizing existing shallow aquifer wells used for domestic water
     supplies.

Based on the above-stated limitations of OU4, the identification and evaluation of ground water
GRAs, technology types and process options is limited to those technologies capable of addressing
the single ground water RAO, protecting human health from shallow aquifer well water that exceeds
the MCLs for the OU4 COPCs.




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Although the NCP (EPA, 1990a) states that potentially usable ground water at CERCLA sites should
be returned to their beneficial uses wherever practicable, the Agency recognizes that restoring some
aquifers to drinking water quality may not be achievable given site-specific limitations (OSWER
Directive 9360.1-02, EPA, 1993). As documented in numerous FS reports for sites within the
District, reducing contaminant concentrations below the MCLs in shallow aquifer ground water
would be economically and technically impracticable due to the natural mineralization remaining in
the shallow aquifer. In addition, installing effective hydraulic controls on the large-scale necessary to
control contaminant migration within the Site would be futile due to the natural heterogeneity,
brecciation, and karstification of the shallow aquifer. For this reason, precedent exists in the District
for invoking waivers of the chemical-specific ground water applicable or relevant and appropriate
requirements (ARARs) based on the technical impracticability of achieving the MCLs. A thorough
discussion supporting the justification for waiving ground water ARARs is presented in the FS for the
Ground Water OU of the Jasper County, Missouri, Site (Dames & Moore, 1997). A similar
justification would likely apply to the Tar Creek Site, but addressing remediation of the shallow
aquifer is outside the scope of OU4.

The ground water GRAs within the scope of OU4 include the following:

•    No Action - Evaluation of the no action GRA is required by the NCP
     [40 CFR Part 300.430 (e) 6].

•    Alternative Water Supplies – This GRA includes actions designed to provide affected
     households with domestic water from sources other than the shallow aquifer, such as providing
     bottled water, drilling new private deep wells, or expanding or constructing new public water
     supply systems.

•    Ground Water Treatment – The technologies listed under this GRA consist of point-of-use
     ground water treatment systems suitable for addressing potential human health risks in individual
     residences. Ground water treatment systems for public water supplies are not considered under
     OU4 because all public water systems are supplied by deep aquifer wells, which are outside the
     defined scope of OU4.

•    The following list of potentially applicable technologies for each ground water GRA is provided
     for further analysis during the initial screening described in Section 4.2:

No Action:
     •    No Action


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     •    Ground Water Monitoring
     •    Alternative Water Supplies
     •    Individual Water Supplies
     •    Provide Bottled Water
     •    Private Water Supplies
     •    Drill New Deep Wells for Groups of Affected Residents
     •    Public Water Supply
     •    Connect to Existing Public Water Systems
     •    Organize New Rural Water Districts
     •    Ground Water Treatment
     •    Point-of-Use Treatment Systems
     •    Water Softeners
     •    Reverse Osmosis Units
     •    Public Water Supply Treatment (Outside the scope of OU4, as all public supplies are from
          deep aquifer wells.)

4.2 Initial Technology Screening
This section presents the initial screening of the remedial technologies identified in the previous
section. This initial screening step is designed according to EPA guidance (1988) to be a qualitative
screen for obtaining a manageable subset of technically feasible and generally applicable process
options from the larger universe of identified technologies. During this step, process options that have
no technical applicability or possibility of being implemented due to technical or economic
infeasibility are eliminated from further consideration, thereby streamlining subsequent technology
evaluations.

The following criteria are used to evaluate the technical feasibility and general applicability of
process options during the initial screening step:

•    Applicability of the process option to the Site-specific conditions, including limitations imposed
     by the definition of the targeted operable unit;

•    Applicability of the process option for addressing the RAOs;

•    Effectiveness of the process option in addressing the Site-specific COPCs.




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The initial screening of technologies for source materials and affected soils, surface water, and
ground water are presented in the following subsections. To simplify these presentations, the results
of the initial screening process are summarized in tabular format with the rationales for eliminating
whole technology types or individual process options discussed in the text of each subsection.


4.2.1 Initial Screening of Source Material and Affected Soils Technologies
The results of the initial screening of source material technologies are presented in this subsection and
in Table 4-1. The rationales for eliminating process options in this initial screening step are
summarized as follows:

•    The in place stabilization options of in situ vitrification, grout injection, and pyrokiln thermal
     encapsulation are eliminated from further consideration because they have not been tested or
     proven effective in immobilizing metal contaminants in large-scale mine waste piles, such as
     those found at the Site.

•    Under the Surficial Source Removal GRA, excavation with off-site disposal is eliminated from
     further consideration because prior experience in the District indicates there are no off-site
     disposal sites available to place the large amount of materials currently located within the Site.

•    Under the Treatment GRA, the reprocessing treatment options of hydro- and pyro-metallurgical
     reprocessing are eliminated based on their technical infeasibility and anticipated ineffectiveness
     at reducing metal concentrations to environmentally acceptable levels. Historically, most chat
     deposits found within the Tar Creek Site were previously re-milled by increasingly efficient
     metallurgical processes to recover more of the metal values. Source materials have been largely
     oxidized through milling and natural weathering that has occurred since the materials were
     brought to the surface. Oxidation has rendered these materials resistant to metallurgical
     processing without first undergoing costly chemical treatments. Extensive treatability studies
     conducted in conjunction with the Galena, Kansas, Site proved that further “remilling” of source
     materials for metals recovery by current state-of-the-art technologies would not be cost-effective
     in achieving any significant reductions in toxicity of the remaining mill wastes. In addition, the
     “tailings” resulting from re-milling would be approximately the same volume as the initial chat
     volume and would still require remediation or disposal by other technologies.

•    Under the Treatment GRA, the physical/chemical treatment options of in-situ leaching, batch
     leaching, chemical extraction, incineration, in-situ chemical precipitation, electro-kinetic
     remediation, and in-situ or ex-situ metal reduction are eliminated from further consideration.


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     These process options are unproven for extracting or permanently immobilizing metals in mine
     wastes outside of the laboratory or small pilot projects. Without extensive treatability testing, it is
     uncertain if large-scale leaching and chemical extraction treatment systems would be feasible to
     implement. The electro-kinetic and metal reduction process options were evaluated during the Tar
     Creek OU2 FS. While these technologies were considered potentially applicable for addressing
     residential yard soils, they were ultimately eliminated from the selected remedy due to
     uncertainty about their effectiveness and high cost. Large-scale lime treatment of mining waste-
     rock deposits is documented for neutralizing acidic conditions and preventing the onset of acid
     rock drainage. However, lime treatment of net alkaline materials, such as Tar Creek chat deposits
     is not expected to cause any reduction in mobility or toxicity. Chemical precipitants other than
     lime have not been demonstrated feasible at large mine sites.

•    Under the Treatment GRA, the biological treatment process options known as phyto-remediation
     and phyto-extraction are eliminated from further consideration, at least for the current time
     because these process options have not been proven effective outside small pilot projects. The
     literature describing the phyto-remediation pilot studies indicate these technologies are currently
     too expensive to be economically feasible over the large areas requiring remediation at the Tar
     Creek Site. However, phyto-remediation or phyto-extraction may be reconsidered in the future
     pending the results of new field-scale pilot testing being conducted by private companies within
     the Tar Creek Site.


4.2.2 Initial Screening of Surface Water Technologies
The results of the initial screening of surface water technologies are presented in this subsection and
in Table 4-2. The rationales for eliminating process options in this initial screening step are
summarized as follows:

Under the Surface Water Treatment GRA, the only physical and chemical treatment process retained
for further analysis was conventional chemical precipitation. Treatability studies conducted under Tar
Creek OU1 determined that conventional lime precipitation was the most cost-effective water
treatment option available (OWRB, 1983). Although numerous innovative water treatment
technologies have been developed since the time of the OU1 treatability studies, experience at mine
sites indicates lime precipitation is still the most cost-effective active treatment method for removing
metals, including cadmium, iron, lead, and zinc from large volumes of water. Process improvements,
such as the high-density sludge (HDS) process, have made lime precipitation even more cost-
effective than it was in 1983.


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•    The passive treatment processes of anoxic limestone drains, open limestone drains, passive
     chemical addition, and land application might be applicable to treat point source discharges of
     acidic water. However, acid drainage occurs within the Tar Creek Site only in the form of mine
     discharges, which are outside the scope of OU4. These technologies are not effective by
     themselves in removing heavy metals from surface waters and are, therefore, eliminated from
     further consideration.

•    The physico-chemical treatment processes of dissolved-air flotation, activated carbon, molecular
     sieves, reverse osmosis, ultra- or nano-filtration, electrodialysis, distillation, evaporation, freeze
     crystallization, liquid-liquid extraction, ion exchange, electrowinning, and zeolite sorption are
     eliminated from further consideration because all these technologies are applicable to relatively
     low-volume applications or industrial water systems that require high removal efficiencies. These
     process options are potentially applicable for removing recalcitrant pollutants that are not
     amenable to lime precipitation. Neither high removal efficiencies nor removal of recalcitrant
     pollutants are required for OU4.

•    The biological process options of activated sludge, RBCs, the bio-sulfate process, immobilized
     biomass, enzyme treatment, and rhyzo-filtration are eliminated as biological treatment processes.
     Activated sludge and RBCs were evaluated during treatability studies for the Tar Creek OU1 FS
     (OWRB, 1983). The OWRB found that these two processes were capable of removing Cadmium,
     lead, and zinc from Tar Creek surface waters. However, the toxicity of these metals to the
     treatment organisms required high dilution ratios, thereby rendering these technologies infeasible.
     The bio-sulfate process has been demonstrated effective at the Britannia Mine is British
     Columbia, but it is uncertain whether the sulfate concentrations in Tar Creek surface waters are
     high enough to make this process viable. Treatability studies would be required to evaluate the
     potential applicability of the bio-sulfate process at the Tar Creek Site. Immobilized biomass,
     enzyme treatment, and rhyzo-filtration are eliminated because they are considered experimental
     and have only proven effective in small pilot demonstration systems. Rhyzo-filtration is an
     innovative technology that could potentially be applicable but is currently too expensive TBC
     implementable on a large scale.


4.2.3 Initial Screening of Ground Water Technologies
The results of the initial screening of ground water technologies are presented in this subsection and
in Table 4-3. As indicated in this table, all of the process options identified in Section 4.1.3 of this FS
report are retained for further consideration, except formation of new rural water districts. Formation


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of new rural water districts was successfully implemented in Jasper and Newton Counties, Missouri,
to address households with mining-affected shallow aquifer wells. In the Tar Creek Site, however,
only two households relying on affected shallow aquifer wells were identified. Formation of a new
water district to address this small number of households would be impractical.


4.3 Final Screening of Potentially Applicable Technologies
This section presents the final screening of candidate remedial technologies for OU4 of the Tar Creek
Site. In accordance with the NCP (40 CFR Part 300.430(e)(7)) and EPA Guidance (EPA, 1988),
process options that proved technically implementable in the initial screening step are further vetted
with respect to their effectiveness, implementability, and cost.

At this stage in the technology screening process, the effectiveness criterion is a measure of the ability
of a process option to address the identified RAOs, the site-specific COPCs and media of interest, and
human health and ecological risks reliably and permanently, given the size and physical conditions
present at the Site.

The implementability criterion is a judgment of a process option’s technical and administrative
feasibility to be installed and operated under Site-specific conditions, including considerations such as
the availability of equipment and personnel needed to install, operate, and maintain the technology.

The cost evaluation at this level of screening is limited to qualitative judgments of the capital and
long-term operation and maintenance (O&M) costs associated with a specific process option. Cost
evaluations take Site conditions, such as the affected land area, volume of materials present, and other
factors into consideration to arrive at a qualitative estimate of a process option’s costs. At this level of
screening, estimates of the capital and O&M costs are assigned ratings of either low, moderate, high,
or very high.

The final screening of candidate technologies for source materials and affected soils, surface water,
and ground water is summarized in Tables 4-4 through 4-6. The following subsections of this FS
report present medium-specific discussions of the final screening evaluations in more detail than table
summaries, as warranted.


4.3.1 Final Screening of Source Material and Affected Soils Technologies
This subsection discusses the final screening of source materials and affected soils technologies, as
summarized in Table 4-4. The final list of candidate technologies reflects the need for a categorical



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approach to remedial actions, as well as the large scale of the task of remediating source materials and
affected soils within the Tar Creek Site.

Based on experience in other District Sites, a categorical approach to remediation is warranted due to
the diversity of source material and soil categories present at the Site, including the following:

•    Chat piles

•    Chat bases

•    Fine tailings, including both chat-washing fines and floatation tailings

•    Smelter wastes

•    Transition-zone soils

•    Residential yard soils

•    Smelter-affected soils

The final list of candidate technologies recognizes that no single process option exists that would be
applicable for all source materials and affected soils. Instead, the final technology list takes the
diversity of materials into account by retaining category-specific process options, i.e., process options
that may be applicable for remediating one or two source material categories but not others. For
example, deep tilling has proven effective in reducing COPC concentrations below risk-based levels
in chat bases and transition-zone soils at other District sites, but deep tilling would not be effective or
implementable for remediating chat or fine tailings deposits.

The final list of technologies for addressing source materials and affected soils also reflects the
magnitude of the challenge of dealing with approximately 50 million yd3 of materials. In general,
technologies suitable for addressing relatively small-scale contamination, such as phosphate, fly ash,
or pozzolanic stabilization; asphalt or synthetic membrane cover systems; wet or oxygen-consuming
covers; and biological remineralization, would not be cost-effective or implementable for remediating
the large volume of materials present within the Site. While effective and implementable on small
areas, these “small-scale” technologies have no chance of being implemented Site-wide and are
eliminated from further consideration.

Chat, a valuable resource, is by far the largest category of source materials present at the Site. The
final list of technologies retains a group of process options designed to facilitate continued chat
processing and beneficial re-use while addressing the potential exposure routes and risks associated


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with large chat deposits. Process options designed to facilitate continued chat utilization include on-
site integration with or without capping, grading and slope reduction, soil washing, slope
stabilization, surface armoring, size grading and screening, and chat reprocessing.

Several innovative technologies are retained in the final list of candidate technologies, including
excavation with injection into underground mine workings, disposal in mine shafts or subsidence pits.
Both these innovative options have been demonstrated to be cost-effective and implementable
through field-scale testing. Region 6 EPA has tested and refined the injection of source materials into
underground mine working through several pilot testing projects at the Tar Creek Site. Subsidence pit
disposal was implemented on a large scale at the Galena Subsite of the Cherokee County, Kansas, Site
and was also tested at the Waco designated area under OU1 of the Jasper County, Missouri Site. Most
recently, subsidence pit disposal was also field tested at the Tar Creek Site by the OCC. No negative
impacts on ground water quality have been observed at any of these subsidence pit disposal projects.


4.3.2 Final Screening of Surface Water Technologies
This subsection discusses the final screening of surface water technologies, as summarized in
Table 4-5. The final list of surface water technologies reflects the limited scope of surface water
actions under OU4 and the creation of a new operable unit, OU5, which will deal specifically with
surface water issues at a later time.

The final list of surface water technologies emphasizes surface runoff and erosion control options
designed to reduce the transport of COPCs from source material deposits. As indicated in Table 4-5,
a wide variety of cost-effective and implementable civil engineering options is available to prevent
the bulk, solid-phase transport of COPCs into Site surface water bodies. In addition, a number of
process options are retained for reducing the dissolved-phase transport of COPCs in seepage from
source material deposits.

The conventional lime precipitation treatment option is eliminated from further consideration in the
development of remedial alternatives for two reasons. First, OU4 limits consideration of surface water
risks to those associated with COPC loadings contributed by source materials in ephemeral storm
runoff and seepage. Storm runoff and seepage are generally characterized by wide variations in
volume and metal concentrations that are most appropriately addressed through best management
practices, drainage and erosion controls, and pollution prevention measures. In contrast, the
conventional treatment option would only be cost-effective and implementable for addressing steady-
flowing sources of consistent-quality waters, such as mine drainage, which is outside the scope of



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OU4. Second, the new OU5 is expected to address risks associated with COPCs have already entered
Site surface waters as dissolved-phase contaminants or solid sediments.

Passive anaerobic treatment is retained for further consideration based on positive results obtained by
the University of Oklahoma’s School of Civil Engineering and Environmental Sciences from pilot-
scale treatability tests conducted at the Site. Under OU4, the applicability of passive treatment would
most likely be limited to small seeps emanating from chat deposits.


4.3.3 Final Screening of Ground Water Technologies
This subsection discusses the final screening of ground water technologies, as summarized in
Table 4-6 of this FS report. For reasons stated in Section 4.2.3 of this FS report and as indicated
Table 4-6, alternative water supplies (other than formation of new rural water districts) and point-of-
use treatment systems are the only technology types considered cost-effective and implementable for
addressing ground water risks and exposure routes specifically defined under OU4.


4.4 Framework for Institutional Controls
This section provides information on institutional controls that could be used to enhance engineering
remedies designed to address the RAOs for OU4. Institutional controls are defined as non-engineered
access or land use restrictions designed to reduce or prevent residual human health or ecological risks
that may remain following the implementation of engineered remedial actions at CERCLA sites. The
use of institutional controls to supplement engineering remedies has undergone rigorous study and
evolution since CERCLA was enacted in 1980. Since that time, legal and administrative controls have
been used successfully to help reduce or prevent risks at numerous mining-related sites.

The framework for institutional controls presented in this section is based on available EPA guidance
and prior experience within the District. Most recently, EPA adopted a strategy for ensuring
successful and nationally consistent implementation of institutional controls at superfund sites (EPA,
2004a). This strategy establishes administrative measures for identifying, tracking, and addressing
problems with institutional controls implementation nation wide. In 2002, EPA prepared draft
guidance for implementing institutional controls at superfund, brownfields, RCRA, and other
federally listed sites (EPA, 2002).

According to the NCP, evaluating RAAs at superfund sites should begin with the assumption that
treatment or engineering controls will be used to address the unacceptable risks. At the same time, the
NCP recognizes the value of institutional controls for supplementing engineering controls during all


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phases of the cleanup and of the completed remedy, especially when active response measures are
determined to be impracticable for meeting the ARARs or remediation goals (40 CFR
300.430(a)(1)(iii)(D). Section 121(d)(2)(B) of CERCLA authorizes EPA to use institutional controls
as appropriate for enhancing the long-term protectiveness of remedies at superfund sites (EPA,
2000b).

A voluntary relocation option, which is technically applicable to all remedial alternatives, is discussed
in detail in Section 6.4. Institutional controls prescribed by EPA in a selected remedy will still be
implemented whether the entire affected population elects to relocate or a small population declines
the relocation option and elects to stay in affected areas of the Site.

Two general categories of institutional controls are recognized by EPA and authorized under
CERCLA and the NCP as potentially applicable to conditions at the Tar Creek Site under OU4,
including the following:

•    Land use restrictions to protect engineered components of the remedy.

•    Land use restriction, zoning regulations, and health ordinances to enhance the remedy’s
     protectiveness of human health.

•    Institutional controls pertaining to the two categories identified above have been made part of the
     selected remedies at mining Superfund sites within the District and in other parts of the country.


4.4.1 Source Material and Affected Soils Institutional Controls
This subsection discusses institutional controls available for supplementing the effectiveness of
engineering controls pertaining to source materials and affected soils under OU4 of the Tar Creek Site.

4.4.1.1     Land Use Restriction to Protect Engineered Components
Land use restrictions that may be used as part of the OU4 remedy include the following:

•    Access Controls – Access control may be useful for preventing human exposure to source
     materials as well as to protect the engineered components of remedial actions from human
     disturbance or destruction. Access controls include warning signs, surveillance, and legal controls
     on access, such as enforceable prohibitions on trespassing.

•    Dedication of Land for Public Uses – Acquisition of real property interests or dedication of
     lands for public parks, open space, recreation areas, or other uses may be an appropriate means of
     ensuring long-term maintenance, management, and protection of remediated sites or waste


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     repositories. EPA is authorized under Section 104(j) of CERCLA to acquire real property
     interests needed to conduct remedial actions provided the State is willing to accept transfer of the
     interests following the remedial actions (EPA, 2000b).

•    Land Use Restrictions – Land use restrictions that run with the land are capable of ensuring
     long-term protection of remediated sites or waste repositories. Land use restrictions could include
     temporary or perpetual easements, deed notices, fee simple acquisition, and other agreements
     affecting real property interests. Again, however, the NCP and CERCLA require that the State
     hold any real property interests acquired to ensure the reliability of the institutional controls once
     the site goes into the O&M phase (40 CFR 300.510(f)).

4.4.1.2     Land Use Restriction, Zoning Regulations, and Health Ordinances to Enhance the
            Remedy’s Protectiveness of Human Health.
•    A land use restriction that would eliminate permanent habitation of contaminated properties
     and/or properties potentially subject to subsidence (State buyout program) would reduce potential
     exposure to Site contaminants and lower the risk associated with any alternative. Property
     buyouts and occupant relocation to non-hazardous areas fall into this category. Demolition of
     structures following occupant relocation would eliminate re-occupancy and make the control
     more readily enforceable and permanent if combined with deed restrictions to prevent new
     construction.


4.4.2 Ground Water Institutional Controls
Based on the screening of ground water technologies presented in Sections 4.2.3 and 4.3.3,
institutional controls will likely be necessary to supplement the engineering remedies for addressing
shallow aquifer water well at the Tar Creek Site. As indicated in the technology screening part of the
Feasibility Study, the only remedial actions deemed cost-effective and implementable for addressing
the ground water RAOs would result in elevated concentration levels of COPCs remaining in affected
areas of the shallow aquifer. Institutional ground water management strategies are considered during
the development of candidate remedial alternatives, including ongoing monitoring programs,
restrictions on the use of shallow aquifer water for domestic uses, prohibitions on the construction of
new shallow wells within affected areas, or requiring residents to utilize alternative water supplies.
These may be used as institutional controls under all action remedial alternatives.




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5.0 Development and Screening of Candidate
  Remedial Alternatives

This section presents the development and screening of candidate remedial alternatives for OU4 of
the Tar Creek Site. The logical framework for combining the process options retained through the
final technology-screening step into comprehensive Site-wide alternatives and the initial screening of
those alternatives is described in the following subsections of this FS report.

Section 5.1 describes the categorical approach used in developing a range of candidate remedial
alternatives for consideration. Each alternative developed through this process represents a general
thematic approach to addressing the RAOs. In Section 5.2, this range of candidate alternatives is
screened in accordance with EPA guidance (EPA, 1988). The purpose of this screening step is to
refine the range of candidate alternatives so only the most cost-effective and implementable
alternatives are carried forward to the detailed analysis presented in Section 6 of this FS report.

Because OU4 covers an area of nearly 45 square miles, it is not possible to develop and analyze
alternatives designed specifically to address each individual locale within the Site where mine and
mill waste pose unacceptable risks. Instead, the range of process options obtained from the
technology screening process are combined systematically to create thematic alternatives that each
address all the source material and affected media categories in a manner as comprehensive and Site-
wide as possible. This approach recognizes that none of the candidate alternatives is likely to contain
the precise range of actions that will ultimately be implemented at all locations of the Site. However,
the alternatives developed through this approach and their evaluations presented in this FS report
provide detailed information on how the specific process options are likely to perform across the Site.
Because the differences in the nature of the source materials and environmental settings are
considered early on in the development and screening of alternatives, this FS report identifies a range
of cost-effective and feasible actions from which to draw during the remedy selection process.

In addition to technological approaches, EPA may consider permanent relocation as a remedial
alternative as part of the FS if certain site conditions are encountered. Under CERCLA




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Section 101(24), explicit authority is granted to conduct permanent relocations by defining the
remedial action to include:

          “…the costs of permanent relocation of residents and businesses and community facilities
          where the President determines that, alone or in combination with other measures, such
          relocation is more cost-effective than and environmentally preferable to the transportation,
          storage, treatment, destruction, or secure disposition off-site of hazardous substances, or may
          otherwise be necessary to protect the public health…”

Because permanent relocation is considered a remedial action, it is selected for use at a Superfund site
only when it has been evaluated through the remedy selection process and determined to be the best
overall remedy for the site. The primary reasons for conducting a permanent relocation is to address
an immediate human health risk where an engineered solution is not readily available or where the
structures themselves prevent or hinder the implementation of a remedial action (EPA, 1999b).


5.1 Development of Candidate Remedial Alternatives
This subsection describes the categorical approach used to develop a range of comprehensive Site-
wide remedial alternatives. Under this approach, the general categories of source materials and
affected media are paired with the physical settings in which they reside to create more specific and
defined categories of source materials and affected media. Refining the source material and affected
media categories serves the following purposes:

•    It takes into consideration the interactions between source materials and various media to focus
     the proposed remedial actions on more narrowly defined risks, exposure pathways, and receptors.

•    It takes into consideration the differences in the effectiveness and implementability of various
     process options when applied to different materials, media, physical settings, and risks.

•    It provides a method of managing geographic diversity and complexity in order to streamline the
     development of comprehensive Site-wide alternatives at the same time providing the necessary
     level of detail in the alternative development and screening process.


5.1.1 Defining Source Material and Affected Media Categories
Table 5-1 illustrates the pairing of source materials and affected media with the physical settings in
which they are found at the Tar Creek Site. This table provides area and volume estimates for the
resulting material categories as defined in the original Draft FS Report. The categories provide a


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general basis for subsequent development and screening of candidate remedial alternatives and can be
viewed individually or combined together to develop and evaluate candidate technologies and
remedial approaches. The source material and affected media categories presented in Table 5-1 are
defined below.

•    Urban Chat – The urban chat category consists of any chat accumulations located within 500
     feet of urbanized areas of the Site. For this FS report, urbanized areas include the incorporated
     towns and villages of Cardin, Commerce, Picher, and Quapaw. Urbanized areas may also include
     unincorporated residential developments containing urban characteristics and infrastructure, such
     as closely spaced residences, paved streets, sewage collection and treatment systems, and
     organized water supply and transmission systems. Designation of urban chat as an FS category
     reflects its potential to become a human health risk due to its proximity to populated areas.

•    Near-Stream Chat – The near-stream chat category includes chat accumulations located within
     the active floodways of perennial streams and major tributaries. Near-stream chat consists of chat
     deposits that are subject to stream erosion during flooding events and may also include sources of
     out-washing chat or chat seepage that are capable of being transported to and deposited in
     perennial streams and major tributaries by surface water. Near-stream chat includes the more
     significant surface water loading sources within the Site.

•    Upland Chat – The upland chat category includes any chat accumulations located in rural areas
     of the site outside of floodplains or floodways that are not subject to stream erosion and are not
     sources of out-washing chat or chat seepage capable of being transported to Site streams by
     surface waters.

•    Urban Chat Bases – This category consists of chat bases located within 500 feet of urbanized
     areas of the Site, as defined under urban chat. Chat bases are defined as areas previously occupied
     by chat piles but now covered by relatively thin layers of chat after the chat piles have been
     mostly removed through various types of reprocessing. Chat bases may contain several inches to
     several feet of chat but are characterized by little or no topographic relief due to the prior removal
     of all but the bottom layers of the previously existing chat piles. Chat bases may or may not be
     vegetated. Often, old mill foundations, mining related refuse, and domestic solid wastes are
     associated with chat bases.

•    Near-Stream Chat Bases – The near-stream chat base category includes chat bases located
     within the active floodways of perennial streams and major tributaries. Near-stream chat bases are
     subject to stream erosion during flooding events and may act as significant surface water loading

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     sources within the Site. Near-stream chat bases may also act as sources of out-washing chat that
     are capable of being transported to and deposited in perennial streams and major tributaries by
     surface water.

•    Upland Chat Bases – Upland chat bases include chat bases located in rural areas of the Site that
     are not subject to stream erosion and are not sources of out-washing chat or chat seepage capable
     of being transported to Site streams by surface waters.

•    Urban Fine Tailings – The urban fine tailings category consists of fine tailings deposits located
     within 500 feet of urbanized areas of the Site, as defined under the urban chat category. Fine
     tailings include floatation tailings from the former ore milling processes and wash fines, the fine
     sands, and silts generated by chat processing operations.

•    Near-Stream Fine Tailings – The near-stream fine tailings category includes floatation tailings
     and chat wash fines located within the active floodways of perennial streams and major
     tributaries, as defined under the near-stream chat category.

•    Upland Fine Tailings – Upland fine tailings include floatation tailings and chat wash fines
     located in rural areas of the Site that are not subject to stream erosion and are not sources of out-
     washing tailings or seepage capable of being transported to Site streams by surface waters.

•    General Affected Soils (All Settings) – As used in this FS, general affected soils include soils
     within 50 feet of existing and former mill waste accumulations (transition soils) and chat covered
     areas associated with historic and abandoned roads, and chat-contaminated non-operating railroad
     grades. Not include in this category are smelter-affected and rural residential yard soils that
     belong to their own categories. Soils extending for a distance of 50 feet from the edge of any mill
     waste deposits and chat bases are assumed to exceed the risk-based remediation goals based on
     the RI soil sampling results.

•    Smelter-Affected Soils and Smelter Wastes– Only one category of smelter-affected soils is
     identified because these soils exist in only one physical setting within the Site. The RI results
     indicate that smelter-affected soils occur within about 500 feet of the Site’s only known smelter,
     the Ottawa Smelter, formerly located near Hockerville, Oklahoma.

•    Rural Residential Yard Soils – Rural residential yard soils are yard soils that are typically found
     in remote rural areas within the OU4 Site boundary and that have not been addressed as part of
     the remedial actions completed under OU2.



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•    Storm Runoff and Seepage – In accordance with the definition of OU4, surface runoff and
     seepage from mine and mill waste deposits are the only surface water categories addressed in this
     FS. Throughout this FS, runoff and seepage are combined into a single category to simplify the
     alternative development and evaluation processes.

•    Shallow Aquifer Well Water – As stipulated in the AOC, shallow aquifer well water is the only
     ground water category addressed as part of OU4. This category consists of domestic water supply
     wells completed in the shallow Boone aquifer that are currently being used as the only source of
     drinking water in Site residences. Only 13 such wells were identified during the RI field
     investigations. All these wells were located outside the urbanized areas of the Site. Consideration
     of shallow aquifer wells in this FS includes wells that potentially could be installed in the future
     by residents of new rural developments.


5.1.2 Development of Candidate Alternatives
This subsection describes the alternative development process for OU4. The process of developing a
set of Site-wide comprehensive remedial alternatives for this FS consists of the following steps:

•    Process options deemed cost-effective and implementable through the technology screening
     process described in Section 4 of this FS are carried forward to address the media-specific risks
     and RAOs.

•    The cost-effective and implementable process options are grouped around themes designed to
     address the combined risks and RAOs comprehensively. These thematic groupings of process
     options are selected to ensure a full range of alternatives is developed and considered.

•    From each thematic grouping of process options, specific actions are prescribed for each source
     material and affected media category described in this section, thereby ensuring the Site-wide
     applicability of each alternative.

•    The alternatives are established with the primary goal of addressing human health and ecological
     risks presented by source materials while facilitating maximum beneficial reuse of chat through
     processing (by others, not as part of the remedy itself).

•    Table 5-2 presents the candidate alternatives developed for OU4 and include the following:

•    Alternative 1 – No Further Action

•    Alternative 2 – In place Source Stabilization and Institutional Controls


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•    Alternative 3 - Stabilization and Institutional Controls

•    Alternative 4 – Phased Consolidation, On-site Disposal and Institutional Controls

•    Alternative 5 - Voluntary Relocation, Phased Consolidation, On-site Disposal and Institutional
     Controls

•    Alternative 6 - Partial Source Consolidation, Stabilization, Upland Disposal and Institutional
     Controls

•    Alternative 7 - Partial Source Consolidation, Stabilization, Underground Mine Disposal and
     Institutional Controls

•    Alternative 8 - Total Source Consolidation, On-site Disposal, and Institutional Controls

•    Alternative 9 - Excavation and Disposal in Upland Repositories and Institutional Controls

•    Alternative 10 - Excavation and Disposal in Underground Mine Workings and Institutional
     Controls


5.2 Initial Screening of Candidate Remedial Alternatives
This section describes the initial screening of the candidate remedial alternatives developed in
Section 5.1 of this FS report. In accordance with EPA guidance, each candidate alternative is
evaluated with respect to three screening-level criteria, including effectiveness, implementability, and
cost. The resulting screening-level analysis of each alternative is summarized in Table 5-3.

The purpose of this initial screening step is to ensure that only the most cost-effective and
implementable alternatives are carried forward to the more rigorous detailed analysis conducted in
Section 7. Elimination of poor performing alternatives early on in the evaluation process streamlines
the analysis and allows more detailed scrutiny to be focused on the more viable candidate
alternatives. The resulting more intensely focused analysis helps to ensure the selected remedy is
precisely and accurately targeted on the identified risks and RAOs.

Consistent with EPA guidance, the three screening-level evaluation criteria used in this initial
evaluation of alternatives are defined as follows:

•    Effectiveness – The effectiveness criterion at this level of screening is a qualitative judgment
     regarding an alternative’s ability to protect human health and the environment. This judgment
     involves the alternative’s ability to address all identified human health and ecological risks and all

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     the Site-wide, media-specific RAOs. Both short-term and long-term effectiveness are included in
     this evaluation. Short-term effectiveness refers to the alternative’s anticipated protectiveness
     during the remedial action period, while long-term effectiveness refers to the period after
     completion of remedial actions continuing into the future.

•    Implementability – Implementability refers to an alternative’s probability of actually being
     constructed, operated, and maintained under the Site-specific conditions. Factors considered
     under this criterion include the alternative’s technical as well as administrative feasibility.
     Technical feasibility refers to the ability to construct and operate the hardware and structural
     elements of the alternative, whereas administrative feasibility refers to ability to establish the
     necessary human, legal, and regulatory components.

•    Cost – Screening-level cost evaluations are comparative and qualitative in nature. The cost
     comparisons among candidate alternatives consist of order-of-magnitude estimates of the direct
     and indirect capital costs, as well as the long-term O&M costs. No quantitative cost estimates are
     prepared at the screening level. Instead, relative cost indicators are assigned to each alternative,
     including low, moderate, high, or very high. These relative indicators roughly correspond to the
     following cost ranges:

          − Low: Capital costs ranging up to $1,000,000 and annual O&M costs of less than
                $500,000.
          − Moderate: Capital costs ranging between $1,000,000 and $10,000,000 and annual O&M
                costs between $500,000 and $1,000,000.
          − High: Capital costs ranging between $10,000,000 and $100,000,000 and annual O&M
                costs between $1,000,000 and $10,000,000.
          − Very High: Capital costs exceeding $100,000,000 and annual O&M costs over
                $10,000,000.

5.2.1 Summary of Initial Screening
Table 5-3 presents a summary of the initial screening results. The screening process retained
Alternatives 1, 4, 5, and 8 for further consideration and detailed analysis and eliminated
Alternatives 2, 3, 6, 7, 9, and 10. Reasons cited for not retaining the alternatives included increased
costs while not increasing the overall protectiveness of the remedy to concentration levels greater than
the other alternatives and the likely inability to administer and implement particular approaches that
proposed mass removal of chat and preventing the ongoing beneficial reuse of the material (i.e. chat
processing and sales.

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6.0 Detailed Description of Remedial Alternatives

In this section, the candidate remedial alternatives retained through the initial screening process are
described in detail. The purpose of this section is to provide sufficient detail for each of the candidate
alternatives to enable a thorough engineering analysis and cost evaluation. The detailed analysis and
cost evaluations of each alternative are presented in Section 7 - Detailed Analysis of Alternatives.

As indicated in Table 5-3, four of the ten alternatives are carried forward from the initial screening.
Each of the three action alternatives represents a thematic approach for addressing the identified risks
and RAOs. The purpose of creating a range of thematic alternatives is to facilitate the detailed
analysis and comparison of different types of technologies in addressing the Site-specific RAOs. A
range of alternatives is needed to address the diversity of settings that exist within the Site, and to
offer the flexibility required to address the differences in mine and mill waste, land uses, and potential
risks. The thematic alternatives allow the flexibility of selecting one of the candidate alternatives as a
preferred alternative or developing a remedy consisting of a combination of different technology
types and process options based on the different physical settings and different types of mill waste.

Engineering terms used in the descriptions of the candidate alternatives are defined, as follows:

•    BMPs – BMPs are broadly defined by EPA under Section 304 of the Clean Water Act as
     schedules of activities, prohibitions of practices, maintenance procedures, and other management
     practices to prevent or reduce the pollution of water of the US. BMPs also include treatment
     requirements, operating procedures, and practices to control industrial site runoff, spillage or
     leaks, or drainage from raw material storage piles. BMPs for various industrial activities,
     including mining are further defined in the EPA document entitled, Storm Water Management for
     Industrial Activities, Developing Pollution Prevention Plans and Best Management Activities,
     Document Number EPA 832-R-92-006 (EPA, 1992) and in the State of Oklahoma’s Pollutant
     Discharge Elimination System (OPDES), OAC 252:606-13(b)(3)(L) that addresses storm water
     discharges from industrial facilities.

•    Biosolids – “Biosolids” is a technical term that refers specifically to the semi-solid residual
     materials from municipal wastewater treatment plants that use activated sludge treatment
     processes. Biosolids are commonly known as sewage sludge. Federal regulations have been
     promulgated under 40 CFR Part 503 that apply specifically to the disposal of biosolids. It is this
     regulated material that is referred to as biosolids in this FS.

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•    Consolidated Deposit – A consolidated deposit is defined as an agglomeration of materials that
     are temporarily placed or prior to being put to some beneficial use or in preparation for transport
     or final disposal.

•    Floodplain – Floodplains are defined as the area inundated by a flood with a return interval of
     100 years, as officially designated and mapped by the Federal Emergency Management Agency
     (FEMA). In addition, the term floodplain includes the areas inundated by a 100-year storm event
     associated with the smaller streams and tributaries within the Site, even though many of these
     areas have not been mapped or officially designated by FEMA.

•    Floodways – Floodways are defined as the areas within floodplains that produce the highest
     velocities and deepest waters during flooding events. Particular to this FS, floodways include the
     areas within stream channels and drainage ways where velocities are sufficiently during runoff
     events to mobilize chat-sized particles and transport them downstream.

•    Geo-composite Soil Cover – A geo-composite soil cover is defined as a multi-layered cover
     system consisting of at least three distinct components, including an impermeable layer, such as a
     geo-membrane or geo-synthetic clay layer, a drainage layer, and a moisture storage and plant
     growth layer. Geo-composite covers are designed to maximize runoff and evapotranspiration and
     minimize infiltration through the cover.

•    Organic Matter – The term “organic matter” is used generically throughout this FS as any type
     of natural composted or non-composted plant materials, animal manures, or sewage sludge used
     for a variety of applications, such as amending and stabilizing soils, mulching, creating anaerobic
     treatment systems, and other remedial actions. Biosolids, poultry litter, spent mushroom compost,
     cow manure, hay, yard wastes, wood chips, sawdust, or other similar materials are all examples of
     organic matter that fall under this generic term.

•    Simple Soil Cover – Simple soil covers are defined for purposes of this FS as a covering of
     topsoil and subsoil layers designed to sustain a permanent vegetative cover under local climatic
     conditions. The simple soil covers described in this FS Report consist of 12 inches of agronomic
     soils plus 12 inches of clayey soils placed over integrated or consolidated mill waste deposits to
     prevent erosion, promote evapotranspiration, and reduce, but not eliminate infiltration. Modeling
     results indicate that some infiltration and seepage will continue to occur through soil covers of
     any design due to climatic conditions in northeast Oklahoma, regardless of the depth of the soil
     layer.



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•    Soil Amendment – “Soil amendment” is another generic term, like organic matter that refers to a
     variety of organic and non-organic materials used for fertilizing, stabilizing, or improving the
     physical or chemical composition of soils. Soil amendments are typically used to create favorable
     conditions for plant growth or revegetating disturbed sites. Specific examples of soil amendments
     include organic matter; clay materials, such as vermiculite; lime; or various forms of nitrogen,
     potassium, or phosphate fertilizers.

•    Waste Containment Cell – A waste containment cell is defined for the purposes of this FS
     Report as any place where mill wastes are intended for permanent disposal by covering with a
     simple soil cover, including wastes that are covered in place. Containment cells are revegetated in
     order to protect the soil covering from erosion or other types of damage or degradation and will
     also reduce, but not eliminate, infiltration and seepage.


6.1 Key Assumptions Applicable to all Alternatives

6.1.1 Commercial Chat Processing
All alternatives, including the No Further Action alternative, share the same commercial chat
processing assumptions. Operations by private operators are ongoing at the Site and include
commercial sales of both processed and unprocessed chat. It is recognized that ongoing processing
by others has the effect of beneficially reusing the materials and ultimately reduces the volume of
chat that may have to be addressed by a remedial alternative.

Chat processors shall not contribute to additional lead contamination or cause further damage of
natural resources through their operations. Further damages to resources or causing or contributing to
a release may result in future liability. Implementation of BMPs by chat processors, under State
supervision, is suggested as a means to prevent further damages or releases to the environment.

For the purposes of the Feasibility Study, it is assumed that the following controls will be in place
under State supervision:

•    Environmental controls on chat processing include compliance with the requirements of existing
     stormwater regulations, such as implementing BMPs and SWPPPs. Other chat processing
     controls include requirements for dust control and proper handling of washed fines, similar to that
     prescribed in the ODEQ-Bingham consent order or the EPA and Department of Interior (DOI)
     model site operations plan for pilot(s) involved with the sale of chat on Indian land.



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•    Engineering controls on source material are anticipated to be used in all settings in addition to
     environmental controls on chat processing operations. Engineering controls include posting
     signage and management of stormwater runoff.

To be consistent across all alternatives, each assumes that private chat processing is a part of the
remedy and is conducted for a period of 20 years at an annual rate of 1.9 million tons. The processing
rate is based upon an EPA study that concluded that it is potentially feasible to process chat at an
annual processing rate of 1.9 million tons under an “expanded market” scenario. The expanded
market scenario looked at the demand for asphalt within an expanded 200-mile radius of the Tri-State
Mining District and concluded this rate was feasible (EPA, 2006e). Using the stated processing
assumptions, an estimated 38 million tons, equivalent to approximately 29.2 million yd3 or 76 percent
of all chat, shall be removed from the Site through processing by others in this assumed timeframe.
The conversion of chat from tons to cubic yards assumes a factor of 1.3 tons per cubic yard.

In 2005, the EPA entered into an agreement with DOI regarding chat sales from restricted Quapaw
allotments. Under this agreement, DOI was able to approve Indian-owned chat sales under EPA
authority and oversight in a manner that is consistent with and in furtherance of EPA’s long term
response at OU4 and consistent with the NCP. In addition, DOJ working through EPA, has used its
inherent settlement authority to provide settlements with chat sellers who might otherwise be deterred
from participation by fears of potential liability under CERCLA. The DOJ/EPA settlements have
provided liability protections for chat sellers. Liability protection for Indian and non-Indian chat
sellers helps expedite chat sales. EPA has agreed to work with DOI and with DOJ toward expanding
liability protection to more chat sellers.

EPA recognizes that most private chat owners may be able to sell their chat piles; however, due to the
complicated ownership pattern, and due to the restrictions on alienation that exist at the chat piles
owned by Quapaw allottees, EPA and DOI agree that chat sales are integral part of the remedy for
OU4. Consequently, EPA has included the sale of all chat (Indian-owned and non Indian-owned) as
part of the proposed remedial alternatives. The Department of Interior (DOI), in accordance with an
agreement with the EPA, will manage Indian-owned chat sales.

To further support expanded chat processing, ongoing efforts are aimed at enhancing the
protectiveness of chat processing and facilitating increased processing and use of chat. EPA’s
Criteria for the Safe and Environmentally Protective use of Granular Mine Tailings know as “Chat,”
was signed by EPA on June 5, 2007, and was published final in the Federal Register on July 18, 2007
(EPA, 2007a). This rule provides mandatory criteria for the environmentally protective use of chat in


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transportation projects carried out in whole or in part with federal funds. The objective of the rule is
to increase the use of granular mine tailings in cement or concrete projects and transportation projects
that are carried in whole or in part using federal funds. In addition, the preamble guidance and EPA’s
June 2007 fact sheet on Tri-State Mining District Chat Mining Waste (EPA,2007b) that applies to
non-transportation, non-residential projects also applies to chat processing as part of the remedial
alternatives.

Inclusion of chat sales in the remedial alternatives requires an administrative cost (i.e., indirect cost)
to implement. This includes costs for compliance, health and safety programs, implementation of the
Off-Site Rule under the NCP [40 CFR 300.440], environmental monitoring such as air monitoring,
and oversight of the activities.

Generation of New Washed Fines from Chat Processing
As chat is processed, fines are separated from the chat through either a wet or dry mechanical sieving
process. The most common practice utilizes wet sieving. Historically and even currently, wet sieving
operations have resulted in the deposition of large volumes of washed fines, often covering over areas
formerly utilized as fine tailing impoundments. Given the estimated volume of chat that is assumed
to be processed (29.2 million yd3), an estimated 3,215,000 yd3 of new washed fines may be generated.
This volume is based upon an assumed 11 percent fines contained within the chat. It should be noted
that chat may be removed without washing (pile run) depending upon how the material is used. If
significant quantities of chat were removed without washing, less washed fines would be generated.

More recently, through positive results obtained through EPA pilot studies implemented at the Site,
direct injection of the wash waters into the underground mine workings is being attempted by one
chat processor with good success and economic viability. Plans are underway for continued and
expanded use of this approach by the chat processor. Therefore, it is assumed that going forward into
the next 20 years, operators will continue to advance, refine, and pursue this approach for
management of the fines that are produced. Accordingly, the remedial alternatives will only be
required for a small portion (for the purposes of the Feasibility Study, assumed to be 10 percent) of
new fines that are generated and deposited on the surface as opposed to being injected by the
processor.


6.1.2 Watershed Management
It is recognized and acknowledged that any active remedial alternative that addresses source
materials, particularly source materials present in near stream environments, may adversely affect the
local watershed through implementation of the action. An example of a potential impact would be the

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removal of a chat pile from a near stream environment causing increased erosion, stream
channelization, and possible local or downstream flooding. This could conceivably result from the
removal of the chat pile and with it, the large water storage and retention capacity the pile presents.

In order to address these potential issues, a watershed-based approach will be taken to review and
assess the potential affects the remedial actions may have on the local watersheds. Flooding concerns
would be documented and evaluated using a watershed hydrology model. A baseline hydrology
model would be developed as part of the remedial design to reflect the existing land uses in the basin
and reflect any rainfall storage within the source materials. The model would be calibrated to recent
flood events on the receiving streams. The baseline hydrology model would then be used to evaluate
the impact of chat removal in terms of increased storm runoff and downstream flooding risks. As
source materials are removed, the capacity of the soil and proposed land use to absorb rainfall would
be evaluated. The model could also be used as a planning and design tool to prepare a comprehensive
watershed plan to mitigate any potential runoff increases. Possible mitigation measures may include:

•    Deep tilling of soils, particularly compacted soils that may underlie source material removal
     areas, is an effective method of increasing infiltration and preventing runoff, in addition to the
     aeration that occurs which is beneficial to vegetation establishment.

•    Contouring and grading measures such as the establishment of harrows, hummocks, and mounds
     to slow overland flow and increase infiltration.

•    Implementation of BMPs.

•    Design and construction of stormwater detention systems or constructed treatment wetlands.

Complete details of this approach and possible control and mitigation measures will be formulated
during the remedial design.


6.2 Detailed Description of Alternative 1: No Further Action
This section presents the rationale and detailed description for Alternative 1, the no further action
alternative. Table 6-1 summarizes remedial actions prescribed under Alternative 1.


6.2.1 Alternative 1 Rationale
Consideration of a no action alternative is required by the NCP as a baseline for comparing the other
RAAs. An alternative based on no further action prescribes no new remedial actions but takes into
consideration the natural attenuation; removal and remedial actions; rules, regulations, institutional

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controls; and current business, cultural and land use practices that are already occurring or are
planned to be performed or implemented. Current, planned, and proposed actions and practices
include the ongoing remedial actions prescribed under OU1 and OU2; implementation of remediation
and reclamation projects conducted around the perimeter of the Site under the Oklahoma Plan; chat
processing and removal by private operators; a planned State buyout of properties that are at highest
risk for potential subsidence; and continued monitoring of Site conditions.

In the absence of identified present or future risks related to certain source material or affected media
categories, the no further action alternative may be as effective as implementing additional active
engineering controls in addressing the RAOs. Therefore, in addition to representing a baseline,
evaluation of the no further action alternative is performed to identify conditions for which no action
may be appropriate.


6.2.2 Detailed Description of Alternative 1
Under the no further action alternative, no new actions are performed under CERCLA to address the
RAOs. However, measures currently being performed or planned for the future a discussed below.

6.2.2.1     Chat Processing
Continued chat processing by private operators is expected to continue into the future. Using the
stated processing assumptions, an estimated 29.2 million yd3, or 76 percent of all chat shall be
removed from the Site and an estimated 9.4 million yd3 of chat will remain after the 20-year
timeframe if no other actions are taken, as suggested by this alternative. Although a significant
volume of chat is removed by ongoing processing performed by others, it is very likely that the area
or footprint occupied by chat piles and bases will not be reduced to any significant level. In typical
practice, chat piles ultimately become chat bases after processing is complete. The overall area is
often unchanged or reduced and in some cases, may actually increase as chat material is worked and
spread at the processing site to establish areas for heavy equipment operation and haul roads. Chat
bases and chat piles found in dense urban environments or in small isolated deposits are often not
targeted for processing by private operators, leaving them as long-term continuing sources for
potential exposure. Generally, it is expected that lead concentrations in processed chat are reduced to
levels below the remediation goals by wet or dry processing. However, the subsequent chat wash
fines typically contain high concentrations of lead and continue to be generated and disposed on-site.
These new wash fines and the existing wash fines and fine tailings are not addressed by this
alternative.



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6.2.2.2     Other Site Source Materials and Affected Media
Other Site source materials, such as smelter waste, fine tailings and existing washed fines, and
affected media such as transition zone soils, smelter-affected soils, and rural residential shallow well
supplies, would not be addressed under the No Further Action alternative.

6.2.2.3     Residential Yard Soil
Soils in urban and some rural residential yards containing COPCs in concentrations exceeding the
remediation goals continue to be excavated and replaced with clean soils. The excavated soils are
disposed on-site. These yard soil actions continue as needed under the ROD for OU2. However, some
rural residential yards exceeding the risk-based remediation goals may not be addressed under this
alternative.

6.2.2.4     Oklahoma Plan
Remedial actions are being performed or are planned to be performed under the Oklahoma Plan for
Tar Creek. The Oklahoma Plan is a cooperative effort by Federal, State, and Tribal agencies to
reclaim and remediate selected areas of the Tar Creek Site. The Oklahoma Plan operates outside the
CERCLA process with funding from various Federal and State sources. An announced State buyout,
discussed in Section 6.3, is being implemented. As part of this plan, funding to the Oklahoma Plan is
being re-allocated to the buyout; therefore, certain elements of the Oklahoma Plan discussed below
may not receive additional funding and may not be completed:

•    The OCC plans to remediate mine and mill waste affected lands on the west side of Commerce,
     Oklahoma. Planned actions include disposing of mill wastes in aboveground repositories and in
     underground mine workings or subsidence pits, filling mineshafts, and recontouring and
     revegetating the site.

•    ODEQ plans to remediate mine and mill waste affected lands in some perimeter areas of the Site,
     including the Bird Dog, Barrett, and Holders properties.

•    OCC and the City of Commerce are remediating the Enoch property on the south side of
     Commerce, Oklahoma. Materials from the Enoch property are planned to be disposed in two
     water-filled subsidence features known as the red and green holes.

•    The Ottawa County Board of Commissioners is in the process of paving several miles of chat-
     paved roads within the Site.




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6.2.2.5     Pilot and Treatability Studies
Treatability studies are being conducted within the Tar Creek Site to evaluate the cost-effectiveness
several emerging technologies, including disposal of source materials in underground mine workings
and passive wetland treatment systems. Several of these studies consist of field-scale demonstrations
that have already successfully remediated some areas within the Site.

6.2.2.6     Ongoing Monitoring
Various monitoring efforts continue to be conducted, including ambient air monitoring conducted by
the Quapaw Tribe and water quality monitoring conducted by USGS and ODEQ. Water quality
monitoring results over the past two decades indicate that acid mine drainage and its associated water
quality impacts are being naturally attenuated.

6.2.2.7     2005 State Buyout
Completion of a buyout program through a State of Oklahoma established trust in 2005 led to the
relocation of 51 families from the Cardin and Picher areas. The mission of this trust was expanded in
2006 with the commitment by Congress for $18.9 million in federal funds. The trust is now in the
process of conducting a voluntary relocation of the highest priority residents and businesses.


6.3 Detailed Description of Alternative 4: Phased
        Consolidation, On-site Disposal and Institutional Controls
This section presents the rationale and detailed description of Alternative 4, an alternative that
proposes phased consolidation, on-site disposal methods, and institutional controls to address the
RAOs.

As stated in Section 5, the source material and affected media categories provide a general basis for
subsequent development and screening of candidate remedial alternatives and can be viewed
individually or combined together to develop and evaluate candidate technologies and remedial
approaches. As such, two remedial alternatives, Alternatives 4 and 5, combine different categories.
Specifically, chat piles, chat bases, and fine tailings, are placed into two categories – near stream and
all other areas. The near-stream definition is similar to that described in Section 5.1 while all other
areas accounts for urban and upland settings. In addition, the term buffer zone soil is used
interchangeably with transition zone soils to describe soils that are potentially affected within a zone
approximately 50 feet beyond the edge of source materials. Table 6-2 summarizes the source
material categories used for development of Alternatives 4 and 5 and their respective volumes and


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areas. Figure 6-1 presents the source material locations and classifications for Alternatives 4 and 5
and Figure 6-2 is a graphical representation of the source material volumes.


6.3.1 Alternative 4 Rationale
Alternative 4 addresses all source materials using a flexible array of technologies and approaches.
Similar to the other alternatives, Alternative 4 assumes that long-term operation of private chat
processing companies to reduce the volume of chat that ultimately requires action through remedy
implementation.

Alternative 4 seeks to maximize the beneficial reuse of chat while significantly reducing the overall
area or footprint left behind after remedial actions are complete. To accomplish this, Alternative 4
proposes to excavate and haul large volumes of chat found in piles and bases from distal or remote
areas of the Site. The distal areas are further from the areas of heavy mining and are established
primarily to obtain a significant Site footprint reduction that leaves less land with future use
restrictions and long-term operation and maintenance requirements. The distal areas are also focused
on specific local watersheds, which is expected to provide an added benefit of overall water quality
improvement in within those watersheds.

All other source materials will be addressed within an overall 20-year timeframe. This includes any
chat that is not processed by private operators. At the end of the 20-year timeframe, all source
materials are expected to be under a controlled setting or environment, either through remedy
implementation and completion, or in the case of chat source materials, by being under a controlled
setting at a chat processing operation. Alternative 4 will utilize institutional controls to manage
potential residual risks because source materials, such as non-processed chat and fine tailings, remain
on-site indefinitely.

Alternative 4 proposes early actions, completed in an early phase of work, to shorten the timeframe
for addressing the RAOs and to address the threats not readily remediated by chat removal alone.
Early actions are proposed for unacceptable risk or potentially higher risks that include:

•    Addressing source materials found in the creek beds of Site creeks and in the near-stream
     environment.

•    Removal of smelter wastes and disposal in an on-site constructed repository.

•    Addressing impacted rural residential yards and affected shallow-aquifer drinking wells.

•    Seepage and erosion control of near-stream source materials.

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•    Addressing fine tailings source material.

Alternative 4 proposes longer-term actions, completed in a second phase of work, to address the
RAO’s primarily associated with chat source material. Chat that is not processed and that is not
excavated and hauled to a private washing operation will be addressed by the following remedial
actions:

•    Injection into underground mine workings.

•    Pushing into subsidence or mineshaft feature.

•    Excavation and hauling to an on-site constructed repository.

Through this Alternative, only a portion of fine tailings material, the repository, and subsidence
features used for infilling are covered and will require institutional controls and long-term operation
and maintenance.


6.3.2 Detailed Description of Alternative 4
Alternative 4 utilizes a phased approach and an array of remedial technologies to achieve the RAOs.
Appendix B contains a series of graphs that summarize source materials and their respective remedial
alternatives for both Alternative 4 and 5 and Table 6-3 summarizes remedial actions prescribed under
Alternative 4.


6.3.3 Phase 1 Elements
In general, the following elements will be initiated in the beginning of the remedial process as early
response actions completed approximately in the first ten (10) years of Site activities.

6.3.3.1     Remedial Actions in Distal Areas
Chat found in chat piles, chat bases, and historic haul roads and non-operating railroad grades from
distal areas of the Site will be addressed early in the remedial action process. This effort will be
accomplished in order to substantially reduce the overall footprint of contamination and minimize the
need for land use restrictions, institutional controls, and operation and maintenance. A subsequent
and additional benefit derived from this action is the potential for water quality improvements since
the distal areas are partially established based upon local watersheds. Distal areas of the Site are
generally rural and are outside of the high-density mining areas. As part of a more detailed analysis
for the Feasibility Study, the distal areas and the source materials present were divided into a




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Northeast, Southeast, and the Elm Creek Distal Zones. Figure 6-3 depicts these three distal zones
and the associated watersheds.

Chat found in distal areas will be excavated down to native soils where feasible. Chat present in chat
piles and chat bases in the distal areas is estimated at 6,159,000 yd3. The excavated material will be
managed following the decision tree presented as Figure 6-4. Management options include using the
excavated material as fill in subsidence features, releasing the material to a chat processor, direct
injection of the material into flooded underground mine caverns and, disposal of the material in an
on-site repository. Components of the on-site repository will be developed during the Remedial
Design and will include measures to address infiltration, grading, and closure. Upon excavation of
chat, samples of the native soils will be collected and analyzed to confirm that the remediation goal is
obtained.

Owners of chat and/or the land that chat is present on in distal areas will be contacted, and where
these owners agree, chat will be excavated and addressed by the available management options. If
the owners will not release the chat for excavation and disposition, they will be asked to provide a
plan and schedule for final disposition that is consistent with the management approaches presented
in Figure 6-4. Disposition under the owner’s plans must be completed within three to five years.

In distal areas, soil cover would not be hauled in for installation in excavated areas. Rather, soils will
be rebuilt naturally to sustain vegetation using standard land preparation practices such as ripping,
contouring, addition of amendments, disking, fertilizing, planting, and seeding.

Transition zone soil, or soil that surround source materials, will be removed if contaminant
concentrations exceed the remediation goal. The removed soil may be used for interim cover on the
repository. In areas that are excavated, nearby transition zone soils that do not exceed the
remediation goal, will be used in the natural soil rebuilding process that is implemented after
excavation.

For Feasibility Study cost estimating purposes, it is assumed that all of the chat excavated from the
distal area is released to a chat processor.

6.3.3.2     Smelter Waste Remedial Actions
Smelter wastes will be excavated and disposed of in an on-site repository located in an area that is
already contaminated. Smelter-affected soils will be managed in the same manner as transition zone
soils as described above. Soils underlying excavated areas will be rebuilt naturally as described
above under the Distal Area discussion.


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6.3.3.3     Fine Tailings Remedial Actions
Where it is determined to be both feasible on the basis of a hydrogeologic study and cost effective,
fine tailings will be injected into flooded underground mine workings using a decision tree presented
as Figure 6-5. Monitoring of groundwater and surface water will be conducted as appropriate to
assess the effectiveness of the injection. In the event that fine tailings cannot be injected, they will be
covered in place.

For Feasibility Study cost estimating purposes, it is assumed that the fine tailing ponds with the
largest volume to surface area ratio (i.e., very deep ponds) will be covered in place with a soil cover.
Based upon this assumption, an estimated 4,437,000 yd3 of fine tailings covering an area of 251 acres
will be covered in place with a soil cover and the remaining volume, an estimated 4,719,000 yd3 of
fine tailings that cover an estimated area of 569 acres will be injected. In addition, it is assumed that
a portion of newly generated washed fines from chat processing will also be injected. This volume is
equivalent to 322,000 yd3, or 10 percent of an estimated 3,215,000 yd3 expected to be generated
through chat processing. Together, the total fines volume injected equals 5,041,000 yd3. The
remaining portion of the newly generated washed fines is assumed to be addressed by the private
operators through injection into underground mine workings. Figure 6-6 identifies the fine tailings
located at the Site and their proposed disposition. Transition zone soils and the soils underlying the
fine tailing ponds that were excavated and injected will be rebuilt as described above under the Distal
Area discussion.

6.3.3.4     Hydrogeologic Study
Alternative 4 prescribes the injection of source materials, namely fine tailings and chat, into flooded
underground mine caverns as a remedial approach and disposal method. Injection of this type is
regulated under the Underground Injection Control (UIC) Program, specifically as a Class V Injection
Well. Requirements for owners or operators of Class V Injection Wells must assess and determine if
the injection causes endangerment to underground sources of drinking water and complete proper
closure of the well upon completion of injection activities (40 CFR Part 144 Subpart G; EPA,
1999). The use of injection prompts the study of groundwater.

Before implementing injection under the Operable Unit 4 Record of Decision, a hydrogeological
study will be performed to assess the potential for injection to cause further harm to groundwater and
surface water. Furthermore, surface water quality will be monitored to determine if additional
measures, such as temporary water treatment, are needed. The study will also assess if there is
hydraulic connectivity between the Picher Mining Field and the Commerce mine workings while
considering possible strategic subsurface injection sites for the fine tailings. The potential intent of

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this consideration is to locate the injection sites such that the local hydrogeology may be altered in
such a way as to improve the long-term effectiveness of the injection.

6.3.3.5     Remedial Actions Addressing Source Materials Present in Site Creeks
Source materials such as chat or fine tailings, if present in Site creeks such as Tar Creek, Lytle Creek,
Elm Creek, or Beaver Creek, or other Site waterways, will be addressed on a priority basis through
excavation and/or the installation of a flexible membrane liner (FML). The purpose of these actions
is to minimize or eliminate the contaminant loading from in-stream source materials to surface water
and groundwater and to prevent direct contact with source materials. As an interim measure,
engineering controls such as berms, sheet piling, constructed wetlands, or other engineering controls,
may be installed for near-stream source control to prevent contaminants from migrating to surface
water. Excavated in-stream materials will be returned to their near-stream origin (i.e., chat piles or
bases). Streambeds addressed by excavation will have erosion control measures installed that may
include gabion basket wire and rock embankments, boulders, or constructed wetlands. Figure 6-7
identifies sections along Tar Creek that may require engineering controls.

6.3.3.6     Remedial Actions Addressing Rural Residential Wells
Where concentrations of mining-related contaminants in water drawn from rural residential wells
exceeds 0.015 milligrams per liter (mg/L) for lead, the remedy will be to provide an alternative water
supply. Rural households that are within the area that has been designated for relocation under the
State of Oklahoma’s relocation program, and participate in the relocation program, would not be
eligible for an alternative water supply. Due to the uncertainty of water supply systems that will
remain after the State’s relocation, the method for supplying the water will be determined during the
Remedial Design. If eligible households are connected to existing municipal or rural water supplies,
the owner/residents of the household would be responsible for payment of continued water service
and for household water system repairs.

6.3.3.7     Remedial Actions Addressing Rural Residential Yard Soil
Where rural residential properties that are not participating in the State’s voluntary relocation
program are found to have lead concentrations in yard soils that exceed 500 parts per million (ppm),
the yard soil will be excavated. The soil will be excavated to a maximum depth of 12-inches, the area
backfilled with clean soil, contoured to promote drainage as feasible, and revegetated. If
contaminated soils are known to remain beyond the excavation depth, a warning material (typically
high-visibility orange construction fencing) will be placed at the bottom of the excavation prior to
backfilling. The warning material would serve to alter those conducting future earthmoving activity.


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6.3.3.8     Construction of an On-site Repository
An on-site repository will be constructed to accept Site source materials for final disposal. The
repository will be constructed in an area already contaminated. The repository will cover an
estimated 28 acres and will be capable of receiving an estimated 1,000,000 yd3 of source materials,
affected soils, and other Site-related materials such as wood, concrete, and miscellaneous debris. The
repository design shall consider components of the repository that include performance measures to
address infiltration, grading, and closure. For Feasibility Study cost estimating purposes, a clay liner,
filter sand bed, and a soil cover are assumed.

6.3.3.9     Five Year Reviews
The on-going remedy would be reviewed every five years since hazardous substances remain on-site
with concentration levels that do not allow for unrestricted use and unrestricted exposure. The
remedy would be reviewed to assess the ability of the remedy to provide for the protection of human
health and the environment. As part of the review, EPA will evaluate the progress of chat sales at
least every five years. Starting with the second five-year review (i.e., after 10 years), chat piles and
chat bases that remain and that are non-marketable will be identified. This determination will be
made with input from the chat landowners, DOI, appropriate Tribal representatives, and the
commercial operators. Chat determined to be non-marketable will be addressed by a remedial action.


6.3.4 Phase 2 Elements
In general, the following long-term response actions and other measures will be completed
approximately through the second ten (10) years of remedial actions occurring at the Site.

6.3.4.1     Remedial Actions Addressing Non-Marketable Chat
Within the heavily mined area or core of the Site, a significant volume of chat is present in small
piles, bases, and historic non-operating railroad grade and roadbeds. While the chat itself is often of
the appropriate composition and quality for end uses of chat such as in asphalt mixes, the low volume
of material at any given location typically renders them non-marketable for chat processors.
Therefore, owners of non-marketable chat and/or the land that chat is present on will be contacted,
and where these owners agree, chat will be excavated and addressed by the available management
options as shown in Figure 6-4. Management options include using the excavated material as fill in
subsidence features, releasing the material to a chat processor, direct injection of the material into
flooded underground mine caverns and, disposal of the material in an on-site repository. A
preference is assigned, as reflected in the cost estimate assumptions, to the option to release the
material to a chat processor for processing since the material is beneficially reused, and therefore does

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not require a subsequent remedy like injection into underground mine workings or pushing into a
subsidence feature. The chat will be excavated down to native soils where feasible.

For Feasibility Study alternative comparisons and cost estimating, the volume of non-marketable chat
is estimated at 9,380,000 yd3, or 24 percent of all chat. However, as non-marketable chat is
consolidated at processing operations through this alternative, the actual volume of truly non-
marketable chat (poor quality/composition for end uses) is expected to be lower than the estimated
value.

If the owners will not release the chat for disposition, they will be asked to provide a plan and
schedule for final disposition that is consistent with the management approaches presented in Figure
6-4. Disposition under the owner’s plans must be completed within three to five years.

Soil cover would not be hauled in for installation in excavated areas. Rather, soils will be rebuilt
naturally to sustain vegetation using standard land preparation practices such as ripping, contouring,
addition of amendments, disking, fertilizing, planting, and seeding.

Transition zone soil, or soil that surround source materials, will be removed if contaminant
concentrations exceed the remediation goal. The removed soil may be used for interim cover on the
repository. In areas that are excavated, nearby transition zone soils that do not exceed the
remediation goal, will be used in the natural soil rebuilding process that is implemented after
excavation.

For Feasibility Study cost estimating purposes, it is assumed that the chat would be addressed in the
following manner:

•    75 percent, or 7,035,000 yd3, would be excavated and released to a chat processor where it would
     stockpiled in a controlled setting until processed. The 7.0 million yd3 of chat is excavated and
     hauled as part of the remedy to commercial chat processing operations where the chat (and the
     estimated 184 acres occupied by the chat) will be in a controlled setting that prohibits potential
     human contact with the material while facilitating beneficial reuse of the chat. It is anticipated
     that continued commercial chat processing of this material beyond the assumed timeframe of this
     alternative will likely continue and will result further volume reduction. At current processing
     assumptions, this volume would be processed in approximately five years. At the end of
     commercial processing, if source materials remain they will be evaluated and if it is determined
     that they exceed RAOs, additional remedial actions will be required. These potential future
     actions are not included in the cost estimate for this alternative.


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•    10 percent, or 938,000 yd3, would be excavated and sent to an on-site repository.

•    10 percent, or 938,000 yd3, would be used to backfill subsidence features.

•    5 percent , or 469,000 yd3, would be injected into flooded underground mine workings.

In addition to the above assumptions, all chat found in historic haul roads and non-operating railroad
grades will be managed in the same manner as shown on the decision tree (Figure 6-4). The
estimated volume of chat from haul roads and railroad grades, 702,000 yd3, is accounted for in the
total estimated volume of non-marketable chat.


6.3.5 Other Planned Actions Common to Both Phases
Institutional controls and operation and maintenance activities would be implemented at locations
where source materials are covered in place. This includes subsidence features that are backfilled
with source materials and subsequently covered, tailing ponds that are covered, and the on-site
repository, which would be covered when closure is completed. Specifically, three institutional
controls are anticipated to be applied under Alternative 4:

•    Deed notices will be recorded on all properties where wastes are covered and left in place.

•    Annual public notices will be published in area newspapers explaining that some areas where
     wastes were removed still may pose a risk if excavation occurs and identify where additional
     information may be obtained.

•    Additionally, the state water well permitting board will prohibit the drilling of any new shallow
     water wells for potable or domestic supply in the area.

Monitoring of ambient and near-source air, surface water, groundwater, or sediment will be
completed as appropriate during remedial action activities. Pilot projects and treatability studies (i.e.,
chat sales) will continue through completion of the Remedial Design. To help eliminate the
possibility of potential exposure to Site source materials, community education and awareness
activities will be conducted throughout the duration of the remedial actions.




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6.4 Detailed Description of Alternative 5: Voluntary Relocation,
        Phased Consolidation, On-site Disposal and Institutional
        Controls
This section presents the rationale and detailed description of Alternative 5, an alternative that
proposes voluntary relocation, phased consolidation, and on-site disposal methods and institutional
controls to address the RAOs. The remedial actions proposed under Alternative 5 are identical to
those proposed in Alternative 4 with the only exception being the phasing of when the actions are
implemented. Table 6-4 summarizes the voluntary relocation and remedial actions prescribed under
Alternative 5. Figure 6-1 identifies the locations of the primary source materials that are addressed
under Alternative 5 and Figure 6-2 presents a graphical summary of site source materials by volume.


6.4.1 Alternative 5 Rationale
The remedial alternatives under Alternative 5 are identical to the remedial alternatives under
Alternative 4; however, Alternative 5 includes a voluntary relocation component and the remedial
actions are phased over an assumed 30-year period instead of 20 years as in Alternative 4. The
relocation component is expected to provide incremental risk reduction and protectiveness to those
individuals that participate in the voluntary relocation program. At the end of the 30-year timeframe,
all source materials are expected to be under a controlled setting or environment, either through
remedy implementation and completion, or in the case of chat source materials, by being under a
controlled setting at a chat processing operation.

It should be noted that the voluntary relocation component, as discussed in Alternative 5, could be
added to any of the alternatives; however, for reporting efficiency, it is only discussed as part of this
alternative.


6.4.2 Voluntary Relocation
CERCLA grants explicit authority to conduct permanent relocations and EPA has issued interim
policy on the use of permanent relocations as part of a remedial action at a site (EPA, 1999b). Since
permanent relocation is considered a remedial action, it can only be selected for implementation at a
site after it has been evaluated through the FS process and determined to be the best overall remedy for
the site. Generally, the primary reasons for considering permanent relocation include addressing 1) an
immediate human health risk or 2) buildings or structures that impede implementation of a cleanup.


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EPA’s interim policy identifies criteria for a permanent relocation to be considered as a remedial
alternative. Summarized below are two applicable criteria for considering permanent relocation:

•    That in order to maintain protectiveness of the remedy or to prevent exposure, the remedial or
     response actions may impose unreasonable use restrictions on the community. Examples include
     limiting or prohibiting children from conducting normal activities such as playing in their yards
     or neighborhoods. These types of use restrictions may not be effective in the long-term and are
     often not acceptable to the community.

•    When temporary relocation is anticipated to last longer than one year, permanent relocation may
     be considered. It is assumed that based upon the estimated length of time required to implement
     remedial actions under any of the action-alternatives detailed in this FS, temporary relocation if
     necessary might exceed one year in duration, making permanent relocation a possibility.

In June 2004, the State of Oklahoma established a local trust to oversee the relocation of families with
children less than seven years of age from the area surrounding the towns of Picher and Cardin.
Fifty-one families were relocated under this program. The mission of this trust was expanded in 2006
with the commitment by Congress of $18.9 million in federal funds. The trust is now in the process
of conducting a voluntary relocation of the highest priority residents and businesses. Currently
committed funds are, however, not sufficient to provide relocation to all residences and business in
the area. Therefore, the following key assumptions apply to the voluntary relocation component of
this alternative:

     1) The State of Oklahoma would implement their voluntary relocation program in a manner
          similar to the previous buyout and at costs expected to be similar to those incurred in 2005.

     2) The State of Oklahoma program would assign priority and allocation of funding to relocating
          residential and commercial properties (Trust, 2006). Lower priority properties affected by
          the limitation in funds are assumed to be addressed by this alternative.

     3) The voluntary relocation component of this alternative shall be conducted in accordance with
          URA and is based on the unreasonable use restrictions imposed by implementing certain
          aspects of the remedy. URA regulations provide specific rules for conducting permanent
          relocations (EPA, 2004b).




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6.4.3 Remedial Actions
The remedial actions proposed under Alternative 5 are identical to those presented under
Alternative 4 in Section 6.2.1 and Section 6.2.2. The only variance is that the implementation of the
remedial actions is conducted over a 30-year period as opposed to the 20-year period assumed in
Alternative 4. The approach is based on the assumption that the voluntary relocation would allow or
result in the ability to implement long-term remedial actions over a longer duration, potentially
resulting in cost savings. Specifically, the timeframe used for Alternative 5 cost estimating purposes
and for alternative comparisons is as follows:

•    Phase 1 activities completed in years 1 through 10 are identical for Alternatives 4 and 5.

•    Phase 2 activities for Alternative 5 are completed during years 21 through 30. This allows for a
     window in time from years 11 to 20 for processors to “catch-up” with processing of materials
     already present plus the volume delivered through distal area actions.


6.4.4 Detailed Description of Alternative 5
The specific actions prescribed under Alternative 5 include the following:

6.4.4.1     Voluntary Relocation
Voluntary relocation will remove a limited populace from potential exposure sources from higher risk
areas. Ultimately, risk will remain as will the exposure pathway for anyone who visits the source
materials until such time as the remedial actions are completed. Members of the community who
elect not to participate in the voluntary relocation would remain in the area near sources of potential
exposure. Institutional controls such as deed notices prohibiting new construction shall be placed on
the properties to enhance the protectiveness sought through the voluntary relocation. Figure 6-8
presents the buyout boundary as determined by the State of Oklahoma.

The following elements define the assumptions used in developing the voluntary relocation
component.

•    The remaining properties not addressed under the State buyout program would be addressed
     under this alternative and include residential properties and commercial properties. The
     voluntary relocation will take tribal land ownership into consideration. The voluntary relocation
     will follow URA regulations.

•    The estimated number of properties being considered for the State’s buyout program is 744,
     which consists of 678 residential and 66 commercial properties. On the assumption that the State

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     program can address the relocation of approximately 341 residential properties and 25
     commercial properties, a total of 337 residential properties and 41 commercial properties remain
     to be relocated (ODEQ, 2007a).

•    Vacant lots are considered a low priority that will be addressed by the State program in the future;
     therefore, vacant lots are not considered in the voluntary relocation.

•    Demolition and disposal of all structures purchased by the government is assumed.

•    The full scope of a relocation program, at this point in the FS process, is uncertain and is very
     complex. However, EPA’s Superfund Permanent Relocation Statement of Work Template and
     Users’ Guide provides insight into the anticipated scope of work and services that are common to
     relocation programs (EPA, 2004b). The elements include planning, coordination and
     communication, advisory services, appraisals and acquisitions, relocation, follow-up activities,
     appeals, reporting, and project management and closeout. With the exception of the relocation
     element, which is estimated separately, the cost estimate for all other elements will be based upon
     percentages of the relocation element.

•    The estimated timeframe for completion of the voluntary relocation program is 3 years, which
     assumes approximately 6 months to form and establish the program, 2 years to implement
     (assumes 16 properties a month can be processed on average), and 6 months of follow-up,
     appeals, reporting, and closeout actions.

•    EPA will initially own the purchased properties, but after demolition of structures and recording
     of deed notices preventing future construction and habitation, the parcels will be transferred to the
     State or to the Tribe as appropriate.

6.4.4.2     Remedial Actions
The remedial actions proposed under Alternative 5 are identical to those presented under
Alternative 4 in Section 6.2.1 and Section 6.2.2. The only variance is that the time-phasing of the
remedial actions is conducted over a 30-year period as opposed to the 20 year period assumed in
Alternative 4. The approach is based on the assumption that the voluntary relocation would allow or
result in the ability to implement long-term remedial actions over a longer duration, potentially
resulting in cost savings. Specifically, the timeframe used for Alternative 5 cost estimating purposes
and for alternative comparisons is as follows:

•    Phase 1 activities completed in years 1 through 10 are identical for Alternatives 4 and 5.



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•    Phase 2 activities for Alternative 5 are completed during years 21 through 30. This allows for a
     window in time from years 11 to 20 for processors to “catch-up” with processing of materials
     already present plus the volume delivered through distal area actions.


6.5 Detailed Description of Alternative 8: Total Source
        Consolidation, On-site Disposal, and Institutional Controls
This section presents the rationale and detailed description for Alternative 8. Table 6-4 summarizes
prescribed remedial actions under Alternative 8.


6.5.1 Alternative 8 Rationale
Alternative 8 addresses the RAOs through combinations of long-term source removal and early
response actions similar to those prescribed under Alternative 4 and 5. Like the previous alternatives,
Alternative 8 assumes that significant chat removal results from the ongoing chat processing
performed by commercial operators, thereby ultimately reducing the volume that would be addressed
by the alternative.

This alternative includes the early action of massive bulk removal and consolidation of chat found in
urban and near-stream settings into existing upland chat deposits. The consolidated chat remains
available for commercial processing and sales by private companies. Chat consolidation actions
included in Alternative 8 aim at reducing the timeframe for addressing the potential human health and
environmental risks posed by these source materials categories and reduce the land area subject to
institutional controls and restricted land use, especially in urban settings. Similar to Alternative 4,
Alternative 8 assumes all remedial actions are performed within a 20-year timeframe and that all
source materials, especially chat, are either acted upon by the remedy or in a controlled setting at a
commercial chat processing facility.


6.5.2 Detailed Description of Alternative 8
Alternative 8 utilizes the definitions for the various source material and affected media categories,
such as urban, near-stream, and upland, as discussed in Section 5.1 and presented on Tables 5-1
Alternative 8 includes the following specific actions:

6.5.2.1     Chat Remedial Actions
•    All chat sources (piles, bases, etc.) located in urban and near-stream settings are excavated,
     transported to existing upland chat deposits, and consolidated for future processing and removal

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     by commercial processors. Where possible, chat is transported and consolidated in existing
     upland deposits where active chat processing facilities are already in place. Alternatively, chat
     processing facilities could be established by commercial chat processors at the new consolidated
     chat deposits to facilitate future processing and removal.

•    The purpose of this action is to reduce the timeframe for addressing the potential human health
     and environmental risks presented in these important settings. In addition, these actions aim to
     reduce the reliance on administrative agreements for meeting the RAOs, eliminate potential
     residual risks and reliance on institutional controls in urban areas, and maximize future
     unrestricted land uses in these settings.

•    Under this alternative, the chat sources are excavated down to native soils and the excavated areas
     are reclaimed by deep tilling, amending the soils, and revegetating with Site-adapted plant
     species, as described in greater detail under the Alternative 4 discussion.

•    Chat not processed or left remaining in the urban setting will be disposed through injection into
     underground mine workings or subsidence pits during the course of the 20-year remedy.

•    Under Alternative 8, upland chat piles remain available for eventual processing and removal by
     commercial processors.

•    Existing upland chat bases are excavated and consolidated on-site for commercial processing.
     Excavated areas are reclaimed by deep tilling, amending with biosolids or organic matter, and
     revegetating with site-appropriate plant species, as described in greater detail under the
     Alternative 4 discussion.

•    All non-processed upland chat in piles and upland consolidated bases are either disposed in
     subsidence pits or injected into underground mine workings. Institutional controls consisting of
     easements and deed notices are placed on any subsidence feature that is used for infilling and
     covered to manage residual risks.

6.5.2.2     Fine Tailings Remedial Actions
•    Fine tailings deposits located in urban and near-stream areas are excavated and permanently
     disposed in underground mine workings through injection. Excavated areas are reclaimed similar
     to actions for chat source materials.

•    Upland tailings impoundments are stabilized or repaired and subsequently covered with a simple
     soil cover to prevent future releases of tailings to the surrounding environments.


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6.5.2.3     Smelter Waste and Affected Soils Remedial Actions
•    Smelter wastes are consolidated on-site and covered with vegetated soil covers or excavated and
     disposed of in nearby subsidence pits. The covered areas are reclaimed with vegetation and
     protected by institutional controls. Smelter-affected soils are deep tilled to reduce metal
     concentrations in the upper layers, amended with biosolids or other organic matter, and
     revegetated with site appropriate species.

6.5.2.4     Site Affected Soils
•    Transition zone soils are deep tilled to reduce metal concentrations in the upper layers, amended
     with biosolids or other organic matter, and revegetated with site appropriate species. Abandoned
     chat roadways, and chat-contaminated non-operating railroad grades are excavated and disposed
     of in covered upland repositories. Covered areas are protected by institutional controls.

6.5.2.5     Remedial Actions Addressing Rural Residential Yard Soil
•    Prescribed actions are same as described under Alternatives 4 and 5.

6.5.2.6     Remedial Actions Addressing Rural Residential Wells
•    Prescribed actions are same as described under Alternatives 4 and 5




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7.0 Detailed Analysis of Alternatives

This section presents the detailed analysis of the candidate alternatives described in Section 6. A
description of the detailed analysis process is presented in Section 7.1, followed by separate detailed
analyses of each candidate alternative in Sections 7.2 through 7.5.


7.1 Detailed Analysis Process
This section presents the detailed analysis process with respect to the nine criteria prescribed by the
National Contingency Plan (NCP) (40 CFR Part 300) (EPA, 1990a) and EPA guidance documents
(EPA, 1988). The analysis consists of a three-tiered process with the initial tier consisting of an
evaluation with respect to the two threshold criteria:

1. Overall protectiveness of human health and the environment. This criterion determines whether
     an alternative eliminates, reduces, or controls threats to public health and the environment.

2. Compliance with Applicable or Relevant and Appropriate Requirements (ARARs). This criterion
     evaluates whether the alternative meets Federal and State environmental statutes, regulations, and
     other requirements that pertain to the site, or whether a waiver is justified.

The second tier evaluation consists of evaluating the alternative with respect to five balancing criteria
that include:

3. Long-term effectiveness and permanence. This criterion considers the ability of an alternative to
     maintain protection of human health and the environment over time.

4. Short-term effectiveness. This criterion considers the length of time needed to implement an
     alternative and the risks the alternative presents to workers, residents, and the environment during
     implementation.

5. Reduction of toxicity, mobility, or volume (TMV) through treatment. This criterion evaluates the
     use of treatment by the alternative to reduce the harmful effects of principal contaminants, their
     ability to move in the environment, and the amount of contamination that is present.

6. Implementability. This criterion evaluates the technical and administrative feasibility of
     implementing an alternative, including factors such as the relative availability of goods and
     services.

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7. Cost. This criterion evaluates the estimated capital and annual operation and maintenance costs
     of an alternative, as well as the present worth cost. Present worth is the total cost of the
     alternative over time in terms of present day dollar value. Cost estimates are expected to be
     accurate within a range of -30 to +50 percent.

The third tier evaluation consists of evaluating the alternative with respect to modifying criteria that
include:

8. State acceptance. This criterion considers whether the State agrees with EPA’s analysis and
     recommendations, as described in the Remedial Investigation/Feasibility Study and the Proposed
     Plan.

9. Public acceptance. This criterion considers whether the local community agrees with EPA’s
     preferred alternative as presented in the Proposed Plan. Comments received on the Proposed Plan
     are an important indicator of public acceptance.

This third tier evaluation is usually reserved for presentation in the ROD and can only be completed
after the public and State agencies have commented on the Feasibility Study Report and the Proposed
Plan. However, this step is often initiated in the Feasibility Study stage based upon an assessment of
what is currently known regarding public and State concerns regarding their support for specific or
proposed remedial actions. The remedial alternatives as described in Alternative 4 and Alternative 5
exemplifies that process since they have been modified to address feedback received through
consultation with the State, the Quapaw Tribe, and the 10 downstream Tribes.

The following subsections provide additional background information on the evaluation criteria used
in the detailed analysis.


7.1.1 Threshold Criteria
The threshold criteria are so called because they must be satisfied for an alternative to be carried
forward in the remedy selection process. The two threshold criteria consist of overall protection of
human health and the environment and compliance with ARARs. If both threshold criteria are not
satisfied, an individual alternative cannot be considered for selection as the Site remedy with one
exception. This exception consists of provisions contained in the NCP for waiving compliance with
ARARs under certain site-specific circumstances that would prevent the ARARs from being achieved
(40 CFR Part 300.430(f)(1)(ii)(C)).

The specific factors comprising the threshold criteria are described in the following paragraphs.


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7.1.1.1     Overall Protection of Human Health and the Environment
This criterion requires EPA to determine, as a threshold requirement, whether each alternative meets
the requirement that it is protective of human health and the environment. The overall assessment of
protection is based on a composite of factors assessed under the evaluation criteria, especially long-
term effectiveness and permanence, short-term effectiveness, and compliance with ARARs. To be
deemed protective, an alternative must meet the RAOs, reduce risks to acceptable levels, meet the
remediation goals, and generally satisfy the balancing criteria.

7.1.1.2     Compliance with ARARs
Compliance with ARARs is a judgment based on an alternative’s ability to satisfy a comprehensive
list of applicable or relevant and appropriate state and federal statutory and regulatory requirements.

To satisfy this criterion, the actions prescribed under an individual alternative must be capable of
meeting applicable or relevant and appropriate technology- or risk-based, medium-specific
concentration limits for the contaminants of concern identified at the Site. These concentration limits
are known as chemical-specific ARARs. In addition to meeting the chemical-specific ARARs, an
alternative must comply with action-specific and location-specific ARARs. Action-specific ARARs
are requirements, standards, or criteria that govern specific remedial activities, such as criteria for
designing and building solid waste disposal facilities. Location-specific ARARs consist of
requirements, standards, or criteria pertaining to special categories of sites, such as statutory
requirements pertaining to jurisdictional wetlands or historical or archaeological sites.

According to the NCP, applicable requirements are defined as environmental requirements, criteria,
or standards promulgated under federal, state, or tribal laws that apply specifically to the conditions and
circumstances at the site. Relevant and appropriate requirements consist of environmental requirements,
criteria, or standards promulgated under federal, state, or tribal laws that do not technically apply under
the exact conditions at the site, but are applicable to similar conditions or circumstances.

In addition to considering the ARARs, the detailed analysis of alternatives may take into
consideration other criteria, advisories, or guidance identified as “TBC” guidance. Although TBCs
are not ARARs, they may provide useful guidelines for developing or evaluating response actions at
CERCLA sites.

Tables 7-1, 7-2, and 7-3 of this FS report present the potential chemical-specific, action-specific, and
location-specific ARARs and TBCs identified for OU4 of the Tar Creek Site, respectively. It is
emphasized that not all the legal or regulatory requirements and TBCs identified in these tables will
ultimately be determined to be ARARs for all the candidate alternatives. A broad spectrum of

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potential ARARs and TBCs is identified in this section to set the stage for evaluating each candidate
alternatives for compliance. In the following subsections of the report, preliminary determinations are
made regarding which of the potential ARARs and TBCs actually pertain to the specific remedial
actions prescribed under each alternative. Then each alternative is vetted for compliance with a
possibly unique set of alternative-specific ARARs and TBCs. The final determination as to which
requirements are applicable or relevant and appropriate will be made by EPA Region 6 in cooperation
with the State of Oklahoma and the Quapaw Tribe during the remedy selection process.

7.1.1.3     Surface Water ARARs
As presented in EPA’s Risk Management Decision (EPA, 2006b), surface water as a media of
concern is not directly considered in OU4. However, the pathway from source materials to surface
water is within the scope of OU4. An action-oriented goal to address this pathway has been developed
and consists of reducing the loading from the source materials to surrounding soils and surface waters
through the implementation of stormwater controls and BMPs and other actions.

7.1.1.4     Ground Water ARARs
As indicated in Table 7-1, the National and Oklahoma Primary and Secondary Drinking Water
Standards are chemical-specific ARARs for Tar Creek ground water. However, achieving chemical-
specific ground water ARARs is outside the scope of work for OU4 (EPA, 2003a).

7.1.1.5     Source Materials
In preparing Table 7-2 of this FS report, an analysis of the federal, state, and tribal solid and
hazardous waste regulations was conducted to identify potential action-specific ARARs relating to
the storage, transportation, or disposal of mill wastes at the Site.

Although mill wastes appear to meet the definition of solid wastes under RCRA, they are specifically
excluded from regulation as hazardous wastes under Subtitle C. The mill wastes present in the Tar
Creek Site meet the conditions for exclusion from regulation as hazardous wastes under 40 CFR,
Part 261.4(b)(7) that states, “solid wastes from the extraction, beneficiation, and processing of ores
and minerals” are solid wastes that are not hazardous wastes. The requirements of Subtitle C are,
therefore, not applicable requirements.

Review of the Oklahoma Solid Waste Management regulations (252 OAC, Chapter 515) indicates
that the mill wastes present in the Tar Creek Site would be considered solid wastes under the
Oklahoma statutes and regulations. Hence, the Oklahoma solid waste regulations are considered
ARARs for all alternatives. Oklahoma has adopted the federal regulations for its Hazardous Waste



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Management Code (252 OAC, Chapter 205). Hence, Oklahoma’s hazardous waste laws and
regulations are not considered ARARs based on the analysis of the federal regulations presented above.

The Federal Underground Injection Control (UIC) program consists of sections of the Safe Drinking
Water Act aimed specifically at protecting groundwater supplies from disposal of wastes in
underground injection wells. Of particular importance to the Tar Creek Site are provisions defining
Class V injection wells that include wells used to backfill tailings or sand into underground mine
workings. Such wells are generally exempt from the permitting requirements of the UIC.

7.1.1.6     Relocation
EPA Guidance “Interim Policy on the Use of Permanent Relocations as Part of Superfund Remedial
Actions” (EPA, 1999b) is used as a TBC on how to evaluate relocations and will be utilized in the
FS. In addition, Federal relocations are required to be performed in accordance Federal Uniform
Relocation Assistance and Real Property Acquisition Policies Act of 1970. The Act is considered
applicable to relocations.


7.1.2 Primary Balancing Criteria
This subsection describes the primary balancing criteria that are used in the detailed analysis of
alternatives. The extent to which alternatives are analyzed during the detailed analysis is influenced
by the available data, the number and types of alternatives being evaluated, and the degree to which
alternatives were analyzed during their development and screening. The balancing criteria are
grouped together because they represent the primary technical criteria upon which the detailed
analysis is based (EPA, 1990b). These criteria consist of the following:

•    Long-term effectiveness and permanence

•    Short-term effectiveness

•    Reduction of TMV through treatment

•    Implementability

•    Cost

Each of these criteria have subcriteria that are briefly described in the following paragraph. It should
be noted that all alternatives may not need to be evaluated with respect to all the subcriteria. The key
is to identify the subcriteria by which the alternatives vary significantly and to focus the detailed
analysis on those factors (EPA, 1990b).


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7.1.2.1     Long-Term Effectiveness and Permanence
Under CERCLA, EPA is required to select remedies that utilize permanent solutions to the maximum
extent practicable (42 U.S.C. § 9621(b)(1)). In order to compare the remedy alternatives, long-term
effectiveness and permanence of each alternative should be viewed along a continuum (i.e., an
alternative can offer a greater or lesser degree of long-term effectiveness and permanence).
Alternatives that are more effective in the long-term are more permanent. See A Guide to Preparing
Superfund Proposed Plans, Records of Decision, and Other Remedy Selection Decision Documents,
1-23P at p. 3-9 (EPA, 1999d). Under the NCP at 40 CFR 300.439(e), factors that shall be considered,
as appropriate, in determining the long-term effectiveness and permanence of a remedy include the
following enumerated criteria in italics:

          (1)        Magnitude of residual risk remaining from untreated waste or treatment residuals
          remaining at the conclusion of the remedial activities. The characteristics of the residuals
          should be considered to the degree that they remain hazardous, taking into account their
          volume, toxicity, mobility, and propensity to bioaccumulate.

The type of mining waste and mill waste that are addressed under any of the Alternatives at OU4 is a
high volume low-level threat waste and EPA expects to use engineering controls instead of treatment
for this type of waste (40 CFR § 300.430(a)(1)(iii)(B)). Consequently, when engineering controls are
the exclusive mechanism used to address low-level threat waste, this criterion—“ Magnitude of
residual risk remaining from untreated waste or treatment residuals remaining at the conclusion of the
remedial activities” would not be pertinent. However, under all the action alternatives, chat sales will
be facilitated and chat sales includes chat processing, which involves treatment. Specifically, two
methods of treatment are used in preparing chat for sale. The treatment methods include dry
screening or wet washing to remove fine particles which contain the highest concentrations of lead
and other hazardous substances. These treatment processes greatly reduce the concentration of
hazardous substances in the chat. In summary, all of the alternatives since they all include chat
processing, involve the same magnitude of residual risk with respect to chat processing residuals.

          (2)        Adequacy and reliability of controls such as containment systems and institutional
          controls that are necessary to manage treatment residuals and untreated waste. This factor
          addresses in particular the uncertainties associated with land disposal for providing long-
          term protection from residuals; the assessment of the potential need to replace technical
          components of the alternative, such as a cap, a slurry wall, or a treatment system; and the
          potential exposure pathways and risks posed should the remedial action need replacement.



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7.1.2.2     Adequacy and Reliability of Controls
All action alternatives deploy adequate and reliable engineering controls but they differ with respect
to the reliability and permanence of the prescribed disposal options. All action alternatives propose
engineering controls considered to be adequate for addressing Site risks. These include injection of
source materials into underground mine workings, disposal in a constructed repository that is covered
and closed, infilling of subsidence features and subsequent covering, and covering source materials in
place with a soil cover.

Disposal in flooded underground mine workings is considered to be the most permanent and reliable
disposal technology since the material injected no longer presents a source of potential exposure at
the surface to human or ecological receptors. Institutional controls are not required and long-term
maintenance or repair is not required for the engineering control itself.

Disposal in an engineered repository is considered the second most reliable and permanent
engineering control. This disposal method is considered more reliable and permanent than disposal in
a subsidence feature or covering in place since the repository is designed to performance standards
that establish criteria for achieving longer-term reliability and permanence. The repository is subject
to institutional controls to supplement this engineering control and long-term operation and
maintenance will be required.

Disposal in subsidence features that are subsequently covered is considered the third most reliable
and permanent engineering control. Potential contact with receptors is reduced by this engineering
control since a greater volume of source materials are placed at greater depth and then covered.
Source materials disposed of in subsidence features will be subject to institutional controls to
supplement the engineering control and long-term operation and maintenance will be required.
Disposal of mining waste in this manner has been completed at many sites and found to be effective
and reliable. Secondary benefits are also realized that include elimination of dangerous fall hazards
and prevention of debris and municipal waste accumulation in and around the feature.

Covering of source materials in place is a common remedial application that reliably and adequately
controls risk to humans through elimination of the exposure routes. The soil cover prescribed
consists of 1-feet of clay overlain by 1-feet of loam soil. The prescribed soil covers help prevent
direct runoff from source materials and reduce erosion and sediment transport and are expected to
substantially reduce infiltration and seepage (NewFields, 2003). However, compared to the other
disposal options evaluated, covering in place is considered the least reliable and permanent
engineering control over the long-term. This is because often the source materials to be covered are


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present in less than ideal settings, such as close to urban populated areas or in floodplains were
potential flooding and erosion of the engineering control could potentially occur. Source materials
covered in place will be subject to institutional controls to supplement the engineering control and
long-term operation and maintenance will be required.

Deep tilling is prescribed in all action alternatives to address buffer zone soils, smelter-affected soils,
and soils underlying source materials if they have been excavated and removed. Deep tilling of soils
is expected to meet the RAOs and remediation goals for soil; therefore, institutional controls and
long-term operation and maintenance is not expected for affected soils.

Institutional controls will be prescribed under all the action alternatives. The purpose of these
institutional controls is to supplement the engineering controls by preventing the potential for future
human disturbance of soil-covered chat, fines, and smelter wastes that could cause the release of
COPCs resulting in potential risks to future Site residents. Institutional controls are considered
adequate and reliable management controls to prevent future disturbance of covered source materials.
However, it also makes sense that a remedial alternative with a lower institutional control requirement
is likely to be more effective, reliable, and permanent over the long-term at providing protection to
human health and ecological receptors. In consideration of this, the volume and area of source
materials subject to institutional controls is compared in the detailed analysis of each alternative.

Volume of Source Materials Subject to Institutional Controls and Long-Term O&M
The degree to which Site source materials are addressed by an alternative is one way to evaluate long-
term effectiveness and permanence of the alternatives. In this comparison, the alternative with the
smallest volume subject to institutional controls and long-term operation and maintenance, after
engineering controls have been completed, is considered more effective, reliable, and permanent. Note
that in this comparison, source materials injected into underground mine workings are not included in
the volume tally as being subject to institutional controls and long-term operation and maintenance.
Table 8-3 summarizes this comparison for all action alternatives.

Area Occupied by Source Materials Subject to Institutional Controls and Long-Term O&M
Similar to the comparison of source material volume addressed by an alternative, the area occupied by
source materials that is addressed (or not addressed) through engineering controls provides another
means of comparison. In this comparison, the alternative with the smallest area subject to institutional
controls and long-term operation and maintenance, after engineering controls are completed, is
considered more effective, reliable, and permanent. Table 8-3 summarizes this comparison for all the
action alternatives.


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Long-Term Permanence of Controls
Alternatives that prescribe more reliable and permanent disposal methods to address Site source
materials are considered to be more favorable than those that are heavily dependent upon disposal
methods deemed less permanent and reliable over the long-term. Injection of source materials is
considered to be the most permanent and reliable disposal method, followed by disposal in an on-site
constructed repository, infilling and covering of subsidence features, and covering in place. In
consideration of this, each alternative is evaluated relative to the four disposal methods.

7.1.2.3     Short-Term Effectiveness
The short-term effectiveness criterion addresses the potential impacts an alternative might have on
human health or the environment during the construction or implementation phase, up to the time the
RAOs are achieved. The following factors are considered in the short-term effectiveness assessment:

•    The level of risk prevention afforded communities during remedial actions

•    Protections afforded workers engaged in the remedial activities

•    The potential impacts on the environment during construction or implementation and the
     reliability of mitigation measures for preventing or reducing these potential impacts

•    The time required to implement the proposed remedial measures and achieve RAOs

7.1.2.4     Reduction of Toxicity, Mobility, or Volume
The NCP states a preference for remedies that reduce toxicity, mobility, or volume (TMV) of
hazardous constituents through treatment. This criterion addresses the extent to which the proposed
remedy relies on treatment to address the RAOs. Factors used in deciding if an alternative meets the
statutory preference for a treatment-based remedy include the following:

•    The extent to which contaminants are destroyed through treatment

•    The reduction in total mass of contaminants

•    The irreversibility of reductions in contaminant mobility

•    The reduction in total volume of contaminated materials

•    The type and quantity of treatment wastes

In applying this criterion, it is emphasized that metals are elements that cannot be destroyed by
treatment. EPA has modified the applicability of this criterion at mining-related sites through


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OSWER Directive No. 9355.0-26 (SC-20) entitled Advancing the Use of Treatment Technologies for
Superfund Remedies (EPA, 1989). Among other things, this directive states that engineering controls,
such as containment, are generally more appropriate than treatment technologies at large sites
characterized by high-volume, low-toxicity mining and milling wastes.

Under all action alternatives, chat sales would occur as part of the remedy, and chat sales includes
chat processing by dry screening or wet washing which is a form of treatment. Specifically, these two
methods are used to remove fine particles that contain the highest concentrations of lead and other
hazardous substances. These treatment processes greatly reduce the concentration of hazardous
substances in the chat. The higher concentrations are left on-site as “washed fines” and are addressed
with source materials under all action alternatives.

7.1.2.5     Implementability
The implementability criterion is a measure of the technical and administrative feasibilities of an
individual alternative. Under technical feasibility, alternatives are evaluated with respect to the
following subcriteria:

•    The site-specific constructability and operability of the proposed remedies

•    The reliability of the technology and potential for technical problems to delay or prevent
     achieving the RAOs

•    The ease of undertaking additional actions aimed at augmenting the initial remedy

•    The ability to monitor the effectiveness of the remedy

The following factors are considered in evaluating the alternatives with respect to the administrative
subcriteria:

•    The ability to obtain approvals from other agencies

•    Anticipated problems in coordinating with state and local agencies and private property owners

•    The availability of necessary equipment and skilled personnel to construct and operate facilities
     or implement remedial actions

•    The adequacy of on-site or off-site treatment, storage, and disposal services




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•    The general availability of technologies prescribed by an alternative, level of development of
     innovative technologies, and the need for treatability or pilot testing to demonstrate the
     appropriateness of a proposed technology

7.1.2.6     Cost
Evaluation of the capital and O&M costs of each alternative is performed under the cost criterion.
During the detailed analysis, the NCP requires that capital and O&M cost estimates be assembled for
each alternative with an accuracy range of at least +50 to –30 percent. Costs should be discounted to a
common base year to evaluate expenditures over time. The remedial cost estimates were prepared
using current year (2007) pricing data and forecast over a 30-year construction and operation and
maintenance period to determine net present value. A discount rate should be used in the net present
value analysis of alternatives. The discount rate used is 7 percent before taxes and after inflation
(EPA, 1996; EPA, 2000a).

In accordance with EPA guidance (EPA, 2000a), the cost criterion for this evaluation is comprised of
the following cost analyses:

•    Direct capital costs, including construction costs; equipment, labor, and materials; site
     development and building costs; disposal facility costs.

•    Indirect capital costs, including institutional controls program implementation, remedial design
     engineering, project management, construction management and contingency allowances.

•    Annual O&M costs, including post construction labor, maintenance, administration costs, e.g. for
     institutional controls, long-term monitoring, equipment replacement costs, and costs for periodic
     reviews.


7.1.3 Modifying Criteria
Modifying criteria include State Acceptance and Community Acceptance. State acceptance is a
judgment as to the level of state support, reservations, or opposition to proposed remedial actions.
Community acceptance addresses possible citizen concerns expressed during the public comment
period. The final assessment of State and Community Acceptance is presented in the ROD after the
state and public have commented on the completed FS report and proposed plan. However, in
accordance with EPA guidance, the evaluation of alternatives with respect to the modifying criteria
will be initiated in this FS report based on known input provided by the State of Oklahoma and the
Quapaw Tribe during MOU and FS meetings and consultations held during development of the FS
(EPA, 1990b).

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7.2 Detailed Analysis of Alternative 1: No Further Action
The detailed analysis of the no further action alternative is presented in this section. This alternative
prescribes no new remedial actions but recognizes and takes into consideration the engineering
actions, rules, regulations, and institutional controls that are currently being implemented or planned
to be performed under existing cultural and economic practices.


7.2.1 Alternative 1: Threshold Criteria Evaluations
Evaluation of the no further action alternative with respect to the threshold criteria is presented in this
section.

7.2.1.1     Overall Protectiveness of Human Health and the Environment
Alternative 1 does not meet the RAOs and is not protective of human health and the environment.
Even if the Oklahoma Plan were to receive full funding and completed full implementation, it only
accomplishes remediation at a few select mine and mill waste affected areas on the perimeter of the
Site remote from existing residential areas. Human exposure to COPCs remains possible in
unremediated areas of the Site, including all chat bases and tailings deposits, smelter waste, and
affected soils. Similarly, although humans participating in the subsidence-related State Buyout would
be removed from the potential for direct exposure to site contaminants, the sources remain and
present a potential risk to those not participating in the buyout and visitors to the area.

Commercial chat processing operations are estimated to remove 29,231,000 cubic yards of chat
source materials based upon the processing rates and timeframes shared by all Alternatives for
comparison purposes. While this does have a significant impact on overall chat volume, it is
anticipated that chat found in bases will not be impacted and that as piles are commercially processed
they will become future bases. This is because chat processors typically leave a thin layer of chat on
the ground at the end of their processing for economic and technical reasons. Chat processors
typically do not reclaim the footprints of the chat piles that have been reduced to bases by previous
processing therefore several hundred existing chat bases are not address by this alternative and no
anticipated reduction in Site footprint or area is expected. Under Alternative 1, existing chat bases
are likely to remain on-site and unremediated indefinitely.

Fine tailings, and the risk they present, are not addressed by Alternative 1. Fine tailing are usually
left uncovered and are not always maintained to control runoff or prevent breached dikes and the
release of tailings to the surrounding environment. Tailings impoundments typically do not constitute
habitat for terrestrial or aquatic biota, so ecological exposures may be minimal. However, tailings

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impoundments may pose long-term risks to human health because the potential for human exposure to
COPCs remains uncontrolled into the future. Similar to fine tailings, smelter waste is not addressed by
Alternative 1 and remains a potential risk.

Yard soil remediation continues in urban and some rural areas under OU2; however, a small number
of rural residences with affected yard soils are not addressed under Alternative 1. Similarly, exposure
to COPCs in drinking water remains possible for a small number of rural households that rely on
affected shallow aquifer well water as their sole source of domestic water supplies.

Future potential risks to human health from new residential development on transition-zone and
smelter-affected soils, chat bases, or wash fine deposits are not addressed by this alternative due to
the absence of any land use controls or health ordinances to regulate or monitor new development on
these areas. Although no legal restrictions on land use are imposed, the future beneficial use of lands
are limited by the presence of waste deposits.

Alternative 1 fails to meet the source material RAOs that aim to prevent discharge of lead, cadmium,
and zinc to surface water in order to prevent ingestion of these chemicals by riparian biota including
waterfowl. Source materials present in Site creeks and waterbodies are not addressed under
Alternative 1 and remain as a potential risk for direct contact with human and ecological receptors.

7.2.1.2     Compliance with ARARs
Alternative 1 does not comply with all ARARs identified for OU4.

Chemical-Specific ARARs
Consumption of water that exceeds MCLs continues in a small number of shallow aquifer wells under
the no further action alternative. Under Alternative 1, new shallow aquifer wells can still be installed.
Some new wells could result in possible exceedances of MCLs, thereby being non-compliant with
this ARAR.

Action-Specific ARARs
Action-specific ARARs are not applicable under a no action alternative.

Location-Specific ARARs
Location-specific ARARs are not applicable under a no action alternative.

TBCs
Source materials and affected soils continue to exceed TBC guidance for lead in soils.




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7.2.2 Alternative 1: Primary Balancing Criteria Evaluations
Evaluation of the no further action alternative with respect to the five primary balancing criteria is
presented in this section.

7.2.2.1     Long-Term Effectiveness and Permanence
Magnitude of Residual Risks
Since Alternative 1 does not propose active treatment as a part of its remedy, magnitude of residual
risk resulting from treatment residuals is not a consideration.

Adequacy and Reliability of Controls
Given the commercial chat processing assumptions common to all alternatives, a large volume of chat
source material is removed under Alternative 1. However, as presented on Table 7-4, even with an
estimated 29.2 million yd3 being removed through commercial chat processing, an estimated 18.5
million yd3 of source materials remain on-site that are not addressed by engineering controls and
remain an exposure risk. Similarly, the 4,220 acres occupied by source materials remains unchanged,
even with commercial chat processing occurring there is no anticipated reduction in the potential
exposure area or Site footprint.

The extent (volume and area) of source materials remaining on-site that are not addressed by
commercial chat processing or engineering controls is extensive. The uncontrolled source materials
have concentrations of COPCs that exceed the RAOs for the Site and therefore pose a long-term risk
to human health and the environment.

Institutional controls are not prescribed in a no further action alternative. The ROD for OU2 does
provide for institutional controls, but these controls are only designed to manage potential residual
risks associated with the repository sites constructed to contain the yard-soils excavated during the
OU2 residential removal actions. These institutional controls consist of deed notices that will be
placed on the yard-soil repository sites when all OU2 remedial actions are completed (McAteer,
2005).

Alternative 1 does not specify the use of any specific engineering controls to mitigate potential
exposure to Site source materials. Inactive chat piles and bases (i.e., absent chat processing
operations) are generally not secured against human access, protected from deterioration such as
erosion, or maintained to prevent future releases to the environment.




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7.2.2.2     Short-Term Effectiveness
Community Protection
Exposure to COPCs in airborne particulate matter (dust) is not identified as a potential exposure
pathway. However, approximately 70 miles of the roads serving the Site are unpaved. Heavy truck
traffic as well as normal automobile traffic on these unpaved roads creates nuisance dust emissions. In
addition, disturbance of chat piles (normally self-armoring) or dry millponds may create nuisance dust
conditions. The Quapaw Tribe conducts ambient air monitoring for use in identifying potential risks to
local communities from air borne particles. Ambient air concentrations for lead are below the National
Ambient Air Quality Standards (NAAQS).

The Oklahoma Plan, if fully implemented, contains provisions for reducing exposure to COPCs in
dust, such as paving some chat-graded roads and directly revegetating chat piles and dry millponds in
proximity to residences. Paving chat-covered roads is not part of OU4.

Although private chat companies are currently removing some of the larger urban chat piles, the
companies have tended to avoid operating in proximity to urbanized residential areas to prevent
conflicts with local residents over nuisance dust, noise, and vibration. Community protection
concerns are one reason why source materials remain unprocessed in residential areas, particularly in
the Cardin and Picher areas.

The Tar Creek MOU requests that the federal government take the steps necessary to identify and
mitigate imminent public health risks during remedial actions conducted under the Oklahoma Plan.
The MOU also recommends creating a health database for the Tar Creek Site as a means of
monitoring and evaluating public health issues.

Worker Protection
Worker protection subcriterion is not applicable given that no action is proposed.

Potential Environmental Impacts
Potential environmental impacts is not an applicable subcriterion given that no actions are proposed
that could potentially cause adverse impacts. Under the no further action alternative, runoff and
seepage from chat deposits, chat bases, and breached tailings impoundments continue impact water
and sediment quality in Site streams.

Time until RAOs Are Achieved
The RAOs are never achieved under Alternative 1 as source materials remain unremediated,
uncontrolled, and continue to pose risk indefinitely. Similarly, affected soils RAOs are unlikely to be


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fully achieved because transition-zone, smelter-affected, and affected rural yard soils remain
unremediated indefinitely.

7.2.2.3     Reduction of Toxicity, Mobility, or Volume through Treatment
No treatment technologies are proposed under Alternative 1.

7.2.2.4     Implementability
Technical Feasibility
No technical actions are proposed under Alternative 1 so this subcriterion is not applicable.

Administrative Feasibility
No administrative actions are proposed under Alternative 1 so this subcriterion is not applicable.

Availability of Materials and Labor
No actions requiring materials or labor are proposed so this subcriterion is not applicable.

7.2.2.5     Cost
No actions involving cost are proposed so this subcriterion is not applicable.


7.2.3 Alternative 1: Modifying Criteria Evaluations
This section presents the evaluation of Alternative 1 with respect to the modifying criteria.

7.2.3.1     State Acceptance
Alternative 1 does not meet the threshold criteria and likely would not be accepted by the State of
Oklahoma or the Quapaw Tribe of Oklahoma.

7.2.3.2     Public Acceptance
Alternative 1 does not meet the threshold criteria and likely would be met with public opposition as
general expectations are for a more complete remediation of the Site.


7.3 Detailed Analysis of Alternative 4: Phased Consolidation,
        On-site Disposal and Institutional Controls
This section presents the detailed analysis of Alternative 4. Alternative 4 is a comprehensive
alternative that addresses all source materials and affected soils by pairing phased early response
actions with long-term removal and on-site disposal measures and institutional controls.




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Under Alternative 4, early response actions are envisioned for potentially higher risk source media,
such as fine tailings with higher concentrations of COPCs, and in distal (remote) areas for the purpose
of substantial footprint reduction, which eliminates the need for land use restrictions in the distal
areas. The distal actions also have the secondary benefit of potentially improving the water quality
found in the watersheds affected by distal source materials through the elimination direct seepage and
runoff into Site creeks and water bodies. Other early actions include addressing impacted residential
properties and ground water drinking wells, smelter wastes and smelter affected soils, injection or
covering of fine tailings, removal of source materials present in Site creeks and water bodies, and
seepage and erosion control. Longer-term actions address remaining non-commercially processed
chat through excavation and hauling to commercial chat processors, disposal in subsidence features or
in the Site repository, or injection into underground mine workings.


7.3.1 Alternative 4: Threshold Criteria Evaluations
Evaluation of Alternative 4 with respect to the threshold criteria is presented in this section.

7.3.1.1     Overall Protectiveness of Human Health and the Environment
Alternative 4 meets the RAOs and is protective of human health and the environment in that all Site
source materials and affected soils are addressed and controlled, reducing site risks to acceptable
levels.

Commercial chat processing operations are estimated to remove 29,231,000 cubic yards of chat
source materials based upon the processing rates and timeframes shared by all alternatives for
comparison purposes. All remaining non-commercially processed chat is addressed by Alternative 4
through a variety of remedial methods that include disposal in the on-site repository, injection into
underground mine workings, infilling subsidence features, and excavating and hauling chat to
commercial chat processing for future processing under controlled conditions. After remedial actions
are complete, all source materials will be addressed through engineering controls or in a controlled
setting. The remedy through deep tilling, the addition of soil amendments, and revegetating addresses
buffer zone soils and smelter-affected soils.

7.3.1.2     Compliance with ARARs
Alternative 4 is capable of meeting the ARARs identified for this alternative.

Chemical-Specific ARARs
Alternative 4 addresses the chemical-specific ARARs. The chemical-specific groundwater ARARs
are met at the tap through the remedial action. Groundwater chemical-specific ARARs are not


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addressed since groundwater is outside the scope of Operable Unit 4. The potential residual risk
attributable to chemicals of concern remaining in the Site groundwater are managed through
institutional controls designed to prevent the installation of new shallow aquifer wells for domestic
water supply.

Potential fugitive dust emissions that may result from implementation of this remedy have the
potential to exceed chemical-specific ARARs for air. However, dust control measures capable of
preventing these exceedances are readily implementable.

Action-Specific ARARs
Alternative 4 is capable of complying with action-specific ARARs aimed at controlling stormwater
runoff and seepage from waste deposits. ARAR compliance will require adequate oversight and full
implementation of the prescribed BMPs and interim drainage and erosion controls around existing
source materials deposits.

Oklahoma’s regulations pertaining to aboveground disposal of chat wash fines are met by either
disposing of the wash fines in underground mine workings or in aboveground impoundments
designed to prevent future releases of the fines to the environment.

Alternative 4 is capable of complying with action-specific ARARs aimed at protection of
groundwater supplies under the Federal Underground Injection Control (UIC) program, specifically
as it relates to the disposal of wastes through injection wells.

Location-Specific ARARs
The in place covering of select fine tailings deposits and the excavation, consolidation, and drainage
and erosion control measures proposed for near-stream source materials under Alternative 4 are
capable of complying with the endangered species, wildlife, and wetland protection regulations.
Compliance is achieved by timing the remedial actions performed in critical habitats, designs that
ensure regulatory compliance, and coordination with USFWS, the Quapaw Tribe, and OCC.


7.3.2 Alternative 4: Primary Balancing Criteria Evaluations
Evaluation of Alternative 4 with respect to the primary balancing criteria is presented in this section.

7.3.2.1     Long-Term Effectiveness and Permanence
Alternative 4 is expected to meet the criteria for long-term effectiveness and permanence as discussed
in greater detail below.




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Magnitude of Residual Risks
Alternative 4, like all of the action alternatives, includes chat sales as part of the remedy. Typically,
as a part of processing chat for sales, the fine particles are removed from the chat by dry sieving or
wet sieving (washing). Processing assumptions common to all the action alternatives assumes that
chat processing will generate an estimated 3,215,000 yd3 of washed fines that will be addressed by
source control measures as part of the remedy. Specifically, the material will be injected into flooded
underground mine caverns either by the normal operations of the private chat processor or through
remedial action. For the purpose of the FS cost estimate, it was assumed that 10 percent of the
washed fines would be addressed by the remedial action.

Adequacy and Reliability of Controls
Alternative 4 deploys adequate and reliable engineering controls. As summarized in Table 7-5, an
estimated 40.7 million yd3 of source materials are addressed through engineering controls or other
actions such as commercial processing. An estimated 13.3 million yd3 of source materials, or
approximately 28 percent of the current total volume, remain on-site at full implementation.
However, the 13.3 million yd3 includes 7.0 million yd3 of chat that is in a controlled pile setting at a
commercial chat processing operation awaiting future processing, while the remaining 6.3 million yd3
consists of a combination of source materials that are addressed by engineering controls. The
remaining 6.3 million yd3 of source materials addressed by engineering controls represents 13 percent
of the original source material volume.

The 7.0 million yd3 of chat is excavated and hauled as part of the remedy to commercial chat
processing operations where the chat (and the estimated 184 acres occupied by the chat) will be in a
controlled setting that prohibits potential human contact with the material while facilitating beneficial
reuse of the chat. It is anticipated that continued commercial chat processing of this material beyond
the assumed timeframe of this alternative will likely continue and will result further volume
reduction. At current processing assumptions, this volume would be processed in approximately five
years. At the end of commercial processing, if source materials remain they will be evaluated and if
it is determined that they exceed RAOs, additional remedial actions will be required. These potential
future actions are not included in the cost estimate for this alternative.

Injection of Source Materials
Alternative 4 prescribes the injection of 5.5 million yd3 of source materials, which is considered the
most reliable and permanent disposal option. This volume consists of 4.7 million yd3 of fine tailings,
an additional 322,000 yd3 of new washed fines generated through commercial processing, and



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469,000 yd3 of chat. Since the material is injected underground, institutional controls and long-term
operation and maintenance will not be required.

Disposal in a Constructed Repository
Alternative 4 prescribes that 938,000 yd3 of chat is disposed of in a constructed repository that is built
on-site, the second most reliable and permanent disposal option. The repository is estimated to
require 28 acres to construct and will be covered during closure of the repository. The 28 acres
occupied by the repository will require institutional controls and long-term operation and
maintenance.

Infilling and Covering of Subsidence Features
Alternative 4 prescribes the disposal of 938,000 yd3 of chat by pushing the chat into subsidence
features or open mine shafts, the third most reliable and permanent disposal option. The area
occupied by source materials disposed of in subsidence features is estimated to be 43 acres. The
infilled areas will be covered and therefore will require institutional controls and long-term operation
and maintenance.

Covering in Place
Alternative 4 prescribes the disposal of 4.4 million yd3 of fine tailings in place by covering with a
simple soil cover, the fourth most reliable and permanent disposal option. While this is a large
volume, the actual area occupied by fine tailings that are covered in place is estimated to be 251
acres, a relatively low acreage. This acreage will be subject to institutional controls and long-term
operation and maintenance.

Residential Yards and Shallow Aquifer Wells
Actions planned for residential yard waste and shallow aquifer wells serving households are proven
and permanent risk reduction methods.

Institutional Controls
Through coordination with Federal, State, Tribal, county and local officials, institutional controls will
be utilized as a part of the alternative to manage supplement the disposal methods identified above.
In particular, land use restrictions will be used for the purpose of preventing the potential for future
disturbance of these materials by human activities. In the absence of land use restrictions, future
residential or commercial development could result in damage to the engineered components of the
remedy. To prevent this potential for future disturbance of covered source materials, temporary or
permanent easements will be sought to restrict post-remedial land uses. The easements would restrict
the allowable uses of the soil-covered source materials to uses that are compatible with protecting the

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engineered cover. Allowable uses may include park spaces, natural areas, pasturelands, or other
passive uses that involve minimal earth moving activity. Residential or commercial development of
these areas would only be permitted if any disturbed source materials are removed and properly
disposed. In coordination with Federal, State, Tribal, county and local officials, deed notices will be
sought for the properties to alert future owners of the restricted land uses. In accordance with the
NCP and CERCLA, the State of Oklahoma is assumed to hold any easements and issue the deed
notices in order for the prescribed institutional controls to be implemented on State land.
Coordination with the Department of the Interior, the Bureau of Indian Affairs, and the Quapaw Tribe
of Oklahoma will be required when Tribal lands or restricted allotted lands are involved.

In summary, Alternative 4 addresses 40.7 million yd3 of Site source materials through engineering
controls while 7.0 million yd3 are in a controlled pile setting operated by a commercial chat
processor. After engineering controls are implemented and complete, an estimated 6.3 million yd3 are
left on-site and are subject to institutional controls and long-term operation and maintenance. Under
Alternative 4, 322 acres are subject to institutional controls and long-term operation and maintenance,
with 3,898 acres reclaimed for future unrestricted use. A total of 184 acres are associated with chat
that is in a controlled pile setting at a commercial chat processing operation.

7.3.2.2     Short-Term Effectiveness
Alternative 4 is expected to meet the criteria for short-term effectiveness as discussed in detail below.

Community Protection
Potential risks to the local communities could occur during implementation of the remedial actions
under the alternative. In particular, human exposure to chemical of concern through the generation of
fugitive dust during remedial construction may be possible. Similarly, human exposure to source
materials or affected soils that may be accidentally deposited on urban streets and roadways (as an
example, mud and dirt trackings from haul vehicles) may pose a potential risk to local residents.
These risks can be mitigated and managed through conventional and readily implementable control
techniques such as dust control measures and frequent cleaning of transport vehicles and through
management approaches such as the work-phasing proposed in this alternative.

Physical hazards are also posed by heavy earth moving equipment that will be deployed during
remedial construction. These risks are routinely and commonly mitigated through proper planning,
engineering controls, construction management and scheduling, worker and public safety training and
education, and public involvement activities. Construction impacts also include noise, vibration, and
traffic congestion that may occur in the local communities during construction of the remedy. Similar


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to other risks, these risks can be managed by readily available mitigation and common control
measures that work staging, traffic management plans, and noise abatement controls.

It should be noted that large areas of the Site are currently unsuitable for residential, commercial, or
recreational use due to the presence of large deposits of source materials. The alternative reclaims a
large area of land for future beneficial uses that are currently precluded for such uses by the presence
of the source materials.

Worker Protection
Short-term risks to workers implementing the remedy are addressed and readily mitigated through the
legally required worker health and safety training requirements and personal protective measures and
equipment that will be deployed. All remedial activities accomplished through chat sales will have
appropriate Occupational Health and Safety Administration (OSHA) training provided to workers
involved with chat sales. Site work would be performed under an approved health and safety plan
and medical monitoring programs.

Potential Environmental Impacts
Removal of source materials from near-stream settings, the streambeds, or other discrete locations or
settings on the Site may cause damage to sensitive ecosystems. Proper scheduling of these actions
would significantly minimize this potential risk. As an example, removal of source materials from
streambeds may be done during dry seasons during periods of low flow in Site streams. Similarly,
site work in these areas can be scheduled and controlled to minimize the impact actions may have on
sensitive species and their mating and nesting behaviors. These areas, after remedial actions have
occurred, are expected to have an improved ecosystem that should promote enhanced flora and
fauna.

Excavation and removal of agronomic soils for use in constructing the soil cover systems has the
potential to degrade the areas where the borrow soil is obtained. This concern is typically managed
through plans that address future use scenarios for the land after the borrow soils have been removed.
For instance, the area may be reclaimed as a wetland or as grasslands for pasture.

The volume and aerial extent of soil removed from borrow source areas to meet the needs of the soil
cover system is also a potential concern in that these soils are often in productive use as agricultural
or pasture lands. This alternative requires an estimated 1,189,000 yd3 of cover soil, which is an
amount considered to be locally available and would result in minimal impacts to the environment,
especially when management plans are used to address future uses of the land.



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Time until RAOs Are Achieved
For cost estimating and comparison purposes, the remedial actions prescribed under Alternative 4 are
assumed to take 20 years to complete. It should be noted that the injection of fines may take an
estimated 17 years to achieve. This is based upon the volume planned for injection, which is
approximately half of the fine tailings at the Site, at an assumed rate of 200 tons per hour. It is
conceivable that multiple injection operations could simultaneously operate to offset the extended
duration.

As part of Alternative 4, an estimated 7,035,000 yd3 is excavated and hauled as part of the remedy to
commercial chat processing operations where the chat (and the area occupied by the chat) will be in a
controlled setting. This setting is expected to prohibit potential human contact with the material
while facilitating beneficial reuse of the chat. It is anticipated that continued commercial chat
processing of this material beyond the assumed timeframe of this alternative will likely continue and
will result further volume reduction. At current processing assumptions, this volume would be
processed in approximately five years. At the end of commercial processing, if source materials
remain they will be evaluated and if it is determined that they exceed RAOs, additional remedial
actions will be required. These potential future actions are not included in the cost estimate for this
alternative. As required by CERCLA, five-year reviews of the implemented remedy will be
conducted. If the review concludes that the RAOs are not being obtained or that commercial chat
processing is not progressing at an acceptable rate, EPA will evaluate the situation and recommend
appropriate actions.

7.3.2.3     Reduction of Toxicity, Mobility, or Volume through Treatment
Treatment under Alternative 4 is accomplished through chat sales which includes chat processing by
dry and wet sieving techniques. These treatment processes greatly reduce the concentration of
hazardous substances in the chat.. An estimated 29.2 million yd3 of chat are assumed to be treated by
processing that involves dry or wet sieving, with an estimated 3.2 million yd3 of washed fines being
generated.

7.3.2.4     Implementability
Alternative 4 is expected to meet the criteria for implementability as discussed in greater detail below.

Technical Feasibility
The alternative relies upon proven, conventional, and readily implementable technologies and
construction techniques for addressing the vast majority of source materials and affected soils. Chat
processing has been going on for many years using relatively simple technology that is readily


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available. The technical feasibility of injecting source materials into flooded underground mine
workings has been demonstrated through pilot studies that have been conducted by EPA. The studies
have concluded that the injection of both chat and fine tailings is feasible, with the injection of fines
being a more efficient process than the injection of chat. Treatability studies completed as part of the
Feasibility Study conducted under Operable Unit 1 of the Jasper County, Missouri Site have proven
the technical feasibility and safety of disposing of source materials in subsidence features.

It should be noted that the injection of fines may take an estimated 17 years to achieve. This is based
upon the volume planned for injection, which is approximately half of the fine tailings at the Site, at
an assumed rate of 200 tons per hour. It is conceivable that multiple injection operations could
simultaneously operate to offset the extended duration.

Administrative Feasibility
Implementation of the alternative will require significant but not uncommon levels of coordination
and cooperation between Federal, State, Tribal, county and local entities. Furthermore, the alternative
will require the cooperation of land owners, chat owners, and chat processors. In particular, the
remedy relies on the assumption that chat processors will continue to process chat for the foreseeable
future. To see that chat is safely used, the record keeping requirements in the Chat Rule is applied to
Alternative 4. In addition, the Off-Site Rule applies to each shipment of chat that leaves the Site.
These requirements are similar between all action alternatives.

The use and implementation of institutional controls will also require the coordination and
cooperation of many entities and land owners to issue and administer permanent easements. Ottawa
County does not have zoning or land use ordnances that could be used as a vehicle for implementing
institutional controls. Therefore, a layered approach to institutional controls is warranted. Layering
means using a combination of legal mechanisms to enhance the protectiveness of the remedy. As an
example, temporary or permanent easements in combination with deed notices will be sought as
actions to supplement the engineering controls. This combination of institutional controls is expected
to be administratively implementable, but is dependent upon the State’s, the Tribe’s, and the
Department of the Interior’s acceptance and the location in question. Alternative 4 has a relatively
low acreage subject to institutional controls and long-term operation and maintenance at 322 acres.

Availability of Materials and Labor
The required labor and materials are readily available to implement Alternative 4, including all
necessary labor and materials to support chat processing.




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The availability of borrow soils to construct the cover systems may be difficult to obtain. There may
be reluctance by local land owners to allow their lands to be mined for borrow soils, particularly if the
land is producing income through agricultural or other means. Importing of cover soils from other
areas more distant from the Site is a feasible and implementable option; however, costs would
increase to transport the soil.

7.3.2.5     Cost
The estimated cost for Alternative 4 is $172,899,000, which is based upon the net present value, and
is summarized in Table 7-6. The net present worth of this alternative was calculated based on a 7-
percent discount rate over 30 years. The detailed cost estimate developed for Alternative 4 is
presented in Table C-1 of Appendix C. Appendix D contains information on the unit rate costs that
were developed and used in all the cost estimates. Appendix E contains EPA’s cost estimate for
administration and compliance activities associated with chat sales.


7.3.3 Alternative 4: Modifying Criteria Evaluations
Evaluation of Alternative 4 with respect to the modifying criteria is presented in this section.

7.3.3.1     State Acceptance
State of Oklahoma acceptance cannot be fully determined until later in the public comment period.
However, Alternative 4 proposes remedial approaches and disposal methods that are believed to be
generally accepted by the State of Oklahoma. This knowledge is based upon ongoing feedback
received from the State that has been taken into consideration by EPA and included in Alternative 4.
In particular, the injection of fine tailings as a disposal method is thought to be viewed positively by
the State, as are other remedial approaches and disposal methods. This knowledge is based upon the
ongoing feedback, consultation, and submittal of a proposed remedial alternative developed by the
State and submitted to EPA (ODEQ, 2007).

Similarly, acceptance by the Quapaw Tribe of Oklahoma or other downstream Tribes cannot be fully
determined until later in the public comment period. However, the Quapaw Tribe and other
downstream tribes have provided feedback to EPA that has been incorporated into Alternative 4.
This knowledge is based upon the ongoing feedback, consultation, and submittal of a proposed
remedial alternative developed by the Quapaw Tribe of Oklahoma (Quapaw Tribe, 2007).

7.3.3.2     Public Acceptance
Available information is insufficient for evaluating possible public acceptance of Alternative 4 at this
time. The potential for public acceptance may be partially understood by recognizing that chat


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processing is an important part of the local economy. Alternative 4 does not propose remedial
methods or approaches that prevent commercial processing from continuing. In fact, the remedy
facilitates this process by consolidating some of the chat at local processing operations. The public is
likely to support remedies that allow continued processing and sale of chat.


7.4 Detailed Analysis of Alternative 5: Voluntary Relocation,
        On-site Disposal, and Institutional Controls
This section presents the detailed analysis of Alternative 5, an alternative that proposes voluntary
relocation, phased consolidation, and on-site disposal methods and institutional controls to address
the RAOs. The remedial actions proposed under Alternative 5 are identical to those proposed in
Alternative 4 with the only exception being the phasing of when the actions are implemented. A 30-
year timeframe is assumed based upon implementation of the voluntary relocation component of this
alternative.


7.4.1 Alternative 5: Threshold Criteria Evaluations
Evaluation of Alternative 5 with respect to the threshold criteria is presented in this section.

7.4.1.1      Overall Protectiveness of Human Health and the Environment
Alternative 5 meets the RAOs and is protective of human health and the environment in that all Site
source materials and affected soils are addressed and controlled, reducing site risks to acceptable
levels. Since the remedial alternatives proposed in Alternative 5 are identical to Alternative 4 with
the exception of the voluntary relocation component, refer to Section 7.3.1 for the discussion of this
criterion.

The voluntary relocation component is expected to provide incremental risk reduction and
protectiveness to those individuals that participate in the voluntary relocation program. Individuals
not participating in the relocation program remain and are potentially exposed to source materials
until such time that the full remedy is complete and the RAOs are met.

7.4.1.2      Compliance with ARARs
Alternative 5 is capable of meeting the ARARs identified for this alternative.

Chemical-Specific ARARs
Alternative 5 addresses the chemical-specific ARARs. The chemical-specific groundwater ARARs
are met at the tap through the remedial action. Groundwater chemical-specific ARARs are not

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addressed since groundwater is outside the scope of Operable Unit 4. The potential residual risk
attributable to chemicals of concern remaining in the Site groundwater are managed through
institutional controls designed to prevent the installation of new shallow aquifer wells for domestic
water supply.

Potential fugitive dust emissions that may result from implementation of this remedy have the
potential to exceed chemical-specific ARARs for air. However, dust control measures capable of
preventing these exceedances are readily implementable.

Action-Specific ARARs
Alternative 5 is capable of complying with action-specific ARARs aimed at controlling stormwater
runoff and seepage from waste deposits. ARAR compliance will require adequate oversight and full
implementation of the prescribed BMPs and interim drainage and erosion controls around existing
source materials deposits.

Oklahoma’s regulations pertaining to aboveground disposal of chat wash fines are met by either
disposing of the wash fines in underground mine workings or in aboveground impoundments
designed to prevent future releases of the fines to the environment.

Alternative 5 is capable of complying with action-specific ARARs aimed at protection of
groundwater supplies under the Federal Underground Injection Control (UIC) program, specifically
as it relates to the disposal of wastes through injection wells.

Voluntary relocations will be conducted in accordance with Oklahoma’s laws and URA.

Location-Specific ARARs
The in place covering of select fine tailings deposits and the excavation, consolidation, and drainage
and erosion control measures proposed for near-stream source materials under Alternative 5 are
capable of complying with the endangered species, wildlife, and wetland protection regulations.
Compliance is achieved by timing the remedial actions performed in critical habitats, designs that
ensure regulatory compliance, and coordination with USFWS, the Quapaw Tribe, and OCC.


7.4.2 Alternative 5: Primary Balancing Criteria Evaluations
Evaluation of Alternative 5 with respect to the primary balancing criteria is presented in this section.

7.4.2.1     Long-Term Effectiveness and Permanence
Alternative 5 is expected to meet the criteria for long-term effectiveness and permanence. Since
Alternative 5 remedial actions are identical to that of Alternative 4 with the only exception being the


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voluntary relocation component of Alternative 5, refer to Section 7.3.2. for a discussion of this
criterion. Alternative 5 includes a voluntary relocation component, which does not involve
engineering controls to address potential Site risks, therefore the evaluation of the adequacy and
reliability of controls under the long-term effectiveness and permanence criteria is not applicable.

7.4.2.2     Short-Term Effectiveness
Alternative 5 is expected to meet the criteria for short-term effectiveness. Since Alternative 5
remedial actions are identical to that of Alternative 4 with the only exception being the voluntary
relocation component of Alternative 5, refer to Section 7.3.2 for a discussion of this criterion.

The voluntary relocation component is assumed to be accomplished in the early phases of the
remedial action and last approximately 3 years. The voluntary relocation would be an effective short-
term solution to prevent the potential exposure of those residents included in the buyout to Site source
materials that could result from remedial construction activities. Residents not participating in the
buyout may still face the potential risks associated with the ongoing remedial construction.

Time until RAOs Are Achieved
The RAOs will be fully achieved over an estimated period of 30 years. As required by CERCLA,
five-year reviews of the implemented remedy will be conducted. If the review concludes that the
RAOs are not being obtained or that commercial chat processing is not progressing at an acceptable
rate, EPA will evaluate the situation and recommend appropriate actions.

7.4.2.3     Reduction of Toxicity, Mobility, or Volume through Treatment
Since Alternative 5 remedial actions are identical to that of Alternative 4 with the only exception
being the voluntary relocation component of Alternative 5, refer to Section 7.3.2 for a discussion of
this criterion.

7.4.2.4     Implementability
Alternative 5 is expected to meet the criteria for implementability. Since Alternative 5 remedial
actions are identical to that of Alternative 4 with the only exception being the voluntary relocation
component of Alternative 5, refer to Section 7.3.2 for a discussion of this criterion, with differences
noted below.

Technical Feasibility
Voluntary relocation is technically feasible and has been previously implemented at the Site by the
State of Oklahoma in 2005 and has been implemented at other sites.




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Administrative Feasibility
The voluntary relocation component, while likely to require substantial administrative effort to
implement, is considered administratively feasible.

Availability of Materials and Labor
All equipment, materials, and labor required to implement Alternative 5 are readily available.
Additional labor force will be required to demolish and dispose of residential and commercial
structures after they are purchased through the voluntary relocation program.

7.4.2.5     Cost
The estimated cost for Alternative 5 is $214,893,000. The cost estimate is based upon the net present
value and is summarized in Table 7-8. The net present worth of this alternative was calculated based
on a 7 percent discount rate over 30 years. Detailed capital, O&M, and present worth cost estimates
for Alternative 5 are presented in Table C-2 (voluntary relocation costs) and Table C-2 Continued
(remedial alternatives cost) in Appendix C. Appendix D contains information on the unit rate costs
that were developed and used in all the cost estimates. Appendix E contains EPA’s cost estimate for
administration and compliance activities associated with chat sales.


7.4.3 Alternative 5: Modifying Criteria Evaluations
Evaluation of Alternative 5 with respect to the modifying criteria is presented in this section.

7.4.3.1     State Acceptance
State of Oklahoma acceptance cannot be fully determined until later in the public comment period.
However, Alternative 5 proposes remedial approaches and disposal methods that are believed to be
generally accepted by the State of Oklahoma. This knowledge is based upon ongoing feedback
received from the State that has been taken into consideration by EPA and included in Alternative 5.
In particular, the injection of fine tailings as a disposal method is thought to be viewed positively by
the State, as are other remedial approaches and disposal methods. This knowledge is based upon the
ongoing feedback, consultation, and submittal of a proposed remedial alternative developed by the
State and submitted to EPA (ODEQ, 2007b).

Regarding the relocation component of Alternative 5, State acceptance is anticipated to favor this
element of the alternative based upon the completion of a State-supported buyout of 51 families in
2005. In addition, the State has supported a continuation of the 2005 buyout (ODEQ, 2007).

Similarly, acceptance by the Quapaw Tribe of Oklahoma or other downstream Tribes cannot be fully
determined until later in the public comment period. However, the Quapaw Tribe and other

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downstream tribes have provided feedback to EPA that has been incorporated into Alternative 5.
This knowledge is based upon the ongoing feedback, consultation, and submittal of a proposed
remedial alternative developed by the Quapaw Tribe of Oklahoma (Quapaw Tribe, 2007).

7.4.3.2     Public Acceptance
Available information is insufficient for evaluating possible public acceptance of Alternative 5 at this
time. The majority of the public is likely to support a relocation component based upon a public
opinion survey (USACE, 2006).


7.5 Detailed Analysis of Alternative 8: Total Source
        Consolidation, Stabilization, and Institutional Controls
This section presents the detailed analysis of Alternative 8. Alternative 8 is a comprehensive
alternative that addresses all source materials and affected soils and expedites the removal of source
materials most likely to result in human exposure to the COPCs.


7.5.1 Alternative 8: Threshold Criteria Evaluations
The evaluation of Alternative 8 with respect to the threshold criteria is presented in this section.

7.5.1.1     Overall Protectiveness of Human Health and the Environment
Alternative 8 meets all the RAOs through aggressive early response actions and long-term source
removal and containment measures designed to prevent exposure to COPCs. This alternative is
protective of human health and the environment. Alternative 8 addresses all source materials
currently present on-site. Early response actions are implemented to remove urban and near-stream
source materials, thereby preventing human exposure to COPCs under an expedited timeframe.
Source materials remain on-site at the completion of all remedial actions, but are contained and
stabilized in upland settings to meet the RAOs and prevent future potential risks. Institutional controls
are not needed to manage potential remaining risks in urban or near-stream settings. Institutional
controls are only needed to address potential remaining risks in rural upland areas of the Site.

7.5.1.2     Compliance with ARARs
Alternative 8 is capable of complying with all ARARs identified in Tables 7-1 through 7-3.

Chemical-Specific ARARs
Alternative 8 addresses the chemical-specific ARARs. The chemical-specific groundwater ARARs
are met at the tap through the remedial action. Groundwater chemical-specific ARARs are not

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addressed since groundwater is outside the scope of Operable Unit 4. The potential residual risk
attributable to chemicals of concern remaining in the Site groundwater are managed through
institutional controls designed to prevent the installation of new shallow aquifer wells for domestic
water supply.

Potential fugitive dust emissions that may result from implementation of this remedy have the
potential to exceed chemical-specific ARARs for air. However, dust control measures capable of
preventing these exceedances are readily implementable.

Action-Specific ARARs
Alternative 8 is capable of complying with action-specific ARARs aimed at controlling stormwater
runoff and seepage from waste deposits. ARAR compliance will require adequate oversight and full
implementation of the prescribed BMPs and interim drainage and erosion controls around existing
source materials deposits.

Oklahoma’s regulations pertaining to aboveground disposal of chat wash fines are met by either
disposing of the wash fines in underground mine workings or in aboveground impoundments
designed to prevent future releases of the fines to the environment.

Alternative 8 is capable of complying with action-specific ARARs aimed at protection of
groundwater supplies under the Federal Underground Injection Control (UIC) program, specifically
as it relates to the disposal of wastes through injection wells.

Location-Specific ARARs
The in place covering of select fine tailings deposits and the excavation, consolidation, and drainage
and erosion control measures proposed for near-stream source materials under Alternative 8 are
capable of complying with the endangered species, wildlife, and wetland protection regulations.
Compliance is achieved by timing the remedial actions performed in critical habitats, designs that
ensure regulatory compliance, and coordination with USFWS, the Quapaw Tribe, and OCC.


7.5.2 Alternative 8: Primary Balancing Criteria Evaluations
The evaluation of Alternative 8 with respect to the primary balancing criteria is presented in this section.

7.5.2.1     Long-Term Effectiveness and Permanence
Magnitude of Residual Risks
Alternative 8, like all of the action alternatives, includes chat sales as part of the remedy. Typically,
as a part of processing chat for sales, the fine particles are removed from the chat by dry sieving or


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wet sieving (washing). Processing assumptions common to all the action alternatives assumes that
chat processing will generate an estimated 3,215,000 yd3 of washed fines that will be addressed by
source control measures as part of the remedy. Specifically, the material will be injected into flooded
underground mine caverns either by the normal operations of the private chat processor or through
remedial action. For the purpose of the FS cost estimate, it was assumed that 10 percent of the
washed fines would be addressed by the remedial action.

Adequacy and Reliability of Controls
Alternative 8 deploys adequate and reliable engineering controls. As summarized in Table 7-9, an
estimated 47.8 million yd3 of source materials are addressed through engineering controls or other
actions such as commercial processing. An estimated 11.8 million yd3 of source materials, or
approximately 25 percent of the current total volume, remain on-site at full implementation.

Injection of Source Materials
Alternative 8 prescribes the injection of 6.7 million yd3 of source materials, which is considered the
most reliable and permanent disposal option. This volume consists of 2.0 million yd3 of fine tailings
and 4.7 million yd3 of chat. Since the material is injected underground, institutional controls and
long-term operation and maintenance will not be required.

Disposal in a Constructed Repository
Alternative 8 does not prescribe that any source materials be disposed of in a constructed repository
that is built on-site, the second most reliable and permanent disposal option.

Infilling and Covering of Subsidence Features
Alternative 8 prescribes the disposal of 4.7 million yd3 of chat by pushing the chat into subsidence
features or open mine shafts, the third most reliable and permanent disposal option. The area
occupied by source materials disposed of in subsidence features is estimated to be 213 acres. The
infilled areas will be covered and therefore will require institutional controls and long-term operation
and maintenance.

Covering in Place
Alternative 8 prescribes the disposal of 7.2 million yd3 of source materials in place by covering with a
simple soil cover, the fourth most reliable and permanent disposal option. The area occupied by
source materials covered in place is estimated to be 633 acres. This acreage will be subject to
institutional controls and long-term operation and maintenance.




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Residential Yards and Shallow Aquifer Wells
Actions planned for residential yard waste and shallow aquifer wells serving households are proven
and permanent risk reduction methods.

Institutional Controls
Through coordination with Federal, State, Tribal, county and local officials, institutional controls will
be utilized as a part of the alternative to manage supplement the disposal methods identified above.
In particular, land use restrictions will be used for the purpose of preventing the potential for future
disturbance of these materials by human activities. In the absence of land use restrictions, future
residential or commercial development could result in damage to the engineered components of the
remedy. To prevent this potential for future disturbance of covered source materials, temporary or
permanent easements will be sought to restrict post-remedial land uses. The easements would restrict
the allowable uses of the soil-covered source materials to uses that are compatible with protecting the
engineered cover. Allowable uses may include park spaces, natural areas, pasturelands, or other
passive uses that involve minimal earth moving activity. Residential or commercial development of
these areas would only be permitted if any disturbed source materials are removed and properly
disposed. In coordination with Federal, State, Tribal, county and local officials, deed notices will be
sought for the properties to alert future owners of the restricted land uses. In accordance with the
NCP and CERCLA, the State of Oklahoma is assumed to hold any easements and issue the deed
notices in order for the prescribed institutional controls to be implemented on State land.
Coordination with the Department of the Interior, the Bureau of Indian Affairs, and the Quapaw Tribe
of Oklahoma will be required when Tribal lands or restricted allotted lands are involved.

In summary, Alternative 8 addresses 47.8 million yd3 of Site source materials through engineering
controls. After engineering controls are implemented and complete, an estimated 11.8 million yd3 are
left on-site and are subject to institutional controls and long-term operation and maintenance. Under
Alternative 8, 846 acres are subject to institutional controls and long-term operation and maintenance,
with 3,374 acres reclaimed for future unrestricted use.

7.5.2.2     Short-Term Effectiveness
Community Protection
Urban chat removal actions prescribed under Alternative 8 have the potential to disrupt normal
activities in existing communities due to the large volume of heavy truck traffic, vibrations, and
noise. Removing all mill wastes from urban areas of the Site within an expedited timeframe results in
a significantly higher intensity of truck traffic than under current conditions. An increase in the
number of large trucks increases the physical and environmental hazards to local residents, including

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increased fugitive dust emissions and risks of traffic accidents. Effective construction management
strategies are required to prevent or mitigate construction impacts on local communities.

Future beneficial land uses in urban and near-stream areas are unrestricted under Alternative 8. Some
land use restrictions are necessary on a small portion (631 acres) of the rural upland areas of the Site
and the covered smelter waste, and the 213 acres associated with covered subsidence features. These
restrictions are not expected to affect the community adversely because of the small area subject to
the restrictions.

Worker Protection
Short-term risks to workers implementing the remedy are addressed and readily mitigated through the
legally required worker health and safety training requirements and personal protective measures and
equipment that will be deployed. All remedial activities accomplished through chat sales will have
appropriate Occupational Health and Safety Administration (OSHA) training provided to workers
involved with chat sales. Site work would be performed under an approved health and safety plan
and medical monitoring programs.

Potential Environmental Impacts
Removal of source materials from near-stream settings, the streambeds, or other discrete locations or
settings on the Site may cause damage to sensitive ecosystems. Proper scheduling of these actions
would significantly minimize this potential risk. As an example, removal of source materials from
streambeds may be done during dry seasons during periods of low flow in Site streams. Similarly,
site work in these areas can be scheduled and controlled to minimize the impact actions may have on
sensitive species and their mating and nesting behaviors. These areas, after remedial actions have
occurred, are expected to have an improved ecosystem that should promote enhanced flora and fauna.

Excavation and removal of agronomic soils for use in constructing the soil cover systems has the
potential to degrade the areas where the borrow soil is obtained. This concern is typically managed
through plans that address future use scenarios for the land after the borrow soils have been removed.
For instance, the area may be reclaimed as a wetland or as grasslands for pasture.

The volume and aerial extent of soil removed from borrow source areas to meet the needs of the soil
cover system is also a potential concern in that these soils are often in productive use as agricultural
or pasture lands. This alternative requires an estimated 2,713,000 yd3 of cover soil, which is
significant amount that may be difficult to obtain locally.




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Time until RAOs Are Achieved
Under Alternative 8, the RAOs are achieved in urban and near stream areas in approximately 5 to 10
years. If trucks and 5-yard front-end loaders are used to consolidate all the urban chat located on-site,
as is the current practice, 10 years is a reasonable estimate of the time required to remove all the
urban chat. However, this timeframe can be shortened significantly by using large-scale mining or
quarrying equipment. Using larger loaders and material handling vehicles, the timeframe to achieve
the RAOs in urban areas is estimated at approximately 5 years.

After all urban source materials are removed and consolidated, removing or disposing of the
remaining source materials would require approximately another 10 to complete.

7.5.2.3     Reduction of Toxicity, Mobility, or Volume through Treatment
Treatment under Alternative 8 is accomplished through chat sales which includes chat processing by
dry and wet sieving techniques. These treatment processes greatly reduce the concentration of
hazardous substances in the chat.. An estimated 29.2 million yd3 of chat are assumed to be treated by
processing that involves dry or wet sieving, with an estimated 3.2 million yd3 of washed fines being
generated.

7.5.2.4     Implementability
Technical Feasibility
Consolidating all urban chat in existing upland deposits within a reasonable timeframe is technically
challenging due to the large amount of materials present in urban settings. Engineering solutions to
meet this challenge include conveyor systems, rail transport, or use of large-scale open pit mining
equipment. The best method for achieving the expedited removal of the urban chat is determined
during remedial design.

The alternative relies upon proven, conventional, and readily implementable technologies and
construction techniques for addressing the vast majority of source materials and affected soils. Chat
processing has been going on for many years using relatively simple technology that is readily
available. The technical feasibility of injecting source materials into flooded underground mine
workings has been demonstrated through pilot studies that have been conducted by EPA. The studies
have concluded that the injection of both chat and fine tailings is feasible, with the injection of fines
being a more efficient process than the injection of chat. Treatability studies completed as part of the
Feasibility Study conducted under Operable Unit 1 of the Jasper County, Missouri Site have proven
the technical feasibility and safety of disposing of source materials in subsidence features.




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Administrative Feasibility
This alternative requires owners of urban chat to sell or combine their chat with other owners’ to
complete the remediation of urban areas. The willingness of owners to allow their chat to be
consolidated and combined with chat from other sources is uncertain. In addition, tracking payments
from combined chat piles back to the original owners complicates the administrative components of
this alternative. EPA Region 6 and the BIA are currently conducting a chat sales treatability study to
determine the willingness of chat owners to sell chat at current market rates through a sealed bidding
process.

To see that chat is safely used, the record keeping requirements in the Chat Rule is applied to
Alternative 4. In addition, the Off-Site Rule applies to each shipment of chat that leaves the Site.
These requirements are similar between all action alternatives.

Institutional controls are only a minor component of the remedy under this alternative and are
expected to be implementable. EPA’s strategic plan for ensuring successful implementation of
institutional controls at CERCLA sites (EPA, 2004a) describes a variety of methods available for
addressing administrative implementability issues pertaining to institutional controls.

Availability of Materials and Labor
All equipment, materials, and labor needed to implement this alternative are readily available,
including all necessary labor and materials to support chat processing.. However, specialized large-
scale mining equipment or conveyor systems may need to be imported from outside the immediate
area in order to expedite the removal of urban source materials.

Agricultural soils in sufficient supplies to construct all the soil covers prescribed under this alternative
may be difficult to obtain on-site. Local farmers and ranchers may be reluctant to allow their lands to
be mined for borrow soils. Importing soil from off-site locations would increase the cost of the remedy.

7.5.2.5     Cost
The estimated cost for Alternative 8 is $262,540,000, which is based upon the net present value, and
is summarized in Table 7-10. The net present worth of this alternative was calculated based on a 7-
percent discount rate over 30 years. The detailed cost estimate developed for Alternative 8 is
presented in Table C-3 of Appendix C. Appendix D contains information on the unit rate costs that
were developed and used in all the cost estimates. Appendix E contains EPA’s cost estimate for
administration and compliance activities associated with chat sales




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7.5.3 Alternative 8: Modifying Criteria Evaluations
Evaluation of Alternative 8 with respect to the modifying criteria is presented in this section.

7.5.3.1     State Acceptance
Available information is insufficient for evaluating possible State acceptance of Alternative 8 at this
time.

7.5.3.2     Public Acceptance
Available information is insufficient for evaluating possible public acceptance of Alternative 8 at this
time.




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8.0 Comparative Analysis of Alternatives

This section evaluates the relative performance of each alternative by comparing the results of the
detailed analyses presented in Section 7. Separate subsections describe the relative performance of
alternatives with respect to each of the two threshold and five balancing criteria to identify the
advantages and disadvantages of each alternative in side-by-side comparisons. Evaluations of the two
modifying criteria, State Acceptance and Public Acceptance, are also discussed. As a general guide,
the comparative analysis usually focuses on the differences between alternatives with respect to the
primary balancing criteria since these factors play the major role in determining which alternatives
are cost-effective and which remedy utilizes permanent solutions (EPA, 1996). Since none of the
remedial alternatives reduce toxicity, mobility, and volume through treatment, the comparative
analysis under that criterion is truncated. An effective way to organize the comparison is to discuss
the alternative that performs best overall under each criterion, followed by other alternatives
discussed in order of their relative performance (EPA, 1996).


8.1 Comparative Analysis of Remedial Alternatives with
        Respect to the Threshold Criteria
This section presents the comparative analysis of remedial alternatives with respect to the threshold
criteria of overall protectiveness of human health and the environment and compliance with ARARs.
The results of this comparative analysis are summarized in tabular format in Tables 8-1 and 8-2.


8.1.1 Overall Protection of Human Health
Alternatives 4, 5 and 8 meet the criteria by meeting the RAOs for the protection of human health.
Alternative 1 fails to meet the RAOs for protecting human health, therefore, Alternative 1 is not
carried forward in the comparative analysis discussion since it does not satisfy this threshold.


8.1.2 Overall Protection of the Environment
Alternatives 4, 5 and 8 meet the criteria by meeting the RAOs for the protection of the environment.
Alternative 1 fails to meet the RAOs for protecting the environment, therefore, Alternative 1 is not
carried forward in the comparative analysis discussion.




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8.1.3 Compliance with ARARs
This subsection presents the comparative analysis of remedial alternatives with respect to compliance
with ARARs.

8.1.3.1     Chemical-Specific ARARs
Chemical-specific ARARs identified for OU4 are consistently met by all the action alternatives. The
chemical-specific ground water ARARs are met at residents’ taps under all the action alternatives, but
are not met in the shallow aquifer in affected areas of the Site. Remediation of the shallow aquifer is
not part of the scope of OU4. However, potential residual risks attributable to COPCs remaining in
the shallow aquifer are managed under all the action alternatives through institutional controls
designed to prevent the construction of new shallow aquifer wells for domestic water supplies.

8.1.3.2     Action-Specific ARARs
All of the candidate action alternatives are equally capable of meeting the action-specific ARARs
identified for the individual alternatives.

8.1.3.3     Location-Specific ARARs
All the candidate action alternatives are equally capable of meeting the location-specific ARARs
identified for the individual alternatives.


8.2 Comparative Analysis of Remedial Alternatives with
        Respect to the Primary Balancing Criteria
This section presents the comparative analysis of remedial alternatives with respect to the five
primary balancing criteria. The comparison of alternatives with respect to these five criteria is
presented in narrative form and summarized in Table 8-3 through Table 8-7. Table 8-8 presents the
results of the comparative analysis.


8.2.1 Long-Term Effectiveness and Permanence
This subsection presents the comparative analysis of remedial alternatives with respect to the
balancing criterion of long-term effectiveness and permanence. The comparison of alternatives with
respect to this criterion is summarized in Table 8-3.




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8.2.1.1      Magnitude of Residual Risks
The type of mining waste and mill waste that we will address under any of the Alternatives at OU4 is
a high volume low-level threat waste and EPA expects to use engineering controls instead of
treatment for this type of waste (40 CFR § 300.430(a)(1)(iii)(B)). Consequently, when engineering
controls are the exclusive mechanism used to address low-level threat waste, this criterion—“
Magnitude of residual risk remaining from untreated waste or treatment residuals remaining at the
conclusion of the remedial activities” would not be pertinent. However, under all the action
alternatives, chat sales will be facilitated and chat sales includes chat processing, which involves
treatment. Specifically, two methods of treatment are used in preparing chat for sale. The treatment
methods include dry screening or wet washing to remove fine particles which contain the highest
concentrations of lead and other hazardous substances. These treatment processes greatly reduce the
concentration of hazardous substances in the chat. In summary, all of the alternatives since they all
include chat processing, involve the same magnitude of residual risk with respect to chat processing
residuals.

8.2.1.2      Adequacy and Reliability of Controls
In summary, Alternatives 4 and 5 would have the least volume and area subject to institutional
controls and long-term operation and maintenance and are considered more effective, reliable, and
permanent than Alternative 8. Alternatives 4 and 5 assume that 6.3 million yd3 and 322 acres are
subject to institutional controls and long-term operation and maintenance after remedial
implementation. Alternative 8 assumes that 11.8 million yd3 and 846 acres are subject to institutional
controls and long-term operation and maintenance. Alternatives 4 and 5 reclaim an estimated 3,898
acres of land, providing unrestricted use of this land, compared to 3,374 acres for Alternative 8.

Alternative 8 addresses the largest volume of Site source materials through injection, the most reliable
and permanent control, at 6.7 million yd3 followed by Alternatives 4 and 5 at 5.5 million yd3 each.
This volume of source material and the area it once occupied would not be subject to institutional
controls or long-term operation and maintenance.

Alternatives 4 and 5 prescribe that some source materials be addressed through disposal in an on-site
constructed repository, the second most reliable and permanent disposal option. The area occupied
by the repository would cover only 28 acres but would require institutional controls and long-term
operation and maintenance. Alternative 8 does not propose that any source materials be disposed
using the second most reliable and permanent option.




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Under Alternative 8 a large volume of source material would be infilled into subsidence features, the
third most reliable and permanent disposal option. Alternatives 4 and 5 also prescribe that source
materials are also addressed through infilling into subsidence features, but not at the high volume
prescribed under Alternative 8. Alternatives 4 and 5 will each require an estimated 43 acres that
would be subject to institutional controls and long-term operation and maintenance. Alternative 8
will require an estimated 213 acres that would be subject to institutional controls and long-term
operation and maintenance.

Alternatives 4 and 5 each prescribe that a smaller volume of materials be covered in place compared
to Alternative 8. The area occupied by materials covered in place and subject to institutional controls
and long-term operation and maintenance is smaller for Alternatives 4 and 5 (251 acres each)
compared to Alternative 8 (631 acres).

Due to the different remedial timeframes assumed (20 years for Alternative 4 and 30 years for
Alternative 5), it is estimated that Alternative 4 would leave approximately 7.0 million yd3 of chat,
occupying an estimated 184 acres, in a controlled pile setting that is operated by commercial chat
processors. Under Alternative 4, the chat delivered to a controlled pile setting would be reduced over
time as the chat was processed; consequently, it is projected that ultimately Alternative 4 would leave
essentially the same footprint that would be left under Alternative 5. That is, the volume of source
material remaining on the surface and the area that the source material would occupy on the surface
would be about the same as they would be under Alternative 5; although, it is estimated based upon
chat processing rates that Alternative 4 would reach this footprint size in less time than Alternative 5.

Voluntary Relocation
Alternative 5 includes a voluntary relocation component, which does not involve engineering controls
to address potential Site risks, therefore the evaluation of the adequacy and reliability of controls
under the long-term effectiveness and permanence criteria is not applicable.


8.2.2 Short-Term Effectiveness
This section presents the comparative analysis of remedial alternatives with respect to the balancing
criterion of short-term effectiveness. Table 8-4 summarizes the alternatives with respect to this
criterion.

8.2.2.1      Risks to the Local Communities
Potential risks to local communities during remedial actions, while reasonably similar under all action
alternatives, is more favorable under Alternatives 4 and 5 as compared to Alternative 8. This


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expectation derives from the fact that remedial actions under Alternative 4 and 5 are implemented in a
manageable and controlled phased-approach, with less reliance upon heavy and intense construction
efforts in sensitive urban areas as prescribed by Alternative 8. The higher intensity of urban source
removal actions prescribed under Alternative 8 results in a higher level of risks due to physical
hazards, such as traffic accidents.

Permanent relocation, as discussed under the voluntary relocation component of Alternative 5, could
potentially lessen the impact and inconvenience associated with these use restrictions, but not at any
greater level than expected through common construction management approaches and techniques.

8.2.2.2     Potential Risks to Workers
All identified short-term risks to workers can be mitigated through legally required worker health and
safety training and protection measures, including appropriate training and protective measures
relating to workers involved in chat sales. However, while potential risks to workers during remedial
actions are reasonably similar under all the action alternatives, they are expected to be smaller under
Alternative 4, followed by Alternatives 5 and 8. Alternative 8 potentially poses greater risk to
workers since it is dependent upon more intense and heavy construction methods and approaches.
The voluntary relocation component of Alternative 5 would also pose additional risk to workers
engaged in demolition of purchased structures that is not prescribed in Alternatives 4 and 8.

8.2.2.3     Potential Environmental Impacts
Potential environmental impacts will be similar for each of the action alternatives and can be
controlled through management approaches and scheduling of activities. One key differentiator
between the remedial alternatives involves the dependence upon covering of materials in place and
the required volume of borrow soils. The volume and aerial extent of soil removed from borrow
source areas to meet the needs of the soil cover system is a potential concern in that these soils are
often in productive use as agricultural or pasture lands. Alternatives 4 and 5 have the smallest
requirement of cover soils at an estimated 1,189,000 yd3 of cover soil, which is an amount considered
locally available and would result in minimal impacts to the environment, especially when
management plans are used to address future uses of the borrow source land. Alternative 8 has a
cover soil requirement estimated at 2,713,000 yd3, a volume and area requirement that would lead to a
greater potential of environmental impacts and an increased management burden to control the
potential impacts. In addition, the volume of soil required under Alternative 8 may be difficult to
obtain locally, thereby increasing the cost of cover soils as they are hauled in from greater distances.




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8.2.2.4     Time Until RAOs Are Achieved
Alternative 8 achieves full implementation of the RAOs within a 20-year timeframe. Alternative 4
achieves control of all source materials within a 20-year timeframe but some of the volume is in a
controlled setting at a commercial chat processing operation (as opposed to being addressed by an
engineering control). This volume, and the area occupied by the volume, is expected to be reduced
significantly within approximately 5 years as commercial processing continues. Alternative 5 is
expected to take 30 years to meet the RAOs The additional time associated with Alternative 5 is
associated with the effects of the voluntary relocation and the phased approach of the work. The
voluntary relocation component of Alternative 5 is estimated to require three years to complete.


8.2.3 Reduction of Toxicity, Mobility, or Volume Through Treatment
Under all action alternatives, chat sales would occur as part of the remedy, and chat sales includes
chat processing by dry screening or wet washing which is a form of treatment. Specifically, these two
methods are used to remove fine particles which contain the highest concentrations of lead and other
hazardous substances. These treatment processes greatly reduce the concentration of hazardous
substances in the chat. The higher concentrations are left on-site as “washed fines” and are addressed
with source materials under all action alternatives. All alternatives share the same chat processing
assumptions, so all action alternatives are comparable with respect to this criterion. Table 8-5
summarizes the alternatives with respect to this criterion.


8.2.4 Implementability
This section presents the comparative analysis of alternatives with respect to the implementability
criterion. Table 8-6 summarizes the alternatives with respect to this criterion.

8.2.4.1     Technical Feasibility
All alternatives rely upon proven, conventional, and readily implementable technologies and
construction techniques for addressing the vast majority of source materials and affected soils. The
technical feasibility of injecting source materials into flooded underground mine workings has been
demonstrated through pilot studies that have been conducted by EPA. The studies have concluded
that the injection of both chat and fine tailings is feasible, with the injection of fines being a more
efficient process than the injection of chat. Chat processing has been occurring for many years and
uses relatively simple technology that is readily available.




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8.2.4.2     Administrative Implementability
Alternative 4 is expected to be the most administratively feasible alternative to implement, followed
by Alternative 8 and Alternative 5. Alternative 4 and Alternative 5 have the least requirement for the
implementation and administration of institutional controls, followed by Alternative 8. Alternative 5,
while similar to Alternative 4, would require a significantly greater administrative effort to implement
and manage the voluntary relocation. Alternative 8 is also expected to be more difficult to implement
administratively due to the mass removal, heavy construction, and short duration required to remove
chat from urban and near stream settings. This effort is expected to require significant cooperation
and administration between land owners, chat owners, and chat processors in order to implement.

To see that chat is safely used, the record keeping requirements in the Chat Rule is applied to all
action alternatives. In addition, the Off-Site Rule applies to each shipment of chat that leaves the
Site. These requirements are similar between all action alternatives.

Availability of Materials and Labor
The required labor and materials are readily available to implement all alternatives but Alternative 4
is expected to be the least likely of the alternatives to be affected by availability of materials or labor.
With respect to the availability of borrow soils to construct the cover systems, Alternative 4 and 5
each have identical requirements that are less than that of Alternative 8. Alternative 5 has an
increased labor requirement associated with both the administration and implementation of the
voluntary relocation component. In particular, an additional labor force will be necessary to demolish
and dispose of the residential and commercial properties purchased through the voluntary relocation.
While this labor force is expected to be available, it is an increased requirement of Alternative 5.


8.2.5 Cost
Table 8-7 presents a quantitative comparison of cost among alternatives. As part of the cost analysis,
a cost sensitivity analysis was performed that assumed 25 percent of the borrow soils would be
imported from a greater distance than locally available soils. Results of the analysis indicate that
alternatives that require the greatest volume of soil would be the most affected by importing soil and
that the cost of each alternative would increase slightly.

Tables C-1 through C-3 in Appendix C present detailed cost estimates for each of the action
alternatives. The cost for Alternative 1 is not calculated. For the remedial alternatives, in terms of net
present value costs, Alternative 4 is the lowest cost alternative at $172,899,000. Alternative 5, with
identical remedies to Alternative 4 plus voluntary relocation, is the second highest cost alternative at
$214,893,000. Alternative 8 is the highest cost alternative at $262,540,000.

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9.0 References

AATA, 2004a. Data Gap Analysis, Tar Creek OU4 RI/FS Program. Tar Creek Superfund Site,
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AATA, 2004b. Work Plan, Tar Creek OU4 RI/FS Program. Tar Creek Superfund Site, Ottawa,
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AATA, 2005b. Remedial Investigation Report, Tar Creek OU4 RI/FS Program. Tar Creek Superfund
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AATA, 2005c. Sampling and Analysis Plan, Tar Creek OU4 RI/FS Program. Tar Creek Superfund
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Adams, R., L. Bingham, and M. Williams. 2005. Personal communication about chat processing
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Brichta, L.C. 1960. Catalog of recorded exploration drilling and mine workings, Tri-State Zinc-Lead
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Brown and Root Environmental. 1995. Sampling and Analysis Plan for Mining Waste, RI/FS Tar
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Brown, S., R. Chaney, J. Hallfrisch, J.A. Ryan, and W.R. Berti. 2004. In-situ Soil Treatment to
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C.C. Johnson and Malhotra, P.C. 1999. Final Additional Site Evaluation Findings Report. Tar Creek
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Cates, D 2003. Background concentrations for soils in Ottawa County, ODEQ Technical Memo, pp.
          19.




USEPA\348273\DRAFT_FINAL_FS_07252007.DOC         9-1                                              JULY 2007
                                                                                   TAR CREEK SUPERFUND SITE
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                                                                                 DRAFT-FINAL FEASIBILITY STUDY


Christenson, S.C., Parkhurst, D.L., and Fairchild, R.W. 1990. Geohydrology and water quality of the
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Clevener, T.E. 1992. Preliminary Study of Lead, Cadmium, and Zinc Contamination in the Southwest
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CH2M HILL, 1985. Draft Remedial Investigation, Existing Data Evaluation, Galena subsite,
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CH2M HILL, 2006. Draft Final Human Health Risk Assessment, Tar Creek OU4, Ottawa County,
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USEPA\348273\DRAFT_FINAL_FS_07252007.DOC           9-2                                               JULY 2007
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                                                                                  DRAFT-FINAL FEASIBILITY STUDY


Emmett, W.W., 1980. A field calibration of the sediment-trapping characteristics of the Helley-Smith
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USEPA\348273\DRAFT_FINAL_FS_07252007.DOC          9-3                                                 JULY 2007
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                                                                                  DRAFT-FINAL FEASIBILITY STUDY


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USEPA\348273\DRAFT_FINAL_FS_07252007.DOC          9-4                                                 JULY 2007
                                                                                       TAR CREEK SUPERFUND SITE
                                                                                              OPERABLE UNIT NO. 4
                                                                                     DRAFT-FINAL FEASIBILITY STUDY


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USEPA\348273\DRAFT_FINAL_FS_07252007.DOC            9-5                                                  JULY 2007
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                                                                                         OPERABLE UNIT NO. 4
                                                                                DRAFT-FINAL FEASIBILITY STUDY


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United States Bureau of Indian Affairs (BIA). 2005. Chat Sales Treatability Study Work Plan for the
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United States Department of the Interior (DOI) and United States Environmental Protection Agency
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USEPA\348273\DRAFT_FINAL_FS_07252007.DOC          9-6                                               JULY 2007
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                                                                                DRAFT-FINAL FEASIBILITY STUDY


United States Environmental Protection Agency (EPA). 1990a. National Oil and Hazardous
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United States Environmental Protection Agency (EPA). 1990b. The Feasibility Study: Detailed
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United States Environmental Protection Agency (EPA). 1999b. Interim Policy on the Use of
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          Documenting Cost Estimates during the Feasibility Study. OSWER Directive 9355.0-75.
          EPA 540-R-00-002. July 2000.



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United States Environmental Protection Agency (EPA). 2000b. Institutional Controls: A Site
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          attached with the Tar Creek OU4 AOC), ACS/EPA Region VI GIS Support Team
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          Statement of Work Template and Users’ Guide. Office of Superfund Remediation and
          Technology Innovation. OSWER 9230.0-108. August 2004

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          Ecological Risk Assessment, Ottawa County, Oklahoma. November 2005.

United States Environmental Protection Agency (EPA). 2005b. Interim Data Report for Chat Placement
          Pilot Study, Tar Creek Superfund Site, Ottawa County, Oklahoma. Technical Direction




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          Document Nos. 06-04-01-0010/06-08-0008. Prepared by Weston Solutions, Inc., San Antonio,
          Texas. February 2005.

United States Environmental Protection Agency (EPA). 2006a. Chat and Chat Fines Placement Pilot
          Studies, Tar Creek Superfund Site, Ottawa County, Oklahoma. Technical Direction Document
          No. 06-04-01-0010. Prepared by Weston Solutions, Inc. San Antonio, Texas, July 2006.

United States Environmental Protection Agency (EPA). 2006b. Risk Management Decision for
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          Preliminary Remediation Goals, Cherokee County Superfund Site. July 2006.

United States Environmental Protection Agency (EPA). 2006d. Record of Decision Amendment,
          Cherokee County Superfund Site, Operable Units #03 and #04, Cherokee County, Kansas.
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          Benefits, and other Impacts of Chat Use in Transportation Projects. Economics, Methods,
          and Risk Analysis Division, Office of Solid Waste, U.S. Environmental Protection Agency,
          RCRA Docket Number EPA-HQ-2006-0097. revised February 22, 2006.

United States Environmental Protection Agency (EPA). 2007a. “Criteria for the Safe and
          Environmentally Protective Use of Granular Mine Tailings Known as Chat.” Federal
          Register. Final Rule. 40 CFR Part 278. Vol. 71, No. 64. July 18, 2007.

United States Environmental Protection Agency (EPA). 2007b. Tri-State Mining District – Chat
          Mining Waste. June 2007.

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          Data for Oklahoma, USGS Site No. 07185000, Neosho River near Commerce, OK.
          http://waterdata.usgs.gov/ok/nwis/sw

United States Geologic Survey (USGS). 2005. Characterization of Chat Leachate and Mine Discharge
          into Tar Creek, Ottawa County, Oklahoma. Draft report by Caleb Cope and Mark F. Becker.

United States Government Printing Office. 2005. Solid Waste Disposal Act (42 U.S.C. 6961 et seq)
          Sec. 6006. Title VI, Section 6018, Safe, Accountable, Flexible, and Efficient Transportation
          Equity Act of 2005 (Public Law 109-59).



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Weidman, S. 1932. Miami-Picher Zinc-Lead District. University of Oklahoma Press, Norman, OK.

Wilde et al. 1999. National field manual for the collection of water-quality data: U.S. Geological
          Survey TWRI Book 9.

Wright, C.A. 1918. Mining and milling of lead and zinc ores in the Missouri-Kansas-Oklahoma Zinc
          District. U.S. Bureau of Mines Bulletin 154, pp. 134.




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Tables
 TABLE 2-1
 Mine and Mill Wastes Within the Site Boundary
 Tar Creek Superfund Site

                                                          Proportion of                          PROPORTION OF
       Source Material              Total Area (acres)                      Total Volume (yd3)
                                                         Site Acreage (%)                        SITE VOLUME (%)

  Development Rock                  21                   <1                 197,000              <1

  Chat Pile                         767                  18                 31,200,000           65

  Chat Base                         2,079                49                 6,709,000            14

  Rail/Road Beds (Chat)             552                  13                 702,000              <1

  Fine Tailings                     820                  19                 9,156,000            19

  Smelter Waste                     2                    <1                 1,846                <1

  Total                             4,241                100%               47,965,846           100%




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE2-1.DOC           PAGE 1 OF 1                                   JULY 2007
TABLE 3-1
Remedial Action Objective Summary for Tar Creek Operable Unit 4
Tar Creek Superfund Site
   Environmental                                                       Remedial Action Objective                                                      Preliminary
      Medium                                                                                                                                        Remediation Goal

Source Materials and         Prevent adolescents from coming in direct contact, through the ingestion and inhalation exposure pathways,          Adolescents:
smelter waste,               with lead-contaminated source material and smelter waste where lead concentrations exceed 500 mg/kg.
                                                                                                                                                 500 mg/kg lead in source
transition zone soil,        The purpose of this objective is to reduce the central estimate of blood lead concentration in adults (i.e., the
                                                                                                                                                 material and smelter
and soil which               mature adolescents in question) that have been exposed to Site source materials to a level which ensures
                                        th
                                                                                                                                                 waste, in transition zone
underlies source             that the 95 percentile fetal blood lead concentration in their offspring does not exceed 10 ug/dl. This
                                                                                                                                                 soil, and in the soil which
material and smelter         objective will also be protective for children who live on-site in the event they come in direct contact with the
                                                                                                                                                 underlies source material
waste                        source material through the ingestion and inhalation exposure pathways.
                                                                                                                                                 and smelter waste.




                             Prevent terrestrial fauna from coming in direct (or indirect through plant ingestion) contact, the ingestion        Terrestrial Fauna:
                             exposure pathway, with cadmium-, lead-, or zinc-contaminated source materials and smelter waste where
                                                                                                                                                 10.0 mg/kg for cadmium,
                             cadmium, lead, or zinc exceed their respective remediation goals of 10.0 mg/kg, 500 mg/kg, and 1,100
                                                                                                                                                 500 mg/kg for lead, and
                             mg/kg.
                                                                                                                                                 1,100 mg/kg for zinc in
                                                                                                                                                 source material, smelter
                                                                                                                                                 waste, in transition zone
                                                                                                                                                 soil, and in the soil which
                                                                                                                                                 underlies source material
                                                                                                                                                 and smelter waste.

                             Prevent riparian biota including waterfowl from coming into contact, through the ingestion exposure pathway,        Zero discharge of
                             with dangerous concentrations of lead, cadmium, and zinc in surface water and sediment by eliminating all           cadmium, lead, and zinc
                             discharge of cadmium, lead, and zinc from source materials to surface water.                                        from source materials to
                                                                                                                                                 surface water. Zero




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE3-1.DOC                                         PAGE 1 OF 3                                                                   JULY 2007
TABLE 3-1
Remedial Action Objective Summary for Tar Creek Operable Unit 4
Tar Creek Superfund Site
   Environmental                                                       Remedial Action Objective                                                         Preliminary
      Medium                                                                                                                                           Remediation Goal
                                                                                                                                                    discharge is defined as
                                                                                                                                                    discharge concentration
                                                                                                                                                    levels that would be
                                                                                                                                                    consistent with the
                                                                                                                                                    concentration levels that
                                                                                                                                                    would be expected from
                                                                                                                                                    soil that has background
                                                                                                                                                    concentrations of these
                                                                                                                                                    chemicals.

Soils                        Prevent children who live on the Site from coming in direct contact, through the ingestion and inhalation              Children:
                             exposure pathways, with lead contaminated soil where soil concentrations exceed 500 mg/kg.
                                                                                                                                                    500 mg/kg lead in soil
                             The purpose of this objective is to limit exposure to soil lead levels such that a typical (a hypothetical) child or   (See OU2 Record of
                             group of similarly exposed children living on-site would have an estimated risk of no more than 5% exceeding           Decision for Tar Creek
                             10 ug/dl blood lead level.                                                                                             Residential Areas).

                             Prevent terrestrial fauna from coming in direct (or indirect through plant ingestion) contact, the ingestion           Terrestrial Fauna:
                             exposure pathway, with cadmium-, lead-, or zinc-contaminated source materials and smelter waste where
                                                                                                                                                    10.0 mg/kg for cadmium,
                             cadmium, lead, or zinc exceed their respective remediation goals of 10.0 mg/kg, 500 mg/kg, and 1,100
                                                                                                                                                    500 mg/kg for lead, and
                             mg/kg.
                                                                                                                                                    1,100 mg/kg for zinc in
                                                                                                                                                    source material, smelter
                                                                                                                                                    waste, in transition zone
                                                                                                                                                    soil, and in the soil which
                                                                                                                                                    underlies source material
                                                                                                                                                    and smelter waste



USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE3-1.DOC                                         PAGE 2 OF 3                                                                       JULY 2007
TABLE 3-1
Remedial Action Objective Summary for Tar Creek Operable Unit 4
Tar Creek Superfund Site
   Environmental                                                      Remedial Action Objective                                                Preliminary
      Medium                                                                                                                                 Remediation Goal

Ground Water                 Prevent Site residents from the ingestion of water from private wells that contains lead in concentrations   0.015 mg/l lead at water
                             exceeding the National Primary Drinking Water Standards.                                                     tap.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE3-1.DOC                                       PAGE 3 OF 3                                                           JULY 2007
TABLE 4-1
Results of the Initial Screening of Source Material Technologies
Tar Creek Superfund Site

    General                Remedial                                                                                                                              Retained for
   Response               Technology                  Process                                         Screening Comments                                           Further
     Action                  Type                     Option                                           for Tar Creek OU-4                                         Analysis

                   None                     No Further Action         Consideration required by the NCP                                                          Yes

No Action

                   Monitoring               Environmental             Provides a tool for assessing environmental conditions and future potential                Yes
                                            Monitoring                risks. Required for future review of any selected remedy.


                                            Direct Revegetion         An effective tool for stabilizing waste piles and preventing water and wind erosion.       Yes
                                                                      Vegetative covers are also effective in reducing infiltration of incident precipitation.

                                            Habitat Modification      Can be used effectively to reduce risks to terrestrial biota. Also important               Yes
                                                                      for restoring damaged or degraded habitat.

                                            Surface Armoring          Armoring may be effective in preventing sediment transport and preventing                  Yes
                                                                      use of an area by people or wildlife to prevent exposure to COCs.

                                            Soil/Clay Covering        Soil covers are used extensively to immobilize contaminants in various                     Yes
                                            Systems                   forms. Highly applicable at mining sites, such as the Tar Creek Site.

                   Capping and Physical     Synthetic Membrane        Potentially applicable at the Tar Creek Site for capping individual waste                  Yes
                   Reconfiguration          or Geotextile Covers      piles or as part of an engineered cover system for a waste repository.

                                            Asphaltic Concrete        Potentially applicable at the Tar Creek Site for capping individual waste                  Yes
                                            Cover Systems             piles or as part of an engineered cover system for a waste repository.

                                            Composite Cover           Potentially applicable at the Tar Creek Site for capping individual waste                  Yes
                                            Systems                   piles or as part of an engineered cover system for a waste repository.

                                            Wet or Submerged          Can be an effective method of preventing acid rock drainage and dissolution                Yes
                                            Covering                  of metal containing minerals.

                                            Oxygen-Consuming          Potentially effective in reducing oxidation of sulfide minerals, thereby                   Yes
                                            Covers                    reducing metal dissolution and mobilization by surface or groundwater

                                            Slope Stabilization       Effective in preventing erosional transport of source materials. Also useful in            Yes
                                                                      enhancing the effectiveness of other remedial technologies, such as capping.

                                            Grading and Slope         Effective in preventing erosional transport of source materials. Also useful in            Yes
                                            Reduction                 enhancing the effectiveness of other remedial technologies, such as capping.

                                            Terracing                 Effective in preventing erosional transport of source materials. Also useful in            Yes
                                                                      enhancing the effectiveness of other remedial technologies, such as capping.

                                            Deep Tilling              Potentially effective in reducing metal concentrations in soils by mixing                  Yes
                                                                      soil layers of different concentrations.


Containment and
Stabilization

                                            Stabilization w/ Phos.    This technology is innovative and may be applicable for reducing the                       Yes
                                            or Hydroxy-Apatite        mobility and bio-availability of metals in soils and vegetated chat. Treatability
                                                                      studies were conducted at the Jasper County, Missouri, Site.

                                            Lime Stabilization        Technically feasible for raising the pH of acid mine wastes. Lime may not prove            No
                                                                      a permanent or reliavle stabilization technology for immobilizing metals.

                                            Fly Ash Stabilization     Proven effective and technically feasible in solidifying many different types of           Yes
                                                                      wastes. Potentially applicable at the Tar Creek Site due to a nearby source of
                                                                      fly ash.

                   In-Place Stabilization   Pozzolanic                Has recently been demonstrated at large-scale mine sites. May have limited                 Yes
                   or Fixation              Stabilization             applicability for addressing some waste piles in Tar Creek.

                                            In Situ                   May be effective in stabilizing small batches of waste, but has little                     No
                                            Vitrification             applicability for addressing large waste piles, such as those in Tar Creek.

                                            Grout Injection           Not applicable for addressing the types of source material piles present at the            No
                                                                      Tar Creek Site.

                                            Pyro-kiln Thermal         May be effective in stabilizing small batches of waste, but has little                     No
                                            Encapsulation             applicability for addressing large waste piles, such as those in Tar Creek.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE4-1.DOC                      PAGE 1 OF 2                                                                           JULY 2007
TABLE 4-1
Results of the Initial Screening of Source Material Technologies
Tar Creek Superfund Site

                                                       Excavation w/ On-Site          Applicable and potentially effective for addressing the RAOs for OU-4.
                                                       Consolidation without                                                                                                Yes
                                                       Capping

                                                       Excavation w/ On-Site           Applicable and potentially effective for addressing the RAOs for OU-4.
                                                       Consolidation and                                                                                                    Yes
                                                       Capping w/ Soil Cover

                                                       Excavation w/ On-Site          Applicable and potentially effective for addressing the RAOs for OU-4.
Surficial Source        Excavation and                 Consolidation in an                                                                                                  Yes
Removal                 Disposal                       Engineered Repository

                                                       Disposal or Placement          Field pilot demonstrations of this technology proved its technical feasibility at
                                                       in Mine Shafts or              the Jasper County and Tar Creek Sites.                                                Yes
                                                       Subsidence Pits

                                                       Excavation w/ Injection        EPA field demonstrations of this technology proved its technical feasibility at       Yes
                                                       into Underground Mines         the Tar Creek Site.

                                                       Excavation w/ Off-Site         Experience in the Tri-State Mining District indicates there are no acceptable         No
                                                       Disposal                       off site disposal facilities or locations for the large amounts of Tar Creek source
                                                                                      materials.

                                                       Chat Reprocessing for          Applicable and potentially effective in addressing the RAOs for OU-4 of the           Yes
                                                       Sand & Gravel Recovery         Tar Creek Site.

                                                       Direct Reuse as                Applicable and potentially effective in addressing the RAOs for OU-4 of the           Yes
                                                       Construction Fill, ect.        Tar Creek Site.

                        On-Site/Off-Site               Direct Recycling of            Potentially applicable, but no significant volumes of smelter wastes have been        No
                        Reprocessing, Reuse            Some Smelter Wastes            identified at the Tar Creek Site.
                        or Recycling
                                                       Hydrometallurgical             Not effective in reducing metal concentrations to acceptable levels. Most mill        No
                                                       Reprocessing                   wastes have already been reprocessed, some more than once. Significant
                                                                                      additional metal removal is not likely using available milling processes.

                                                       Pyrometallurgical              Technically infeasible without first concentrating the metals by hydro-               No
                                                       Reprocessing                   metallurgical methods.

                                                       In Situ Leaching               Technically infeasible to perform leaching due to the wide-spread nature              No
                                                                                      of mill wastes at the Site. Unlikely to reduce metals to acceptable levels.

                                                       Soil Washing                   Chat hauling companies are essentially performing soil washing today by their         Yes
                                                                                      chat processing operations. Reduces volume and appears to concentrate lead
                                                                                      in the wash fines. Actions are needed to address risks associated with fines.

                                                       Chemical Extraction            Not proven effective in extracting metals for chat or tailings. Likely not            No
                                                                                      effective for treating the types of source materials found at the Site.

                        Physical/ Chemical             Fluidized Bed                  Not applicable for treating the types of source materials present at the Site.        No
                        Treatment                      Incineration

Treatment                                              Batch Leaching                 Not proven effective in extracting metals for chat or tailings. Likely not            No
                                                                                      effective for treating the types of source materials found at the Site.

                                                       Size Grading or                Potentially effective in reducing volume. May also reduce toxicity by                 Yes
                                                       Screening for TMV              concentrating metals, primarily lead, in the smaller partical fractions.
                                                       Reduction

                                                       Electro-kinetic                Deemed feasible during the Tar Creek OU-2 FS. However, no treatability work           No
                                                       Remediation                    was ever performed. Therefore, the technical feasibility is uncertain.

                                                       In Situ or Ex Situ Metal       Deemed feasible during the Tar Creek OU-2 FS. However, no treatability work           No
                                                       Reduction                      was ever performed. Therefore, the technical feasibility is uncertain.

                                                       In Situ Chemical               Technically feasible for neutralizing low-pH materials and potentially for            No
                                                       Precipitation                  immobilizing metals, thereby reducing toxicity. Would require treatability studies
                                                                                      and leach testing to identify specific chemical precipitants.

                                                       Phyto-Remediation or           Currently unproven experimental technologies for addressing large land areas.         No
                                                       Phyto-Extraction               May be reconsidered in the future if large-scale field demonstrations prove
                                                                                      successful.

                        Biological                     Organic Matter or Bio-         Adding bio-solids or organic matter is usually necessary for direct revegetation.     Yes
                        Treatment                      Solids Addition                Organic matter is also thought to reduce the mobility and bio-availability of heavy
                                                                                      metals, although the treatment effective has not been conclusively proven.

                                                       In Situ Biological             Potentially effective. Has been used succefully at large mine sites.                  Yes
                                                       Remineralization


Drainage and            Refer to Table 4-2 for the initial screening of Drainage and Erosion Control
Erosion Controls        technologies and process options.


Note: Shaded boxes indicate process options are eliminated from further consideration.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE4-1.DOC                                        PAGE 2 OF 2                                                                          JULY 2007
TABLE 4-2
Results of the Initial Screening of Surface Water Technologies
Tar Creek Superfund Site

    General                  Remedial                                                                                                                                         Retained for
   Response                 Technology                            Process                                                Screening Comments                                     Further
     Action                    Type                               Option                                                  for Tar Creek OU-4                                   Analysis

No Action            None                             No Action                            Consideration required by the NCP                                                      Yes


                     Monitoring                       Environmental                        Provides a tool for assessing environmental conditions and future potential            Yes
                                                      Monitoring                           risks. Required for future review of any selected remedy.


Containment and      Refer to Table 4-1 for the initial screening of Containment and Stabilization
Stabilization        technologies and process options.



Surficial Source     Refer to Table 4-1 for the initial screening of Surficial Source Removal
Removal              technologies and process options.


                                                      Gabion Walls, Check Dams             Effective for preventing or reducing erosion of source material deposits               Yes
                                                      Berms, Revetment, Rip-Rap            that are located in flood prone areas or along stream channels.

                                                      Channel Liners or                    Effective for preventing or reducing erosion of source material deposits               Yes
                     Embankment and                   Channelization                       that are located along stream channels.
                     Channel Stabilization
                                                      Detention and Sedimentation          Effective as a best management practice for improving runoff water quality             Yes
                                                      Basins                               by controlling bulk transport of source materials during storm events.

                                                      Grade Control Structures             Effective for preventing head cutting in active stream channels.                       Yes


Drainage and
Erosion Controls                                      Open Channel Stream                  Potentially effective in preventing erosion of source materials, diverting clean       Yes
                                                      Diversions or Ditches                water away from contaminant sources, keeping storm runoff from entering
                                                                                           mine workings, and diverting contaminated water to treatment facilities.

                                                      Seep Collection                      Potentially effective for diverting clean water away from contaminant sources          Yes
                                                      Impoundments                         or collecting contaminated water for retention or treatment.

                     Diversion and
                     Collection Actions               Storage in Subsidence                Potentially effective in diverting, storing or treating storm runoff. However,         No
                                                      Pits                                 this action would run counter to the actions prescribed under OU-1 by
                                                                                           possibly introducing more water into the shallow aquifer or mine workings.

                                                      Runoff Impoundments                  Potentially effective in diverting, storing or treating storm runoff.                  Yes
                                                      or Retention Basins

                                                      Closed Channel Storm                 Effective in preventing erosional transport of source materials. Also                  Yes
                                                      Drains                               potentially effective in diverting water for a variety of reasons.




      USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE4-2.DOC                               PAGE 1 OF 2                                                                     JULY 2007
TABLE 4-2
Results of the Initial Screening of Surface Water Technologies
Tar Creek Superfund Site

                                                        Conventional Chemical             Treatability studies conducted by OWRB in 1983 determined lime                        Yes
                                                        Precipitation                     precipitation was the most cost-effective water treatment option available.
                                                                                          No innovative technologies have supplanted this option for use at mine sites.

                                                        Anoxic Limestone                  Not applicable or effective for addressing conditions in Tar Creek OU-4.              No
                                                        Drains                            May be applicable for addressing low pH mine seepage, but addressing
                                                                                          mine seepage is specifically excluded from the scope of OU-4.

                                                        Passive Chemical                  Primarily applicable for addressing low pH mine drainage. Not effective               No
                                                        Addition Systems                  for removing metals from stream basins as a stand-alone action. Could be
                                                                                          applicable as part of a comprehensive passive treatment system.

                                                        Dissolved Air                     Not applicable for conditions in Tar Creek OU-4.                                      No
                                                        Flotation

                                                        Activated Carbon                  Potentially applicable but not technically feasible to implement on the               No
                                                        Treatment                         scale needed at the site. Was eliminated from consideration during OU-1
                                                                                          based on OWRB's 1983 treatability studies.

                                                        Molecular Sieves                  Potentially applicable but not technically feasible to implement on the               No
                                                                                          scale needed at the site. More appropriate for small industrial applications.

                                                        Reverse Osmosis                   Potentially applicable but not technically feasible to implement on the               No
                                                                                          scale needed at the site. More appropriate for small industrial applications.

                                                        Ultra- or Nano-Filtration         Potentially applicable but not technically feasible to implement on the               No
                                                                                          scale needed at the site. More appropriate for small industrial applications.

                                                        Electrodialysis                   Potentially applicable but not technically feasible to implement on the               No
                                                                                          scale needed at the site. More appropriate for small industrial applications.

                        Physical and Chemical           Distillation                      Potentially applicable but not technically feasible to implement on the               No
                        Treatment Processes                                               scale needed at the site. More appropriate for small industrial applications.

                                                        Spray, Mechanical, or             Potentially applicable but not technically feasible to implement on the               No
                                                        Solar Evaporation                 scale needed at the site. More appropriate for small industrial applications.

                                                        Freeze Crystalization             Potentially applicable but not technically feasible to implement on the               No
                                                                                          scale needed at the site. More appropriate for small industrial applications.

                                                        Liquid-Liquid Extraction          Potentially applicable but not technically feasible to implement on the               No
                                                                                          scale needed at the site. More appropriate for small industrial applications.

                                                        Ion Exchange                      Potentially applicable but not technically feasible to implement on the               No
                                                                                          scale needed at the site. Was eliminated from consideration during OU-1
                                                                                          based on OWRB's 1983 treatability studies.

                                                        Land Application                  Potentially applicable but not technically feasible to implement on the               No
Surface Water                                                                             scale needed at the site.
Treatment
                                                        Electrowinning                    Potentially applicable but not technically feasible to implement on the               No
                                                                                          scale needed at the site. Metals concentrations may be too low to be
                                                                                          effective at the Tar Creek Site.

                                                        Zeolite Sorption/Ion Exch.        Potentially applicable but not technically feasible to implement on the               No
                                                                                          scale needed at the site.

                                                        Activated Sludge                  Potentially applicable but not technically feasible to implement on the               No
                                                                                          scale needed at the site. Was eliminated from consideration during OU-1
                                                                                          based on OWRB's 1983 treatability studies.

                                                        Rotating Bilogical                Potentially applicable but not technically feasible to implement on the               No
                                                        Contactors                        scale needed at the site. Was eliminated from consideration during OU-1
                                                                                          based on OWRB's treatability studies.

                                                        Passive Anaerobic                 Innovative and potentially applicable for removing heavy metals from small            Yes
                                                        Treatment Systems                 streams and seeps. Passive treatment was deemed feasible at the Tar
                                                                                          Creek Site based on treatability studies conducted by Okla. University.

                                                        Passive Aerobic                   Not applicable for removing heavy metals as a stand-alone technology.                 No
                                                        Wetland Treatment                 May be applicable in combination with other treatment technologies.

                        Biological Treatment            Immobilized Biomass               Potentially applicable but not technically feasible to implement on the               No
                                                        or Bio-Sorption                   scale needed at the site.

                                                        Enzyme Treatment                  Potentially applicable but not technically feasible to implement on the               No
                                                        Systems                           scale needed at the site.

                                                        Rhyzo-Filtration                  Experimental, but potentially applicable. Probably not technically feasible           No
                                                                                          to implement on the scale needed at the site. Treatability studies would be
                                                                                          needed for further evaluation. Other more cost-effective options are available.


Note: Shaded boxes indicate process options are eliminated from further consideration.




      USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE4-2.DOC                                    PAGE 2 OF 2                                                                        JULY 2007
TABLE 4-3
Results of the Initial Screening of Groundwater Technologies
Tar Creek Superfund Site


   General                    Remedial                                                                                                                            Retained for
  Response                   Technology                    Process                                         Screening Comments                                       Further
    Action                      Type                       Option                                        for the Jasper County Site                                Analysis

                      None                         No Further Action            Consideration required by the NCP                                                 Yes
No Action

                      Monitoring                   Environmental                Provides a tool for assessing environmental conditions and future potential       Yes
                                                   Monitoring                   risks. Required for future review of any selected remedy.



                                                   Water Softeners with         Technically feasible and proven effective in removing COPCs from drinking         Yes
                                                   NaCl or KCl                  water.
                      Point-of-Use
                      Treatment Systems
                                                   Reverse Osmosis              Technically feasible and proven effective in removing COPCs from drinking         Yes
Groundwater                                        Systems                      water.
Treatment
                      Public Water Supply          Various Physical/            Treatment of public water supplies is routinely conducted, but is outside the     No
                      Treatment                    Chemical Treatments          scope of OU-4 because all public water supplies are from the deep aquifer.




                      Individual Water             Provide Bottled              Technically feasible. Has previously been implemented in the Tri-State            Yes
                      Supplies                     Water                        Mining District.


Alternative           Private Water Supply         Provide Water Through        Technicalloy feasible. New deep wells have been drilled in the Tar Creek          Yes
Water Supplies        Systems                      Private Deep Wells           Site to replace affected deep wells.


                                                   Connect to Existing          Technically feasible. Has previously been implemented in the Tri-State            Yes
                                                   Municipal or Rural Water     Mining District.
                                                   Systems
                      Public Water Supply
                      Systems
                                                   Organize and Construct       Technically feasible. Has previously been implemented in the Tri-State            Yes
                                                   New Rural Water              Mining District.
                                                   Districts


Note: Shaded boxes indicate process options are eliminated from further consideration.




            USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE4-3.DOC                          PAGE 1 OF 1                                                                JULY 2007
TABLE 4-4
Final Screening of Candidate Technologies for Source Materials and Affected Soils
Tar Creek Superfund Site

    General               Remedial
   Response              Technology                 Process                            Effectiveness                                 Implementability                     Cost     Retained?
     Action                 Type                    Option

                  None                     No Further Action        Potentially as effective as other options             Readily implementable.                   None            Yes
                                                                    for some source material categories
No Action
                  Monitoring               Environmental            Effective for continued evaluation of site            Readily implementable.                   Low capital     Yes
                                           Monitoring               conditions and risks.                                                                          Low O&M


                                           Direct Revegetion        Effective for reducing infiltration, surface          Readily implementable.                   Moderate capital Yes
                                                                    erosion and runoff from SM deposits.                                                           Low O&M

                                           Habitat Modification     May be effective for addressing site-                 Difficult to implement on a large        Moderate capital No
                                                                    specific ecological risks (Need BERA).                scale, but may be implementable          Low O&M
                                                                                                                          on small areas to address specific
                                                                                                                          risks.

                                           Surface Armoring         Potentially effective for addressing specific         Implementable on a small scale to        High capital    Yes
                                                                    risks on small targeted areas. Other options          address specific circumstances.          Low O&M
                                                                    available for large-scale remediation.

                                           Soil/Clay Covering       Effective for reducing infiltration, surface          Readily implementable.                   High capital    Yes
                                           Systems                  erosion and runoff from SM deposits.                                                           Low O&M

                  Capping and Physical     Synthetic Membrane       Not a permanent remedy as a stand-alone               Readily implementable.                   High capital    No
                  Reconfiguration          or Geotextile Covers     option. May be permanent and reliable as a                                                     High O&M
                                                                    component of a composit cover system.

                                           Asphaltic Concrete       Effective as a short-term interim action, but         Readily implementable.                   High capital    No
                                           Cover Systems            asphalt cracks and deteriorates over time.                                                     High O&M

                                           Composite Cover          Effectively eliminates COPC transport from            Readily implementable.                   High capital    Yes
                                           Systems                  seepage and runoff from SM deposits.                                                           Moderate O&M

                                           Wet or Submerged         Proven effective in immobilizing COPCs in             Would be difficult to implement due to   High capital    No
                                           Covering                 tailings deposits but other more cost-effective       flatness of the local topography.        High O&M
                                                                    options exist for this Site.

                                           Oxygen-Consuming         Potentially effective but the long-term reliability   Implementable on a small scale to        Moderate capital No
                                           Covers                   is uncertain as a stand-alone remedy.                 address individual hot-spots.            High O&M

Containment and                            Slope Stabilization      Effective in reducing surface erosion and bulk        Readily implementable by a variety of    Moderate capital Yes
Stabilization                                                       transport of source materials.                        means.                                   Moderate O&M

                                           Grading and Slope        Effective in reducing surface erosion and bulk        Readily implementable by a variety of    Moderate capital Yes
                                           Reduction                transport of source materials.                        means.                                   Moderate O&M

                                           Terracing                May be effective for controlling erosion on           Expected to be difficult to construct    Moderate capital No
                                                                    some large chat piles.                                and maintain.                            High O&M

                                           Deep Tilling             Has proven effective in reducing metals               Readily implementable.                   Low capital     Yes
                                                                    concentrations to below risk-based levels in                                                   Low O&M
                                                                    chat bases and transition zone soils.

                                           Stabilization w/ Phos.   Proven effective for reducing the bioavailability     Implementable for addressing targeted Low capital        No
                                           or Hydroxy-Apatite       of lead in soil, but long-term reliability is         areas like residential yards.         High O&M
                                                                    uncertain. Treatment may need to be repeated.

                  In-Place Stabilization   Fly Ash Stabilization    Effective in stabilizing wastes but may actually      A source of fly ash is available nearby, High capital    No
                  or Fixation                                       increase surface runoff and erosion on large          so could be implemented at the Tar       Moderate O&M
                                                                    chat piles compared with current conditions.          Creek Site.

                                           Pozzolanic               Effective in stabilizing wastes but may actually      Implementable.                           High capital    No
                                           Stabilization            increase surface runoff from on large                                                          Moderate O&M
                                                                    chat piles compared with current conditions.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE4-4.DOC                        PAGE 1 OF 2                                                                                   JULY 2007
TABLE 4-4
Final Screening of Candidate Technologies for Source Materials and Affected Soils
Tar Creek Superfund Site

                                                      Excavation w/ On-Site          Potentially effective for reducing seepage, run-     Readily implementable.                   High capital     Yes
                                                      Consolidation without          off and erosion from targeted SM deposits. Also                                               Low O&M
                                                      Capping                        effective in reducing human exposure.

                                                      Excavation w/ On-Site          Effective and permanent for addressing source        Readily Implementable.                   High capital     Yes
                                                      Consolidation and              material, soil, and surface water RAOs and                                                    Moderate O&M
                                                      Capping w/ Soil Cover          identified risks.

                                                      Excavation w/ On-Site          Effective and permanent for addressing source        Readily Implementable.                   Very high capital Yes
Surficial Source        Excavation and                Consolidation in an            material, soil, and surface water RAOs and                                                    High O&M
Removal                 Disposal                      Engineered Repository          identified risks.

                                                      Disposal or Placement          Proven effective through field demonstrations in     Implementability is limited at the Tar   Moderate capital Yes
                                                      in Mine Shafts or              Jasper County, Missouri, and at the Tar Creek        Creek Site due to the lack of large      Low O&M
                                                      Subsidence Pits                Site. A permanent remedy.                            subsidence features.

                                                      Excavation w/ Injection        Proven effective and permanent in reducing the       Technical implementability problems      High capital     Yes
                                                      into Underground Mines         volume of source materials left on site through      were solved through pilot testing at     Low O&M
                                                                                     Tar Creek field demonstrations.                      the Site.




                                                      Chat Reprocessing for          Proven effective and permanent in reducing the       Already being implemented on a large     Low capital      Yes
                                                      Sand & Gravel Recovery         volume of source materials on site, but would        scale. New markets could speed up        Low O&M
                        On-Site/Off-Site                                             require decades to meet RAOs at present rates.       reprocessing rates.
                        Reprocessing, Reuse
                        or Recycling                  Direct Reuse as                Proven effective and permanent in reducing the       Implementability is limited by small     Low capital      Yes
                                                      Construction Fill, ect.        volume of source materials on site, but would        local markets for bulk chat.             Low O&M
                                                                                     require decades to meet RAOs at present rates.

                                                      Soil Washing                   Proven effective in reducing lead concentrations     Chat washing is a routine practice       High capital     Yes
                                                                                     in bulk chat below human health risk levels.         and is readily implementable.            High O&M
                                                                                     However, wash fines contain high lead levels
Treatment               Physical/ Chemical                                           and require containment and/or disposal.
                        Treatment
                                                      Size Grading or                May be effective in concentrating lead in fine       Only feasible in conjunction with chat   High capital     No
                                                      Screening for TMV              materials, but coarse fraction still contains lead   reprocessing, but not as a stand-        High O&M
                                                      Reduction                      above risk-based levels.                             alone process option.


                                                      Organic Matter or Bio-         Effective for immobilizing metals in source          Implementable, but the local supply      Moderate capital Yes
                                                      Solids Addition                materials and soils. A necessary treatment prior     of biosolids is small. Other sources     Low O&M
                        Biological                                                   to direct revegetation.                              of organic matter would be needed.
                        Treatment
                                                      In Situ Biological             Effective for immobilizing metals in source          Implementable on a small scale, but      High capital     No
                                                      Remineralization               materials and soils. However, remineralization is    would be difficult to achieve over large High O&M
                                                                                     likely not permanent due to natural weathering.      land areas.

Drainage and            Refer to Table 4-5 for the initial screening of Drainage and Erosion Control
Erosion Controls        technologies and process options.


Note: Shaded boxes indicate process options are eliminated from further consideration.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE4-4.DOC                                          PAGE 2 OF 2                                                                                 JULY 2007
TABLE 4-5
Final Screening of Candidate Technologies for Surface Water
Tar Creek Superfund Site
      General                       Remedial
     Response                      Technology                       Process                                 Effectiveness                               Implementability                    Cost        Retained?
       Action                         Type                          Option

No Action                   None                            No Further Action            Potentially as effective as other options under      Readily implementable.                 None               Yes
                                                                                         OU-4, as mine drainage is the major loading
                                                                                         contributor to surface waters but is outside the
                                                                                         scope of this operable unit.

                            Monitoring                      Environmental                Effective for continued evaluation of site           Readily implementable.                 Low capital        Yes
                                                            Monitoring                   conditions and risks.                                                                       Low O&M


Containment and             Refer to Table 4-4 for the initial screening of Containment and Stabilization
Stabilization               technologies and process options.



Surficial Source            Refer to Table 4-4 for the initial screening of Surficial Source Removal
Removal                     technologies and process options.


                                                            Gabion Walls, Berms,         Effective for reducing erosion and bulk transport    Readily implementable.                 Low Capital        Yes
                                                            Revetment, Rip-Rap, or       of COPCs from source material deposits.                                                     Low O&M
                                                            Check Dams

                                                            Channel Liners or            Effective for reducing erosion and bulk transport    Readily implementable.                 Moderate Capital   Yes
                            Embankment and                  Channelization               of COPCs from source material deposits.                                                     Moderate O&M
                            Channel Stabilization
                                                            Detention and                Effective for improving storm runoff quality by      Readily implementable but would        Moderate Capital   Yes
                                                            Sedimentation Basins         removing suspended sediments and reducing            require frequent sediment removal.     High O&M
                                                                                         peak storm runoff volumes.

                                                            Grade Control                Effective for preventing head cutting in stream      Implementable but would likely have    Low Capital        Yes
                                                            Structures                   channels.                                            limited applicability at this Site.    Low O&M

Drainage and
Erosion Controls                                            Open Channel Stream          Potentially effective for diverting streams away     Implementable for targeted segments    Moderate Capital   Yes
                                                            Diversions or Ditches        from SM deposits, thereby reducing erosion.          where streams run through or near      Moderate O&M
                                                                                                                                              source material deposits.

                                                            Seep Collection              Potentially effective if implemented in              Implementable for small seeps as       Moderate Capital   Yes
                                                            Impoundments                 conjunction with passive treatment.                  part of a treatment system.            High O&M
                            Diversion and
                            Collection Actions
                                                            Runoff Impoundments          Potentially effective for retaining small flows to   Implementable for small runoff areas   High Capital       Yes
                                                            or Retention Basins          reduce sediment loads. Would require frequent        but probably not implementable for     High O&M
                                                                                         maitenance.                                          streams and tributaries.

                                                            Closed Channel Storm         Effective for reducing erosion and bulk transport    Readily implementable.                 Moderate Capital   Yes
                                                            Drains                       of COPCs from source material deposits.                                                     Moderate O&M




                            Physical and Chemical           Conventional Chemical        Highly effective in reducing metal concentrations    Only implementable for steady flows    High Capital       No
                            Treatment Processes             Precipitation                in surface water.                                    of consistent water quality, such as   High O&M
                                                                                                                                              mine drainage. Not implementable
Surface Water                                                                                                                                 for highly variable storm runoff.
Treatment

                            Biological Treatment            Passive Anaerobic            Proven effective by on Site treatability testing     May be implementable for collecting    Moderate Capital   Yes
                                                            Treatment Systems            for treating small seeps and mine discharges.        and treating small seeps eminating     Low O&M
                                                                                         However, may cease to function during seasonal       from source material deposits.
                                                                                         low flow periods or droughs.



Note: Shaded boxes indicate process options are eliminated from further consideration.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE4-5.DOC                                                   PAGE 1 OF 1                                                                                           JULY 2007
TABLE 4-6
Final Screening of Candidate Technologies for Groundwater
Tar Creek Superfund Site

    General                  Remedial
   Response                 Technology                       Process                                 Effectiveness                                 Implementability                     Cost        Retained?
     Action                    Type                           Option

                       None                         No Further Action              May be as effective as other options unless          Readily implementable.                   None               Yes
                                                                                   residents rely on shallow aquifer wells for
No Action                                                                          domestic water supplies.

                       Monitoring                   Environmental                  Effective as a tool for evaluating site conditions   Readily implementable.                   Low Capital        Yes
                                                    Monitoring                     and risks.                                                                                    Low O&M
                                                                                                                                        impose restrictions.


                                                    Water Softeners with           Proven effective for removing metals, such as        Readily implementable but requires       Low Capital        Yes
                                                    NaCl or KCl                    lead from drinking water.                            regular maintenance.                     Moderate O&M
Groundwater            Point-of-Use
Treatment              Treatment Systems
                                                    Reverse Osmosis                Proven effective for removing metals, such as        Available in household units for those   Moderate Capital Yes
                                                    Systems                        lead from drinking water.                            with sensitivity to NaCl.                Low O&M


                       Individual Water             Provide Bottled                Effective as an interim measure, but residents       Readily implementable.                   Low Capital        Yes
                       Supplies                     Water                          could remain exposed to COPCs due to                                                          Moderate O&M
                                                                                   continued availability of well water in affected
                                                                                   households.

Alternative            Private Water Supply         Provide Water Through          Effective in preventing residential exposure         Readily implementable. Several new       Moderate Capital Yes
Water Supplies         Systems                      Private Deep Wells             to COPCs.                                            deep wells were previously drilled       Moderate O&M
                                                                                                                                        to replace contaminated wells.

                                                    Connect to Existing            Effective in preventing residential exposure         Feasability and cost depends on          Variable Capital   Yes
                                                    Municipal or Rural Water       to COPCs.                                            proximity of affected residences to      Low O&M
                                                    Systems                                                                             existing piped water systems.
                       Public Water Supply
                       Systems
                                                    Organize and Construct         Effective in preventing residential exposure         Likely not feasible for the small        High Capital       No
                                                    New Rural Water                to COPCs.                                            number of affected households            High O&M
                                                    Districts                                                                           identified in during the RI sampling.




Note: Shaded boxes indicate process options are eliminated from further consideration.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE4-6.DOC                                                       PAGE 1 OF 1                                                                                    JULY 2007
 TABLE 5-1
 Source Material and Affected Media Categories for Tar Creek OU4
 Tar Creek Superfund Site
 Physical Setting/             Urban Areas         Near Streams         Upland Areas        Total
   Material Type

 Chat                       11,509,000 Cubic      6,048,000 Cubic       13,643,000 Cubic    31,200,000 Cubic
                            Yards                 Yards                 Yards               Yards

                            254 Acres             132 Acres             380 Acres           766 Acres

 Chat Bases                 1,287,000 Cubic       1,252,000 Cubic       4,170,000 Cubic     6,709,000 Cubic
                            Yards                 Yards                 Yards               Yards

                            399 Acres             388 Acres             1,292 Acres         2079 Acres

 Rail/Road Beds             None                  None                  702,000 Cubic       702,000 Cubic
 (Chat)                                                                 Yards               Yards

                                                                        552 acres           552 acres

 Fine Tailings              344,000 Cubic         1,654,000 Cubic       7,158,000 Cubic     9,156,000 Cubic
                            Yards                 Yards                 Yards               Yards

                            45 Acres              145 Acres             631 Acres           821 Acres

 Smelter Wastes             None                  None                  1,846 Cubic Yards   1,846 Cubic Yards

                                                                        2.3 Acres           2.3 Acres

 General Affected           1000 Acres
 Soils (All Settings)

 Smelter-Affected           None                  None                  12 Acres            12 Acres
 Soils

 Residential Yards          Outside the Scope     None                  5 Households        5 Households
                            of OU4

 Storm Runoff and           Quantity Estimates Not Available
 Seepage
 (All Settings)

 Affected Shallow           None                  None                  2 Households        2 Households
 Aquifer Well Water




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-1.DOC           PAGE 1 OF 1                                    JULY 2007
    TABLE 5-2
    Candidate Remedial Alternative Summary
    Tar Creek Superfund Site
     Source Material           Remedial Action      Alternative 1:          Alternative 2:         Alternative 3:      Alternative 4 (also     Alternative 5 (also     Alternative 6:       Alternative 7:      Alternative 8:         Alternative 9:      Alternative 10:
    or Affected Media            Objectives                                                                             see footnote 1):       see footnotes 1 &                                                 Total Source
        Category                                  No Further Action       In-Place Source        Stabilization and          Phased                     2):            Partial Source        Partial Source      Consolidation,        Excavation and      Excavation and
                                                                          Stabilization and        Institutional         Consolidation,                               Consolidation,        Consolidation,     On-Site Disposal,        Disposal in         Disposal in
                                                                            Institutional            Controls          On-Site Disposal            Voluntary           Stabilization,        Stabilization,    and Institutional          Upland           Underground
                                                                              Controls                                  and Institutional         Relocation,        Upland Disposal,       Underground            Controls          Repositories and      Mine Workings
                                                                                                                            Controls                Phased           and Institutional      Mine Disposal,                             Institutional      and Institutional
                                                                                                                                                 Consolidation,          Controls          and Institutional                             Controls             Controls
                                                                                                                                                On-Site Disposal,                              Controls
                                                                                                                                                and Institutional
                                                                                                                                                    Controls

    Urban Chat                Source Material     Chat processing         Same as                Consent decrees,      Classified as chat      Same as               Same as              Same as              All urban chat is     All urban chat is    Same as
                                                  continues by            Alternative 1,         administrative        pile only.              Alternative 4.        Alternative 3,       Alternative 6        excavated and         excavated,           Alternative 9,
                                                  private operators at    except all urban       orders, or various    Processing of chat      Includes voluntary    except that all      except that all      consolidated in       consolidated in      except all
                                                  an assumed rate of      chat deposits are      incentives are used   piles by private        relocation            urban chat           remaining chat is    existing upland       upland deposits      excavated
                                                  1.9 million tons per    fenced and legal       to facilitate         processors is           component to          remaining after 10   disposed in          deposits for future   and covered with     materials are
                                                  year. Chat piles        restrictions against   selective             facilitated. Any        prevent exposure      years is excavated   underground mine     processing.           (a) vegetated soil   disposed of in
                                                  that are processed      trespassing are        processing and        remaining chat is       to source             and disposed of in   workings.            Excavated areas       covers or (b) geo-   underground
                                                  become bases with       implemented.           removal of urban      either injected into    materials.            upland               Excavated areas      are reclaimed.        composite cover      workings,
                                                  no effective            Private companies      chat by private       mine workings,          Remedial              repositories.        are reclaimed.                             systems.             subsidence pits, or
                                                  reduction in area       continue chat          companies to          hauled to a             timeframe             Excavated areas                                                 Excavated areas      open mine shafts.
                                                  footprint. EPA          processing and         reduce human          repository, pushed      extended as a         are reclaimed.                                                  are reclaimed.
                                                  continues with chat     sales but              exposure. Non-        in to subsidence        result of voluntary
                                                  treatability study of   implement BMPs         processed chat is     areas, or hauled to     relocation.
                                                  Indian-owned chat.      but no effective       covered in place.     a private washing
                                                  State of Oklahoma       footprint reduction                          operation. All areas
                                                  implements              is achieved as                               are reclaimed.
                                                  subsidence-related      piles become
                                                  voluntary               bases after
                                                  relocation.             processing.

    Near-Stream Chat          Source Material     Chat processing         Site-appropriate in-   Same as               Near stream chat        Same as               Near-stream chat     Same as              Same as               All near-stream      Same as
                                                  continues by            place stabilization    Alternative 2,        is removed from         Alternative 4.        subject to stream    Alternative 6.       Alternative 6.        chat is excavated,   Alternative 9,
                                                  private operators at    measures are           except consent        floodway and            Includes voluntary    erosion and                                                     consolidated in      except all
                                                  an assumed rate of      installed to prevent   decrees,              integrated into the     relocation            sources of out-                                                 upland deposits      excavated
                                                  1.9 million tons per    stream erosion and     administrative        original source of      component to          washing chat are                                                and covered with     materials are
                                                  year. Chat piles        out-washing of         orders, or various    chat. Processing of     prevent exposure      excavated and                                                   soil or geo-         disposed of in
                                                  that are processed      chat from existing     incentives are used   chat piles by           to source             consolidated in                                                 composite cover      underground
                                                  become bases with       near- stream           to facilitate         private processors      materials.            existing upland                                                 systems.             workings,
                                                  no effective            deposits. Private      selective             is facilitated. Any                           chat deposits for                                               Excavated areas      subsidence pits, or
                                                  reduction in area       companies              processing and        remaining chat is                             future processing                                               are reclaimed.       open mine shafts.
                                                  footprint. EPA          continue chat          removal of near-      injected into mine                            and removal by
                                                  continues with chat     processing and         stream chat by        workings, hauled to                           private companies.
                                                  treatability study of   sales but              private companies     a repository,                                 Excavated areas
                                                  Indian-owned chat.      implement BMPs         to reduce surface     pushed in to                                  are reclaimed.
                                                  State of Oklahoma       but no effective       water transport.      subsidence areas,
                                                  implements              footprint reduction                          or hauled to a
                                                  subsidence-related      is achieved as                               private washing
                                                  voluntary               piles become                                 operation. All areas
                                                  relocation.             bases after                                  are reclaimed.
                                                                          processing.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-2.DOC                                                                                               PAGE 1 OF 8                                                                                                            JULY 2007
    TABLE 5-2
    Candidate Remedial Alternative Summary
    Tar Creek Superfund Site
     Source Material           Remedial Action      Alternative 1:          Alternative 2:         Alternative 3:     Alternative 4 (also     Alternative 5 (also     Alternative 6:        Alternative 7:       Alternative 8:          Alternative 9:      Alternative 10:
    or Affected Media            Objectives                                                                            see footnote 1):       see footnotes 1 &                                                   Total Source
        Category                                  No Further Action       In-Place Source        Stabilization and         Phased                     2):            Partial Source        Partial Source        Consolidation,         Excavation and      Excavation and
                                                                          Stabilization and        Institutional        Consolidation,                               Consolidation,        Consolidation,       On-Site Disposal,         Disposal in         Disposal in
                                                                            Institutional            Controls         On-Site Disposal            Voluntary           Stabilization,        Stabilization,      and Institutional           Upland           Underground
                                                                              Controls                                 and Institutional         Relocation,        Upland Disposal,       Underground              Controls           Repositories and      Mine Workings
                                                                                                                           Controls                Phased           and Institutional      Mine Disposal,                                Institutional      and Institutional
                                                                                                                                                Consolidation,          Controls          and Institutional                                Controls             Controls
                                                                                                                                               On-Site Disposal,                              Controls
                                                                                                                                               and Institutional
                                                                                                                                                   Controls

    Upland Chat               Source Material     Chat processing         Same as                Same as              Classified as chat      Same as               Same as               Same as               Same as                Upland chat          Same as
                                                  continues by            Alternative 1,         Alternative 2,       pile only.              Alternative 4.        Alternative 3,        Alternative 6         Alternative 6          deposits are         Alternative 9,
                                                  private operators at    except all urban       except remaining     Processing of chat      Includes voluntary    except non-           except non-           except that all non-   consolidated on-     except all
                                                  an assumed rate of      chat deposits are      non-processed        piles by private        relocation            processed chat is     processed chat is     processed              site and covered     excavated
                                                  1.9 million tons per    fenced and legal       chat is covered in   processors is           component to          disposed of in        disposed of in        materials are          with soil or geo-    materials are
                                                  year. Chat piles        restrictions against   place using soil     facilitated. Chat       prevent exposure      upland                underground mine      disposed of in         composite covers     disposed of in
                                                  that are processed      trespassing are        covers.              piles in distal         to source             repositories.         workings.             underground mine       systems.             underground
                                                  become bases with       implemented.                                (remote) areas,         materials.                                                        workings by            Excavated areas      workings,
                                                  no effective            Private companies                           which are very                                                                            injection or pushed    are reclaimed.       subsidence pits, or
                                                  reduction in area       continue chat                               similar to upland                                                                         into subsidence                             open mine shafts.
                                                  footprint. EPA          processing and                              areas, are                                                                                pits.
                                                  continues with chat     sales but                                   excavated and
                                                  treatability study of   implement BMPs                              hauled to private
                                                  Indian-owned chat.      but no effective                            washing operation.
                                                  State of Oklahoma       footprint reduction                         Any remaining chat
                                                  implements              is achieved as                              is either injected
                                                  subsidence-related      piles become                                into mine workings,
                                                  voluntary               bases after                                 hauled to a
                                                  relocation which        processing.                                 repository, pushed
                                                  has limited impact                                                  in to subsidence
                                                  in Upland areas                                                     areas, or hauled to
                                                  due to buyout                                                       a private washing
                                                  boundaries.                                                         operation. All areas
                                                                                                                      are reclaimed.

    Urban Fine                Source Material     No further action.      Existing tailings      Same as              Classified as all       Same as               Existing tailings     Same as               Same as                All urban tailings   Same as
    Tailings                                      Additional wash         deposits are           Alternative 2.       other fine tailings     Alternative 4.        deposits are          Alternative 6         Alternative 7.         deposits are         Alternative 9,
                                                  fines are generated     covered with                                other than in near      Includes voluntary    excavated and         except excavated                             excavated and        except all
                                                  through processing      vegetated soil                              stream setting.         relocation            disposed of in        tailings are                                 consolidated in      excavated
                                                  of chat. State of       covers. New chat                            Tailings are either     component to          upland                disposed of in                               upland deposits      materials are
                                                  Oklahoma                wash fines are                              covered in place or     prevent exposure      repositories.         underground mine                             and covered with     disposed of in
                                                  implements              disposed of by                              injected into           to source             Excavated areas       workings.                                    soil or geo-         underground
                                                  subsidence-related      pumping into                                underground mine        materials.            are reclaimed. New    Excavated areas                              composite cover      workings,
                                                  voluntary               underground mine                            workings. The                                 chat wash fines are   are reclaimed. New                           systems.             subsidence pits, or
                                                  relocation.             workings. Deed                              breached berms of                             disposed of by        chat wash fines are                          Excavated areas      open mine shafts.
                                                                          notices are placed                          existing deposits                             pumping into          disposed of by                               are reclaimed.
                                                                          on covered                                  are repaired Deed                             underground mine      pumping into
                                                                          deposits.                                   notices are placed                            workings.             underground mine
                                                                                                                      on covered                                                          workings
                                                                                                                      deposits.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-2.DOC                                                                                              PAGE 2 OF 8                                                                                                               JULY 2007
    TABLE 5-2
    Candidate Remedial Alternative Summary
    Tar Creek Superfund Site
     Source Material           Remedial Action      Alternative 1:        Alternative 2:         Alternative 3:        Alternative 4 (also     Alternative 5 (also     Alternative 6:         Alternative 7:      Alternative 8:       Alternative 9:     Alternative 10:
    or Affected Media            Objectives                                                                             see footnote 1):       see footnotes 1 &                                                   Total Source
        Category                                  No Further Action     In-Place Source        Stabilization and            Phased                     2):            Partial Source          Partial Source      Consolidation,      Excavation and     Excavation and
                                                                        Stabilization and        Institutional           Consolidation,                               Consolidation,          Consolidation,     On-Site Disposal,      Disposal in        Disposal in
                                                                          Institutional            Controls            On-Site Disposal            Voluntary           Stabilization,          Stabilization,    and Institutional        Upland          Underground
                                                                            Controls                                    and Institutional         Relocation,        Upland Disposal,         Underground            Controls        Repositories and     Mine Workings
                                                                                                                            Controls                Phased           and Institutional        Mine Disposal,                           Institutional     and Institutional
                                                                                                                                                 Consolidation,          Controls            and Institutional                           Controls            Controls
                                                                                                                                                On-Site Disposal,                                Controls
                                                                                                                                                and Institutional
                                                                                                                                                    Controls

    Near-Stream Fine          Source Material     No further action.    Existing deposits      Same as                 Near stream             Same as               Near-stream            Same as              Same as             All near-stream     Same as
    Tailings                                      Additional wash       are stabilized in      Alternative 2.          tailings are            Alternative 4.        tailings deposits      Alternative 6        Alternative 7.      tailings are        Alternative 9,
                                                  fines are generated   place using site-                              removed from the        Includes voluntary    are excavated and      except excavated                         excavated,          except all
                                                  through processing    appropriate erosion                            floodway,               relocation            disposed of in         tailings are                             consolidated in     excavated
                                                  of chat. State of     control measures.                              integrated with         component to          upland                 disposed of in                           upland deposits     materials are
                                                  Oklahoma              Sources of out-                                original tailing        prevent exposure      repositories.          underground mine                         and covered with    disposed of in
                                                  implements            washing tailings                               source, and either      to source                                    workings.                                soil or geo-        underground
                                                                                                                                                                     Remaining
                                                  subsidence-related    are stabilized in                              covered in place or     materials.                                                                            composite cover     workings,
                                                  voluntary             place. Institutional                           injected into                                 deposits are                                                    systems.            subsidence pits, or
                                                  relocation. OCC       controls are                                   underground mine                              stabilized in place.                                            Excavated areas     open mine shafts.
                                                  and ODEQ may          implemented to                                 workings. All areas                           Placing new                                                     are reclaimed.
                                                  reclaim selected      prohibit new                                   are reclaimed. The                            tailings in
                                                  fine tailings         tailings deposits in                           breached berms of                             floodways is
                                                  deposits with State   flood ways.                                    existing deposits                             prohibited.
                                                  funding under                                                        are repaired. Deed
                                                  Oklahoma Plan (if                                                    notices are placed
                                                  funded).                                                             on covered
                                                                                                                       deposits.

    Upland Fine               Source Material     No further action.    Same as                The breached            Upland fine tailings    Same as               Same as                Same as              Same as             Upland tailings     Same as
    Tailings                                      Additional wash       Alternative 1,         berms of existing       are either covered      Alternative 4.        Alternative 3.         Alternative 3.       Alternative 3.      deposits are        Alternative 9,
                                                  fines are generated   except chat            deposits are            in place or injected    Includes voluntary                                                                    consolidated on-    except all
                                                  through processing    processors are         repaired and the        into underground        relocation                                                                            site and covered    excavated
                                                  of chat. State of     required to dispose    existing tailings are   mine workings. All      component to                                                                          with soil or geo-   materials are
                                                  Oklahoma              of new chat-wash       stabilized in place     areas are               prevent exposure                                                                      composite covers    disposed of in
                                                  implements            fines in covered,      using site-             reclaimed. The          to source                                                                             systems. Newly      underground
                                                  subsidence-related    above-ground           appropriate             breached berms of       materials.                                                                            generated chat      workings,
                                                  voluntary             containment cells      measures. Chat          existing deposits                                                                                             wash fines are      subsidence pits, or
                                                  relocation which      or by pumping into     processors are          are repaired. Deed                                                                                            disposed of in      open mine shafts.
                                                  has limited impact    underground mine       required to dispose     notices are placed                                                                                            aboveground
                                                  in Upland areas       workings. Deed         of new chat-wash        on covered                                                                                                    containment cells
                                                  due to buyout         notices are placed     fines in covered,       deposits.                                                                                                     or pumped into
                                                  boundary. OCC         on new and             above-ground                                                                                                                          underground mine
                                                  and ODEQ may          existing deposits.     containment cells                                                                                                                     workings.
                                                  reclaim selected                             or by pumping into
                                                  fine tailings                                underground mine
                                                  deposits with State                          workings. Deed
                                                  funding under                                notices are placed
                                                  Oklahoma Plan (if                            on new and
                                                  funded).                                     existing deposits.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-2.DOC                                                                                               PAGE 3 OF 8                                                                                                           JULY 2007
    TABLE 5-2
    Candidate Remedial Alternative Summary
    Tar Creek Superfund Site
     Source Material           Remedial Action      Alternative 1:       Alternative 2:          Alternative 3:      Alternative 4 (also     Alternative 5 (also     Alternative 6:        Alternative 7:      Alternative 8:       Alternative 9:        Alternative 10:
    or Affected Media            Objectives                                                                           see footnote 1):       see footnotes 1 &                                                  Total Source
        Category                                  No Further Action    In-Place Source         Stabilization and          Phased                     2):            Partial Source         Partial Source      Consolidation,      Excavation and        Excavation and
                                                                       Stabilization and         Institutional         Consolidation,                               Consolidation,         Consolidation,     On-Site Disposal,      Disposal in           Disposal in
                                                                         Institutional             Controls          On-Site Disposal            Voluntary           Stabilization,         Stabilization,    and Institutional        Upland             Underground
                                                                           Controls                                   and Institutional         Relocation,        Upland Disposal,        Underground            Controls        Repositories and        Mine Workings
                                                                                                                          Controls                Phased           and Institutional       Mine Disposal,                           Institutional        and Institutional
                                                                                                                                               Consolidation,          Controls           and Institutional                           Controls               Controls
                                                                                                                                              On-Site Disposal,                               Controls
                                                                                                                                              and Institutional
                                                                                                                                                  Controls

    Urban Chat Bases          Source Material     No further action.   All urban chat          Urban chat bases      Classified as chat      Same as               Same as               Same as              Same as             All urban chat         Same as
                                                  Bases are not        bases are covered       are excavated and     base. Processing        Alternative 4.        Alternative 3,        Alternative 6.       Alternative 6.      bases are              Alternative 9,
                                                  likely to be         in place with           consolidated on-      of chat bases by        Includes voluntary    except that the                                                excavated,             except all
                                                  processed by chat    vegetated soil          site for processing   private processors      relocation            urban chat bases                                               consolidated in        excavated
                                                  operators. OCC       covers. Institutional   and removal. Non-     is facilitated. Any     component to          are consolidated in                                            upland deposits        materials are
                                                  and ODEQ may         controls are            processed             remaining chat is       prevent exposure      existing upland                                                and covered with       disposed of in
                                                  reclaim selected     implemented to          materials are         injected into mine      to source             chat deposits for                                              soil or geo-           underground
                                                  chat bases with      require testing,        covered on-site       workings, hauled to     materials.            future processing                                              composite cover        workings,
                                                  State funding        protection of the       with vegetated soil   a repository,           Remedial              and removal by                                                 systems.               subsidence pits, or
                                                  under Oklahoma       soil covers, and        covers.               pushed in to            timeframe             private companies.                                             Excavated areas        open mine shafts.
                                                  Plan (if funded).    remedial actions, if                          subsidence areas,       extended as a         Excavated areas                                                are reclaimed.
                                                  State of Oklahoma    needed, during any                            or hauled to a          result of voluntary   are reclaimed.
                                                  implements           new residential                               private washing         relocation since
                                                  subsidence-related   development.                                  operation. All areas    relocation
                                                  voluntary                                                          are reclaimed deep      populace is no
                                                  relocation.                                                        tilled.                 longer potentially
                                                                                                                                             exposed.

    Near-Stream Chat          Source Material     No further action.   Site-appropriate in-    Near-stream chat      Near-stream chat        Same as               Same as               Same as              Same as             All near-stream        Same as
    Bases                                         Bases are not        place stabilization     bases are             bases are               Alternative 4.        Alternative 3.        Alternative 3.       Alternative 3.      chat bases are         Alternative 9,
                                                  likely to be         measures are            excavated and         relocated out of        Includes voluntary                                                                   excavated,             except all
                                                  processed by chat    installed to prevent    consolidated in       floodway and            relocation                                                                           consolidated in        excavated
                                                  operators. OCC       stream erosion and      existing upland       integrated with         component to                                                                         existing upland        materials are
                                                  and ODEQ may         out-washing of          chat deposits.        source. Source is       prevent exposure                                                                     deposits and           disposed of in
                                                  reclaim selected     chat from near-                               addressed in same       to source                                                                            covered with soil or   underground
                                                  chat bases with      stream deposits.                              manner as               materials.                                                                           geo-composite          workings,
                                                  State funding                                                      described under                                                                                              cover systems.         subsidence pits, or
                                                  under Oklahoma                                                     urban chat bases.                                                                                                                   open mine shafts.
                                                  Plan (if funded).
                                                  State of Oklahoma
                                                  implements
                                                  subsidence-related
                                                  voluntary
                                                  relocation.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-2.DOC                                                                                             PAGE 4 OF 8                                                                                                             JULY 2007
    TABLE 5-2
    Candidate Remedial Alternative Summary
    Tar Creek Superfund Site
     Source Material           Remedial Action      Alternative 1:       Alternative 2:         Alternative 3:        Alternative 4 (also     Alternative 5 (also     Alternative 6:         Alternative 7:      Alternative 8:       Alternative 9:        Alternative 10:
    or Affected Media            Objectives                                                                            see footnote 1):       see footnotes 1 &                                                   Total Source
        Category                                  No Further Action    In-Place Source        Stabilization and            Phased                     2):            Partial Source          Partial Source      Consolidation,      Excavation and        Excavation and
                                                                       Stabilization and        Institutional           Consolidation,                               Consolidation,          Consolidation,     On-Site Disposal,      Disposal in           Disposal in
                                                                         Institutional            Controls            On-Site Disposal            Voluntary           Stabilization,          Stabilization,    and Institutional        Upland             Underground
                                                                           Controls                                    and Institutional         Relocation,        Upland Disposal,         Underground            Controls        Repositories and        Mine Workings
                                                                                                                           Controls                Phased           and Institutional        Mine Disposal,                           Institutional        and Institutional
                                                                                                                                                Consolidation,          Controls            and Institutional                           Controls               Controls
                                                                                                                                               On-Site Disposal,                                Controls
                                                                                                                                               and Institutional
                                                                                                                                                   Controls

    Upland Chat Bases         Source Material     No further action.   Same as                Upland chat bases       Classified as chat      Same as               Same as                Same as              Same as             Same as                Same as
                                                  Bases are not        Alternative 1.         are excavated and       bases only. Chat        Alternative 4.        Alternative 3,         Alternative 6        Alternative 6,      Alternative 8,         Alternative 9,
                                                  likely to be                                consolidated on-        bases in distal         Includes voluntary    except non-            except non-          except all non-     except                 except all
                                                  processed by chat                           site for future         (remote) areas,         relocation            processed              processed chat is    processed           consolidated chat      excavated
                                                  operators. OCC                              processing and          which are very          component to          materials are          disposed of in       materials are       is covered with soil   materials are
                                                  and ODEQ may                                removal. Non-           similar to upland       prevent exposure      excavated and          underground mine     disposed of in      or geo-composite       disposed of in
                                                  reclaim selected                            processed               areas, are              to source             disposed of in         workings.            underground mine    cover systems.         underground
                                                  chat bases with                             materials are           excavated and           materials.            upland                                      workings or                                workings,
                                                  State funding                               covered on-site         hauled to private                             repositories.                               subsidence pits.                           subsidence pits, or
                                                  under Oklahoma                              with vegetated soil     washing operation.                                                                                                                   open mine shafts.
                                                  Plan (if funded).                           covers. Excavated       Any remaining chat
                                                  State of Oklahoma                           areas are               is either injected
                                                  implements                                  reclaimed.              into mine workings,
                                                  subsidence-related                                                  hauled to a
                                                  voluntary                                                           repository, pushed
                                                  relocation but has                                                  in to subsidence
                                                  little impact in                                                    areas, or hauled to
                                                  Upland areas due                                                    a private washing
                                                  to the buyout                                                       operation. All areas
                                                  boundary.                                                           are reclaimed.

    Historic Railroad         Source Material     No Action            Institutional          Same as Alt. 2 plus     Addressed with          Same as               Addressed with         Same as              Same as             Same as                Same as
    Beds and Roads                                                     controls are           soils are deep tilled   chat pile and chat      Alternative 4.        Site affected soils.   Alternative 6.       Alternative 6.      Alternative 6.         Alternative 6.
    (Chat)                                                             implemented to         to reduce metal         base materials at                             Soils are deep
                                                                       require testing and    concentrations and      shared location;                              tilled to reduce
                                                                       remediation prior to   revegetated.            addressed by                                  metal
                                                                       any new residential                            excavation and                                concentrations and
                                                                       development.                                   hauling to a                                  revegetated.
                                                                                                                      repository, pushing
                                                                                                                      into a subsidence
                                                                                                                      feature, hauling to
                                                                                                                      a private washing
                                                                                                                      operation, and
                                                                                                                      injection into
                                                                                                                      underground mine
                                                                                                                      workings. All areas
                                                                                                                      reclaimed with
                                                                                                                      vegetation.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-2.DOC                                                                                              PAGE 5 OF 8                                                                                                               JULY 2007
    TABLE 5-2
    Candidate Remedial Alternative Summary
    Tar Creek Superfund Site
     Source Material           Remedial Action      Alternative 1:      Alternative 2:         Alternative 3:        Alternative 4 (also    Alternative 5 (also     Alternative 6:      Alternative 7:      Alternative 8:       Alternative 9:      Alternative 10:
    or Affected Media            Objectives                                                                           see footnote 1):      see footnotes 1 &                                                Total Source
        Category                                  No Further Action   In-Place Source        Stabilization and            Phased                    2):            Partial Source       Partial Source      Consolidation,      Excavation and      Excavation and
                                                                      Stabilization and        Institutional           Consolidation,                              Consolidation,       Consolidation,     On-Site Disposal,      Disposal in         Disposal in
                                                                        Institutional            Controls            On-Site Disposal           Voluntary           Stabilization,       Stabilization,    and Institutional        Upland           Underground
                                                                          Controls                                    and Institutional        Relocation,        Upland Disposal,      Underground            Controls        Repositories and      Mine Workings
                                                                                                                          Controls               Phased           and Institutional     Mine Disposal,                           Institutional      and Institutional
                                                                                                                                              Consolidation,          Controls         and Institutional                           Controls             Controls
                                                                                                                                             On-Site Disposal,                             Controls
                                                                                                                                             and Institutional
                                                                                                                                                 Controls

    Smelter Wastes,           Source Material     No action.          Smelter wastes are     Smelter wastes are      Smelter wastes are     Same as               Same as             Same as              Same as             Smelter wastes are   Same as
    All Settings                                                      covered in place       consolidated on-        excavated and          Alternative 4.        Alternative 3.      Alternative 3.       Alternative 3.      excavated,           Alternative 9
                                                                      with vegetated soil    site and covered        hauled to a                                                                                               consolidated in      except all
                                                                      covers.                with vegetated soil     repository. All                                                                                           upland deposits      excavated
                                                                                             covers.                 areas are                                                                                                 and covered with     materials are
                                                                                                                     reclaimed.                                                                                                soil or geo-         disposed of in
                                                                                                                                                                                                                               composite cover      underground
                                                                                                                                                                                                                               systems.             workings,
                                                                                                                                                                                                                               Excavated areas      subsidence pits, or
                                                                                                                                                                                                                               are reclaimed.       open mine shafts.

    Buffer Zone Soils –       Soils               No action.          Institutional          Buffer zone soils       Buffer zone soils      Same as               Same as             Same as              Same as             Same as              Same as
    All Settings.                                                     controls are           are deep tilled to      are deep tilled to     Alternative 4.        Alternative 3.      Alternative 3.       Alternative 3.      Alternative 3.       Alternative 3.
                                                                      implemented to         reduce metal            reduce metal
                                                                      require testing and    concentrations and      concentrations and
                                                                      remediation prior to   revegetated.            revegetated.
                                                                      any new residential
                                                                      development on TZ
                                                                      soils.

    Rural Residential         Soils               No action, but      Yards of existing      Same as                 Same as                Same as               Same as             Same as              Same as             Same as              Same as
    Yard Soils                                    remediation of      rural residences       Alternative 2.          Alternative 2.         Alternative 2.        Alternative 2.      Alternative 2.       Alternative 2.      Alternative 2.       Alternative 2.
                                                  urban residential   are tested. Soils
                                                  yards continues     are excavated and
                                                  under OU2.          replaced if COPCs
                                                                      exceed PRGs.

    Smelter-Affected          Soils               No action.          Institutional          Smelter affected        Same as                Same as               Same as             Same as              Same as             Smelter affected     Same as
    Soils                                                             controls are           soils are deep tilled   Alternative 3.         Alternative 3.        Alternative 3.      Alternative 3        Alternative 3.      soils are            Alternative 9
                                                                      implemented to         to reduce metals                                                                                                                  excavated,           except excavated
                                                                      require testing and    concentrations,                                                                                                                   consolidated in      materials are used
                                                                      remediation prior to   amended with                                                                                                                      upland source        as the sub-layers
                                                                      any new residential    organic materials                                                                                                                 material deposits    of cover systems.
                                                                      development on         and revegetated.                                                                                                                  and covered with
                                                                      smelter-affected                                                                                                                                         soil or geo-
                                                                      soils.                                                                                                                                                   composite soil
                                                                                                                                                                                                                               covers.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-2.DOC                                                                                            PAGE 6 OF 8                                                                                                          JULY 2007
    TABLE 5-2
    Candidate Remedial Alternative Summary
    Tar Creek Superfund Site
     Source Material           Remedial Action      Alternative 1:         Alternative 2:         Alternative 3:     Alternative 4 (also     Alternative 5 (also     Alternative 6:        Alternative 7:      Alternative 8:        Alternative 9:    Alternative 10:
    or Affected Media            Objectives                                                                           see footnote 1):       see footnotes 1 &                                                  Total Source
        Category                                  No Further Action      In-Place Source        Stabilization and         Phased                     2):            Partial Source         Partial Source      Consolidation,       Excavation and    Excavation and
                                                                         Stabilization and        Institutional        Consolidation,                               Consolidation,         Consolidation,     On-Site Disposal,       Disposal in       Disposal in
                                                                           Institutional            Controls         On-Site Disposal            Voluntary           Stabilization,         Stabilization,    and Institutional         Upland         Underground
                                                                             Controls                                 and Institutional         Relocation,        Upland Disposal,        Underground            Controls         Repositories and    Mine Workings
                                                                                                                          Controls                Phased           and Institutional       Mine Disposal,                            Institutional    and Institutional
                                                                                                                                               Consolidation,          Controls           and Institutional                            Controls           Controls
                                                                                                                                              On-Site Disposal,                               Controls
                                                                                                                                              and Institutional
                                                                                                                                                  Controls

    Perennial Streams         Source Materials    No action, except      Drainage and           Near-stream          Near-stream             Same as               Near-stream           Same as              Same as              Same as            Same as
    and Major                 RAO                 for surface water      erosion controls       source materials     source materials        Alternative 4.        source materials      Alternative 6.       Alternative 6        Alternative 8      Alternative 9
    Tributaries                                   diversions installed   are used to            subject to stream    subject to stream                             subject to stream                          except that all      except all         except all
                                                  under OU1.             stabilize near-        erosion and          erosion and                                   erosion and                                excavated near-      consolidated       excavated
                                                                         stream source          sources of out-      sources of out-                               sources of out-                            stream materials     source materials   materials are
                                                                         materials. Sources     wash chat and        wash chat and                                 wash chat and                              are disposed of in   are covered with   disposed of in
                                                                         of out-wash chat       tailings are         tailings are                                  tailings are                               underground mine     soil or geo-       underground
                                                                         and tailings are       stabilized or        relocated out of                              excavated and                              workings.            composite soil     workings,
                                                                         stabilized in place.   excavated and        floodway,                                     disposed of in                                                  covers systems.    subsidence pits, or
                                                                                                integrated on-site   integrated with                               upland repositories                                                                open mine shafts.
                                                                                                to reduce surface    original source,                              or underground
                                                                                                water transport.     and addressed by                              mine workings.
                                                                                                                     appropriate
                                                                                                                     remedy.
                                                                                                                     Engineering
                                                                                                                     controls (i.e. sheet
                                                                                                                     piling) used to
                                                                                                                     prevent control
                                                                                                                     seepage. The
                                                                                                                     breached berms of
                                                                                                                     existing deposits
                                                                                                                     are repaired or
                                                                                                                     replaced to
                                                                                                                     minimize source
                                                                                                                     materials from re-
                                                                                                                     entering the
                                                                                                                     streams.

    Source Material in        Source Material     No action.             Not addressed.         Not addressed.       Source materials in     Same as               Not addressed.        Not addressed.       Not addressed.       Not addressed.     Not addressed.
    Stream Beds                                                                                                      stream beds are         Alternative 4.
                                                                                                                     removed and
                                                                                                                     integrated with
                                                                                                                     original source
                                                                                                                     material. Stream
                                                                                                                     bed and banks are
                                                                                                                     reclaimed. Flexible
                                                                                                                     Membrane Liners
                                                                                                                     used as necessary
                                                                                                                     to cover thick
                                                                                                                     deposits to avoid
                                                                                                                     excessive
                                                                                                                     excavation and
                                                                                                                     backfilling in
                                                                                                                     stream beds.



USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-2.DOC                                                                                             PAGE 7 OF 8                                                                                                          JULY 2007
    TABLE 5-2
    Candidate Remedial Alternative Summary
    Tar Creek Superfund Site
     Source Material           Remedial Action      Alternative 1:           Alternative 2:          Alternative 3:    Alternative 4 (also    Alternative 5 (also     Alternative 6:      Alternative 7:      Alternative 8:         Alternative 9:        Alternative 10:
    or Affected Media            Objectives                                                                             see footnote 1):      see footnotes 1 &                                                Total Source
        Category                                  No Further Action        In-Place Source         Stabilization and        Phased                    2):            Partial Source       Partial Source      Consolidation,        Excavation and        Excavation and
                                                                           Stabilization and         Institutional       Consolidation,                              Consolidation,       Consolidation,     On-Site Disposal,        Disposal in           Disposal in
                                                                             Institutional             Controls        On-Site Disposal           Voluntary           Stabilization,       Stabilization,    and Institutional          Upland             Underground
                                                                               Controls                                 and Institutional        Relocation,        Upland Disposal,      Underground            Controls          Repositories and        Mine Workings
                                                                                                                            Controls               Phased           and Institutional     Mine Disposal,                             Institutional        and Institutional
                                                                                                                                                Consolidation,          Controls         and Institutional                             Controls               Controls
                                                                                                                                               On-Site Disposal,                             Controls
                                                                                                                                               and Institutional
                                                                                                                                                   Controls

    Shallow Aquifer           Groundwater         No action, except        Households with         Same as             Same as                Same as               Same as             Same as              Same as               Same as               Same as
    Well Water                                    for monitoring           wells exceeding         Alternative 2.      Alternative 2.         Alternative 2.        Alternative 2.      Alternative 2.       Alternative 2.        Alternative 2.        Alternative 2.
                                                  possibly conducted       primary MCLs are
                                                  by ODEQ or               connected to
                                                  others. State of         existing rural water
                                                  Oklahoma                 districts or
                                                  implements               provided
                                                  subsidence-related       alternative water
                                                  voluntary                supply. Institutional
                                                  relocation but not       controls are
                                                  likely to affect rural   implemented to
                                                  areas of the Site        prohibit new
                                                  due to the buyout        shallow wells in
                                                  boundary.                mining affected
                                                                           areas.

    Notes:
    1. For Alternative 4 and 5 the source materials are classified as chat piles, chat bases, and fine tailings. Within in each source material, there are two settings; near stream and all other settings.
    2. A voluntary relocation component is included with Alternative 5 that is technically applicable to all of the action alternatives. The voluntary relocation would be completed in accordance with URA regulations and addresses residential properties, commercial
        properties, and other various properties in Cardin, Hockerville, and Picher.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-2.DOC                                                                                              PAGE 8 OF 8                                                                                                             JULY 2007
TABLE 5-3
Candidate Remedial Alternatives - Initial Screening Summary
Tar Creek Superfund Site
      Alternative                                                                                                                                                 Retained
                                                      Effectiveness                                            Implementability                     Cost
     Description                                                                                                                                                   Yes/No

Alternative 1: No            •     The volume of chat decreases slowly over time                 •      Chat is currently being processed     Capital Costs:   Yes – The NCP
Further Action                     through ongoing chat processing but with limited                     at the Site.                          Low              requires
                                   impact to human and ecological exposures to COPCs                                                                           detailed
                                                                                                 •      Limited buyout has previously been
                                   since chat piles become chat bases with no effective                                                                        analysis of the
                                                                                                        completed at site.                    O&M Costs:
                                   reduction in area of potential exposure (i.e., footprint                                                                    no action
                                   reduction).                                                   •      Limited pilot studies focusing        Low
                                                                                                                                                               alternative.
                                                                                                        primarily on addressing chat source
                             •     Implementation of the Oklahoma Plan, if fully funded,
                                                                                                        materials have been completed at
                                   provides limited reductions in human health and
                                                                                                        the Site and additional studies can
                                   ecological risks in outlying areas of the Site.
                                                                                                        be implemented in the future if
                             •     Surface water quality improves over an extremely long                warranted.
                                   timeframe through natural attenuation and as a result
                                   of continued chat removal by processing, but ALC
                                   continue to be exceeded due to metal loadings from
                                   underground workings.

                             •     State of Oklahoma’s subsidence-related buyout would
                                   help control or prevent some of the potential for human
                                   exposures to Site contaminants but would not provide
                                   complete control since the source materials still remain
                                   as a source to other humans not included in or
                                   participating in the buyout. Similarly, the source
                                   materials would present a possible exposure to Tribal
                                   members not participating in the buyout.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-3.DOC                                           PAGE 1 OF 9                                                                     JULY 2007
TABLE 5-3
Candidate Remedial Alternatives - Initial Screening Summary
Tar Creek Superfund Site
      Alternative                                                                                                                                                     Retained
                                                      Effectiveness                                              Implementability                       Cost
     Description                                                                                                                                                         Yes/No

                             •     No actions are taken with respect to chat that is not
                                   processed or other source materials such as fine
                                   tailings, chat in historic rail and road beds, and smelter
                                   wastes, affected soils, and rural residential drinking
                                   water, thereby presenting a long-term continuing
                                   source of potential exposure to human and ecological
                                   receptors.

Alternative 2: In-
                             •     Human and ecological exposures to COPCs in chat                 •      Prescribed engineering controls         Capital Costs:   No –
Place Source
                                   decrease slowly over time through ongoing chat                         have been proven implementable          High             Alternative 2 is
Stabilization, and
                                   processing, fines disposal and closure requirements,                   through on-site treatability studies.                    similar in
Institutional Controls
                                   and access controls.                                                                                                            effectiveness

                                                                                                   •      Materials and equipment needed to                        and

                             •     Some source materials closest to residential areas                     construct the engineering controls      O&M Costs:       implementability

                                   may remain indefinitely due to lack of processing, and                 are locally available.                  Low              to other

                                   possible community concerns over chat processing in                                                                             alternatives, but

                                   urbanized areas.                                                                                                                at a greater
                                                                                                   •      The administrative implementabilty
                                                                                                                                                                   cost. Costs to
                                                                                                          of requirements for BMPs, fines
                                                                                                                                                                   implement
                             •     Implementation of the Oklahoma Plan, if fully funded,                  disposal, and closure plans by
                                                                                                                                                                   Alternative 2
                                   provides limited reductions in human health and                        private companies is being
                                                                                                                                                                   would be
                                   ecological risks in outlying areas of the Site.                        evaluated through EPA treatability
                                                                                                                                                                   excessive when
                                                                                                          studies.
                                                                                                                                                                   compared to the
                             •     Soil cover systems reduce potential human and
                                                                                                                                                                   overall
                                   ecological exposures in urban settings. However,                •      Institutional controls have been
                                                                                                                                                                   effectiveness of


USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-3.DOC                                             PAGE 2 OF 9                                                                       JULY 2007
TABLE 5-3
Candidate Remedial Alternatives - Initial Screening Summary
Tar Creek Superfund Site
      Alternative                                                                                                                                                 Retained
                                                      Effectiveness                                              Implementability                   Cost
     Description                                                                                                                                                     Yes/No

                                   institutional controls and access controls are required               successfully implemented in some                      the remedy.
                                   to manage potential residual risks and leave a larger                 areas of the District.
                                   Site footprint of land that is restricted from beneficial
                                   reuse.                                                         •      Funding may limit the
                                                                                                         implementability of the Oklahoma
                             •     Source material RAOs address source material                          Plan.
                                   pathways to surface water through on-going removal
                                   actions, BMPs and near-stream source stabilization
                                   measures, but ALC continue to be exceeded due to
                                   metal loadings from underground workings.


Alternative 3:
                             Same as Alternative 2, except as follows:                            Same as Alternative 2:                      Capital Costs:   No – Alternative
Stabilization, and
                                                                                                                                              High             3 is similar in
Institutional Controls
                              •    Alternative 3 enhances risk reduction effectiveness             •     Several administrative efforts are                    effectiveness

                                   through administrative controls designed to                           ongoing to facilitate increased                       and

                                   encourage selective processing such that materials                    usage of chat in environmentally                      implementability

                                   closest to residential areas and in near-stream areas                 protective and safe ways (See        O&M Costs:       to other

                                   are addressed in advance of others.                                   Section 6 discussion).               Low              alternatives, but
                                                                                                                                                               at a greater
                                                                                                                                                               cost. Costs to
                                                                                                                                                               implement
                                                                                                                                                               Alternative 3
                                                                                                                                                               would be
                                                                                                                                                               excessive when




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-3.DOC                                            PAGE 3 OF 9                                                                    JULY 2007
TABLE 5-3
Candidate Remedial Alternatives - Initial Screening Summary
Tar Creek Superfund Site
      Alternative                                                                                                                                                   Retained
                                                      Effectiveness                                             Implementability                      Cost
     Description                                                                                                                                                     Yes/No

                                                                                                                                                                 compared to the
                                                                                                                                                                 overall
                                                                                                                                                                 effectiveness of
                                                                                                                                                                 the remedy.


Alternative 4:
                              •    Alternative 4 does not rely upon selective chat                Same as Alternative 3, except as              Capital Costs:   Yes –Alternative
Phased
                                   processing, but rather supports ongoing chat                   follows:                                                       4 offers a high
Consolidation, On-
                                   processing through excavation and hauling of chat to                                                         High             cost but
Site Disposal and
                                   existing wash operations.                                      •      Alternative 4 is expected to be                         potentially
Institutional Controls
                                                                                                         more readily implemented given                          effective

                              •    Distal area removal in early phase obtains significant                that an administrative program for                      remedy with

                                   footprint reduction, reduction in potential for exposure,             selective chat processing in certain                    significant

                                   and secondary benefits to the respective watersheds.                  areas of the Site is not required.                      footprint
                                                                                                                                                                 reduction that
                                                                                                                                                O&M Costs:
                                                                                                                                                                 merits detailed
                              •    Beneficial re-use is maximized through excavation                                                            Low
                                                                                                                                                                 analysis.
                                   and hauling of chat to washing operations.


                              •    Substantial reduction in the Site footprint is expected
                                   under this Alternative due to distal area actions and
                                   injection of a significant portion of fine tailings, thereby
                                   allowing greater unrestricted use of land.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-3.DOC                                            PAGE 4 OF 9                                                                       JULY 2007
TABLE 5-3
Candidate Remedial Alternatives - Initial Screening Summary
Tar Creek Superfund Site
      Alternative                                                                                                                                                     Retained
                                                      Effectiveness                                                Implementability                     Cost
     Description                                                                                                                                                         Yes/No

Alternative 5:
                             Same as Alternative 4, except as follows:                             Same as Alternative 4, except as               Capital Costs:   Yes –Alternative
Voluntary Relocation,
                                                                                                   follows:                                                        5 offers a very
Phased
                             •     Potential direct/indirect exposure risks are reduced                                                           Very High        high cost but
Consolidation, On-
                                   partially for the limited group of residents that have          •      The relocation would be                                  potentially
Site Disposal and
                                   entered into the voluntary relocation program and are                  implemented under URA                                    effective
Institutional Controls
                                   accepted. This effect is greater in urban areas with                   regulations; relocation programs                         remedy that

                                   less reduction occurring in remote or distal areas due                 under URA have been successfully                         merits detailed

                                   to limitations of the buyout boundary.                                 implemented at other Superfund                           analysis.

                                                                                                          sites.
                                                                                                                                                  O&M Costs:
                                                                                                                                                  Low



Alternative 6: Partial
                             Same as Alternative 3, except as follows:                             Same as Alternative 3, except as               Capital Costs:   No – Alternative
Source Consolidation,
                                                                                                   follows:                                       High             6 is similar in
Stabilization, Upland
                             •     Human health and ecological risks are further reduced                                                                           effectiveness
Disposal, and
                                   through engineering (partial source consolidation) and          •      Chat processing would require a                          and
Institutional Controls
                                   removal of source materials from urban and near-                       means of motivating owners of chat                       implementability

                                   stream areas.                                                          targeted for processing to sell their   O&M Costs:       to other

                                                                                                          chat.                                   Moderate         alternatives, but
                                                                                                                                                                   at a greater
                             •     Source material and affected soils RAOs are
                                                                                                                                                                   cost. Costs to
                                   effectively met through excavation and disposal of fine         •      Excavation and consolidation of
                                                                                                                                                                   implement
                                   tailings and source consolidation measures performed                   fine tailings is technically
                                                                                                                                                                   Alternative 6
                                   in urban and near-stream settings.                                     challenging due to their high
                                                                                                                                                                   would be


USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-3.DOC                                             PAGE 5 OF 9                                                                        JULY 2007
TABLE 5-3
Candidate Remedial Alternatives - Initial Screening Summary
Tar Creek Superfund Site
      Alternative                                                                                                                                                   Retained
                                                       Effectiveness                                            Implementability                    Cost
     Description                                                                                                                                                       Yes/No

                                                                                                         plasticity. However, excavation of                      excessive when
                             •     Potential residual risks are reliably managed by
                                                                                                         fine tailings has been achieved at                      compared to the
                                   engineering controls plus institutional controls.
                                                                                                         other locations within the District.                    overall
                                                                                                                                                                 effectiveness of
                                                                                                                                                                 the remedy.


Alternative 7: Partial
                             Same as Alternative 3 and 6, except as follows:                      Same as Alternative 3 and 6, except as        Capital Costs:   No – Alternative
Source Consolidation,
                                                                                                  follows:                                      High             7 is similar in
Stabilization,
                             •     Underground injection of source materials as                                                                                  effectiveness
Underground Mine
                                   prescribed under this alternative is deemed a more             •      Source material injection into                          and
Disposal, and
                                   effective and permanent solution.                                     underground mine workings has                           implementability
Institutional Controls
                                                                                                         been demonstrated as                   O&M Costs:       to other

                                                                                                         implementable through pilot studies                     alternatives, but
                             •     Site footprint is expected to be reduced to a greater                                                        Moderate
                                                                                                         performed at the Site.                                  at a greater
                                   extent over Alternative 6 through the injection of
                                                                                                                                                                 cost. Costs to
                                   source materials.
                                                                                                                                                                 implement
                                                                                                                                                                 Alternative 7
                                                                                                                                                                 would be
                                                                                                                                                                 excessive when
                                                                                                                                                                 compared to the
                                                                                                                                                                 overall
                                                                                                                                                                 effectiveness of
                                                                                                                                                                 the remedy.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-3.DOC                                            PAGE 6 OF 9                                                                      JULY 2007
TABLE 5-3
Candidate Remedial Alternatives - Initial Screening Summary
Tar Creek Superfund Site
      Alternative                                                                                                                                                  Retained
                                                     Effectiveness                                            Implementability                     Cost
     Description                                                                                                                                                    Yes/No

Alternative 8: Chat
                             Same as Alternative 6 and 7, except as follows:                    Same as Alternative 6 and 7, except as         Capital Costs:   Yes – The costs
Processing, Total
                                                                                                follows:                                       Very High        and possible
Source Consolidation,
                             •     The timeframe for reducing human exposure may be                                                                             risk and
On-Site Disposal, and
                                   shortened by consolidating urban chat deposits in            •      The administrative feasibility of                        footprint
Institutional Controls
                                   upland, non-residential areas.                                      chat consolidation is uncertain.                         reduction

                                                                                                       Compensation of chat owners             O&M Costs:       benefits of

                                                                                                       would likely be required prior to                        consolidating all
                             •     Reduction in Site footprint is expected to be significant                                                   Moderate to
                                                                                                       consolidation.                          High             urban and near
                                   under this Alternative.
                                                                                                                                                                stream chat
                                                                                                                                                                warrant more
                                                                                                •      Double-handling of material is likely
                                                                                                                                                                detailed
                                                                                                       under the proposed approach.
                                                                                                                                                                evaluation for
                                                                                                                                                                and comparison
                                                                                                                                                                with removal by
                                                                                                                                                                private
                                                                                                                                                                companies.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-3.DOC                                          PAGE 7 OF 9                                                                        JULY 2007
TABLE 5-3
Candidate Remedial Alternatives - Initial Screening Summary
Tar Creek Superfund Site
      Alternative                                                                                                                                                    Retained
                                                      Effectiveness                                           Implementability                       Cost
     Description                                                                                                                                                        Yes/No

Alternative 9:
                             Same as Alternatives 7, except as follows:                          Same as Alternative 6, except as               Capital Costs:    No – Alternative
Excavation and
                                                                                                 follows:                                       Very High         9 is similar in
Disposal in Upland
                             •     The timeframe for completion of the remedy is reduced                                                                          effectiveness
Repositories and
                                   when compared with removal by private companies;              •      Implementation of this alternative is                     and
Institutional Controls
                                                                                                        problematic because chat is viewed                        implementability

                                                                                                        as a valuable natural resource and                        to other
                             •     Alternative 9 meets all source material and affected                                                         O&M Costs:
                                                                                                        its excavation and disposal would       Initially high,   alternatives, but
                                   soils RAOs but is no more protective than Alternatives
                                                                                                        be viewed negatively by land and        but low to        at a greater
                                   4 and 5 in this regard.
                                                                                                        chat owners.                            moderate          cost. Costs to

                                                                                                                                                after remedial    implement
                             •     Reliance on institutional controls to manage potential
                                                                                                                                                vegetation        Alternative 9
                                   residual risks is limited to the repository sites.
                                                                                                                                                matures.          would be
                                   Reduction in Site footprint is expected to be significant.
                                                                                                                                                                  excessive when
                                                                                                                                                                  compared to the
                             •     Beneficial re-use of chat is not considered.
                                                                                                                                                                  overall
                                                                                                                                                                  effectiveness of
                                                                                                                                                                  the remedy.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-3.DOC                                           PAGE 8 OF 9                                                                        JULY 2007
TABLE 5-3
Candidate Remedial Alternatives - Initial Screening Summary
Tar Creek Superfund Site
      Alternative                                                                                                                                             Retained
                                                     Effectiveness                                            Implementability                Cost
     Description                                                                                                                                                 Yes/No

Alternative 10:
                             Same as Alternative 9, except as follows:                        Same as Alternative 9, except as           Capital Costs:    No – Alternative
Excavation and
                                                                                              follows:                                   Very High         10 is similar in
Disposal in
                             •     The permanence and reliability of disposal sites may                                                                    effectiveness
Underground Mine
                                   be somewhat enhanced by placing the materials              •      Disposal of source materials in                       and
Workings and
                                   underground.                                                      underground workings and                              implementability
Institutional Controls
                                                                                                     subsidence pits has proven          O&M Costs:        to other

                                                                                                     implementable through field scale                     alternatives, but
                             •     Reliance on institutional controls to manage potential                                                Initially high,
                                                                                                     pilot demonstrations in the Tar     but moderate      at a greater
                                   residual risks is further reduced by disposing of
                                                                                                     Creek, Jasper County, and Galena    after remedial    cost. Costs to
                                   materials in the underground mine workings.
                                                                                                     Sites.                              vegetation        implement

                                                                                                                                         matures.          Alternative 10
                                                                                                                                                           would be
                                                                                                                                                           excessive when
                                                                                                                                                           compared to the
                                                                                                                                                           overall
                                                                                                                                                           effectiveness of
                                                                                                                                                           the remedy.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE5-3.DOC                                        PAGE 9 OF 9                                                                    JULY 2007
 TABLE 6-1
 Alternative 1 Remedial Action Summary
 Tar Creek Superfund Site
     Source Material or                                                 Alternative 1 Remedial Actions                                       Estimated Volume or
     Affected Medium                                                                                                                           Area Addressed
                                                                               No Further Action
          Category

 Urban Chat, Chat Bases,           1. Chat processing and sales by private companies continue, as currently. Under current conditions,       11,476,000 Cubic
 and Fine Tailings                      private companies generally avoid processing chat in dense urban areas.                              Yards.
                                   2. As part of the Oklahoma Plan (if funding is made available), mine and mill waste impacted lands west
                                                                                                                                             <10 Acres.
                                        and south of Commerce are to be remediated.
                                   3. State of Oklahoma implements subsidence-related buyout.

 Near-Stream Chat, Chat            1. Chat processing and sales by private companies continue, as currently.                                 5,320,000 Cubic
 Bases, and Fine Tailings          2. As part of the Oklahoma Plan (if funding is made available), several mine and mill waste impacted      Yards,
                                        sites along perimeter area streams are to be remediated.
                                                                                                                                             <10 Acres.
                                   3. State of Oklahoma implements subsidence-related buyout.
 Upland Chat, Chat                 1. Chat processing and sales by private companies continue, as currently.                                 12,435,000
 Bases, and Fine Tailings          2. As part of the Oklahoma Plan (if funding is made available), mine and mill waste impacted lands in
                                                                                                                                             Cubic Yards.
                                        the perimeter areas of the Site are to be remediated.
                                   3. Region 6 EPA continues treatability studies to evaluate underground disposal options.                  <10 Acres.

 Historic Railroad Grades
                                   No action                                                                                                 None
 and Haul Roads

 Smelter Wastes                    No action                                                                                                 None

 General Affected Soils –          1. As part of the Oklahoma Plan (if funding is made available), some mill waste impacted lands in the     Unknown
 All Settings                           perimeter areas of the Site are to be remediated.
                                   2. State of Oklahoma implements subsidence-related buyout.
 Rural Residential Yards           1. Yard soil remediation actions continue under OU2 in urban areas and some rural areas.                  Unknown




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE6-1_ALT1.DOC                                   PAGE 1 OF 2                                                             JULY 2007
 TABLE 6-1
 Alternative 1 Remedial Action Summary
 Tar Creek Superfund Site
       Source Material or                                              Alternative 1 Remedial Actions                                       Estimated Volume or
       Affected Medium                                                                                                                        Area Addressed
                                                                                No Further Action
           Category

 Smelter-Affected Soils            No action.                                                                                               None

 Storm Runoff and                  No action.                                                                                               None
 Seepage

 Shallow Aquifer Well              1. Provide protection of drinking water wells completed in the shallow aquifer.                          Unknown
 Water                             2. State of Oklahoma implements subsidence-related buyout.

 Air                               1. Under the Oklahoma Plan (if funding is made available), chat and gravel roads at the Site are to be   Unknown
                                        paved to reduce dust generation.
                                   2. Under the Oklahoma Plan (if funding is made available), targeted air quality monitoring will be
                                        conducted for Oklahoma Plan projects.
                                   3. Under EPA funding, the Quapaw Tribe is conducting ambient and source air quality monitoring at the
                                        Site.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE6-1_ALT1.DOC                                   PAGE 2 OF 2                                                       JULY 2007
 TABLE 6-2
 Source Materials and Affected Media Categories for Tar Creek OU4
 Alternatives 4 and 5
 Tar Creek Superfund Site
   Material                  Near Stream                  All Other Settings                       Total
        Type

                   Volume             Area (Acres)   Volume            Area (Acres)   Volume         Area (Acres)
                   (Cubic                            (Cubic Yards)                    (Cubic
                   Yards)                                                             Yards)

 Chat Piles        6,104,000          131            25,096,000        636            31,200,000     767

 Chat Bases        995,000            308            5,714,000         1,771          6,709,000      2,079

 Fine              660,000            77             8,496,000         743            9,156,000      820
 Tailings

 Rail/Road         0                  0              702,000           552            702,000        552
 Beds

 Smelter           0                  0              1,846             2              1,846          2
 Waste

 Smelter-          0                  0              0                 12             0              12
 Affected
 Soils

 Residential       None                              5 Households                     5 Households
 Yards

 Storm             Quantity Estimates Not Available
 Runoff and
 Seepage
 (All
 Settings)

 Affected          None               None           2 Households                     2 Households
 Shallow
 Aquifer Well
 Water




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE6-2.DOC          PAGE 1 OF 1                                         JULY 2007
 TABLE 6-3
 Alternative 4 and 5 Remedial Action Summary
 Tar Creek Superfund Site
 Source Material                                                  Alternative 4 and 5 Remedial Actions                                        Estimated Volume
    or Affected                                                                                                                               or Area Addressed
                                                    Phased Consolidation, On-Site Disposal and Institutional Controls
      Medium
      Category

 Phase 1 Actions (years 1 through 10)

 Distal Area Chat        1.    Distal chat found in piles and bases is excavated and hauled to and released at a commercial chat processing   6,159,000 Cubic
                                                                                                                                              Yards
                               operation.

                         2.    Excavated areas and surrounding 50-foot buffer zone is reclaimed using deep tilling, addition of amendments,   1,112 Acres

                               and revegetated.

 Smelter Wastes          1.    Smelter waste is excavated and hauled to local repository.                                                     1,846 Cubic Yards
 and Affected
                         2.    Smelter-affected soils and the area excavated are deep tilled to reduce metal concentrations in the upper      14 Acres
 Soils
                               layers, amended with biosolids or other organic matter, and revegetated with Site-appropriate species.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE6-3_ALT4 AND ALT5.DOC                         PAGE 1 OF 4                                                           JULY 2007
 TABLE 6-3
 Alternative 4 and 5 Remedial Action Summary
 Tar Creek Superfund Site
 Source Material                                                  Alternative 4 and 5 Remedial Actions                                        Estimated Volume
     or Affected                                                                                                                              or Area Addressed
                                                    Phased Consolidation, On-Site Disposal and Institutional Controls
      Medium
      Category

 Fine Tailings           1.    Complete Hydrogeologic Study to assess hydrogeologic system and potential impacts that could result from       Injection:
                               injection.
                                                                                                                                              61 Fine Tailing
                         2.    Inject fine tailings at 61 ponds into underground mine workings. Injection volume includes 10% of new washed   Ponds
                               fines generated by commercial chat processors.
                                                                                                                                              5,041,000 Cubic
                                                                                                                                              Yards
                         3.    Cover 2 fine tailing ponds based upon large surface area to volume ratio (i.e., thick deposits).

                         4.    Excavated areas and surrounding 50-foot buffer zone soil is reclaimed using deep tilling, addition of          831 Acres
                               amendments, and revegetated.
                                                                                                                                              Covering:

                                                                                                                                              2 Fine Tailing Ponds

                                                                                                                                              4,437,000 Cubic
                                                                                                                                              Yards

                                                                                                                                              275 Acres




 Near Stream             1.    Integrate source materials in floodway and near stream environment into original source pile, base, or pond.   1,254,000 Cubic
                                                                                                                                              Yards
 Source Materials
                         2.    Control erosion, runoff, and seepage through engineering controls and best management practices
 (Seepage/Runoff                                                                                                                              581 Acres
                         3.    Revegetate stream banks and disturbed areas.
 )




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE6-3_ALT4 AND ALT5.DOC                          PAGE 2 OF 4                                                              JULY 2007
 TABLE 6-3
 Alternative 4 and 5 Remedial Action Summary
 Tar Creek Superfund Site
 Source Material                                                  Alternative 4 and 5 Remedial Actions                                              Estimated Volume
    or Affected                                                                                                                                     or Area Addressed
                                                    Phased Consolidation, On-Site Disposal and Institutional Controls
      Medium
      Category

 In-Stream Source        1.    Excavate source materials in Site creek/stream beds or waterways.                                                    18,000 Cubic Yards
 Materials
                         2.    Thick deposits of source materials in streams will be excavated to a depth of 2 feet followed by installation of a   35 Acres
                               Flexible Membrane Liner (FML) and a filter blanket to cover source materials.

 Shallow Aquifer         1.    Households with wells exceeding the primary MCLs are connected to existing rural water districts.                    2 Households
 Well Water
                         2.    Institutional controls are implemented to prohibit the construction of new shallow aquifer wells for domestic
                               water supplies.

 Rural Residential       1.    Rural residential yards are addressed as part of an early response action.                                           5 Yards
 Yards
                         2.    Yards of existing residences outside urbanized areas that were not remediated under OU2 are remediated if
                               COPC concentrations exceed PRGs.

                         3.    Remedial actions consist of excavation of affected soils and replacement with clean soils.

                         4.    Excavated soils are disposed of in a local repository.

 Construct On-           1.    An on-site 28 acre repository is constructed in an area already contaminated and is used for the disposal of         1 Repository
 Site Repository               Site source materials. Capacity is approximately 1,000,000 cubic yards.
                                                                                                                                                    1,000,000 Cubic
                                                                                                                                                    Yard Capacity

 Phase 2 Actions (years 11 through 20 for Alternative 4, years 21 through 30 for Alternative 5)




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE6-3_ALT4 AND ALT5.DOC                           PAGE 3 OF 4                                                                JULY 2007
 TABLE 6-3
 Alternative 4 and 5 Remedial Action Summary
 Tar Creek Superfund Site
 Source Material                                                  Alternative 4 and 5 Remedial Actions                                        Estimated Volume
    or Affected                                                                                                                               or Area Addressed
                                                    Phased Consolidation, On-Site Disposal and Institutional Controls
      Medium
      Category

 Non-Processed           1.    Excavate and haul 75% of non-processed chat and release at commercial chat processing operation.               1) 7,035,000 Cubic
                                                                                                                                                 Yards
 Chat (includes
                         2.    Excavate and haul 10% of non-processed chat and dispose in the on-site repository
 chat found in                                                                                                                                2,552 Acres
                         3.    Push 10% of non-processed chat into subsidence features and cover feature
 historic railroad
                         4.    Inject 5% of non-processed chat into underground mine workings.                                                2) 938,000 Cubic
 grades and haul
                                                                                                                                                  Yards
 roads)
                         5.    Excavated areas and surrounding 50-foot buffer zone is reclaimed using deep tilling, addition of amendments,
                                                                                                                                              340 Acres
                               and revegetated.
                                                                                                                                              3) Same as 2 above

                                                                                                                                              4) 469,000 Cubic
                                                                                                                                                  Yards

                                                                                                                                              171 Acres




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE6-3_ALT4 AND ALT5.DOC                         PAGE 4 OF 4                                                           JULY 2007
 TABLE 6-4
 Alternative 8 Remedial Action Summary
 Tar Creek Superfund Site
    Source Material or                                                     Alternative 8 Remedial Actions                                        Estimated Volume
     Affected Medium                                                                                                                             or Area Addressed
                                                       Total Source Consolidation, On-Site Disposal and Institutional Controls
          Category



 Urban Chat and Urban            1.    All urban chat and urban chat bases are excavated and consolidated in existing upland deposits for       12,796,000 Cubic
 Chat Bases                            future processing and removal by private companies.                                                      Yards
                                 2.    Excavated areas and 50-foot buffer zone soils are deep tilled, amended with biosolids or other organic
                                       matter and revegetated.                                                                                  913 Acres

 Near-Stream Chat and            1.    Chat deposits and chat bases located in floodways or that are subject to surface water erosion,          7,300,000 Cubic
 Chat Bases                            seepage, and out-washing are excavated and consolidated into existing upland chat deposits for future    Yards,
                                       processing and removal by private companies.
                                 2.    Excavated areas and 50-foot buffer zone soils are deep tilled, amended with biosolids or other organic   724 Acres

                                       matter and revegetated.

 Upland Chat and Chat            1.    Existing upland chat bases are excavated and consolidated on-site for future processing by private       Consolidated:
 Bases                                 companies.                                                                                               4,170,000 Cubic
                                 2.    Non-processed chat is disposed of in subsidence pits that are then covered and revegetated, or           Yards
                                       injected into underground mine workings.
                                 3.    Excavated areas and 50-foot buffer zone soils are deep tilled, amended with biosolids or other organic   Subsidence Infill:

                                       matter and revegetated.                                                                                  4,690,000 Cubic
                                                                                                                                                Yards

                                                                                                                                                Injection: 4,690,000
                                                                                                                                                Cubic Yards

                                                                                                                                                2,325 Total Acres




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE6-4_ALT8.DOC                                     PAGE 1 OF 3                                                             JULY 2007
 TABLE 6-4
 Alternative 8 Remedial Action Summary
 Tar Creek Superfund Site
    Source Material or                                                     Alternative 8 Remedial Actions                                        Estimated Volume
     Affected Medium                                                                                                                            or Area Addressed
                                                       Total Source Consolidation, On-Site Disposal and Institutional Controls
          Category



 Historic Railroad               1.    Existing chat from historic railroad grades and haul roads is excavated and consolidated in existing     702,000 Cubic Yards
 Grades and Haul Roads                 upland deposits for future processing and removal by private companies.
                                 2.    Excavated areas and 50-foot buffer zone soils are deep tilled, amended with biosolids or other organic   552 acres

                                       matter and revegetated.

 Urban Fine Tailings             1.    Existing urban fine tailings deposits are excavated and disposed of in underground mine workings.        344,000 Cubic Yards
                                 2.    Excavated areas and 50-foot buffer zone soils are deep tilled, amended with biosolids or other organic
                                       matter and revegetated.                                                                                  61 Acres

 Near-Stream Fine                1.    Existing fine tailings located in floodways or that are subject to surface water erosion, seepage, and   1,654,000 Cubic
                                       out-washing are excavated and injected into underground mine workings.
 Tailings                                                                                                                                       Yards
                                 2.    Excavated areas and 50-foot buffer zone soils are deep tilled, amended with biosolids or other organic
                                       matter and revegetated.                                                                                  195 Acres

 Upland Fine Tailings            1.    Breached dikes around existing fine tailings deposits in upland settings are replaced or repaired.       7,158,000 Cubic
                                 2.    Existing tailings impoundments are then covered with simple soil covers and revegetated. 10% of new      Yards
                                       washed fines generated by commercial chat processors will also be covered (no increase to surface
                                                                                                                                                631 Acres In-Place
                                       area covered).
                                 3.    50-foot buffer zone soils are deep tilled, amended with biosolids or other organic matter and            220 Acres Buffer
                                       revegetated.                                                                                             Zone

 Smelter Wastes                  1.    Smelter wastes are consolidated on-site and covered with vegetated soil covers or excavated and          1,846 Cubic Yards

                                       disposed of in nearby subsidence pits. Covered areas are protected by institutional controls.            2 Acres Covered




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE6-4_ALT8.DOC                                     PAGE 2 OF 3                                                           JULY 2007
 TABLE 6-4
 Alternative 8 Remedial Action Summary
 Tar Creek Superfund Site
    Source Material or                                                     Alternative 8 Remedial Actions                                         Estimated Volume
     Affected Medium                                                                                                                             or Area Addressed
                                                       Total Source Consolidation, On-Site Disposal and Institutional Controls
          Category



 Rural Residential Yards         1.    Yards of existing residences outside urbanized areas that were not remediated under OU2 are               5 Yards
                                       remediated if COPC concentrations exceed PRGs. Remedial actions consist of excavation of affected
                                       soils and replacement with clean soils.

 Smelter-Affected Soils          1.    Smelter-affected soils are deep tilled to reduce metal concentrations in the upper layers, amended with   14 Acres
                                       biosolids or other organic matter, and revegetated with Site-appropriate species.

 Storm Runoff and                1.    Source material actions aimed at protecting human health are also designed to reduce the volume and       Not measured
 Seepage                               improve the quality of runoff and seepage entering Site surface water bodies by removing or stabilizing
                                       the loading sources in place.

 Shallow Aquifer Well            1.    Households with wells exceeding the primary MCLs are connected to existing rural water districts.         2 Households
 Water                           2.    Institutional controls are implemented to prohibit the construction of new shallow aquifer wells for
                                       domestic water supplies.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE6-4_ALT8.DOC                                     PAGE 3 OF 3                                                            JULY 2007
  TABLE 7-1
  Potential Federal and State Chemical-Specific ARARs and Guidance to be Considered
  Tar Creek Superfund Site
    Standard, Requirement,                         Citation                                         Description                   Potential     To Be
              Criteria,                                                                                                               ARARs   Considered

           or Limitation

  AIR

  FEDERAL REQUIREMENTS

  Clean Air Act – National              42 USC Secs. 7401 – 7671      The Clean Air Act and implementing regulations define air   X
  Primary and Secondary                                               quality criteria for protecting human health, including
                                        40 CFR Part 50
  Ambient Air Quality                                                 standards for particulate matter and lead.
  Standards

  STATE REQUIREMENTS

  Oklahoma Air Pollution                252 OAC 100                   Set ambient air quality standards for a variety of          X
  Control Act                                                         constituents, including particulate matter and lead.

  GROUNDWATER

  FEDERAL REQUIREMENTS

  Federal Safe Drinking Water           40 CFR Parts 141 and 143      Establishes primary maximum contaminant levels (MCLs)       X
  Act – National Primary and                                          and MCL goals (MCLGs) that are health-based standards
  Secondary Standards                                                 for public drinking water systems, as well as secondary
                                                                      MCLs and MCLGs that are standards for constituents that
                                                                      affect only the aesthetic qualities of drinking water.
                                                                      According to the NCP, MCLs and MCLGs are ARARs for
                                                                      groundwater at Superfund sites.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-1.DOC                                       PAGE 1 OF 2                                                   JULY 2007
  TABLE 7-1
  Potential Federal and State Chemical-Specific ARARs and Guidance to be Considered
  Tar Creek Superfund Site
    Standard, Requirement,                         Citation                                         Description                       Potential       To Be
                Criteria,                                                                                                                 ARARs   Considered

           or Limitation

  STATE REQUIREMENTS

  Oklahoma Water Supply                 27A O.S., Sects. 2-6-301 et   Oklahoma has adopted the Federal Primary and Secondary          X
  Systems Act – Public Water            seq.                          MCLs and MCLGs promulgated under 40 CFR Parts 141
  Supply Operations                                                   and 143, respectively and incorporated them by reference in
                                        252 OAC, Chapter 631
                                                                      their entirety under 252 OAC 631-1-3.

  SOURCE MATERIALS AND SOILS

  Revised Interim Soil Lead             OSWER Directive No. 9355.4-   Recommends a screening level of 400 ppm for lead in                         X
  Guidance for CERCLA Sites             12. July 14, 1994             residential soils. Describes a methodology for developing
  and RCRA Corrective Action                                          site-specific preliminary remediation goals and media
  Facilities.                                                         cleanup standards. Describes a plan for soil lead cleanup
                                                                      at sites with multiple sources of lead. In general, human
                                                                      exposure in OU4 is expected to be minimal. Nevertheless,
                                                                      this directive provides guidance for evaluating the extent to
                                                                      which proposed remedial actions might enhance protection
                                                                      of human health.

  Draft Soil Screening                  OSWER Directive 9355.4-       Recommends the development of site-specific soil                            X
  Guidance                              14FS, December 1994           screening levels. Provides general screening levels below
                                                                      which areas are determined to be adequate and do not
                                        EPA/540/R-94/101 and 106
                                                                      need further assessment. Further evaluation of risks is
                                                                      recommended for areas above the screening levels.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-1.DOC                                       PAGE 2 OF 2                                                        JULY 2007
 TABLE 7-2
 Potential Federal and State Action-Specific ARARs and Guidance to be Considered
 Tar Creek Superfund Site
       Standard, Requirement,                           Citation                                         Description                           Potential         To Be
                 Criteria,                                                                                                                     ARARs           Considered

              or Limitation

 FEDERAL ARARs

 National Ambient Air Quality                 42 USC Sec. 7401 et seq.      These regulations establish ambient air quality standards          X
 Standards (NAAQS)                                                          for emissions of lead and particulate matter. Remedial
                                              40 CFR Part 250
                                                                            actions taken under any of the alternatives (except no
                                                                            action) are likely to result in release of airborne lead and
                                                                            dust. These regulations are applicable to “major sources”
                                                                            as defined under the Clean Air Act. Although remedial
                                                                            actions at the Site are not expected to result in major
                                                                            emission sources, these regulations would be relevant
                                                                            and appropriate.

 Resource Conservation and                    42 USC Sec. 6941              This section of the RCRA regulations requires the closure of       X
 Recovery Act (RCRA), Subtitle D,                                           existing solid waste facilities, design of new landfills, and
                                              40 CFR Part 257, Criteria
 Solid Waste Regulations                                                    disposal of solid wastes to be in accordance with numerous
                                              for Classification of Solid
                                                                            standards and criteria. These standards are applicable to solid
                                              Waste Disposal Facilities
                                                                            waste disposal facilities, including mining and mill waste
                                              and Practices
                                                                            facilities. Among other things, these regulations require that
                                                                            facilities be maintained to prevent wash out of solid wastes and
                                                                            that the public not be allowed uncontrolled access.

 Toxic Substances Control Act –               EPA, February 21, 1991.       This document presents strategies for reducing lead exposures                  X
 Strategies for Reducing Lead                                               by reducing the amount of lead in the environment, as well as
 Exposures                                                                  reducing blood lead levels, especially in children.



USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-2.DOC                                           PAGE 1 OF 11                                                                JULY 2007
 TABLE 7-2
 Potential Federal and State Action-Specific ARARs and Guidance to be Considered
 Tar Creek Superfund Site
       Standard, Requirement,                          Citation                                   Description                       Potential     To Be
                 Criteria,                                                                                                          ARARs       Considered

              or Limitation

 Surface Mining Control and                   30 USC Secs. 1201-1328   SMCRA regulations govern coal exploration and active         X
 Reclamation Act (SMCRA)                                               coal mining. Hence, these regulations are not applicable
                                              30 CFR Part 816
                                                                       to remedial actions taken under OU4 of the Tar Creek
                                                                       Site. Nevertheless, some of the surface mining standards
                                                                       found in 30 CFR Part 816 are relevant and appropriate
                                                                       requirements because the address circumstances that are
                                                                       similar to those found at the Tar Creek Site. The relevant
                                                                       and appropriate requirements include Part 816.45,
                                                                       Sediment Control Measures; Part 816.46, Siltation
                                                                       Structures; Part 816.102, Grading Requirements; and Part
                                                                       816. 111, Revegetation.

 DOT Hazardous Materials                      49 CFR Parts 107, 171-   This section regulates transportation of hazardous           X
 Transportation Regulations                   177                      materials and would be relevant and appropriate for the
                                                                       transport of excavated materials within the Site.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-2.DOC                                    PAGE 2 OF 11                                                        JULY 2007
 TABLE 7-2
 Potential Federal and State Action-Specific ARARs and Guidance to be Considered
 Tar Creek Superfund Site
       Standard, Requirement,                          Citation                                       Description                        Potential     To Be
                 Criteria,                                                                                                               ARARs       Considered

              or Limitation

 Federal Clean Water Act - Dredge             33 USC Sec. 1344 (1988)     Section 404 of the CWA broadly regulates discharge of          X
 or Fill Requirements (Section 404                                        dredged or fill material into navigable waters. This Section
                                              33 CFR Parts 320–330
 of the CWA)                                                              generally that a permit be obtained from the U.S. Army
                                              Corps Regulations
                                                                          Corps of Engineers for discharge of fill materials in to
                                              40 CFR Parts 230 et seq.    most water bodies. However, nation-wide permits exist for
                                                                          35 categories of activities, including some mining
                                                                          activities. A nation-wide permit also exists for activities
                                                                          associated with cleanup of hazardous or toxic wastes.

 Federal Clean Water Act -                    33 USC Sec. 1342 (1988)     The NPDES is a comprehensive system of laws and                X
 Effluent Discharge Standards                                             regulations governing and setting standards for the
 (Section 402 of the CWA)                                                 discharge of a wide variety of pollutants to waters of the
                                              40 CFR Part 122, 124, and   U.S. The NPDES contains provisions for regulating and
                                              125                         permitting point discharges and setting technology-based
                                                                          and water quality-based standards for water bodies. The
                                              The National Pollutant
                                                                          Federal NPDES are not the applicable regulations for the
                                              Discharge Elimination
                                                                          Tar Creek Site because Oklahoma has implemented its
                                              System (NPDES)
                                                                          own program called the Oklahoma Pollutant Discharge
                                                                          Elimination System (OPDES). Surface water as a media
                                                                          of concern is not directly considered in OU4. However,
                                                                          The Federal regulations may be relevant or appropriate as
                                                                          pertains to the pathway from source materials to surface
                                                                          water within the scope of OU4.



USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-2.DOC                                        PAGE 3 OF 11                                                         JULY 2007
 TABLE 7-2
 Potential Federal and State Action-Specific ARARs and Guidance to be Considered
 Tar Creek Superfund Site
       Standard, Requirement,                          Citation                                     Description                             Potential     To Be
                 Criteria,                                                                                                                  ARARs       Considered

              or Limitation

 Federal Clean Water Act –                    33 USC Sec. 1342(l)(2)   These rules were established specifically for discharges of          X
 Discharges Composed Entirely of                                       waters composed entirely of storm water from industrial
 Storm Water                                                           facilities, including most mining facilities, that are not already
                                              40 CFR Sec. 122. 26      the subject of an NPDES permit. The Federal Storm Water
                                                                       regulations include requirements for obtaining storm water
                                                                       permits, implementing best management practices (BMPs) and
                                                                       developing pollution prevention plans (PPPs) at industrial
                                                                       facilities and construction sites. Industrial activity includes
                                                                       active and inactive mining areas. However, under this section,
                                                                       individual permits may not be required because Oklahoma’s
                                                                       implementing program has developed multi-sector and
                                                                       construction site general permits for which dischargers may
                                                                       apply. Oklahoma’s storm water program would be applicable to
                                                                       the Tar Creek Site, but the Federal regulations may be relevant
                                                                       or appropriate for reducing the loading from the source
                                                                       materials to surrounding soils and surface waters through the
                                                                       implementation of stormwater controls and BMPs.

 Federal Uniform Relocation                   42 CFR Part 61           Specific procedures must be followed for relocation projects.        X
 Assistance and Real Property
 Acquisition Policies Act of 1970




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-2.DOC                                      PAGE 4 OF 11                                                              JULY 2007
 TABLE 7-2
 Potential Federal and State Action-Specific ARARs and Guidance to be Considered
 Tar Creek Superfund Site
       Standard, Requirement,                            Citation                                      Description                          Potential         To Be
                 Criteria,                                                                                                                  ARARs           Considered

              or Limitation

 Interim Policy on the Use of                 OSWER Directive 9355.0-    Provides guidance on how to evaluate relocations, including                    X
 Permanent Relocations as Part of             71P, June 1999             Native American considerations.
 Superfund Remedial Actions



 STATE REQUIREMENTS

 Safe Drinking Water Act –                    42 USC Secs. 300f – 300j   The Federal Underground Injection Control (UIC) program            X
 Underground Injection Control                                           consists of sections of the Safe Drinking Water Act aimed
                                              40 CFR Part 144 – 148
 Program                                                                 specifically at protecting groundwater supplies from disposal of
                                                                         wastes in underground injection wells. Of particular importance
                                                                         to the Tar Creek Site are provisions defining Class V injection
                                                                         wells that include wells used to backfill tailings or sand into
                                                                         underground mine workings. Such wells are generally exempt
                                                                         from the permitting requirements of the UIC.

 Oklahoma Air Pollution Control               27A of the Oklahoma        The Oklahoma fugitive particulate matter regulations               X
 Act                                          Statutes                   contain restrictions on the release of particulate matter to
                                                                         ambient air. These regulations are applicable to any dust
                                              Title 252 OAC, Chapter
                                                                         emissions that occur as a result of remedial actions taken
                                              100
                                                                         at the Site.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-2.DOC                                         PAGE 5 OF 11                                                               JULY 2007
 TABLE 7-2
 Potential Federal and State Action-Specific ARARs and Guidance to be Considered
 Tar Creek Superfund Site
       Standard, Requirement,                           Citation                                      Description                            Potential     To Be
                 Criteria,                                                                                                                   ARARs       Considered

              or Limitation

 Oklahoma Pollutant Discharge                 27A O.S. Sections 2-6-201   The OPDES regulates the discharge of constituents from any         X
 Elimination System (OPDES)                   et seq.                     point source, including storm water, into waters of the State.
                                                                          This comprehensive system of regulations provides for the
                                                                          maintenance and protection of public health and aquatic life
                                              Title 252 OAC, Chapter      uses of surface waters. Among other things, the OPDES
                                              606                         requires permits for discharges from point sources of water
                                                                          contamination. Although permits are not required for remedial
                                                                          actions conducted under CERCLA, these regulations may be
                                                                          relevant and appropriate to corrective actions taken at the Site
                                                                          for reducing the loading from the source materials to
                                                                          surrounding soils and surface waters through the
                                                                          implementation of stormwater controls and BMPs. Also,
                                                                          Oklahoma has developed general wastewater permits for certain
                                                                          industry sectors, including General Permit OKG 950000, which
                                                                          covers sand and gravel quarries. The provisions of these general
                                                                          permits may be relevant and appropriate for actions taken at the
                                                                          Site. Other parts of the OPDES may be applicable requirements
                                                                          for the Site, but much of the Oklahoma regulations have
                                                                          incorporated by reference the Federal regulations under 40 CFR
                                                                          Parts 122, 124,125, and 503.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-2.DOC                                        PAGE 6 OF 11                                                             JULY 2007
 TABLE 7-2
 Potential Federal and State Action-Specific ARARs and Guidance to be Considered
 Tar Creek Superfund Site
       Standard, Requirement,                          Citation                                        Description                         Potential     To Be
                 Criteria,                                                                                                                 ARARs       Considered

              or Limitation

 Oklahoma Industrial Wastewater               Title 27A, Sections 2-6-101   This Chapter of the OAC establishes requirements for           X
 Systems Management Act                       through 2-6-106 and 2-6-      industrial surface impoundments, industrial tank systems
                                              501                           and land application of industrial sludge and wastewater,
                                                                            excluding any regulated hazardous wastes. These
                                                                            regulations may be ARARs at the Site for certain activities
                                              Title 252 OAC, Chapter        conducted by chat washing and hauling operations.
                                              616

 Oklahoma Storm Water                         Title 252 OAC, Chapter        The OPDES contains separate permitting requirements            X
 Regulations                                  606                           for discharges comprised entirely of storm water. Storm
                                                                            water discharge permits are required for point source
                                                                            discharges from industrial facilities, including metal and
                                                                            non-metal mining facilities and construction sites that are
                                                                            not already covered under an OPDES permit. However,
                                                                            individual permits may not be required because Oklahoma
                                                                            has established a multi-sector general permit and a
                                                                            general permit for construction sites that may be
                                                                            applicable. Furthermore, permits would not be required for
                                                                            actions taken under CERCLA, although the substantive
                                                                            provisions of these regulations would be applicable. The
                                                                            regulations also require development and implementation
                                                                            of PPPs and BMPs to prevent or reduce the discharge of
                                                                            pollutants in runoff from industrial and construction sites.



USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-2.DOC                                         PAGE 7 OF 11                                                          JULY 2007
 TABLE 7-2
 Potential Federal and State Action-Specific ARARs and Guidance to be Considered
 Tar Creek Superfund Site
       Standard, Requirement,                          Citation                                    Description                         Potential     To Be
                 Criteria,                                                                                                             ARARs       Considered

              or Limitation

 Land Application of Biosolids                Title 252 OAC, Chapter    In addition to the OPDES regulations, 252 OAC Chapter          X
                                              606                       606 also contains rules and regulations pertaining to the
                                                                        land application of biosolids, i.e. solids generated by
                                                                        municipal wastewater treatment systems. Oklahoma has
                                                                        incorporated by reference most or all of the Federal land
                                                                        application regulations under 40 CFR Part 503, including
                                                                        Subparts A, B, D, and E. These regulations may be
                                                                        ARARs if some candidate alternatives contemplate the
                                                                        use of biosolids for amending soils or mill wastes for the
                                                                        purpose of revegetating or stabilizing them.

 Oklahoma Water Supply Systems                27A O.S., Sections 2-6-   The Oklahoma UIC program under 252:652 consists of             X
 Act – Underground Injection                  301 et seq.               the provisions of the Federal UIC program that are
 Control (UIC) Program                                                  incorporated by reference in their entirety, including Title
                                                                        40 CFR Parts 124 and 144 through 148. Therefore, the
                                              Title 252 OAC, Chapter    Oklahoma program is essentially identical to the Federal
                                              652                       program.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-2.DOC                                     PAGE 8 OF 11                                                          JULY 2007
 TABLE 7-2
 Potential Federal and State Action-Specific ARARs and Guidance to be Considered
 Tar Creek Superfund Site
       Standard, Requirement,                           Citation                                  Description                          Potential     To Be
                 Criteria,                                                                                                             ARARs       Considered

              or Limitation

 Oklahoma Well Driller and Pump               Title 82 O.S. (1991),    The Oklahoma Water Resources Board (OWRB) sets                  X
 Installer Licensing Regulations              Sections 1020.16 and     fees and standards for installing, maintaining, and
                                              1085.2.                  abandoning water wells and monitoring wells. These
                                                                       regulations also cover well plugging and proper isolation
                                                                       of possible sources of contamination from existing wells to
                                              Title 785, Chapter 35    protect the quality of groundwater drinking water aquifers.
                                                                       In the past, plugging abandoned wells and institutional
                                                                       controls on new well construction have been included in
                                                                       remedial alternatives other sites within the District. Hence,
                                                                       these regulations are potential ARARs.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-2.DOC                                    PAGE 9 OF 11                                                           JULY 2007
 TABLE 7-2
 Potential Federal and State Action-Specific ARARs and Guidance to be Considered
 Tar Creek Superfund Site
       Standard, Requirement,                          Citation                                        Description                      Potential     To Be
                 Criteria,                                                                                                              ARARs       Considered

              or Limitation

 Oklahoma Solid Waste                         27A O.S., Sections 2-10-   The Oklahoma solid waste management regulations apply          X
 Management Act                               101 et seq.                to the design, permitting, operations, and closure of solid
                                                                         waste disposal facilities used for non-hazardous industrial,
                                                                         commercial, agricultural, infections, and domestic wastes
                                              Title 252 OAC, Chapter     and waste tires. Under the statute 27A O.S. 2-10-103,
                                              515                        mining and milling wastes are not specifically excluded
                                                                         from the definition solid wastes. These regulations are
                                                                         potential ARARs, but mining and milling waste deposits
                                                                         might be excluded from some or all of the regulations if a
                                                                         beneficial reuse was documented, although the
                                                                         requirements would apply for materials accumulated for
                                                                         periods longer than 1 year. If not applicable, the
                                                                         substantive provisions of Chapter 515 may be relevant
                                                                         and appropriate, such as the provisions for runoff controls,
                                                                         PPPs, and general storm water permits for disposal
                                                                         facilities.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-2.DOC                                        PAGE 10 OF 11                                                       JULY 2007
 TABLE 7-2
 Potential Federal and State Action-Specific ARARs and Guidance to be Considered
 Tar Creek Superfund Site
       Standard, Requirement,                           Citation                                      Description                     Potential     To Be
                 Criteria,                                                                                                            ARARs       Considered

              or Limitation

 Oklahoma Mining Commission,                  Title 45 O.S. (1981),       Chapter 10 of Oklahoma’s non-coal mining rules and          X
 Department of Mines – Non-Coal               Sections 1 et seq.          regulations apply specifically to surface mining and
 Mining Rules and Regulations                                             reclamation operations. These rules and regulations
                                                                          contain permitting, performance and closure requirements
                                              Title 460 OAC, Chapter 10   for non-coal surface sites. The law and implementing
                                                                          regulations may not applicable to chat recycling
                                                                          operations because chat piles are not natural formations.
                                                                          However, some of the surface mining standards are
                                                                          relevant and appropriate requirements because they
                                                                          address circumstances that are similar to those at chat
                                                                          recycling and quarrying operations within the Tar Creek
                                                                          Site.

 Lead-Impacted Communities                    2006 OSL 226, [SB 1463]                                                                 X
                                                                          Provides criteria on which households qualify for
 Relocation Act
                                                                          relocation, and stipulations on moving back to the area.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-2.DOC                                       PAGE 11 OF 11                                                      JULY 2007
  TABLE 7-3
  Potential Federal and State Location-Specific ARARs and Guidance to be Considered
  Tar Creek Superfund Site
        Standard, Requirement,                                                                                                                 Potential     To Be
                                                      Citation                                      Description
         Criteria, or Limitation                                                                                                                   ARAR    Considered

  FEDERAL REQUIREMENTS

  Archaeological and Historic               16 USC Sec. 469               Establishes procedures to provide for preservation of                X
  Preservation Act                                                        historical and archaeological data which might be
                                            40 CFR Part 6.301(c)
                                                                          destroyed through alteration of terrain as a result of a
                                                                          Federally licensed activity or program.

  Archaeological Resources                  16 USC Secs. 470 aa - mm      Requires permits for any excavation or removal of                    X
  Protection Act                                                          archaeological resources from public or Indian lands.
                                                                          Provides guidance for federal land managers to protect
                                                                          such resources.

  National Historic Preservation            16 USC Sec. 470               Requires Federal agencies to take into account the effect of         X
  Act                                                                     any Federally assisted undertaking or licensing on any
                                            40 CFR Part 6.301(b)
                                                                          district, site, building, structure, or object that is included in
                                            36 CFR Part 800               or eligible for Register of Historic Places.

                                            Executive Order 11593, May
                                            3, 1971

  Historic Sites, Buildings, and            16 USC Secs. 461-467          Requires Federal agencies to consider the existence and              X
  Antiquities Act                                                         location of landmarks on the National Registry of Natural
                                            40 CFR Part 6.301(a)
                                                                          Landmarks to avoid undesirable impacts on such
                                                                          landmarks.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-3.DOC                                       PAGE 1 OF 3                                                               JULY 2007
  TABLE 7-3
  Potential Federal and State Location-Specific ARARs and Guidance to be Considered
  Tar Creek Superfund Site
        Standard, Requirement,                                                                                                             Potential       To Be
                                                      Citation                                      Description
         Criteria, or Limitation                                                                                                               ARAR    Considered

  Fish and Wildlife Coordination            16 USC Secs. 661-666          Requires any Federal agency or permitted entity to consult       X
  Act                                                                     with the U.S. Fish and Wildlife Service and appropriate
                                            40 CFR Part 6.302(g)
                                                                          state agency prior to modification of any stream or other
                                                                          water body. The intent of this requirement is to conserve,
                                                                          improve, or prevent loss of wildlife habitat and resources.

  Fish and Wildlife Conservation            16 USC Secs. 2901 - 2912      Requires Federal agencies to utilize their statutory and                     X
  Act                                                                     administrative authority to conserve and promote
                                                                          conservation of non-game fish and wildlife species.

  Endangered Species Act of                 16 USC Secs. 1531-1544        Requires Federal agencies to insure that any action              X
  1973                                                                    authorized, funded, or carried out by the agency is not likely
                                            50 CFR Parts 17.402
                                                                          to jeopardize the continued existence of any threatened or
                                            40 CFR Part 6.302(h)          endangered species or destroy or adversely modify critical
                                                                          habitat.

  Federal Migratory Bird Act                16 USC Secs. 703 – 712        Requires remedial actions to conserve habitat and                X
                                                                          consultation with the Department of Interior if any critical
                                                                          habitat is affected.

  Executive Order on Floodplain             Executive Order No. 11988     Requires Federal agencies to evaluate the potential effects                  X
  Management                                                              of actions they may take in a floodplain to avoid, to the
                                            40 CFR Part 6.302(b) and
                                                                          maximum extent possible, the adverse impacts associated
                                            Appendix A
                                                                          with direct and indirect development of a floodplain.

  Executive Order on Protection of          Executive Order No. 11990     Requires Federal agencies to avoid, to the maximum extent                    X



USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-3.DOC                                       PAGE 2 OF 3                                                             JULY 2007
  TABLE 7-3
  Potential Federal and State Location-Specific ARARs and Guidance to be Considered
  Tar Creek Superfund Site
      Standard, Requirement,                                                                                                                   Potential       To Be
                                                       Citation                                      Description
        Criteria, or Limitation                                                                                                                    ARAR    Considered

  Wetlands                                  40 CFR Part 6.302(a) and       possible, the adverse impacts associated with the

                                            Appendix A                     destruction or loss of wetlands and to avoid new
                                                                           construction in wetlands, if a practicable alternative exists.

  Farmland Protection Policy Act            7 USC Sec. 4201 et. seq.       Protects significant or important agricultural lands from                       X
                                                                           irreversible conversion to uses that result in its loss as an
                                            40 CFR Part 6.302 (c)
                                                                           environmental or essential food production resource.

  RCRA – Location Standards for             42 USC Sec. 6901               Requires that solid or hazardous waste facilities be located                    X
  Waste Disposal Facilities                                                outside hazard zones, such as floodplains or seismically
                                            40 CFR Part 257- Solid Waste
                                                                           active zones. Also requires disposal facilities to be
                                            Landfill Standards,
                                                                           designed, constructed, operated, and maintained to avoid
                                            40 CFR Part 264 – Hazardous    washout and control storm water run-on and run-off.
                                            Waste Disposal Facilities

  Rivers and Harbors Act                    33 CFR Parts 320 - 330         Requires preapproval of the US Army Corps of Engineers                          X
                                                                           prior to placement of any structures in waterways and
                                                                           restricts the placement of structures in waterways.

  STATE REQUIREMENTS

  Oklahoma Wildlife Statutes                Title 29, Section 5-412        Requires remedial actions to be designed to conserve endangered     X
                                                                           or threatened species and their habitats, including consultation
                                                                           with the Oklahoma Department of Wildlife, if any critical habitat
                                                                           would be affected.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-3.DOC                                       PAGE 3 OF 3                                                                 JULY 2007
  TABLE 7-4
  Long-term Effectiveness and Permanence of Alternative 1 – No Further Action
  Tar Creek Superfund Site
    Source of Risk                Baseline              Area/Volume          Area/Volume Not           Area/Volume
                                                        Addressed by             Addressed by           Subject to
                                                        Engineering              Engineering           Institutional
                                                     Controls or Other       Controls or Other   Controls and Long-
                                                            Action                   Action            Term O&M

  Land Area Occupied (Acres) (see note below)

  Chat Piles                767                     0                        767                 N/A

  Chat Bases                2,079                   0                        2,079               N/A

  Rail/Road Beds
  (Chat)                    552                     0                        552                 N/A

  Fine Tailings             820                     0                        820                 N/A

  Smelter Waste             2                       0                        2                   N/A

  Total                     4,220                   0                        4,220               N/A

  Volume (Cubic Yards)

  Chat (all sources)
  (see note below)          38,611,000              29,231,000               9,380,000           N/A

  Fine Tailings             9,156,000               0                        9,156,000           N/A

  Smelter Waste             1,846                   0                        1,846               N/A

  Total                     47,768,846              29,231,000               18,537,846          N/A

  Notes:

  1.   Commercial chat processing, an ongoing activity at the Site, results in the assumed removal of
       29,231,000 cubic yards of chat over the 20-year processing timeframe used for comparison with other
       alternatives. In all cases, it is assumed that bases are not processed by commercial chat processors and
       that bases are left behind after processing of a pile is complete; therefore, a reduction in land area
       occupied is not achieved.
  2.   All fine tailing deposits, smelter waste, and affected soils are not addressed and remain uncontrolled
       sources of potential exposure to human and ecological receptors.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-4_ALT1 LTEP.DOC      PAGE 1 OF 1                                           JULY 2007
TABLE 7-5
Long-term Effectiveness and Permanence of Alternative 4
Tar Creek Superfund Site
     Source of Risk              Baseline                   Area/Volume       Area/Volume Not          Area/Volume
                                                            Addressed by          Addressed by          Subject to
                                                            Engineering           Engineering           Institutional
                                                       Controls or Other      Controls or Other        Controls and
                                                               Action                Action           Long-Term O&M

Land Area Occupied (Acres)

Chat Piles                 767                        583                     184 (see note       0
                                                                              below)

Chat Bases                 2,079                      2,079                   0                   0

Rail/Road Beds
(Chat)                     552                        552                     0                   0

Fine Tailings              820                        820                     0                   251

Smelter Waste              2                          2                       0                   0

Infilled Subsidence        0                          43                      0                   43
Features

On-Site                    0                          28                      0                   28
Constructed
Repository

Total                      4,220                      4,107                   184                 322

Volume (Cubic Yards)

Chat (all sources)         38,611,000                 31,576,000              7,035,000 (see      1,876,000 (in
(see notes below)                                                             note below)         subsidence features
                                                                                                  and repository

Fine Tailings              9,156,000                  9,156,000               0                   4,437.000 (covered
                                                                                                  in place)

Smelter Waste              1,846                      1,846                   0                   1,846 (in repository)

Total                      47,768,846                 40,733,846              7,035,000           6,314,846

Notes

Chat Volume Addressed:

1.     Estimated 938,000 cubic yards pushed into subsidence features.
2.     Estimated 938,000 cubic yards disposed in the on-site repository.
3.     Estimated 469,000 cubic yards injected into underground mines (w/ no ICs/FLU restrictions).
4.     Estimated 29,231,000 processed by commercial processing operations (not as part of the remedy).

Chat Volume Not Addressed:

1.     Estimated 7,035,000 cubic yards in controlled pile settings being operated by commercial chat processors.
       Anticipate that this volume would continue to be reduced by chat sales over time (approx. 5 years at 1.9
       million tons/year). This volume is estimated to occupy 184 acres.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-5_ALT4_LTEP.DOC       PAGE 1 OF 1                                       JULY 2007
  TABLE 7-6
  Alternative 4 Estimated Costs
  Tar Creek Superfund Site
      Direct Capital              Indirect Capital         Total Capital     Annual O&M   Net Present Value



  $182,041,000                 $117,858,000               $299,899,000     $375,000       $172,899,000




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-6_ALT4 EC.DOC      PAGE 1 OF 1                                 JULY 2007
 TABLE 7-7
 Long-term Effectiveness and Permanence of Alternative 5
 Tar Creek Superfund Site
      Source of Risk              Baseline                  Area/Volume       Area/Volume Not          Area/Volume
                                                            Addressed by          Addressed by          Subject to
                                                            Engineering           Engineering          Institutional
                                                       Controls or Other      Controls or Other        Controls and
                                                               Action                Action        Long-Term O&M

 Land Area Occupied (Acres)

 Chat Piles                 767                        767                    0                   0

 Chat Bases                 2,079                      2,079                  0                   0

 Rail/Road Beds
 (Chat)                     552                        552                    0                   0

 Fine Tailings              820                        820                    0                   251

 Smelter Waste              2                          2                      0                   0

 Infilled Subsidence        0                          43                     0                   43
 Features

 On-Site                    0                          28                     0                   28
 Constructed
 Repository

 Total                      4,220                      4,291                  0                   322

 Volume (Cubic Yards)

 Chat (all sources)         38,611,000                 38,611,000             0                   1,876,000 (in
 (see notes below)                                                                                subsidence
                                                                                                  features and
                                                                                                  repository

 Fine Tailings              9,156,000                  9,156,000              0                   4,437.000 (covered
                                                                                                  in place)

 Smelter Waste              1,846                      1,846                  0                   1,846 (in
                                                                                                  repository)

 Total                      47,768,846                 47,768,846             0                   6,314,846

 Notes

 Chat Volume Addressed:

 1.     Estimated 938,000 cubic yards pushed into subsidence features.
 2.     Estimated 938,000 cubic yards disposed in the on-site repository.
 3.     Estimated 469,000 cubic yards injected into underground mines (w/ no ICs/FLU restrictions).
 4.     Estimated 29,231,000 processed by commercial processing operations (not as part of the remedy).




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-7_ALT5_LTEP.DOC       PAGE 1 OF 1                                       JULY 2007
 TABLE 7-8
 Alternative 5 Estimated Costs
 Tar Creek Superfund Site
    Direct Capital            Indirect Capital              Total Capital       Annual O&M   Net Present Value

 $222,885,000               $135,216,000                  $358,101,000        $550,000       $214,893,000




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-8_ALT5 EC.DOC         PAGE 1 OF 1                                 JULY 2007
  TABLE 7-9
  Long-term Effectiveness and Permanence of Alternative 8 - Total Source Consolidation, On-Site Disposal, and
  Institutional Controls
  Tar Creek Superfund Site
          Source                   Baseline                 Area/Volume       Area/Volume Not         Area/Volume
                                                            Addressed by          Addressed by          Subject to
                                                            Engineering           Engineering         Institutional
                                                        Controls or Other     Controls or Other       Controls and
                                                              Actions                Action       Long-Term O&M


  Land Area Occupied (Acres)

  Chat Piles                 767                       767                    0                   0

  Chat Bases                 2,079                     2,079                  0                   0

  Rail/Road Beds             552                       552                    0                   0
  (Chat)

  Fine Tailings              820                       820                    0                   631

  Smelter Waste              2                         2                      0                   2

  Infilled Subsidence        0                         213                    0                   213
  Features

  Total                      4,220                     4,433                  0                   846

  Volume (Cubic Yards)

  Chat (all sources)         38,611,000                38,611,000             0                   4,690,000 (in
                                                                                                  subsidence
                                                                                                  features)

  Fine Tailings              9,156,000                 9,156,000              0                   7,158,000
                                                                                                  (covered in place)

  Smelter Waste              1,846                     1,846                  0                   1,846 (covered in
                                                                                                  place)

  Total                      47,768,846                47,768,846             0                   11,849,846

  Remedial Actions

  Notes:

  Chat Volume Addressed:

  1.   Estimated 4,690,000 cubic yards pushed into subsidence features.



USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-9_ALT8 LTEP.DOC       PAGE 1 OF 2                                       JULY 2007
  TABLE 7-9
  Long-term Effectiveness and Permanence of Alternative 8 - Total Source Consolidation, On-Site Disposal, and
  Institutional Controls
  Tar Creek Superfund Site
  2.   Estimated 4,690,000 cubic yards injected into underground mine caverns.
  3.   Estimated 29,231,000 cubic yards processed by commercial processing operations (not as part of the
       remedy).




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-9_ALT8 LTEP.DOC   PAGE 2 OF 2                                         JULY 2007
 TABLE 7-10
 Alternative 8 Estimated Costs
 Tar Creek Superfund Site
    Direct Capital            Indirect Capital             Total Capital       Annual O&M   Net Present Value

 $333,458,000               $175,396,000               $508,854,000          $475,000       $262,540,000




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE7-10_ALT8 EC.DOC       PAGE 1 OF 1                                 JULY 2007
 TABLE 8-1
 Comparative Analysis of Remedial Alternatives with Respect to Overall Protection of Human Health and the Environment
 Tar Creek Superfund Site
            Criterion                    Alternative 4:                      Alternative 5            Alternative 8
                                                                    Voluntary Relocation,             Total Source
                                   Phased Consolidation,
                                                                    Phased Consolidation,       Consolidation, On-Site
                                    On-Site Disposal and
                                                                     On-Site Disposal and            Disposal, and
                                    Institutional Controls
                                                                     Institutional Controls      Institutional Controls


 How the alternative               • Alternative 4 meets all       • Alternative 5 meets all    • Alternative 8 meets all
 provides overall                     RAOs by addressing              RAOs by addressing          RAOs by addressing
 protection of human                  all source materials            all source materials        all source materials
 health and environmental             and affected soils and          and affected soils.         and affected soils and
 protection.                          is protective of human          Incremental                 is protective of human
                                      health and the                  protectiveness gained       health and the
                                      environment.                    through proposed            environment.
                                                                      voluntary relocation.

                                                                   • Alternative 5 is
                                                                      protective of human
                                                                      health and the
                                                                      environment.

 Adequacy, permanence,             • Engineering actions           • Same as Alternative 4      Engineering actions are
 and reliability of waste             are adequate and                except;                   adequate and reliable.
 containment or treatment             reliable. Moderate                                        Moderate use of all
                                                                   • Voluntary relocation
 actions.                             use of all disposal                                       disposal options except
                                                                      permanence
                                      options weighted more                                     disposal in a constructed
                                                                      established by
                                      heavily toward those                                      repository. Weighted
                                                                      institutional controls,
                                      considered more                                           toward disposal by
                                                                      effectively eliminates
                                      reliable and                                              injection but a high
                                                                      potential exposure of
                                      permanent.                                                volume is also addressed
                                                                      affected population to
                                                                                                by covering in place.
                                                                      source materials.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE8-1.DOC                PAGE 1 OF 2                                             JULY 2007
 TABLE 8-1
 Comparative Analysis of Remedial Alternatives with Respect to Overall Protection of Human Health and the Environment
 Tar Creek Superfund Site
          Criterion                      Alternative 4:                        Alternative 5             Alternative 8
                                                                      Voluntary Relocation,              Total Source
                                   Phased Consolidation,
                                                                      Phased Consolidation,        Consolidation, On-Site
                                    On-Site Disposal and
                                                                       On-Site Disposal and             Disposal, and
                                    Institutional Controls
                                                                       Institutional Controls       Institutional Controls


 Timeframe to achieve              • All remedial actions            • Same as Alternative 4,      • All remedial actions
 protection.                          are performed within              except:                      are performed within
                                      20 years. Early                                                20 years, early actions
                                                                     • All remedial actions
                                      actions in distal area                                         in urban setting.
                                                                        performed within 30
                                      results in rapid
                                                                        years.                     • Urban source
                                      reduction in overall
                                                                                                     materials are removed
                                      Site footprint.                • 3 years estimated for
                                                                                                     within 10-year
                                                                        voluntary relocation.
                                   • Early response actions                                          timeframe.
                                      for residential yards,
                                      drinking water, smelter                                      • Early response actions
                                      wastes, and stream                                             for residential yards
                                      reclamation.                                                   and drinking water.


 Compliance with risk-             • Alternative 4 meets all         • Alternative 5 meets all     • Alternative 8 meets all
 based PRGs.                          the PRGs identified for           the PRGs identified for      the PRGs identified for
                                      OU4.                              OU4.                         OU4.


 Degree of reliance on             • An estimated 322                • An estimated 322            • An estimated 846
 institutional controls to            acres of land are                 acres of land are            acres of land are
 supplement engineering               subject to institutional          subject to institutional     subject to institutional
 controls.                            controls.                         controls.                    controls, none in
                                                                                                     urban areas.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE8-1.DOC                  PAGE 2 OF 2                                             JULY 2007
 TABLE 8-2
 Comparative Analysis of Remedial Alternatives with Respect to Compliance with ARARs
 Tar Creek Superfund Site
         Criterion                     Alternative 4                    Alternative 5            Alternative 8
                                                                  Voluntary Relocation,          Total Source
                                 Phased Consolidation,
                                                                 Phased Consolidation,      Consolidation, On-Site
                                  On-Site Disposal and
                                                                  On-Site Disposal and          Disposal, and
                                  Institutional Controls
                                                                  Institutional Controls    Institutional Controls

 Compliance with               • Alternative 4 is capable       • Same as Alternative 4.   • Same as Alternative 4.
 Chemical-Specific                 of meeting the
 ARARs                             chemical-specific
                                   ARARs identified for
                                   OU4.


 Compliance with               • Alternative 4 is capable       • Same as Alternative 4.   • Same as Alternative 4.
 Action-Specific ARARs             of meeting the action-
                                   specific ARARs
                                   identified for OU4.


 Compliance with               • Alternative 4 is capable       • Same as Alternative 4.   • Same as Alternative 4.
 Location-Specific                 of complying with
 ARARs                             location-specific
                                   ARARs identified for
                                   OU4.


 Compliance with Other         • Alternative 4 is capable       • Same as Alternative 4.   • Same as Alternative 4.
 Criteria, Advisories,             of complying with TBCs
 and Guidance (TBCs)               for soils and source
                                   materials identified for
                                   OU4.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE8-2.DOC               PAGE 1 OF 1                                    JULY 2007
TABLE 8-3
Comparative Analysis of Remedial Alternatives with Respect to Long-Term Effectiveness and Permanence
Tar Creek Superfund Site
         Criterion                       Alternative 4                          Alternative 5                 Alternative 8

                                  Phased Consolidation,                Voluntary Relocation,                  Total Source
                                   On-Site Disposal and               Phased Consolidation,             Consolidation, On-Site
                                   Institutional Controls              On-Site Disposal and                   Disposal, and
                                                                       Institutional Controls            Institutional Controls

Magnitude of Residual            • All action alternatives prescribe chat processing at the same rate and therefore all have the
Risks                               same magnitude of residual risk with respect to chat processing residuals. Quantified, this
                                    equates to the generation of an estimated 3.2 million yd3 of washed fines from the chat washing
                                    process that are addressed by the remedial alternatives in the same manner.
                                 • The engineering controls         • The engineering controls         • The engineering controls
Adequacy and Reliability
of Controls                         prescribed under                   prescribed under Alternative      prescribed under
                                    Alternative 4 are adequate         5 are adequate for meeting        Alternative 8 are adequate
                                    for meeting the RAOs.              the RAOs. However, in-            and reliable for meeting the
                                    However, in-place                  place disposal of source          RAOs.
                                    disposal of source                 materials, as prescribed        • The reliance on
                                    materials, as prescribed           under this alternative, may       institutional controls is
                                    under this alternative, may        be impermanent and                further reduced by
                                    be impermanent and                 unreliable because some in-       permanently disposing of
                                    unreliable because some            place disposal sites may be       more source materials in
                                    in-place disposal sites may        unsuitable for long-term          underground mine
                                    be unsuitable for long-            containment.                      workings.
                                    term containment.               • Institutional controls are       • Infiltration and seepage
                                 • Institutional controls are          needed to supplement the          from mill wastes deposits
                                    needed to supplement the           protectiveness of the             to Site surface waters are
                                    protectiveness of the              remedy by preventing future       further reduced by
                                    remedy by preventing               potential disturbance of the      disposing of more mill
                                    future potential                   in-place disposal sites.          wastes in underground
                                    disturbance of the in-place     • Infiltration and seepage           mine workings or
                                    disposal sites.                    from mill wastes deposits to      subsidence pits.
                                 • Infiltration and seepage            Site surface waters is
                                    from mill wastes deposits          reduced by 70 to 48 percent
                                    to Site surface waters is          by soil capping.
                                    reduced by 70 to 48             • Relocation is an effective
                                    percent by soil capping.           control to prevent exposure
                                                                       of the affected population to
                                                                       source materials and
                                                                       affected media.



  USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE8-3.DOC                 PAGE 1 OF 1                                               JULY 2007
 TABLE 8-4
 Comparative Analysis of Remedial Alternatives with Respect to Short-Term Effectiveness
 Tar Creek Superfund Site
           Criterion                      Alternative 4                      Alternative 5             Alternative 8



                                   Phased Consolidation,            Voluntary Relocation,              Total Source
                                    On-Site Disposal and            Phased Consolidation,        Consolidation, On-Site
                                    Institutional Controls           On-Site Disposal and             Disposal and
                                                                     Institutional Controls       Institutional Controls

 Protection of the                 • Some short-term               • Same as Alternative 4       • The increased intensity
 Community During                     disruption of normal            except that the noted        of removal actions in
 Remedial Actions                     activity is caused by           issues are lessened if       urban settings is
                                      the removal of urban            a significant portion of     expected to result in
                                      mill wastes.                    the affected population      greater disturbance of
                                                                      voluntarily relocates.       and increased risks
                                   • Fugitive dust, noise,
                                                                                                   compared to the other
                                      vibration, and traffic
                                                                                                   action alternatives.
                                      hazards increase in
                                      urban areas of the
                                      Site. However, these
                                      potential impacts are
                                      managed through
                                      readily implementable
                                      control and traffic
                                      safety measures.

 Protection of Workers             • Risks to workers are          • Same as Alternative 4       • Similar to Alternative 4
 During Remedial Actions              considered moderate             except that additional       but elevated due to
                                      and controllable                safety measures are          higher intensity of
                                      through appropriate             required relating to         work and potentially
                                      worker health and               demolition and               heavier equipment
                                      safety training, design,        disposal of structures       utilized.
                                      and planning.                   acquired through
                                                                      voluntary relocation
                                                                      program.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE8-4.DOC                PAGE 1 OF 2                                             JULY 2007
 TABLE 8-4
 Comparative Analysis of Remedial Alternatives with Respect to Short-Term Effectiveness
 Tar Creek Superfund Site
           Criterion                      Alternative 4                        Alternative 5             Alternative 8



                                   Phased Consolidation,              Voluntary Relocation,              Total Source
                                    On-Site Disposal and              Phased Consolidation,        Consolidation, On-Site
                                    Institutional Controls             On-Site Disposal and             Disposal and
                                                                       Institutional Controls       Institutional Controls

 Potential Environmental           • The potential                   • Same as Alternative 4       • Same as Alternative 8
 Impacts Caused by the                environmental impacts             except:                      except:
 Remedial Actions                     caused by excavating           • Structures demolished       • Alternative 8 requires
                                      mill wastes from                  and disposed of as           an estimated 2.7
                                      riparian corridors in             part of the voluntary        million cubic yards of
                                      near-stream settings              relocation will impact       borrow soils. This
                                      are the same under                the environment by           volume of borrow soils
                                      this alternative as               requiring significant        may be limited within
                                      under all other                   landfill space to handle     the local area of
                                      alternatives. These               the debris.                  Ottawa County.
                                      potential impacts are
                                      mitigated the same as
                                      under all other action
                                      alternatives.
                                   • An estimated 1.2
                                      million cubic yards of
                                      borrow soils are
                                      needed to implement
                                      the prescribed soil
                                      cover systems.

 Time Until Remedial               • Full implementation of          • Full implementation is      • Same as Alternative 4,
 Actions Objectives Are               the remedy is achieved            achieved in 30 years.        except the RAOs in
 Achieved                             in 20 years with RAO’s                                         urban settings are met
                                                                     • 3 years for voluntary
                                      met in the distal areas                                        within a 10-year
                                                                        relocation component
                                      within 10 years                                                timeframe.
                                                                        to be completed.
                                      resulting in substantial
                                      footprint reduction.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE8-4.DOC                  PAGE 2 OF 2                                             JULY 2007
TABLE 8-5
Comparative Analysis of Remedial Alternatives with Respect to Reduction of Toxicity, Mobility, or Volume through Treatment
Tar Creek Superfund Site
       Criterion                      Alternative 4                        Alternative 5                Alternative 8

                             Phased Consolidation, On-              Voluntary Relocation,               Total Source
                                   site Disposal and             Phased Consolidation, On-        Consolidation, On-Site
                                 Institutional Controls                site Disposal and         Disposal and Institutional
                                                                     Institutional Controls               Controls


Treatment Process            • Chat processing by private        • Same as Alternative 4        • Same as Alternative 4
Used and Materials              operators, at an estimated
Treated                         29.2 million cubic yards, is
                                completed by dry screening
                                or more commonly, wet
                                screening (i.e. washing).
                                This has the effect of
                                significantly lowering the
                                toxicity of the chat since the
                                screening process removes
                                the finer particles which
                                have higher concentrations
                                of lead and other
                                hazardous substances.

Amount of Materials          • An estimated 29.2 million         • Same as Alternative 4        • Same as Alternative 4
Treated                         cubic yards are treated by
                                private chat sales and
                                processing to reduce TMV.

Effectiveness and            • Chat processing is a very         • Same as Alternative 4        • Same as Alternative 4
Irreversibility of              effective and permanent
Treatment                       means of removing the
                                finer, higher-concentration
                                hazardous substances
                                such as lead, from the chat.

Treatment Residuals          • All new wash fines                • Same as Alternative 4        • Same as Alternative 4
Generated                       generated by chat washing
                                (assumed to be 11% of
                                bulk chat) are covered
                                along with existing fine
                                tailings deposits. An
                                estimated 3.2 million cubic
                                yards will be generated and
                                will be addressed by the
                                remedy.




  USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE8-5.DOC            PAGE 1 OF 1                                           JULY 2007
 TABLE 8-6
 Comparative Analysis of Remedial Alternatives with Respect to Implementability
 Tar Creek Superfund Site
           Criterion                      Alternative 4                         Alternative 5          Alternative 8



                                   Phased Consolidation,               Voluntary Relocation,           Total Source
                                    On-Site Disposal and               Phased Consolidation,      Consolidation, On-Site
                                    Institutional Controls              On-Site Disposal and           Disposal, and
                                                                        Institutional Controls     Institutional Controls

 Technical Feasibility –           • Engineering controls             • Same as Alternative 4     • Same as Alternative 4
 Constructability and                 prescribed under                   except:                    except:
 Reliability of Prescribed            Alternative 4 are
                                                                      • Voluntary relocation      • Requirement of 2.7
 Technologies                         technically feasible and
                                                                         and demolition and         million cubic yards of
                                      readily constructible.
                                                                         disposal of structures     cover soil may be
                                   • Chat removal is a                   are technically            difficult to obtain
                                      proven and ongoing                 feasible.                  locally.
                                      economic and cultural
                                      practice.

                                   • Injecting fine tailings
                                      and chat into the
                                      underground mine
                                      workings is proven
                                      technically feasible.

                                   • Requirement of 1.2
                                      million cubic yards of
                                      cover soil is expected
                                      to be available difficult
                                      to obtain locally.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE8-6.DOC                   PAGE 1 OF 3                                             JULY 2007
 TABLE 8-6
 Comparative Analysis of Remedial Alternatives with Respect to Implementability
 Tar Creek Superfund Site
           Criterion                      Alternative 4                        Alternative 5            Alternative 8



                                   Phased Consolidation,              Voluntary Relocation,             Total Source
                                    On-Site Disposal and              Phased Consolidation,        Consolidation, On-Site
                                    Institutional Controls             On-Site Disposal and             Disposal, and
                                                                       Institutional Controls       Institutional Controls

 Administrative Feasibility        • Institutional controls          • Same as Alternative 4       • Same as Alternative 4
                                      prescribed under                  except:                      except:
                                      Alternative 4 are
                                                                     • Voluntary relocation        • Approximately 846
                                      expected to be
                                                                        has been performed           acres are subject to
                                      administratively
                                                                        historically at the Site     institutional controls,
                                      implementable.
                                                                        but will require             none in urban areas.
                                      However, the State or
                                                                        significant additional
                                      other authorized entity
                                                                        administration and
                                      is required under the
                                                                        management to
                                      NCP to hold any
                                                                        accomplish.
                                      easements or issue
                                      deed notices.

                                   • Approximately 322
                                      acres of land are
                                      subject to institutional
                                      controls. Alternative 4
                                      results in the least land
                                      area subject to
                                      institutional controls
                                      and is, therefore,
                                      thought to be the most
                                      administratively
                                      feasibility.

                                   • The administrative and
                                      record-keeping
                                      requirements of the
                                      Chat Rule, and
                                      compliance with the
                                      Off-Site Rule, are
                                      requirements for chat



USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE8-6.DOC                  PAGE 2 OF 3                                           JULY 2007
 TABLE 8-6
 Comparative Analysis of Remedial Alternatives with Respect to Implementability
 Tar Creek Superfund Site
           Criterion                      Alternative 4                    Alternative 5        Alternative 8



                                   Phased Consolidation,          Voluntary Relocation,         Total Source
                                    On-Site Disposal and          Phased Consolidation,     Consolidation, On-Site
                                    Institutional Controls         On-Site Disposal and         Disposal, and
                                                                   Institutional Controls   Institutional Controls

                                      sales under the
                                      Alternative.




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE8-6.DOC              PAGE 3 OF 3                                     JULY 2007
  TABLE 8-7
  Comparative Analysis of Remedial Alternatives with Respect to Cost
  Tar Creek Superfund Site
  Criterion                                       Alternative 1               Alternative 4                 Alternative 5                 Alternative 8
                                              No Further Action        Phased Consolidation, On-       Voluntary Relocation,              Total Source
                                                                            Site Disposal and        Phased Consolidation, On-       Consolidation, On-Site
                                                                          Institutional Controls         Site Disposal, and        Disposal and Institutional
                                                                                                        Institutional Controls              Controls

  Direct Capital Costs                  Not Calculated                 $182,041,000                  $222,885,000                  $333,458,000
  Indirect Capital Costs                Not Calculated                 $117,858,000                  $135,216,000                  $175,396,000
  Total Capital Costs                   Not Calculated                 $299,899,000                  $358,101,000                  $508,854,000
  Operating and Maintenance             Not Calculated                 $375,000/year decreasing to   $375,000/year decreasing to   $475,000/year decreasing to
  Costs                                                                $125,000/year                 $125,000/year for RA;         $225,000/year
                                                                                                     $175,000/year for voluntary
                                                                                                     relocation for 2 years.
  Net Present Value                     Not Calculated                 $172,899,000                  $214,893,000                  $262,540,000
  Assuming a 7% Discount
  Rate
  Cost Sensitivity Analysis: Net        Not Calculated                 $173,297,000                  $215,276,000                  $263,175,000
  Present Value Assuming
  Import of 25% Cover Soils
  (at 7% Discount Rate)




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE8-7.DOC                                       PAGE 1 OF 1                                                         JULY 2007
  TABLE 8-8
  Comparative Analysis Results
  Tar Creek Superfund Site
  Criterion                               Alternative 4                 Alternative 5         Alternative 8

                                    Phased Consolidation,      Voluntary Relocation,          Total Source
                                     On-Site Disposal and      Phased Consolidation,     Consolidation, On-Site
                                     Institutional Controls     On-Site Disposal and         Disposal, and
                                                                Institutional Controls   Institutional Controls

  Overall Protection of            4                          4                          4
  Human Health and the
  Environment

  Compliance with ARARs            4                          4                          4

  Long-Term Effectiveness          4                          4                          2
  and Permanence

  Reduction of Toxicity,           3                          3                          3
  Mobility, or Volume
  Through Treatment

  Short-Term                       3                          3                          3
  Effectiveness

  Implementability                 3                          2                          2

  Cost                             3                          2                          1

  Relative Score:                  24                         22                         19

  Scoring System

  1 – Poor                         2 - Satisfactory           3 - Good                   4 – Excellent




USEPA\348273\PR04\TC_DRAFT-FINALFS_TABLE8-8.DOC           PAGE 1 OF 1                                     JULY 2007
Figures
                                                             SW Treece Rd
                                                                                                                                                                                                                                                                SE Treece Rd                                                                                                                                                                                       Cherokee County, KS
                                                             13-T29N-R22E                                                                                                                                                                                                                                                                                                            W State Line Rd




                                                                                                                                                                    S S70 Rd
                                                                                                                                                                                                                                                                                                                                                                                                                                                                   Ottawa County, OK




                                                                                                                                                                                                                                                               S 592 Rd
                                                                                                                                                                                                              16-T29N-R23E




                                                                                                                                         Tar Creek
       14-T29N-R22E                                                                                          18-T29N-R23E                                          17-T29N-R23E
                                                                                                                                                                                                                                                      k                                                                                                                                                                                                                                         17-T29N-R24E




                                                                                                                                                                                                    N Mable
                                                                                                                                                                                                                                                                                                             14-T29N-R23E                                                                13-T29N-R23E
                                                                                                                                                                                                                                                   ee
                                                                                                                                                                                                                                                                                                                                                                                                                                             18-T29N-R24E
                                                                                                                                                                                                                                                Cr




                                                                                                                                                                                                                                                                                                                                                          S 607 Rd
                                                                                                                                                                                                                                                                                15-T29N-R23E
                                                                                                                                                                                                                                         t le
                                                                                                                                                                                                                                       Ly




                                                                                                                                                                                                       St
                                                                                                          E 20 Rd
                                                                                                                                                                                                              E A St
                                                                                                                                                                                                                                                                                                                                                                                                          E 20 Rd
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                                                                                                                                                                                                                                                                                                                                                                                         io C




                                                                                                                                                                                                                                                                                                                                                                                                                                                                     9
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                                                                                                                                                                                                                                                                                                                                                                                                                             19-T29N-R24E




                                                                                                                                                                                                                                                                                                     S 600 Rd
23-T29N-R22E                                             24-T29N-R22E                                                                                                                                                                                                                                                                                                                                      ree




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                                                                                                              19-T29N-R23E                                         20-T29N-R23E                                                                                                                                                                                                                                k




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                                                                                                                                                                                                                                                                                                                                                                                                                                                     ate
                                                                                                                                                                                 W 8th St




                                                                                                                                                                                                                                                                                                                                                                                                                                                   St
                                                                                                                                  Cardin
                                                                                          Rd




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                                                                                                                                                                                                                                                                                                                                                                                   S 614 Rd




                                                                                                                                                                                                                                                                                                                                                                                                                                   Un
                                                                 E 30 Rd                                                                                                                   ee
                                                                                                                                                                                                                                                                                                                                                                                              OWRB
                                                                                                                                                                 E 30th Rd
                                                                                                                                                                                         Cr
                                                                                                                                                                                                  E 12th St
                                                                                               S 560 Rd




                                                                                                                                                                                                                                                                                                                                 E 30 Rd                                                                                                                           E 30 Rd
             reek




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                                                        25-T29N-R22E                                                                                                             Ly
        Elm C




                                                                                                                                                     Tar Creek
                                                                                                                                                                                                                                                              27-T29N-R23E                                                                                                                                                                                                                      29-T29N-R24E
                                                                                                                             Rd




                                                                                                                                                                                                                                                                                                                                                                                                                                                                              S 630 Rd
                                                                                                              30-T29N-R23E
                                                                                                                          65




                                                                                                                                                                                                          28-T29N-R23E
                                                                                                                                                                                                                                                                                                                 26-T29N-R23E
                                                                                                                        S5




       26-T29N-R22E                                                                                                                                                                                                                                                                                                                                                                                                                        30-T29N-R24E




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                                                                                                                                                                     29-T29N-R23E
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                                                                                                                                                                                                                                                                                 Cr
                                S 550 Rd




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                    E 40 Rd                                                                                                                 E 40 Rd                                                                                                                                                                                                     Be




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                                                        36-T29N-R22E
                                                                                                                                                                                                                                                                                               Quapaw4th St                                                              ee
Elm




                                                                                                                                                                                                                                                                                                    E                                                                      k




                                                                                                                                                                                                                                                S 590 Rd
                                                                                                             31-T29N-R23E                                                                                                                                                                                                                                                                                                                    31-T29N-R24E
                                                                                                                                                                  32-T29N-R23E




                                                                                                                                                                                                                                                                                                                                                                                                                        S 620 Rd
   35-T29N-R22E                                                                                                                                                                                          33-T29N-R23E                                                                                                                                                                                                                                                                       32-T29N-R24E




                                                                                                                                                                                                                                                                                                                                      Whitebird St
                                                                                                                                                                                                                                                                                                                35-T29N-R23E                                                       36-T29N-R23E
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               E 45 Rd




                                                                                                                                                                                                                                                                                                  S 600 Rd
                                                                                                                                                                                                                                                              34-T29N-R23E


                        E 50 Rd                                                                                       E United States Highway 69
                                                                                                                                                                                                                                                                                                                                                          E 50 Rd




                                                                                                                                                                                                                                                                                                                                                                                                                                       S 630 Rd
                                                                                                                                                                                                                                     3-T28N-R23E
               1-T28N-R22E                                                      6-T28N-R23E                                       5-T28N-R23E




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     S 638 Rd
                                                                                                                                                                                    4-T28N-R23E                                                                                      2-T28N-R23E                            1-T28N-R23E
                                                      Commerce                                                                                                                                                                                                                                                                                                                                            6-T28N-R24E
                                                                                                                                                                                                                                                                                                                                                                                                                                                              5-T28N-R24E
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    4-T28N-R24E
                                                                                                                                                                                                                          S 592 Rd




                                                                                                                                                                                                                                                                                                                                                       E 57 Rd                                                                                                                            E 57 Rd
             E 60 Rd                                                     D St                                                                   E 060 Rd
                                                                                   E St
                                                                                                               k




                                                                                                                                                                                                                                                                                                                                                                                                                      E 60 Rd
                                           Maxum Dr




                                                                                                                                                                                                                                                                                                                                                                                              S 620 Rd
                                                                                                            ree




                                                                                                                                                                                                                                                                                                                                                                                                                                                  S 630 Rd
                                                                                                              C




                                                                                                                                                                                                                                     10-T28N-R23E
11-T28N-R22E
                                                                                                          Tar




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            S 642 Rd
                                                                                                                                                                                    9-T28N-R23E
   12-T28N-R22E                                                                                                                   8-T28N-R23E
                                                                                                                                                                                                                                                                                    11-T28N-R23E                                                     12-T28N-R23E                                          7-T28N-R24E
       Newman Rd                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   9-T28N-R24E
                                                                                7-T28N-R23E                                                                                                                                                                                                                                                                                                                                                                   8-T28N-R24E
                                                                                                                                                                                                                                                                                                                                                                                                                   I-44
                                                                                                                                                                                                                                                           Figure 1-1                                                                                   Tar Creek OU4
        M St




                                                                                                                                                                                                                                                                                        E 66 Rd
        N St




                                                                                                                                                                                                                                                                                                                                                                                                                                                  S 630 Rd
                                                                                                                                                                                                                                                                                                                                                                                                                   E 69 Rd

                                                                                                                                     E 70 Rd
                                                                                                                                                                                                                                                                                                                                                      Site Boundary Map
            North Miami
                                                                                                                                                                                                                                                                     S 600 Rd




14-T28N-R22E
P St




                                                                            18-T28N-R23E                                          17-T28N-R23E
                                                                                                                                                                                                              S 590 Rd




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              73 Rd
                                                                                                                  N Elm St
                                                             N Main St




                                                                                                                                                                                                                                                                                                                                              13-T28N-R23E                                                                                                      E 72 Rd              E
                                                                                                                                                                      S 580 Rd




                                                                                                                                                                                                                                                                                Site Boundary                                                Section Boundaries                                                       Roads                                         Rivers and Streams
                                                                                                                                                                                                                                                                                                                  State Highway 137




            13-T28N-R22E
                                                                                                                                                                                                                                                                     14-T28N-R23E                                                                                                                                                                            17-T28N-R24E
                                                                                                                                                                                                                                                                                                                                                                                                          18-T28N-R24E
                                                                                                                                                                                                                         15-T28N-R23E




                                                                                                                                                                                                                                                                                                                                                                                                                                                                               S 638 Rd
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   16-T28N-R24E
                         G St




                                                                                                                                                                                  16-T28N-R23E


       22nd Ave
                                                                                                                                                                                                                                                               AATA INTERNATIONAL, INC. 0                                                                                                                                          1                                                        2 Miles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              F
                                                      B St



                                                                            D St




           24-T28N-R22E                                                     19-T28N-R23E                                          20-T28N-R23E
                                                                                                                                                                                     E 80 Rd
                                                                                                                                                                                  21-T28N-R23E                                     E
                                                                                                                                                                                                                         22-T28N-R23E80 Rd                     Fort Collins, Colorado, USA
                                                                                                                                                                                                                                                                    23-T28N-R23E         24-T28N-R23E                                                                                                    19-T28N-R24E                                          20-T28N-R24E                       21-T28N-R24E
                                                                                                                                                              Hockerville
                                                                                                                                                                                  20th


                                               A Street




                                                                                   Cardin
                                                                                                                                Picher
                                                                                                                                                                                         £
                                                                                                                                                                                         69




                                                                                                                     Con nell
                                                                                                                                                         Quapaw




                                                                                                                                                              £   69
                                                                                                                                                       £66

                                                                                                               £69




                                                                                         Commerce
                                                                       £  69




                                              LEGEND                                                                                                                                                                               Figure 6-1
                                                                                                                                                                                                                         Alternative 4 and 5
                                                          OU4 Site Boundary              Smelter Location
                                                                                                                                                                                          Chat Piles, Chat Bases and Fine Tailings Locations
                                                          Chat Bases                     Near Stream All Materials                                                                                                                 Tar Creek Superfund Site
                                                                                                                                                                                                                                            Operable Unit 4
                                                          Chat Piles                                                                                                       Feet                                                   Ottawa County, Oklahoma
                                                          Fine Tailings
                                                                                                                                         0   2,500   5,000             10,000                  *AERIAL PHOTOGRAPHY PROVIDED BY:AATA INTERNATIONAL INC.
                                                                                                                                                                                                                                Fort Collins, Colorado, USA
File Path: \\chuckwagon\GIS\NWOFiles\Tar Creek\MXD\MAY 2007 FS Report\Figure 6-1.mxd, Date: May 02, 2007
                                                           Figure 6-2
                                                 Alternative 4 and Alternative 5
                                                   Source Material Summary

              35,000,000
                                                                                    Site Totals (47,768,846 CY)

              30,000,000
                                                                                                                 Chat Piles
                                                                                     1%
              25,000,000                                                                  0%
                                                                            14%                                  Fine Tailings & Washed
                                                                                                                 Fines
                                                                                                                 Chat Base
Cubic Yards




              20,000,000                                             19%
                                                                                                       66%       Rail/Road Beds


              15,000,000                                                                                         Smelter Waste (< 1%)



              10,000,000



               5,000,000



                      0
                           Chat Piles   Fine Tailings & Washed        Chat Base                 Rail/Road Beds     Smelter Waste (< 1%)
                                                  Fines

                                                            All Other Settings    Near Stream
                                       Elm Creek                                                                                                                                     NE Distal Zone
                                       Distal Zone
                                                                                                                                 20th




                                                                                                                             Picher
                                                                                                                                                                                          £ Spring River
                                                                                                                                                                                          69


                                          Elm Creek                                                                                                                                            Watershed




                                                                                                                      Con nell
                                          Watershed

                                                                                                                                                                                 SE Distal Zone


                                                                                                                                 Tar Creek
                                                                                                                                 Watershed              Quapaw




                                                                                                                                                             £   69
                                                                                                                                                      £66

                                                                                                                 £
                                                                                                                 69




                                                                                          Commerce
                                                                    £  69




                                                  Legend                                                                                                                                                                              Figure 6-3
                                                                                                                                                                                                          Alternative 4 and 5 Distal Zone Areas
                                                           Watersheds                  Chat Piles
                                                                                                                                                                                                                                   Tar Creek Superfund Site
                                                           Site Boundary               Distal Zones                                                                                                                                         Operable Unit 4
                                                                                                                                                                          Feet                                                    Ottawa County, Oklahoma
                                                           Chat Bases                                                                   0   2,500   5,000             10,000                   *AERIAL PHOTOGRAPHY PROVIDED BY:AATA INTERNATIONAL INC.
                                                                                                                                                                                                                                Fort Collins, Colorado, USA
File Path: \\chuckwagon\GIS\NWOFiles\Tar Creek\MXD\MAY 2007 FS Report\All Distal Zones.mxd, Date: May 02, 2007
      Is the Quality of
                                          No
    Groundwater Known?



                                                 Excavate and Haul
              Yes



                               No



        Is a Surficial
    Subsidence Structure
          Nearby?                              Will a Chat Processor                 Release to a
                                                                          Yes
                                                Accept Materials?                    Chat Washer



              Yes

                                    Yes
                                                         No




      Would the Quality of
   Groundwater be Adversely
     Affected by Filling the
    Subsidence Structure?                        Is it Cost Effective
                                                                                      Release to
                                                 to Inject into Mine      No
                                                                                      Repository
                                                       Working?


              No

                                                         Yes
   Fill Surficial Depression
   (Subsidence Structure)


                                                      Results of
  Monitor Groundwater and                       Hydrogeologic Study
   Subsidence Structure                        Indicates that Injection
                                                                                No

                                                 is a Viable Option?




                                                         Yes



                                               Inject in Mine Workings




Figure 6-4 Decision Flowchart for the Disposal of Chat
Figure 6-5 Decision Flowchart for Fine Tailings
                                                                                                                                                               20th


                                         A Str eet




                                                                                                                                                                                 £
                                                                                                                                                                                 69




                                                                                                                                                               Main
                                                                                                                       Con nell




                                                                                                                                                          £
                                                                                                                                                          69
                                                                                                              £
                                                                                                              69
                                                                                                                                          £
                                                                                                                                          66
                                                                             £ 69




                                                      Legend                                                                                                                                                                   Figure 6-6
                                                                                                                                                                      Alternative 4 and 5 Fine Tailing Locations and Proposed Disposition
                                                              Major Roads
                                                              Fine Tailings Proposed for Covering                                                                                                                              Tar Creek Superfund Site
                                                                                                                                                                                                                                        Operable Unit 4
                                                              Fine Tailings Proposed for Injection                                                                                                                            Ottawa County, Oklahoma
                                                              Site Boundary                                                                        Feet
                                                                                                                   0    2,500     5,000        10,000                                      *AERIAL PHOTOGRAPHY PROVIDED BY:AATA INTERNATIONAL INC.
                                                                                                                                                                                                                            Fort Collins, Colorado, USA
File Path: \\chuckwagon\GIS\NWOFiles\Tar Creek\MXD\MAY 2007 FS Report\Fine Tailings.mxd, Date: May 03, 2007
                                                                                                                 HOWE
                                                                                                                   1085
                                                                                                                   Feet




                                                                                                                      650
                                                                                                                      Feet



                                                                                                                      KENOYER


                                                                                                                             1267
                                                                                                                             Feet




                                                                                                           ADMIRALTY NO. 4


                                                                                                                        2021
                                                                                                                        Feet




                                                                                                                                                                                   Figure 6-7
                                        LEGEND                                                                                                Estimated Source and Seepage Control Locations
                                                  Edge Needing Possible Control                                                                                                      Tar Creek Superfund Site
                                                                                                                                                                                              Operable Unit 4
                                                  Near Stream Chat Pile or Chat Base                                                                                                Ottawa County, Oklahoma
                                                                                                                                       Feet
                                                                                                           0    500     1,000       2,000        *AERIAL PHOTOGRAPHY PROVIDED BY:AATA INTERNATIONAL INC.
                                                                                                                                                                                  Fort Collins, Colorado, USA
File Path: \\chuckwagon\GIS\NWOFiles\Tar Creek\MXD\MAY 2007 FS Report\Figure 6-7.mxd, Date: May 03, 2007
                                                       Relocation Assistance Zone
          Kansas

     Oklahoma                                                                                                                       Hockerville
                                                                                                                                                                  18
                                                                                                                                    14            13
                                                                                        16                  15
                                         18                    17
    14                     13

                                                                         Picher


                                                                                                                                                  24              19
                                                                                                                                     23
                                                                                         21                 22
                                         19                    20
    23                      24



                                                   Cardin

                                                                                                                                                        Hwy 69A
                                                                                                                                                                  30
                                                                                                                                                   25
                                                                                                                                     26
                                                                                             28              27
                                                                29
                             25           30
    26




                                                                                                                       Quapaw




                                                                                                                                                                            Updated 10-5-06
                                                                                                                                                                   31
                                                                                                                                         35            36
                                                                                             33                  34
                                              31                    32
     35                         36



                                                             Hwy 69
                                                                                                                                              1              6          5
                                     6                 5                     4                      3                  2




                                         :
Legend                                                                                                                      Miles
                                                                                  0   0.25    0.5       1        1.5       2
   City Boundaries
   Subsidence Buffer Areas 150 ft                                                                                                    Figure 6-8
   Mine Workings
   Relocation Assistance Zone                          Adopted by the Lead-Impacted Communities Relocation Assistance Trust on August 1, 2006
Appendices
(This page intentionally left blank.)
                               Appendix A
EPA Region 6 Ecological Risk Memorandum
and the background concentrations of these metals are comparable between both of the Cherokee
County Superfund Site and the Tar Creek OU4 Superfund Site.


       The climate at both the Cherokee County Superfund Site and the Tar Creek OU4
Superfund Site is characterized by hot summers and cold winters with the same precipitation and
temperature ranges. The topography at both Sites is characterized by gently rolling plains with
the natural upland terrestrial vegetation composed of grass (switchgrass, bluestem and Indian
grass) with deciduous forest (oak-hickory). Fauna at the Sites is composed of same bird and
mammal communities. Mammals at both Sites include white-tail deer, Virginia opossum,
cottontail rabbit, white-footed mouse, short-tail shrew, hispid cotton rat, deer mouse and
meadow vole. Birds at both Sites include the meadowlark, blue jay, American robin, American
woodcock, cardinal, starling, and flickers.


       The bird and mammal communities at both the Cherokee County Superfund Site and the
Tar Creek OU4 Superfund Site would have the same exposure pathways to the cadmium, lead
and zinc contamination. Exposure to birds and mammals at both Sites can result from the
incidental ingestion of soil and through diet (e.g., contaminated plants, earthworms and insects).
The incidental ingestion of soil can take place during foraging and grooming activities of birds
and mammals. Cadmium, lead and zinc level are present at levels sufficient to present risk to
fauna through ingestion of soil alone at both the Cherokee County Superfund Site and the Tar
Creek OU4 Superfund Site.


       The Screening Level Ecological Risk Assessment for the Tar Creek OU4 Superfund Site
indicated the potential for unacceptable ecological risk and found the primary risk drivers to be
cadmium, lead and zinc. The source of cadmium, lead and zinc contamination at both the
Cherokee County Superfund Site and the Tar Creek OU4 Superfund Site is from the same ore
body - the Picher field ore. The bird and mammals communities at both the Cherokee County
Superfund Site and the Tar Creek OU4 Superfund Site are comparable and these communities
would be exposed by the same exposure pathways (incidental ingestion and diet). Cadmium,
lead and zinc are present at both Sites at levels sufficient to present risk to fauna through the
incidental ingestion of soil alone. The Region 7 Memorandum presented a range of soil
Ecological Preliminary Remediation Goals (considering the direct exposure by incidental soil
ingestion of soil and indirect exposure by the diet) for both birds (i.e., American woodcock) and
mammals (i.e., short-tailed shrew). The Region 7 Memorandum provided the soil Ecological
Preliminary Remediation Goals ranges for cadmium (1 – 10 mg/kg), lead (377 – 1175 mg/kg),
and zinc (156 – 1076 mg/kg) for use at the Cherokee County Superfund Site. Due to the
similarities of the ecosystems at the Cherokee County Superfund Site and at the Tar Creek OU4
Superfund Site, it is my opinion that these soil Ecological Preliminary Remediation Goals ranges
can be used at both Sites.
                            Appendix B
Graphical Summary of the Alternatives
                                         Appendix B-1 Alternative 4 and Alternative 5
                                            Processing Versus Non-Processing

              35,000,000
                                                                                     Site Totals (48,090,846 CY)

              30,000,000
                                                                       18,859,846,
                                                                          39%
              25,000,000
Cubic Yards




              20,000,000                                                                                           29,231,000,
                                                                                                                      61%


              15,000,000



              10,000,000



               5,000,000



                      0
                           Chat Piles   Fine Tailings & Washed       Chat Bases            Rail/Road Beds     Smelter Waste (< 1%)
                                        Fines (includes 10% of
                                        washed fines generated
                                            by processing)

                                                 Processed by Chat Sales   Not Processed by Chat Sales
                                               Appendix B-2 Alternative 4 and Alternative 5
                                              Proposed Remedial Actions by Source Material



              10,000,000
                                                                                                                      Excavate and
               9,000,000                                                                                              Haul to
                                                                                                                      Washing
                                                                                                                      Operation
               8,000,000

               7,000,000                                                                                              Cover in
                                                                                                                      Place
               6,000,000
Cubic Yards




               5,000,000
                                                                                                                      Infill into Mine
                                                                                                                      Shaft or
               4,000,000                                                                                              Subsidence
                                                                                                                      Feature
               3,000,000
                                                                                                                      Excavate and
               2,000,000                                                                                              Haul to Local
                                                                                                                      Repository
               1,000,000

                      0                                                                                               Inject into
                                                                                                                      Mine Cavern
                            Fine Tailings &    Chat Piles      Chat Bases      Rail/Road Beds   Smelter Waste (<1%)
                             Washed Fines
                           (includes 10% of
                             washed fines
                             generated by
                              processing)
                                                             Source Material
                        Appendix B-3 Alternative 4 and Alternative 5
                 Proposed Remedial Actions for All Source Material Combined
                                 18,859,846 Cubic Yards




                                                                              Inject into Mine Cavern


                                                  5,509,000, 29%



7,036,000, 37%                                                                Excavate and Haul to
                                                                              Local Repository




                                                                              Infill into Mine Shaft or
                                                                              Subsidence Feature




                                                                              Cover in Place
                                                      939,846, 5%



                                                 938,000, 5%
                                                                              Excavate and Haul to
                                                                              Washing Operation


                    4,437,000, 24%
                                                    Appendix B-4 Alternative 4 and Alternative 5
                                                Proposed Remedial Actions for Chat Source Material


              10,000,000

                                                                                      Proposed Remedial Actions by Percentage
                                RR Beds
               9,000,000        702,000

                                                                                                                  5%
               8,000,000                                                                                               10%


                                                                                                                              10%
               7,000,000


               6,000,000
Cubic Yards




                                  Bases                                                               75%
                                6,709,000
               5,000,000


               4,000,000
                                                         7,036,000

               3,000,000


               2,000,000


                                   Piles
               1,000,000        1,969,000
                                                                                                             938,000                    938,000
                                                                                    468,000
                      0
                           Chat Not Processed      Excavate and Haul to     Inject into Mine Cavern    Excavate and Haul to     Infill into Mine Shaft or
                           (Requires Remedy)        Washing Operation                                    Local Repository        Subsidence Feature
                                                                          Proposed Remedial Actions
                                                  Appendix B-5 Alternative 8
                                              Processing Versus Non-Processing


              35,000,000
                                                                                          Site Totals (48,090,846 CY)
              30,000,000                                                    18,859,846,
                                                                               39%



              25,000,000
Cubic Yards




                                                                                                                   29,231,000,
              20,000,000
                                                                                                                      61%



              15,000,000



              10,000,000



               5,000,000



                      0
                           Chat Piles   Fine Tailings & Washed      Chat Bases               Rail/Road Beds    Smelter Waste (< 1%)
                                        Fines (includes 10% of
                                        washed fines generated
                                            by processing)

                                                Processed by Chat Sales   Not Processed by Chat Sales
                                                           Appendix B-6 Alternative 8
                                                  Proposed Remedial Actions by Source Material



              10,000,000

               9,000,000
                                                                                                                          Cover in Place
               8,000,000

               7,000,000

               6,000,000
Cubic Yards




               5,000,000                                                                                                  Infill into Mine
                                                                                                                          Shaft or
               4,000,000                                                                                                  Subsidence
                                                                                                                          Feature
               3,000,000

               2,000,000
                                                                                                                          Inject into
               1,000,000                                                                                                  Mine Cavern

                      0
                              Fine Tailings &      Chat Piles      Chat Bases      Rail/Road Beds   Smelter Waste (<1%)
                               Washed Fines
                             (includes 10% of
                               washed fines
                               generated by
                           processing - covered
                                  in place)
                                                                 Source Material
                               Appendix B-7 Alternative 8
                 Proposed Remedial Actions for All Source Material Combined
                                 18,859,846 Cubic Yards




                                                                                Inject into Mine Cavern



                                                               6,688,000, 35%




7,481,846, 40%                                                                  Infill into Mine Shaft or
                                                                                Subsidence Feature




                                                                                Cover in Place




                                 4,690,000, 25%
                                                          Appendix B-8 Alternative 8
                                               Proposed Remedial Actions for Chat Source Material


              10,000,000

                                         RR Beds
               9,000,000                 702,000


               8,000,000


               7,000,000


               6,000,000
Cubic Yards




                                           Bases
                                         6,709,000
               5,000,000


               4,000,000


               3,000,000

                                                                           4,690,000                       4,690,000
               2,000,000

                                            Piles
               1,000,000                 1,969,000


                      0
                           Chat Not Processed (Requires Remedy)     Inject into Mine Cavern   Infill into Mine Shaft or Subsidence
                                                                                                              Feature
                                                                  Proposed Remedial Actions
                 Appendix C
Alternative Cost Estimates
     Table C-1
     Alternative 4 Estimated Costs
     Phased Consolidation, On-Site Disposal and Institutional Controls


Phase 1 Activities (Years 1 to 10)
Item #                       Item Description                            Est. Quantity    Units    Est. Unit Cost Estimated Cost   Cost Basis                                              Assumptions
         Chat Pile and Base Removal from the NE Distal Zone by                                                                                  100% of material located in this area is removed by excavation and hauling; material
1.       Excavation and Hauling                                                                                                                 delivered to chat washing operator located in central portion of the Site.
                                                                                                                                                Entire area of piles and bases plus 50-foot buffer zone area. Does not include removal of
         a. Clear, grub, and remove old structures                                559     acres         $533.50        $298,227       OCC-1     buildings or reinforced structures (i.e., mill foundations, etc.).
         b. Excavate and load chat                                          2,391,000    cu.yds.          $1.70       $4,064,700        CCI     See detail sheets for unit rate development.
         c. Haul, dump and place, 12-mile roundtrip                         2,391,000    cu.yds.          $3.11       $7,436,010        CCI     See detail sheets for unit rate development.
                                                                                                                                                Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         d. Deep till excavated area and buffer zone                              559     acres         $911.00         $509,249         CCI    average speed used. The appropriate number of moves is included in the unit cost.
         e. Amend soils prior to revegetation                                     559     acres         $320.00         $178,880         CCI    2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         f. Revegetate excavated areas                                            559     acres        $1,200.00        $670,800         CCI    Land area is disced, seeded and mulched.
         Subtotal Item 1                                                  $13,157,866

         Chat Pile and Base Removal from the SE Distal Zone by                                                                                  100% of material located in this area is removed by excavation and hauling; material
2.       Excavation and Hauling                                                                                                                 delivered to chat washing operator located in central portion of the Site.
                                                                                                                                                Entire area of piles and bases plus 50-foot buffer zone area. Does not include removal of
         a. Clear, grub, and remove old structures                                172     acres         $533.50          $91,762      OCC-1     buildings or reinforced structures (i.e., mill foundations, etc.).
         b. Excavate and load chat                                            630,000    cu.yds.          $1.70       $1,071,000        CCI     See detail sheets for unit rate development.
         c. Haul, dump and place, 12-mile roundtrip                           630,000    cu.yds.          $3.11       $1,959,300        CCI     See detail sheets for unit rate development.
                                                                                                                                                Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         d. Deep till excavated area and buffer zone                              172     acres         $911.00         $156,692         CCI    average speed used. The appropriate number of moves is included in the unit cost.
         e. Amend soils prior to revegetation                                     172     acres         $320.00          $55,040         CCI    2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         f. Revegetate excavated/deep tilled area                                 172     acres        $1,200.00        $206,400         CCI    Land area is disced, seeded and mulched.
         Subtotal Item 2                                                   $3,540,194

         Chat Pile and Base Removal from the Elm Creek Watershed                                                                                100% of material located in this area is removed by excavation and hauling; material
3        Distal Zone by Excavation and Hauling                                                                                                  delivered to chat washing operator located in central portion of the Site.
                                                                                                                                                Entire area of piles and bases plus 50-foot buffer zone area. Does not include removal of
         a. Clear, grub, and remove old structures                                381     acres         $533.50        $203,264       OCC-1     buildings or reinforced structures (i.e., mill foundations, etc.).
         b. Excavate and load chat                                          3,138,000    cu.yds.          $1.70       $5,334,600        CCI     See detail sheets for unit rate development.
         c. Haul, dump and place, 12-mile roundtrip                         3,138,000    cu.yds.          $3.11       $9,759,180        CCI     See detail sheets for unit rate development.
                                                                                                                                                Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         d. Deep till excavated area and buffer zone                              381     acres         $911.00         $347,091         CCI    average speed used. The appropriate number of moves is included in the unit cost.
         e. Amend soils prior to revegetation                                     381     acres         $320.00         $121,920         CCI    2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         f. Revegetate excavated/deep tilled area                                 381     acres        $1,200.00        $457,200         CCI    Land area is disced, seeded and mulched.
         Subtotal Item 3                                                  $16,223,255




                                                                                                          PAGE 1 OF 8                                                                                                        JULY 2007
     Table C-1
     Alternative 4 Estimated Costs
     Phased Consolidation, On-Site Disposal and Institutional Controls


Item #                        Item Description                           Est. Quantity      Units    Est. Unit Cost Estimated Cost      Cost Basis                                            Assumptions
         Excavate, Haul and Dispose of Smelter Wastes in a Local
4.       Repository
                                                                                                                                                    Includes brush and tree removal around source material area and affected soils area. Does
         a. Clear, grub, and remove old structures                                 14       acres         $533.00           $7,462           OCC-1 not include removal of buildings or reinforced structures.
         b. Excavate and load smelter waste                                     1,846      cu.yds.          $1.70           $3,138             CCI Shallow excavation, approximately 1 feet deep. See details sheets for unit rate development.
         c. Haul, dump and place, 12-mile roundtrip                             1,846      cu.yds.          $3.11           $5,741             CCI See detail sheets for unit rate development.
                                                                                                                                                     Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                    other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         d. Deep till excavated area and smelter affected soils                    14       acres         $911.00          $12,754             CCI average speed used. The appropriate number of moves is included in the unit cost.
         e. Add biosolids or organic matter                                       280        tons           $30.00          $8,400           Jasper 20 tons per acre.
         f. Amend soils prior to revegetation                                      14       acres         $320.00           $4,480             CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         g. Revegetate excavated/deep tilled area                                  14       acres        $1,200.00         $16,800             CCI Land area is disced, seeded and mulched.
         Subtotal Item 4                                                      $58,775

                                                                                                                                                        Assumes 61 ponds containing an estimated 5,041,000 yd3 of material (includes 10% of
5.       Inject Fine Tailings into Mine Workings                                                                                                        washed fines generated by processing) covering an estimated area of 569 acres is injected.
                                                                                                                                                        Entire area of ponds addressed by injection plus 50-foot buffer zone area. Does not include
         a. Clear and grub fine tailings and buffer zone areas                    831        acres        $533.00        $442,923            OCC-1      removal of buildings or reinforced structures (i.e., mill foundations, etc.).
         b. Mobilize/move between ponds and injection locations                   287     location      $13,012.00      $3,734,444              CCI     Assumes one move per injection boring (i.e., location) plus one mobilization.
         c. Injection boring installation                                         286       boring      $16,000.00      $4,582,727   Venture Drilling   One 10-inch diameter injection boring per 17,600 yd3 of fine tailings material.
         d. Extraction boring installation                                         61       boring      $16,000.00       $976,000    Venture Drilling   One 10-inch diameter extraction boring per pond.
         e. Boring abandonment                                                    347       boring      $10,000.00      $3,474,205   Venture Drilling   Bladder installation and cement grout to surface.
         f. Inject fines at 200 tons/hour                                   5,041,000      cu.yds.           $5.76     $29,036,160              CCI     See detail sheets for unit rate development.
                                                                                                                                                         Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the other,
                                                                                                                                                        two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH average
         g. Deep till underlying soils and buffer zone                            831       acres         $911.00         $757,041              CCI     speed used. The appropriate number of moves is included in the unit cost.
         h. Amend soils prior to revegetation                                     831       acres         $320.00         $265,920              CCI     2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         i. Revegetate underlying soils/deep tilled areas                         831       acres        $1,200.00        $997,200              CCI     Land area is disced, seeded and mulched.
         Subtotal Item 5                                                  $44,266,620

6.       Complete Hydrogeologic Studies
                                                                                                                                                   Studies are completed to assess hydrogeologic system and potential impacts resulting from
         a. Hydrogeologic investigations and studies                                1    lump sum    $3,000,000.00      $3,000,000    Quapaw Tribe injection of source materials.
         Subtotal Item 6                                                   $3,000,000




                                                                                                            PAGE 2 OF 8                                                                                                             JULY 2007
     Table C-1
     Alternative 4 Estimated Costs
     Phased Consolidation, On-Site Disposal and Institutional Controls


Item #                       Item Description                            Est. Quantity        Units    Est. Unit Cost Estimated Cost     Cost Basis                                           Assumptions
7.     Cover Fine Tailings in Place with Soil Cover
                                                                                                                                                   Entire area of ponds addressed by covering plus 50-foot buffer zone area. Does not include
         a. Clear and grub fine tailings and buffer zone areas                    275         acres         $533.00         $146,575         OCC-1 removal of buildings or reinforced structures (i.e., mill foundations, etc.).
         b. Regrade and recontour tailings and berms                              251         acres        $2,400.00        $602,400           CCI No change in surface area.
                                                                                                                                                   Soil cover equivalent to 12-inches clay and 12-inches loam. See detail sheets for unit rate
         c. Furnish and load cover soil                                       898,000        cu.yds.         $10.24       $9,195,520           CCI development.
         d. Haul and dump cover soil(14.2 miles round trip)                   898,000        cu.yds.          $3.41       $3,062,180           CCI See detail sheets for unit rate development.
         e. Compact cover soil                                                898,000        cu.yds.          $1.26       $1,131,480           CCI See detail sheets for unit rate development.
                                                                                                                                                       Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                       other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         f. Deep till buffer zone                                                  24         acres         $911.00          $21,864             CCI   average speed used. The appropriate number of moves is included in the unit cost.
         g. Amend soils prior to revegetation                                     275         acres         $320.00          $88,000             CCI   2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         h. Establish cover vegetation/revegetate deep tilled area                275         acres        $1,200.00        $330,000             CCI   Land area is disced, seeded and mulched.
         i. Institutional control - deed notice                                    28         parcel        $500.00          $13,750   Eng. Estimate   Assumes 1 parcel (i.e. deed notice) per 10 acres.
         Subtotal Item 7                                                  $14,591,769

         Integrate Near Stream Source Materials and Control                                                                                            Interim actions that may be required to prevent further damages to resources while chat
8.       Seepage/Runoff                                                                                                                                processing (by others) is ongoing or before full-scale remedial actions can take place.

         a. Clear and grub floodway areas                                         581         acres         $533.50         $309,964            CCI Does not include removal of buildings or reinforced structures (i.e., mill foundations, etc.).
                                                                                                                                                    Assumes near-stream chat within 200 feet of streams requires integration with primary
         b. Integrate floodway chat with original source                    1,252,952        cu.yds.           $2.26      $2,831,672            CCI source. Assumes dozer work with no loading or hauling.
                                                                                                                                                    Assumes near-stream tailings within 200 feet of streams require consolidation outside the
         c. Integrate floodway fine tailings with original source             283,095        cu.yds.           $2.26        $639,795            CCI floodway. Assumes dozer work with no loading or hauling.
                                                                                                                                                    Assumes 48" of rip-rap placed at bends in stream channels where chat or tailings are
                                                                                                                                                    located. Quantity based on 0.44tons/L.F. of stream length(3.2 miles). Rip rap from Midwest
         d. Furnish and install rip-rap or revetment                            4,228       cu.yds.          $39.11        $165,357             CCI Mineral, Quapaw Quarry At $13.50/ton loaded plus 5.85% sales tax
         e. Install berms and dikes - small berms                              71,770       cu.yds.          $14.91       $1,070,091            CCI Assume 2.67 CY of compacted clay per lineal foot of berm. Estimated using D-4 and CAT
         f. Install sheet piling to prevent seepage and direct runoff          90,414    square feet         $25.00       $2,260,350            CCI Assumes estimated linear distance of 5,023 feet, 18-foot sheet length.
                                                                                                                                                     Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                    other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         g. Deep till excavated areas                                             581         acres         $911.00         $529,291            CCI average speed used. The appropriate number of moves is included in the unit cost.
         h. Amend soils prior to vegetation                                       581         acres         $320.00         $185,920            CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         i. Revegetate excavated areas                                            581         acres        $1,200.00        $697,200            CCI Land area is disced, seeded and mulched.
         Subtotal Item 8                                                  $8,689,639




                                                                                                              PAGE 3 OF 8                                                                                                           JULY 2007
      Table C-1
      Alternative 4 Estimated Costs
      Phased Consolidation, On-Site Disposal and Institutional Controls


Item #                           Item Description                         Est. Quantity        Units    Est. Unit Cost Estimated Cost     Cost Basis                                         Assumptions
          Excavation of In-Stream Source Materials from Tar, Lytle,                                                                                    Assumes sections of Tar Creek, Lytle Creek, Elm Creek, and Beavers Creek require source
9.        and Beaver Creeks                                                                                                                            removal from stream beds and immediate banks.
          a. Clear and grub stream banks                                            35         acres        $1,800.00         $63,000            CCI
                                                                                                                                                       Assumes near-stream chat within 200 feet of streams requires integration with primary
                                                                                                                                                       source using a D-8. Assumes a Cat 330 hoe to pull additional material out of the streams
          b. Excavate source materials from streams                             18,394       cu.yds.          $17.51         $322,079            CCI   and D-8 to integrate it with its primary source.
          c. Bank work and regrading                                            49,021       cu.yds.           $2.26         $110,787            CCI   Estimated using D-4
                                                                                                                                                       Assumes 48" of rip-rap placed at bends in stream channels where chat or tailings are
                                                                                                                                                       located. Quantity based on 0.44tons/L.F. of stream length (2.7 miles). Rip rap from Midwest
          d. Furnish and install rip-rap or revetment                            3,595       cu.yds.           $39.11        $140,600            CCI   Mineral, Quapaw Quarry At $13.50/ton loaded plus 5.85% sales tax
          e. Amend bank soils prior to revegetation                                 35        acres          $320.00          $11,200            CCI   2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
          f. Revegetate stream bank                                                 35        acres         $1,200.00         $42,000            CCI   Land area is disced, seeded and mulched.
          Subtotal Item 9                                                     $689,667


          Covering of In-Stream Source Materials from Tar, Lytle, and                                                                                Assumes sections of Tar Creek, Lytle Creek, Elm Creek, and Beavers Creek require
10.       Beaver Creeks Using a Flexible Membrane Liner                                                                                              installation of FML, approximately 6.5 miles of streams, combined, 60 feet wide.
                                                                                                                                                     60 mil HDPE liner 36 feet wide installed in 10.8 miles of stream. 30' wide under stream with
          a. Stream liner (60-mil HDPE)                                      2,059,200    square feet           $2.21      $4,550,832            CCI 3' buried as anchors on each side
                                                                                                                                                       The 152,533 cy is 10.8 miles @ 2' thick and 36' wide. The material will be purchased from a
                                                                                                                                                       local quarry, hauled, dumped, spread, and compacted. Price at the quarry is $3.95/ton
          b. Filter blanket (fines)                                            152,533        cu.yds.         $14.33       $2,185,803            CCI   loaded plus 5.85% sales tax.
          c. Bank work and regrading, ground prep                              305,067        cu.yds.          $2.26        $689,451             CCI   Estimated using D-4
                                                                                                                                                       Assumes 48" of rip-rap placed at bends in stream channels where chat or tailings are
                                                                                                                                                       located. Quantity based on 0.44tons/L.F. of stream length. Rip rap from Midwest Mineral,
          d. Furnish and install rip-rap                                       152,533        cu.yds.          $39.11      $5,965,579            CCI   Quapaw Quarry at $13.50/ton loaded plus 5.85% sales tax.
          e. Amend bank soils prior to vegetation                                   35         acres         $320.00          $11,200            CCI   2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
          f. Revegetate stream bank                                                 35         acres        $1,200.00         $42,000            CCI   Land area is disced, seeded and mulched.
          Subtotal Item 10                                                 $13,444,864

          Provide Alternative Water Supply for Impacted Rural
11.       Residential Wells
                                                                                                                                                      Alternative supplied water system is within economically feasible distance to complete
          a. Connect affected households to supplied water system                    2    households       $15,000.00         $30,000   Best estimate connection.
          Subtotal Item 11                                                     $30,000

12.       Excavate Rural Residential Yard Soils
          a. Excavate, backfill, and restore residential yard soils                  5    households       $28,000.00        $140,000      EPA-2005 Average cost of OU-2 yards completed in 2005.
          Subtotal Item 12                                                    $140,000




                                                                                                               PAGE 4 OF 8                                                                                                          JULY 2007
      Table C-1
      Alternative 4 Estimated Costs
      Phased Consolidation, On-Site Disposal and Institutional Controls


Item #                            Item Description                        Est. Quantity    Units    Est. Unit Cost Estimated Cost     Cost Basis                                          Assumptions
                                                                                                                                                   Construction of a 28-acre repository capable of receiving an estimated 998,000 yd3 of source
13.       Construction and Closure of On-Site Repository                                                                                           materials and associated debris.

          a. Property acquisition including surrounding buffer area                 56     acres        $1,000.00         $56,000   Eng. Estimate 28 acre repository with surrounding 200-foot buffer zone equivalent to 28 additional acres.
                                                                                                                                                  Entire area of proposed repository. Does not include removal of buildings or reinforced
          b. Clear and grub                                                         28     acres         $533.00          $14,924         OCC-1 structures (i.e., mill foundations, etc.).
          c. Grading and site work                                                  28     acres        $2,400.00         $67,200             CCI Upper 6-inches removed and stored.
          d. Furnish and load clay liner soil                                   90,000    cu.yds.          $10.24        $921,600             CCI Liner equivalent to 24-inches clay. See detail sheets for unit rate development.
          e. Haul and dump clay liner soil( 14.2 miles round trip)              90,000    cu.yds.           $3.41        $306,900             CCI See detail sheets for unit rate development.
          f. Compact clay liner soil                                            90,000    cu.yds.           $1.26        $113,400             CCI See detail sheets for unit rate development.
          g. Furnish, load, and install filter sand                             90,000    cu.yds.           $5.00        $450,000   Quapaw Tribe 2-feet thick filter sand layer using drag sands available at no cost.
                                                                                                                                                  Soil cover equivalent to 12-inches clay and 12-inches loam. See detail sheets for unit rate
          h. Furnish and load cover soils                                       90,000    cu.yds.          $10.24        $921,600             CCI development.
          i. Haul and dump cover soils(14.2 miles round trip)                   90,000    cu.yds.           $3.41        $306,900             CCI See detail sheets for unit rate development.
          j. Compact cover soils                                                90,000    cu.yds.           $1.26        $113,400             CCI See detail sheets for unit rate development.
          k. Amend soils prior to vegetation                                        28     acres         $320.00           $8,960             CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
          l. Revegetate excavated areas                                             28     acres        $1,200.00         $33,600             CCI Land area is disced, seeded and mulched.
          m. Institutional control - deed notice                                     1     parcel       $1,000.00          $1,000   Eng. Estimate Assumes 1 parcel (i.e. deed notice) for entire 28-acre repository.
          Subtotal Item 13                                                  $3,315,484

          Total Phase 1 Direct Capital Costs                              $121,148,131



Phase 2 Activities (Years 11 to 20)
          Address Non-Processed Chat from Piles, Bases, and Rail                                                                                   Assumes 76% of all chat has been processed by others (not part of the remedy), with
14.       Road and Road Beds                                                                                                                       9,380,000 yd3 remaining to be addressed by the remedy.
                                                                                                                                                   Assumes 75% (7,035,000 yd3) of non-processed chat is delivered to an on-site chat washing
14.1      Excavate and Haul to Local Washing Operation                                                                                             operation.
                                                                                                                                                 75% of all entire acreage covered by piles and bases including 50-foot buffer zone area but
                                                                                                                                                 excluding the area already addressed by Distal Area remedy. Does not include removal of
          a. Clear, grub, and remove old structures                              2,552     acres         $533.50       $1,361,492          OCC-1 buildings or reinforced structures (i.e., mill foundations, etc.).
          b. Excavate and load chat                                          7,035,000    cu.yds.          $1.70      $11,959,500            CCI See detail sheets for unit rate development.
          c. Haul, dump and place, 12-mile roundtrip                         7,035,000    cu.yds.          $3.11      $21,878,850            CCI See detail sheets for unit rate development.
                                                                                                                                                  Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                  other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
          d. Deep till excavated area and buffer zone                            2,552     acres         $911.00       $2,324,872             CCI average speed used. The appropriate number of moves is included in the unit cost.
          e. Amend soils prior to revegetation                                   2,552     acres         $320.00        $816,640              CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
          f. Revegetate excavated areas                                          2,552     acres        $1,200.00      $3,062,400             CCI Land area is disced, seeded and mulched.
          Subtotal Item 14.1                                               $41,403,754




                                                                                                           PAGE 5 OF 8                                                                                                           JULY 2007
   Table C-1
   Alternative 4 Estimated Costs
   Phased Consolidation, On-Site Disposal and Institutional Controls


Item #                            Item Description                     Est. Quantity    Units    Est. Unit Cost Estimated Cost     Cost Basis                                           Assumptions

14.2     Excavate and Haul to an On-Site Repository                                                                                              Assumes 10% (938,000 yd3) of non-processed chat is delivered to an on-site repository.
                                                                                                                                                 10% of all entire acreage covered by piles and bases including 50-foot buffer zone area but
                                                                                                                                                 excluding the area already addressed by Distal Area remedy. Does not include removal of
         a. Clear, grub, and remove old structures                              340     acres         $533.50        $181,390          OCC-1     buildings or reinforced structures (i.e., mill foundations, etc.).
         b. Excavate and load chat                                          938,000    cu.yds.          $1.70       $1,594,600           CCI     See detail sheets for unit rate development.
         c. Haul, dump and place, 12-mile roundtrip                         938,000    cu.yds.          $3.11       $2,917,180           CCI     See detail sheets for unit rate development.
                                                                                                                                                  Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                 other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         d. Deep till excavated area and buffer zone                            340     acres         $911.00         $309,740             CCI   average speed used. The appropriate number of moves is included in the unit cost.
         e. Amend soils prior to revegetation                                   340     acres         $320.00         $108,800             CCI   2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         f. Revegetate excavated areas                                          340     acres        $1,200.00        $408,000             CCI   Land area is disced, seeded and mulched.
         Subtotal Item 14.2                                              $5,519,710


                                                                                                                                             Assumes 10% (938,000 yd3) of non-processed chat is pushed into a subsidence feature and
14.3     Push Chat into Subsidence Feature                                                                                                   covered.
                                                                                                                                             10% of all entire acreage covered by piles and bases including 50-foot buffer zone area but
                                                                                                                                             excluding the area already addressed by Distal Area remedy. Does not include removal of
         a. Clear, grub, and remove old structures                              340     acres         $533.50         $181,390         OCC-1 buildings or reinforced structures (i.e., mill foundations, etc.).

         b. Push chat into subsidence feature                               938,000    cu.yds.           $2.26      $2,119,880             CCI Assumes dozer work, no transport of material. See detail sheets for unit rate development.
                                                                                                                                               Soil cover equivalent to 12-inches clay and 12-inches loam. See detail sheets for unit rate
                                                                                                                                               development. Assumes typical feature can receive 11,000 yd3 and requires 1,300 yd3 of
         c. Furnish and load cover soil                                     111,000    cu.yds.         $10.24       $1,136,640             CCI cover material per feature.
         d. Haul and dump cover soil (14.2 miles round trip)                111,000    cu.yds.          $3.41        $378,510              CCI See detail sheets for unit rate development.
         e. Compact cover soil                                              111,000    cu.yds.          $1.26        $139,860              CCI See detail sheets for unit rate development.
                                                                                                                                                Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                               other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         f. Deep till excavated area and buffer zone                            340     acres         $911.00         $309,740             CCI average speed used. The appropriate number of moves is included in the unit cost.
         g. Amend soils prior to revegetation                                   340     acres         $320.00         $108,800             CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         h. Revegetate excavated areas                                          340     acres        $1,200.00        $408,000             CCI Land area is disced, seeded and mulched.
                                                                                                                                               Assumes 1 parcel (i.e. deed notice) per feature on the basis that one feature can receive
         i. Institutional control - deed notice                                  85    parcel         $500.00          $42,636   Eng. Estimate 11,000 yd3.
         Subtotal Item 14.3                                              $4,825,456




                                                                                                        PAGE 6 OF 8                                                                                                            JULY 2007
      Table C-1
      Alternative 4 Estimated Costs
      Phased Consolidation, On-Site Disposal and Institutional Controls


Item #                           Item Description                         Est. Quantity      Units    Est. Unit Cost Estimated Cost      Cost Basis                                            Assumptions
                                                                                                                                                                                  3
                                                                                                                                                         Assumes 5% (469,000 yd ) of non-processed chat is injected into flooded underground mine
14.4.     Inject Chat into Mine Workings                                                                                                                 workings.
                                                                                                                                                         5% of all entire acreage covered by piles and bases including 50-foot buffer zone area but
                                                                                                                                                         excluding the area already addressed by Distal Area remedy. Does not include removal of
          a. Clear, grub, and remove old structures                                170       acres         $533.00          $90,610           OCC-1      buildings or reinforced structures (i.e., mill foundations, etc.).
                                                                                                                                                         Moves equivalent to one mobilization and movement between injection sites based upon an
          b. Mobilize/move between piles/bases and injection locations              95     location      $16,193.00      $1,535,096              CCI     average injection of 5,000 yd3 per boring.
          c. Injection boring installation                                          94       boring      $16,000.00      $1,500,800   Venture Drilling   One 10-inch diameter injection boring per 5,000 yd3 of chat material.
          d. Extraction boring installation                                         19       boring      $16,000.00       $300,160    Venture Drilling   One 10-inch diameter extraction boring per every 5 injection borings (20-percent).
          e. Boring abandonment                                                    113       boring      $10,000.00      $1,125,600   Venture Drilling   Bladder installation and cement grout to surface.
          f. Inject chat at 100 tons/hour                                      469,000     cu. yds.           $8.91      $4,178,790              CCI     See detail sheets for unit rate development.
                                                                                                                                                         Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                         other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
          g. Deep till underlying soils and buffer zone                            170       acres         $911.00         $154,870              CCI     average speed used. The appropriate number of moves is included in the unit cost.
          h. Amend soils prior to revegetation                                     170       acres         $320.00          $54,400              CCI     2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
          i. Revegetate underlying soils/deep tilled areas                         170       acres        $1,200.00        $204,000              CCI     Land area is disced, seeded and mulched.
          Subtotal Item 14.4                                                $9,144,326

          Total Phase 2 Direct Capital Costs                               $60,893,247

          Total Direct Capital Costs (Phase 1 + Phase 2)                  $182,041,378

15.       Indirect Capital Costs
          a. Develop and implement institutional controls program                    1    lump sum        $500,000        $500,000     Best estimate
          b Project management                                                       1    lump sum       $9,102,069      $9,102,069      EPA, 2000 Assume 5% of total direct capital cost
          c. Remedial design                                                         1    lump sum       $9,102,069      $9,102,069      EPA, 2000 Assume 5% of total direct capital cost
          d. Construction oversight and management                                   1    lump sum      $10,922,483     $10,922,483      EPA, 2000 Assume 6% of total direct capital cost
                                                                                                                                                    Assume 2% of total direct capital cost; assumes performance of monitoring (i.e., air,
                                                                                                                                                    groundwater, surface water,) during implementation of the remedy and confirmation
          e. Technical support                                                       1    lump sum       $3,640,828      $3,640,828       EPA, 2000 sampling.
          f. Contingencies                                                           1    lump sum      $36,408,276     $36,408,276       EPA, 2000 Assume 20% of total direct capital cost; 15% scope, 5% bid.
          g. Chat sales compliance, environmental monitoring, and
          oversight                                                                  1    lump sum      $48,181,800     $48,181,800       EPA, 2007 Refer to Appendix E
          Subtotal Indirect Capital Costs                                 $117,857,524

16.       Total Capital Costs                                             $299,898,902


17.       Annual Operation and Maintenance Costs
          a. Administer landowner agreements                                         1    lump sum      $100,000.00        $100,000    Best estimate Assume 1 FTE plus expenses
          b. Administer institutional controls                                       1    lump sum       $25,000.00         $25,000    Best estimate Assume 1/4 FTE in the Ottawa County clerk's office plus expenses.
                                                                                                                                                     Assumes management of revegetated areas for 3 years after initial seeding. Goes to zero
          c. Vegetation management                                                   1    lump sum      $250,000.00        $250,000    Best estimate after 20 years.
          Subtotal Annual O&M Costs                                           $375,000




                                                                                                             PAGE 7 OF 8                                                                                                             JULY 2007
      Table C-1
      Alternative 4 Estimated Costs
      Phased Consolidation, On-Site Disposal and Institutional Controls


Item #                        Item Description                              Est. Quantity             Units    Est. Unit Cost Estimated Cost       Cost Basis                                Assumptions
18.    Net Present Value Cost Analysis                                       2007                2008             2009             2010            2011          2012          2013        2014        2015        2016
       Direct Capital Costs                                                  $12,114,813        $12,114,813      $12,114,813      $12,114,813     $12,114,813   $12,114,813 $12,114,813 $12,114,813 $12,114,813 $12,114,813
       Indirect Capital Costs                                                 $5,892,876         $5,892,876       $5,892,876       $5,892,876      $5,892,876    $5,892,876 $5,892,876 $5,892,876 $5,892,876 $5,892,876
       Operation and Maintenance Costs                                                                              $375,000         $375,000        $375,000      $375,000   $375,000    $375,000     $375,000   $375,000
       Total Capital and O&M Costs                                            $18,007,689       $18,007,689      $18,382,689      $18,382,689     $18,382,689   $18,382,689 $18,382,689 $18,382,689 $18,382,689 $18,382,689
       Net Present Value                                                      $16,829,616       $15,728,613      $15,005,750      $14,024,066     $13,106,603   $12,249,162 $11,447,815 $10,698,893 $9,998,965 $9,344,827
       Year                                                                     1                  2                3                4               5             6             7           8           9          10


          Net Present Value Cost Analysis                                     2017               2018              2019            2020            2021          2022          2023        2024        2025            2026
          Direct Capital Costs                                                 $6,089,325        $6,089,325        $6,089,325      $6,089,325      $6,089,325    $6,089,325 $6,089,325 $6,089,325 $6,089,325 $6,089,325
          Indirect Capital Costs                                               $5,892,876        $5,892,876        $5,892,876      $5,892,876      $5,892,876    $5,892,876 $5,892,876 $5,892,876 $5,892,876 $5,892,876
          Operation and Maintenance Costs                                       $375,000          $375,000          $375,000        $375,000        $375,000      $375,000    $375,000    $375,000    $375,000    $375,000
          Total Capital and O&M Costs                                         $12,357,201       $12,357,201       $12,357,201     $12,357,201     $12,357,201   $12,357,201 $12,357,201 $12,357,201 $12,357,201 $12,357,201
          Net Present Value                                                    $5,870,817        $5,486,745        $5,127,799      $4,792,336      $4,478,818    $4,185,811 $3,911,973 $3,656,050 $3,416,869 $3,193,336
          Year                                                                 11                 12                13              14              15            16            17          18          19          20


          Net Present Value Cost Analysis                                     2027               2028              2029            2030            2031          2032         2033        2034         2035        2036         Totals
          Direct Capital Costs                                                                                                                                                                                                $182,041,378
          Indirect Capital Costs                                                                                                                                                                                              $117,857,524
          Operation and Maintenance Costs                                       $375,000          $375,000             $125,000        $125,000     $125,000      $125,000    $125,000    $125,000     $125,000    $125,000     $8,500,000
          Total Capital and O&M Costs                                           $375,000          $375,000             $125,000        $125,000     $125,000      $125,000    $125,000    $125,000     $125,000    $125,000   $308,398,902
          Net Present Value                                                       $90,567          $84,642              $26,368         $24,643      $23,031       $21,524     $20,116     $18,800      $17,570     $16,421   $172,898,550
          Year                                                                 21                 22                   23              24           25            26           27          28           29          30


19.       Total Net Present Value                                           $172,898,550


Notes and Assumptions:
       Phase 1 Direct Capital Costs are spread evenly over the first 10 years in the Net Present Value calculation.
       Phase 2 Direct Capital Costs are spread evenly over the second 10 years in the Net Present Value calculation.
       Assume indirect capital costs are spread evenly over the 20-year construction timeframe.
       Assume O&M costs start in year 3 and continue for 20 years, then drop to $125,000 per year.
       The Net Present Value analysis assumes 30 years of O&M at a discount rate of 7 percent.




                                                                                                                         PAGE 8 OF 8                                                                                          JULY 2007
   Table C-2
   Alternative 5 Estimated Costs
   Voluntary Relocation, Phased Consolidation, On-Site Disposal and Institutional Controls


Item #                       Item Description                         Est. Quantity             Units    Est. Unit Cost Estimated Cost       Cost Basis                                        Assumptions
1.     Relocation Expenses
       1.1 Residential Houses                                                  678            houses                                                     Estimated quantity of residential home properties based upon update from ODEQ, 2007.
       a. Houses to be bought by state program (Phase I)                       341            houses                                                     Estimated quantity based upon update from ODEQ, 2007.
                                                                                                                                                         Remaining quantity of properties based upon update from ODEQ, 2007. Average cost of
                                                                                                                                            State Buyout property equal to State 2005 cost ($51,600) times factor of 1.5, rounded up. No
       b. Remaining houses addressed by Alternative 5                          337            houses        $78,000.00     $26,286,000             2005 differentiation between residences on tribal land or non-tribal land.
                                                                                                                                            State Buyout
       c. Moving allowance                                                     337           relocates       $1,050.00       $353,850      2005/ SB1463 Moving allowance of $1000 per household escalated 5% for one year.
                                                                                                                                                        Vacant lot renters excluded. Reimbursement for one year of rent at cost of $500/month
                                                                                                                                                        ($6,000/year) for comparable rental property in Ottawa County, escalated due to limited
                                                                                                                                           State Buyout availability resulting from buyout. Escalated 1 yr or 6%. Quantity based upon April 26, 2007
       d. Renters assistance                                                    80            renters        $6,360.00        $508,800            2005 update from ODEQ.
       e. Demolition and disposal of remediated houses                         253            houses        $10,600.00      $2,681,800   WESTON, 2005 Assumes $10,000 per structure, escalated 6% for 1 year.
                                                                                                                                                        Assumes OSHA training required for demolition of structures on potentially contaminated
       f. Demolition and disposal of non-remediated houses                      84           houses         $15,000.00      $1,260,000        Eng. Est. residential yards.
       1.2 Commercial Properties                                                66       businesses                                                     Estimated quantity of commercial properties based upon update from ODEQ, 2007.
       a. Commercial properties to be bought by state program
       (Phase I)                                                                25       businesses                                                       Estimated quantity based upon update from ODEQ, 2007.
       b. Remaining commercial properties addressed by Alternative                                                                                      Assumes 41 businesses properties remaining after State buyout at an estimated $196,250,
       5                                                                        41       businesses        $222,877.00      $9,137,957     USACE, 2003 escalated 2 years at 4% and one year at 5%.
                                                                                                                                                        Assumes OSHA training required for demolition of structures on potentially contaminated
       c. Demolition and disposal of commercial properties                      41       businesses         $15,000.00       $615,000         Eng. Est. residential yards.
       Subtotal Direct Capital Costs                                   $40,843,407




                                                                                                                  PAGE 1 OF 2                                                                                                           JULY 2007
     Table C-2
     Alternative 5 Estimated Costs
     Voluntary Relocation, Phased Consolidation, On-Site Disposal and Institutional Controls


Item #                          Item Description                        Est. Quantity           Units   Est. Unit Cost Estimated Cost      Cost Basis                                        Assumptions
                                                                                                                                                     Assumes tasks in EPA 's SF Relocation SOW Template Model SOW (percentages are a
2.       URA Administration (Indirect) Costs                                                                                                EPA 2004 proportion of the direct relocation costs).

         a. Task 1 - Planning                                             $2,042,170                                                                    Assumes 5% for planning, scheduling, mapping, data collection, Real Estate Planning Rpt.

         b. Task 2 - Coordination and Communication                       $3,063,256                                                                    Assumes 7.5% for federal, state agency, tribal coordination, and community involvement.
                                                                                                                                                        Assumes 2.5% to provide assistance to households, explain process and locate
         c. Task 3 - Advisory Services                                    $1,021,085                                                                    comparable housing.
         d. Task 4 - Appraisal and Acquisition                            $2,042,170                                                                    Assumes 5% for appraisals and acquisition administration.
         e. Task 5 - Relocation                                           $2,042,170                                                                    Assumes 5% for administration of relocation process.
         f. Task 6 - Follow Up                                            $1,021,085                                                                    Assumes 2.5% for follow up meetings with relocating families to resolve issues.
                                                                                                                                        OSWER 9355-
         g. Task 7 - Appeals                                              $2,042,170                                                       0.88 2003 Assumes 5% to administer appeals process.
         h. Task 8 - Reporting                                             $816,868                                                                  Assumes 2% for monthly and annual interagency reporting.
         i. Task 9 - Project Management and Closeout                      $1,225,302                                                                 Assumes 3% for records management, documentation and closeout.
         j. Contingencies                                                 $2,042,170                                                                 Assumes 5% of total direct costs for unforeseen issues and oversight.
         Subtotal URA Administration (Indirect) Costs                    $17,358,448

                                                                                                                                                        Equal to Direct Capital Costs + URA Administration Costs; costs are already present
3.       Total Capital Costs (2006 dollars)                              $58,201,855                                                                    values in 2006 dollars.

4.       Annual Operation and Maintenance Costs
         a. Administer institutional controls                                      1 lump sum                $25,000         $25,000     Best estimate Assume 1/4 FTE plus expenses.
         b. Vegetation management                                                  1 lump sum               $150,000        $150,000     Best estimate Assumes management of revegetated areas for 2 years after demolition of structures.
         Subtotal Annual O&M Costs                                          $175,000

                                                                                                                                                        Equal to Direct Relocation Cost + URA Admin Costs; these costs are already present
         Net Present Value of Direct and URA Admin. Costs                $58,201,855                                                                    values in 2006 dollars
         Net Present Value of O&M Costs                                    $597,246                                                                     30 years for Institutional Controls management plus 2 years of vegetation management.
         Total Net Present Value                                         $58,799,101




                                                                                                                 PAGE 2 OF 2                                                                                                          JULY 2007
     Table C-2 Continued
     Alternative 5 Estimated Costs
     Voluntary Relocation, Phased Consolidation, On-Site Disposal and Institutional Controls


Phase 1 Activities (Years 1 to 10)
Item #                       Item Description                          Est. Quantity            Units    Est. Unit Cost Estimated Cost   Cost Basis                                              Assumptions
         Chat Pile and Base Removal from the NE Distal Zone by                                                                                        100% of material located in this area is removed by excavation and hauling; material
1.       Excavation and Hauling                                                                                                                       delivered to chat washing operator located in central portion of the Site.
                                                                                                                                                      Entire area of piles and bases plus 50-foot buffer zone area. Does not include removal of
         a. Clear, grub, and remove old structures                               559            acres         $533.50        $298,227       OCC-1     buildings or reinforced structures (i.e., mill foundations, etc.).
         b. Excavate and load chat                                         2,391,000           cu.yds.          $1.70       $4,064,700        CCI     See detail sheets for unit rate development.
         c. Haul, dump and place, 12-mile roundtrip                        2,391,000           cu.yds.          $3.11       $7,436,010        CCI     See detail sheets for unit rate development.
                                                                                                                                                      Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                      other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         d. Deep till excavated area and buffer zone                             559            acres         $911.00        $509,249          CCI    average speed used. The appropriate number of moves is included in the unit cost.
         e. Amend soils prior to revegetation                                    559            acres         $320.00        $178,880          CCI    2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         f. Revegetate excavated areas                                           559            acres        $1,200.00       $670,800          CCI    Land area is disced, seeded and mulched.
         Subtotal Item 1                                                 $13,157,866

         Chat Pile and Base Removal from the SE Distal Zone by                                                                                        100% of material located in this area is removed by excavation and hauling; material
2.       Excavation and Hauling                                                                                                                       delivered to chat washing operator located in central portion of the Site.
                                                                                                                                                      Entire area of piles and bases plus 50-foot buffer zone area. Does not include removal of
         a. Clear, grub, and remove old structures                               172            acres         $533.50          $91,762      OCC-1     buildings or reinforced structures (i.e., mill foundations, etc.).
         b. Excavate and load chat                                           630,000           cu.yds.          $1.70       $1,071,000        CCI     See detail sheets for unit rate development.
         c. Haul, dump and place, 12-mile roundtrip                          630,000           cu.yds.          $3.11       $1,959,300        CCI     See detail sheets for unit rate development.
                                                                                                                                                      Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                      other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         d. Deep till excavated area and buffer zone                             172            acres         $911.00        $156,692          CCI    average speed used. The appropriate number of moves is included in the unit cost.
         e. Amend soils prior to revegetation                                    172            acres         $320.00         $55,040          CCI    2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         f. Revegetate excavated/deep tilled area                                172            acres        $1,200.00       $206,400          CCI    Land area is disced, seeded and mulched.
         Subtotal Item 2                                                  $3,540,194

         Chat Pile and Base Removal from the Elm Creek                                                                                                100% of material located in this area is removed by excavation and hauling; material
3        Watershed Distal Zone by Excavation and Hauling                                                                                              delivered to chat washing operator located in central portion of the Site.
                                                                                                                                                      Entire area of piles and bases plus 50-foot buffer zone area. Does not include removal of
         a. Clear, grub, and remove old structures                               381            acres         $533.50        $203,264       OCC-1     buildings or reinforced structures (i.e., mill foundations, etc.).
         b. Excavate and load chat                                         3,138,000           cu.yds.          $1.70       $5,334,600        CCI     See detail sheets for unit rate development.
         c. Haul, dump and place, 12-mile roundtrip                        3,138,000           cu.yds.          $3.11       $9,759,180        CCI     See detail sheets for unit rate development.
                                                                                                                                                      Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                      other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         d. Deep till excavated area and buffer zone                             381            acres         $911.00        $347,091          CCI    average speed used. The appropriate number of moves is included in the unit cost.
         e. Amend soils prior to revegetation                                    381            acres         $320.00        $121,920          CCI    2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         f. Revegetate excavated/deep tilled area                                381            acres        $1,200.00       $457,200          CCI    Land area is disced, seeded and mulched.
         Subtotal Item 3                                                 $16,223,255




                                                                                                                  PAGE 1 OF 8                                                                                                        JULY 2007
     Table C-2 Continued
     Alternative 5 Estimated Costs
     Voluntary Relocation, Phased Consolidation, On-Site Disposal and Institutional Controls


Item #                       Item Description                          Est. Quantity              Units    Est. Unit Cost Estimated Cost       Cost Basis                                            Assumptions
         Excavate, Haul and Dispose of Smelter Wastes in a Local
4.       Repository
                                                                                                                                                           Includes brush and tree removal around source material area and affected soils area. Does
         a. Clear, grub, and remove old structures                                14              acres         $533.00            $7,462           OCC-1 not include removal of buildings or reinforced structures.
         b. Excavate and load smelter waste                                    1,846             cu.yds.          $1.70            $3,138             CCI Shallow excavation, approximately 1 feet deep. See details sheets for unit rate development.
         c. Haul, dump and place, 12-mile roundtrip                            1,846             cu.yds.          $3.11            $5,741             CCI See detail sheets for unit rate development.
                                                                                                                                                            Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                           other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         d. Deep till excavated area and smelter affected soils                   14              acres         $911.00           $12,754             CCI average speed used. The appropriate number of moves is included in the unit cost.
         e. Add biosolids or organic matter                                      280               tons           $30.00           $8,400           Jasper 20 tons per acre.
         f. Amend soils prior to revegetation                                     14              acres         $320.00            $4,480             CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         g. Revegetate excavated/deep tilled area                                 14              acres        $1,200.00          $16,800             CCI Land area is disced, seeded and mulched.
         Subtotal Item 4                                                     $58,775

                                                                                                                                                               Assumes 61 ponds containing an estimated 5,041,000 yd3 of material (includes 10% of
5.       Inject Fine Tailings into Mine Workings                                                                                                               washed fines generated by processing) covering an estimated area of 569 acres is injected.
                                                                                                                                                               Entire area of ponds addressed by injection plus 50-foot buffer zone area. Does not include
         a. Clear and grub fine tailings and buffer zone areas                   831               acres        $533.00        $442,923             OCC-1      removal of buildings or reinforced structures (i.e., mill foundations, etc.).
         b. Mobilize/move between ponds and injection locations                  287            location      $13,012.00      $3,734,444               CCI     Assumes one move per injection boring (i.e., location) plus one mobilization.
         c. Injection boring installation                                        286              boring      $16,000.00      $4,582,727    Venture Drilling   One 10-inch diameter injection boring per 17,600 yd3 of fine tailings material.
         d. Extraction boring installation                                        61              boring      $16,000.00       $976,000     Venture Drilling   One 10-inch diameter extraction boring per pond.
         e. Boring abandonment                                                   347              boring      $10,000.00      $3,474,205    Venture Drilling   Bladder installation and cement grout to surface.
         f. Inject fines at 200 tons/hour                                  5,041,000             cu.yds.           $5.76     $29,036,160               CCI     See detail sheets for unit rate development.
                                                                                                                                                                Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the other,
                                                                                                                                                               two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH average
         g. Deep till underlying soils and buffer zone                           831              acres         $911.00        $757,041                CCI     speed used. The appropriate number of moves is included in the unit cost.
         h. Amend soils prior to revegetation                                    831              acres         $320.00        $265,920                CCI     2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         i. Revegetate underlying soils/deep tilled areas                        831              acres        $1,200.00       $997,200                CCI     Land area is disced, seeded and mulched.
         Subtotal Item 5                                                 $44,266,620

6.       Complete Hydrogeologic Studies
                                                                                                                                                          Studies are completed to assess hydrogeologic system and potential impacts resulting from
         a. Hydrogeologic investigations and studies                               1           lump sum    $3,000,000.00      $3,000,000     Quapaw Tribe injection of source materials.
         Subtotal Item 6                                                  $3,000,000




                                                                                                                    PAGE 2 OF 8                                                                                                              JULY 2007
     Table C-2 Continued
     Alternative 5 Estimated Costs
     Voluntary Relocation, Phased Consolidation, On-Site Disposal and Institutional Controls


Item #                       Item Description                           Est. Quantity           Units    Est. Unit Cost Estimated Cost     Cost Basis                                           Assumptions
7.     Cover Fine Tailings in Place with Soil Cover
                                                                                                                                                     Entire area of ponds addressed by covering plus 50-foot buffer zone area. Does not include
         a. Clear and grub fine tailings and buffer zone areas                   275            acres         $533.00        $146,575          OCC-1 removal of buildings or reinforced structures (i.e., mill foundations, etc.).
         b. Regrade and recontour tailings and berms                             251            acres        $2,400.00       $602,400            CCI No change in surface area.
                                                                                                                                                     Soil cover equivalent to 12-inches clay and 12-inches loam. See detail sheets for unit rate
         c. Furnish and load cover soil                                      898,000           cu.yds.         $10.24       $9,195,520           CCI development.
         d. Haul and dump cover soil (14.2 miles round trip)                 898,000           cu.yds.          $3.41       $3,062,180           CCI See detail sheets for unit rate development.
         e. Compact cover soil                                               898,000           cu.yds.          $1.26       $1,131,480           CCI See detail sheets for unit rate development.
                                                                                                                                                          Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                         other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         f. Deep till buffer zone                                                 24            acres         $911.00         $21,864              CCI   average speed used. The appropriate number of moves is included in the unit cost.
         g. Amend soils prior to revegetation                                    275            acres         $320.00         $88,000              CCI   2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         h. Establish cover vegetation/revegetate deep tilled area               275            acres        $1,200.00       $330,000              CCI   Land area is disced, seeded and mulched.
         i. Institutional control - deed notice                                   28            parcel        $500.00         $13,750    Eng. Estimate   Assumes 1 parcel (i.e. deed notice) per 10 acres.
         Subtotal Item 7                                                 $14,591,769

         Integrate Near Stream Source Materials and Control                                                                                              Interim actions that may be required to prevent further damages to resources while chat
8.       Seepage/Runoff                                                                                                                                  processing (by others) is ongoing or before full-scale remedial actions can take place.

         a. Clear and grub floodway areas                                        581            acres         $533.50        $309,964             CCI Does not include removal of buildings or reinforced structures (i.e., mill foundations, etc.).
                                                                                                                                                      Assumes near-stream chat within 200 feet of streams requires integration with primary
         b. Integrate floodway chat with original source                   1,252,952           cu.yds.           $2.26      $2,831,672            CCI source. Assumes dozer work with no loading or hauling.
                                                                                                                                                      Assumes near-stream tailings within 200 feet of streams require consolidation outside the
         c. Integrate floodway fine tailings with original source            283,095           cu.yds.           $2.26       $639,795             CCI floodway. Assumes dozer work with no loading or hauling.
                                                                                                                                                      Assumes 48" of rip-rap placed at bends in stream channels where chat or tailings are
                                                                                                                                                      located. Quantity based on 0.44tons/L.F. of stream length(3.2 miles). Rip rap from Midwest
         d. Furnish and install rip-rap or revetment                           4,228          cu.yds.          $39.11        $165,357             CCI Mineral, Quapaw Quarry At $13.50/ton loaded plus 5.85% sales tax
         e. Install berms and dikes - small berms                             71,770          cu.yds.          $14.91       $1,070,091            CCI Assume 2.67 CY of compacted clay per lineal foot of berm. Estimated using D-4 and CAT
         f. Install sheet piling to prevent seepage and direct runoff         90,414       square feet         $25.00       $2,260,350            CCI Assumes estimated linear distance of 5,023 feet, 18-foot sheet length.
                                                                                                                                                       Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                      other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         g. Deep till excavated areas                                            581            acres         $911.00        $529,291             CCI average speed used. The appropriate number of moves is included in the unit cost.
         h. Amend soils prior to vegetation                                      581            acres         $320.00        $185,920             CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         i. Revegetate excavated areas                                           581            acres        $1,200.00       $697,200             CCI Land area is disced, seeded and mulched.
         Subtotal Item 8                                                 $8,689,639




                                                                                                                  PAGE 3 OF 8                                                                                                           JULY 2007
      Table C-2 Continued
      Alternative 5 Estimated Costs
      Voluntary Relocation, Phased Consolidation, On-Site Disposal and Institutional Controls


Item #                           Item Description                       Est. Quantity            Units    Est. Unit Cost Estimated Cost      Cost Basis                                         Assumptions
          Excavation of In-Stream Source Materials from Tar, Lytle,                                                                                       Assumes sections of Tar Creek, Lytle Creek, Elm Creek, and Beavers Creek require source
9.        and Beaver Creeks                                                                                                                               removal from stream beds and immediate banks.
          a. Clear and grub stream banks                                           35            acres        $1,800.00          $63,000            CCI
                                                                                                                                                          Assumes near-stream chat within 200 feet of streams requires integration with primary
                                                                                                                                                          source using a D-8. Assumes a Cat 330 hoe to pull additional material out of the streams
          b. Excavate source materials from streams                            18,394           cu.yds.         $17.51        $322,079              CCI   and D-8 to integrate it with its primary source.
          c. Bank work and regrading                                           49,021           cu.yds.          $2.26        $110,787              CCI   Estimated using D-4
                                                                                                                                                          Assumes 48" of rip-rap placed at bends in stream channels where chat or tailings are
                                                                                                                                                          located. Quantity based on 0.44tons/L.F. of stream length (2.7 miles). Rip rap from Midwest
          d. Furnish and install rip-rap or revetment                           3,595           cu.yds.          $39.11       $140,600              CCI   Mineral, Quapaw Quarry At $13.50/ton loaded plus 5.85% sales tax
          e. Amend bank soils prior to revegetation                                35            acres         $320.00         $11,200              CCI   2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
          f. Revegetate stream bank                                                35            acres        $1,200.00        $42,000              CCI   Land area is disced, seeded and mulched.
          Subtotal Item 9                                                    $689,667


          Covering of In-Stream Source Materials from Tar, Lytle,                                                                                         Assumes sections of Tar Creek, Lytle Creek, Elm Creek, and Beavers Creek require
10.       and Beaver Creeks Using a Flexible Membrane Liner                                                                                               installation of FML, approximately 6.5 miles of streams, combined, 60 feet wide.
                                                                                                                                                          60 mil HDPE liner 36 feet wide installed in 10.8 miles of stream. 30' wide under stream with
          a. Stream liner (60-mil HDPE)                                     2,059,200       square feet           $2.21      $4,550,832             CCI   3' buried as anchors on each side
                                                                                                                                                          The 152,533 cy is 10.8 miles @ 2' thick and 36' wide. The material will be purchased from a
                                                                                                                                                          local quarry, hauled, dumped, spread, and compacted. Price at the quarry is $3.95/ton
          b. Filter blanket (fines)                                           152,533           cu.yds.         $14.33       $2,185,803             CCI   loaded plus 5.85% sales tax.
          c. Bank work and regrading, ground prep                             305,067           cu.yds.          $2.26        $689,451              CCI   Estimated using D-4
                                                                                                                                                          Assumes 48" of rip-rap placed at bends in stream channels where chat or tailings are
                                                                                                                                                          located. Quantity based on 0.44tons/L.F. of stream length. Rip rap from Midwest Mineral,
          d. Furnish and install rip-rap                                      152,533           cu.yds.          $39.11      $5,965,579             CCI   Quapaw Quarry At $13.50/ton loaded plus 5.85% sales tax
          e. Amend bank soils prior to vegetation                                  35            acres         $320.00          $11,200             CCI   2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
          f. Revegetate stream bank                                                35            acres        $1,200.00         $42,000             CCI   Land area is disced, seeded and mulched.
          Subtotal Item 10                                                $13,444,864

          Provide Alternative Water Supply for Impacted Rural
11.       Residential Wells
                                                                                                                                                         Alternative supplied water system is within economically feasible distance to complete
          a. Connect affected households to supplied water system                   2       households       $15,000.00          $30,000   Best estimate connection.
          Subtotal Item 11                                                    $30,000

12.       Excavate Rural Residential Yard Soils
          a. Excavate, backfill, and restore residential yard soils                 5       households       $28,000.00       $140,000        EPA-2005 Average cost of OU-2 yards completed in 2005.
          Subtotal Item 12                                                   $140,000




                                                                                                                   PAGE 4 OF 8                                                                                                            JULY 2007
      Table C-2 Continued
      Alternative 5 Estimated Costs
      Voluntary Relocation, Phased Consolidation, On-Site Disposal and Institutional Controls


Item #                           Item Description                       Est. Quantity            Units    Est. Unit Cost Estimated Cost      Cost Basis                                           Assumptions
                                                                                                                                                           Construction of a 28-acre repository capable of receiving an estimated 998,000 yd3 of source
13.       Construction and Closure of On-Site Repository                                                                                                   materials and associated debris.

          a. Property acquisition including surrounding buffer area                56            acres        $1,000.00          $56,000   Eng. Estimate 28 acre repository with surrounding 200-foot buffer zone equivalent to 28 additional acres.
                                                                                                                                                         Entire area of proposed repository. Does not include removal of buildings or reinforced
          b. Clear and grub                                                        28            acres         $533.00         $14,924           OCC-1 structures (i.e., mill foundations, etc.).
          c. Grading and site work                                                 28            acres        $2,400.00        $67,200               CCI Upper 6-inches removed and stored.
          d. Furnish and load clay liner soil                                  90,000           cu.yds.          $10.24       $921,600               CCI Liner equivalent to 24-inches clay. See detail sheets for unit rate development.
          d. Haul and dump cover soil (14.2 miles round trip)                  90,000           cu.yds.           $3.41       $306,900               CCI See detail sheets for unit rate development.
          f. Compact clay liner soil                                           90,000           cu.yds.           $1.26       $113,400               CCI See detail sheets for unit rate development.
          g. Furnish, load, and install filter sand                            90,000           cu.yds.           $5.00       $450,000     Quapaw Tribe 2-feet thick filter sand layer using drag sands available at no cost.
                                                                                                                                                         Soil cover equivalent to 12-inches clay and 12-inches loam. See detail sheets for unit rate
          h. Furnish and load cover soils                                      90,000           cu.yds.          $10.24       $921,600               CCI development.
          d. Haul and dump cover soil (14.2 miles round trip)                  90,000           cu.yds.           $3.41       $306,900               CCI See detail sheets for unit rate development.
          j. Compact cover soils                                               90,000           cu.yds.           $1.26       $113,400               CCI See detail sheets for unit rate development.
          k. Amend soils prior to vegetation                                       28            acres         $320.00          $8,960               CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
          l. Revegetate excavated areas                                            28            acres        $1,200.00        $33,600               CCI Land area is disced, seeded and mulched.
          m. Institutional control - deed notice                                    1            parcel       $1,000.00         $1,000     Eng. Estimate Assumes 1 parcel (i.e. deed notice) for entire 28-acre repository.
          Subtotal Item 13                                                 $3,315,484

          Total Phase 1 Direct Capital Costs                             $121,148,131



Phase 2 Activities (Years 11 to 30)
          Address Non-Processed Chat from Piles, Bases, and Rail                                                                                           Assumes 76% of all chat has been processed by others (not part of the remedy), with
14.       Road and Road Beds                                                                                                                               9,380,000 yd3 remaining to be addressed by the remedy.
                                                                                                                                                           Assumes 75% (7,035,000 yd3) of non-processed chat is delivered to an on-site chat washing
14.1      Excavate and Haul to Local Washing Operation                                                                                                     operation.
                                                                                                                                                           75% of all entire acreage covered by piles and bases including 50-foot buffer zone area but
                                                                                                                                                           excluding the area already addressed by Distal Area remedy. Does not include removal of
          a. Clear, grub, and remove old structures                             2,552            acres         $533.50       $1,361,492           OCC-1    buildings or reinforced structures (i.e., mill foundations, etc.).
          b. Excavate and load chat                                         7,035,000           cu.yds.          $1.70      $11,959,500             CCI    See detail sheets for unit rate development.
          c. Haul, dump and place, 12-mile roundtrip                        7,035,000           cu.yds.          $3.11      $21,878,850             CCI    See detail sheets for unit rate development.
                                                                                                                                                           Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                           other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
          d. Deep till excavated area and buffer zone                           2,552            acres         $911.00       $2,324,872              CCI   average speed used. The appropriate number of moves is included in the unit cost.
          e. Amend soils prior to revegetation                                  2,552            acres         $320.00        $816,640               CCI   2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
          f. Revegetate excavated areas                                         2,552            acres        $1,200.00      $3,062,400              CCI   Land area is disced, seeded and mulched.
          Subtotal Item 14.1                                              $41,403,754




                                                                                                                   PAGE 5 OF 8                                                                                                             JULY 2007
   Table C-2 Continued
   Alternative 5 Estimated Costs
   Voluntary Relocation, Phased Consolidation, On-Site Disposal and Institutional Controls


Item #                            Item Description                   Est. Quantity            Units    Est. Unit Cost Estimated Cost      Cost Basis                                           Assumptions

14.2     Excavate and Haul to an On-Site Repository                                                                                                     Assumes 10% (938,000 yd3) of non-processed chat is delivered to an on-site repository.
                                                                                                                                                        10% of all entire acreage covered by piles and bases including 50-foot buffer zone area but
                                                                                                                                                        excluding the area already addressed by Distal Area remedy. Does not include removal of
         a. Clear, grub, and remove old structures                             340            acres         $533.50        $181,390           OCC-1     buildings or reinforced structures (i.e., mill foundations, etc.).
         b. Excavate and load chat                                         938,000           cu.yds.          $1.70       $1,594,600            CCI     See detail sheets for unit rate development.
         c. Haul, dump and place, 12-mile roundtrip                        938,000           cu.yds.          $3.11       $2,917,180            CCI     See detail sheets for unit rate development.
                                                                                                                                                         Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                        other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         d. Deep till excavated area and buffer zone                           340            acres         $911.00        $309,740               CCI   average speed used. The appropriate number of moves is included in the unit cost.
         e. Amend soils prior to revegetation                                  340            acres         $320.00        $108,800               CCI   2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         f. Revegetate excavated areas                                         340            acres        $1,200.00       $408,000               CCI   Land area is disced, seeded and mulched.
         Subtotal Item 14.2                                             $5,519,710


                                                                                                                                                    Assumes 10% (938,000 yd3) of non-processed chat is pushed into a subsidence feature and
14.3     Push Chat into Subsidence Feature                                                                                                          covered.
                                                                                                                                                    10% of all entire acreage covered by piles and bases including 50-foot buffer zone area but
                                                                                                                                                    excluding the area already addressed by Distal Area remedy. Does not include removal of
         a. Clear, grub, and remove old structures                             340            acres         $533.50        $181,390           OCC-1 buildings or reinforced structures (i.e., mill foundations, etc.).

         b. Push chat into subsidence feature                              938,000           cu.yds.           $2.26      $2,119,880              CCI Assumes dozer work, no transport of material. See detail sheets for unit rate development.
                                                                                                                                                      Soil cover equivalent to 12-inches clay and 12-inches loam. See detail sheets for unit rate
                                                                                                                                                      development. Assumes typical feature can receive 11,000 yd3 and requires 1,300 yd3 of
         c. Furnish and load cover soil                                    111,000           cu.yds.         $10.24       $1,136,640              CCI cover material per feature.
         d. Haul and dump cover soil (14.2 miles round trip)               111,000           cu.yds.          $3.41        $378,510               CCI See detail sheets for unit rate development.
         e. Compact cover soil                                             111,000           cu.yds.          $1.26        $139,860               CCI See detail sheets for unit rate development.
                                                                                                                                                       Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                      other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         f. Deep till excavated area and buffer zone                           340            acres         $911.00        $309,740               CCI average speed used. The appropriate number of moves is included in the unit cost.
         g. Amend soils prior to revegetation                                  340            acres         $320.00        $108,800               CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         h. Revegetate excavated areas                                         340            acres        $1,200.00       $408,000               CCI Land area is disced, seeded and mulched.
                                                                                                                                                      Assumes 1 parcel (i.e. deed notice) per feature on the basis that one feature can receive
         i. Institutional control - deed notice                                 85           parcel         $500.00           $42,636   Eng. Estimate 11,000 yd3.
         Subtotal Item 14.3                                             $4,825,456




                                                                                                                PAGE 6 OF 8                                                                                                             JULY 2007
      Table C-2 Continued
      Alternative 5 Estimated Costs
      Voluntary Relocation, Phased Consolidation, On-Site Disposal and Institutional Controls


Item #                           Item Description                        Est. Quantity             Units    Est. Unit Cost Estimated Cost       Cost Basis                                            Assumptions
                                                                                                                                                                                         3
                                                                                                                                                                Assumes 5% (469,000 yd ) of non-processed chat is injected into flooded underground mine
14.4.     Inject Chat into Mine Workings                                                                                                                        workings.
                                                                                                                                                                5% of all entire acreage covered by piles and bases including 50-foot buffer zone area but
                                                                                                                                                                excluding the area already addressed by Distal Area remedy. Does not include removal of
          a. Clear, grub, and remove old structures                               170              acres         $533.00           $90,610           OCC-1      buildings or reinforced structures (i.e., mill foundations, etc.).
                                                                                                                                                                Moves equivalent to one mobilization and movement between injection sites based upon an
          b. Mobilize/move between piles/bases and injection locations             95            location      $16,193.00      $1,535,096               CCI     average injection of 5,000 yd3 per boring.
          c. Injection boring installation                                         94              boring      $16,000.00      $1,500,800    Venture Drilling   One 10-inch diameter injection boring per 5,000 yd3 of chat material.
          d. Extraction boring installation                                        19              boring      $16,000.00       $300,160     Venture Drilling   One 10-inch diameter extraction boring per every 5 injection borings (20-percent).
          e. Boring abandonment                                                   113              boring      $10,000.00      $1,125,600    Venture Drilling   Bladder installation and cement grout to surface.
          f. Inject chat at 100 tons/hour                                     469,000            cu. yds.           $8.91      $4,178,790               CCI     See detail sheets for unit rate development.
                                                                                                                                                                Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                                other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
          g. Deep till underlying soils and buffer zone                           170              acres         $911.00        $154,870                CCI     average speed used. The appropriate number of moves is included in the unit cost.
          h. Amend soils prior to revegetation                                    170              acres         $320.00         $54,400                CCI     2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
          i. Revegetate underlying soils/deep tilled areas                        170              acres        $1,200.00       $204,000                CCI     Land area is disced, seeded and mulched.
          Subtotal Item 14.4                                               $9,144,326

          Total Phase 2 Direct Capital Costs                              $60,893,247

          Total Direct Capital Costs (Phase 1 + Phase 2)                 $182,041,378

15.       Indirect Capital Costs
          a. Develop and implement institutional controls program                   1           lump sum        $500,000        $500,000      Best estimate
          b. Project management                                                     1           lump sum       $9,102,069      $9,102,069       EPA, 2000 Assume 5% of total direct capital cost
          c. Remedial design                                                        1           lump sum       $9,102,069      $9,102,069       EPA, 2000 Assume 5% of total direct capital cost
          d. Construction oversight and management                                  1           lump sum      $10,922,483     $10,922,483       EPA, 2000 Assume 6% of total direct capital cost
                                                                                                                                                           Assume 2% of total direct capital cost; assumes performance of monitoring (i.e., air,
                                                                                                                                                           groundwater, surface water,) during implementation of the remedy and confirmation
          e. Technical support                                                      1           lump sum       $3,640,828      $3,640,828        EPA, 2000 sampling.
          f. Contingencies                                                          1           lump sum      $36,408,276     $36,408,276        EPA, 2000 Assume 20% of total direct capital cost; 15% scope, 5% bid.
          g. Chat sales compliance, environmental monitoring, and
          oversight                                                                 1           lump sum      $48,181,800     $48,181,800        EPA, 2007 Refer to Appendix E
          Subtotal Indirect Capital Costs                                $117,857,524

16.       Total Capital Costs                                            $299,898,902


17.       Annual Operation and Maintenance Costs
          a. Administer landowner agreements                                        1           lump sum      $100,000.00       $100,000      Best estimate Assume 1 FTE plus expenses
          b. Administer institutional controls                                      1           lump sum       $25,000.00        $25,000      Best estimate Assume 1/4 FTE in the Ottawa County clerk's office plus expenses.
                                                                                                                                                            Assumes management of revegetated areas for 3 years after initial seeding. Goes to zero
          c. Vegetation management                                                  1           lump sum      $250,000.00       $250,000      Best estimate after 20 years.
          Subtotal Annual O&M Costs                                          $375,000




                                                                                                                     PAGE 7 OF 8                                                                                                              JULY 2007
      Table C-2 Continued
      Alternative 5 Estimated Costs
      Voluntary Relocation, Phased Consolidation, On-Site Disposal and Institutional Controls


Item #                        Item Description                               Est. Quantity            Units      Est. Unit Cost Estimated Cost           Cost Basis                                     Assumptions
18.    Net Present Value Cost Analysis                                         2007              2008               2009             2010                2011               2012          2013        2014        2015        2016
       Direct Capital Costs                                                   $12,114,813       $12,114,813        $12,114,813      $12,114,813         $12,114,813        $12,114,813 $12,114,813 $12,114,813 $12,114,813 $12,114,813
       Indirect Capital Costs                                                  $5,892,876        $5,892,876         $5,892,876       $5,892,876          $5,892,876         $5,892,876 $5,892,876 $5,892,876 $5,892,876 $5,892,876
       Operation and Maintenance Costs                                                                                $375,000         $375,000            $375,000           $375,000   $375,000    $375,000     $375,000   $375,000
       Total Capital and O&M Costs                                            $18,007,689       $18,007,689        $18,382,689      $18,382,689         $18,382,689        $18,382,689 $18,382,689 $18,382,689 $18,382,689 $18,382,689
       Net Present Value                                                      $16,829,616       $15,728,613        $15,005,750      $14,024,066         $13,106,603        $12,249,162 $11,447,815 $10,698,893 $9,998,965 $9,344,827
       Year                                                                      1                 2                  3                4                   5                  6             7           8           9          10


          Net Present Value Cost Analysis                                      2017               2018              2019               2020              2021               2022             2023             2024     2025             2026
          Direct Capital Costs
          Indirect Capital Costs                                               $2,409,090         $2,409,090        $2,409,090         $2,409,090        $2,409,090         $2,409,090     $2,409,090    $2,409,090   $2,409,090   $2,409,090
          Operation and Maintenance Costs                                       $375,000           $375,000          $375,000           $375,000          $375,000           $375,000       $375,000      $375,000     $375,000     $375,000
          Total Capital and O&M Costs                                          $2,784,090         $2,784,090        $2,784,090         $2,784,090        $2,784,090         $2,784,090     $2,784,090    $2,784,090   $2,784,090   $2,784,090
          Net Present Value                                                    $1,322,701         $1,236,169        $1,155,298         $1,079,718        $1,009,082          $943,068       $881,372      $823,712     $769,824     $719,462
          Year                                                                  11                 12                13                 14                15                 16               17            18           19           20


          Net Present Value Cost Analysis                                      2027               2028              2029               2030              2031               2032             2033          2034         2035         2036         Totals
          Direct Capital Costs                                                 $6,089,325         $6,089,325        $6,089,325         $6,089,325        $6,089,325         $6,089,325     $6,089,325    $6,089,325   $6,089,325   $6,089,325   $182,041,378
          Indirect Capital Costs                                               $3,483,786         $3,483,786        $3,483,786         $3,483,786        $3,483,786         $3,483,786     $3,483,786    $3,483,786   $3,483,786   $3,483,786   $117,857,524
          Operation and Maintenance Costs                                       $375,000           $375,000          $125,000           $125,000          $125,000           $125,000       $125,000      $125,000     $125,000     $125,000      $8,500,000
          Total Capital and O&M Costs                                          $9,948,111         $9,948,111        $9,698,111         $9,698,111        $9,698,111         $9,698,111     $9,698,111    $9,698,111   $9,698,111   $9,698,111   $308,398,902
          Net Present Value                                                    $2,402,599         $2,245,420        $2,045,786         $1,911,950        $1,786,869         $1,669,971     $1,560,721    $1,458,617   $1,363,194   $1,274,013   $156,093,856
          Year                                                                  21                 22                23                 24                25                 26               27            28           29           30


19.       Total Net Present Value                                            $156,093,856


Notes and Assumptions:
       Phase 1 Direct Capital Costs are spread evenly over the first 10 years in the Net Present Value calculation.
       Phase 2 Direct Capital Costs are spread evenly over years 21 through 30 in the Net Present Value calculation.
       Assume indirect capital costs are spread evenly over the 20-year construction timeframe in years 1 to 10 and 21 to 30 with the exception of item "g" which is spread evenly over the first 20 years.
       Assume O&M costs start in year 3 and continue for 20 years, then drop to $125,000 per year.
       The Net Present Value analysis assumes 30 years of O&M at a discount rate of 7 percent.




                                                                                                                           PAGE 8 OF 8                                                                                                          JULY 2007
     Table C-3
     Alternative 8 Estimated Costs
     Total Source Consolidation, On-Site Disposal and Institutional Controls


Item #                      Item Description                            Est. Quantity     Units    Est. Unit Cost Estimated Cost   Cost Basis                                        Assumptions
         Excavate and Consolidate All Urban Chat and Chat Bases                                                                                 Assumes all urban chat and chat bases are excavated and consolidated in existing upland
1.       in Upland Areas                                                                                                                        deposits for commercial processing (by others, not part of the remedy).
                                                                                                                                             Entire area of piles and bases plus 50-foot buffer zone area. Does not include removal of
         a. Clear, grub, and remove old structures                             1,097      acres         $533.50        $585,250       OCC-1  buildings or reinforced structures (i.e., mill foundations, etc.).
         b. Excavate and load chat from urban chat piles                  11,509,000     cu.yds.          $1.70      $19,565,300        CCI  Assumes all chat. See cost estimate sheets for rate development.
         d. Excavate and load chat bases                                   1,287,000     cu.yds.          $1.70       $2,187,900        CCI  Assumes all chat bases. See cost estimate sheets for rate development.
         e. Haul, dump and place chat (12 miles roundtrip)                12,796,000     cu.yds.          $3.11      $39,795,560        CCI  See cost estimate sheets for rate development.
                                                                                                                                             Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                             other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         f. Deep till excavated area                                           1,097      acres         $911.00        $999,367          CCI average speed used. The appropriate number of moves is included in the unit cost.
         g. Amend soils prior to revegetation                                  1,097      acres         $320.00        $351,040          CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         h. Revegetate excavated areas                                         1,097      acres        $1,200.00      $1,316,400         CCI Land area is disced, seeded and mulched.
         Subtotal Item 1                                                 $64,800,817

         Excavate and Consolidate Near-Stream Chat and Chat                                                                                 Assumes excavation and consolidation of all chat within 200 feet of stream channels and
2.       Bases                                                                                                                              all chat bases.
                                                                                                                                            Entire area of piles and bases plus 50-foot buffer zone area. Does not include removal of
         a. Clear, grub, and remove old structures                               908      acres         $533.50        $484,418       OCC-1 buildings or reinforced structures (i.e., mill foundations, etc.).
         b. Excavate and load near-stream chat piles                       6,048,000     cu.yds.          $1.70      $10,281,600        CCI Assumes all chat within 200 feet of stream channels.
         c. Excavate and load near-stream chat bases                       1,252,000     cu.yds.          $1.70       $2,128,400        CCI Assumes all chat bases.
         d. Haul, dump, and place chat in upland deposits (12 miles
         roundtrip)                                                        7,300,000     cu.yds.           $3.11     $22,703,000         CCI See cost estimate sheets for rate development.
                                                                                                                                             Assumes 48" of rip-rap placed at bends in stream channels where chat piles are located.
                                                                                                                                             Quantity based on 0.44tons/L.F. of stream length. Price based Midwest Minerals Quapaw
         e. Furnish and install rip-rap or revetment                             3,574     tons           $39.11       $139,779          CCI Quarry quote of $13.50/ton plus 5.85% sales tax.
                                                                                                                                             Assume 2.67 cubic yards of compacted clay per lineal foot of berm. See cost estimate
         f. Furnish and load berm material                                     154,483   cu.yds.          $10.24      $1,581,906             sheets for rate development.
         g. Haul, dump, and spread berm material in lifts (14.2 miles                                                                        Assume 2.67 cubic yards of compacted clay per lineal foot of berm. See cost estimate
         round trip)                                                           154,483   cu.yds.           $3.41       $526,787              sheets for rate development.
                                                                                                                                             Assume 2.67 cubic yards of compacted clay per lineal foot of berm. See cost estimate
         h. Compact clay in lifts in small berms and dikes                     154,483   cu.yds.           $1.26       $194,649          CCI sheets for rate development.
                                                                                                                                             Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                             other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         i. Deep till excavated areas                                            908      acres         $911.00        $827,188          CCI average speed used. The appropriate number of moves is included in the unit cost.
         j. Amend soils prior to revegetation                                    908      acres         $320.00        $290,560          CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         k. Revegetate excavated areas                                           908      acres        $1,200.00      $1,089,600         CCI Land area is disced, seeded and mulched.
         Subtotal Item 2                                                 $40,247,887




                                                                                                            PAGE 1 OF 6                                                                                                     JULY 2007
     Table C-3
     Alternative 8 Estimated Costs
     Total Source Consolidation, On-Site Disposal and Institutional Controls


Item #                       Item Description                           Est. Quantity      Units    Est. Unit Cost Estimated Cost      Cost Basis                                         Assumptions
         Consolidate Upland Chat Bases and Dispose of Non-
         Processed Chat in Subsidence Pits and Underground
3.       Mine Workings
                                                                                                                                                  Entire area of piles and bases plus 50-foot buffer zone area. Does not include removal of
         a. Clear, grub, and remove old structures                             2,509      acres          $533.50       $1,338,552           OCC-1 buildings or reinforced structures (i.e., mill foundations, etc.).
         b. Consolidate upland chat bases on-site                          4,170,000     cu.yds.           $2.26       $9,424,200             CCI Assumes dozer work with no loading or hauling.
         c. Excavate and load non-processed chat                           9,380,000     cu.yds.           $1.70      $15,946,000             CCI See cost estimate sheets for rate development.
         d. Haul, dump, and spread non-processed chat( 12 miles round
         trip)                                                             9,380,000     cu.yds.            $3.11     $29,171,800              CCI See cost estimate sheets for rate development.
                                                                                                                                                   Assumes dozer work with no loading or hauling. See cost estimate sheets for rate
         e. Push chat into subsidence pits                                 4,690,000     cu.yds.            $2.26     $10,599,400              CCI development.
                                                                                                                                                    Soil cover equivalent to 12-inches clay and 12-inches loam. See detail sheets for unit rate
                                                                                                                                                    development. Assumes typical feature can receive 11,000 yd 3 and requires 1,300 yd3 of
         f. Furnish and load cover soil                                        554,000   cu.yds.           $10.24      $5,672,960                   cover material per feature.
         g. Haul, dump,and spread cover soil (14.2 miles round trip)           554,000   cu.yds.            $3.41      $1,889,140                   See cost estimate sheets for rate development.
                                                                                                                                                     Assumes 12" clay and 12" loam furnished and installed. Also, assumes covered area is
         h. Compact cover soil in cover for consolidated piles                 554,000   cu.yds.            $1.26       $698,040               CCI 1/10 of original chat covered areas after consolidation.
                                                                                                                                                     Moves equivalent to one mobilization and movement between injection sites based upon
                                                                                                                                                     one extraction per 5,000 yd3 of material and one injection boring per chat pile and chat
         i. Mobilize/move between piles/bases and injection locations            939     location      $16,193.00     $15,205,227              CCI base location.
         j. Injection boring installation                                        938       boring      $16,000.00     $15,008,000   Venture Drilling One 10-inch diameter injection boring per 5,000 yd3 of chat material.
         k. Extraction boring installation                                       188       boring      $16,000.00      $3,001,600   Venture Drilling One 10-inch diameter extraction boring per 5 injection wells.
         l. Boring Abandonment                                                 1,126       boring      $10,000.00     $11,256,000   Venture Drilling Bladder installation and cement grout to surface.
         m. Inject chat at 100 tons/hour                                   4,690,000      cu.yds.           $8.91     $41,787,900              CCI See detail sheets for unit rate development.
                                                                                                                                                     Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                     other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         n. Deep till excavated area                                           2,509       acres          $911.00      $2,285,699              CCI average speed used. The appropriate number of moves is included in the unit cost.
         o. Amend soils prior to revegetation                                  2,509       acres         $320.00        $802,880               CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         p. Revegetate excavated and covered areas                             2,509       acres        $1,200.00      $3,010,800              CCI Land area is disced, seeded and mulched.
         q. Institutional control - deed notice                                  426      parcel         $500.00        $213,182     Eng. Estimate Assumes 1 parcel (i.e. deed notice) per feature on the basis that one feature can receive
         Subtotal Item 3                                                $167,311,379




                                                                                                             PAGE 2 OF 6                                                                                                            JULY 2007
     Table C-3
     Alternative 8 Estimated Costs
     Total Source Consolidation, On-Site Disposal and Institutional Controls


Item #                      Item Description                                     Est. Quantity     Units    Est. Unit Cost Estimated Cost        Cost Basis                                            Assumptions
         Excavate and Dispose of Urban Fine Tailings in
4.       Underground Mine Workings
                                                                                                                                                              Entire area of piles and bases plus 50-foot buffer zone area. Does not include removal of
         a. Clear, grub, and remove old structures                                         61      acres         $533.50           $32,544           OCC-1 buildings or reinforced structures (i.e., mill foundations, etc.).
                                                                                                                                                              Assumes all urban tailings are excavated and disposed . See cost estimate sheets for rate
         b. Excavate and load fine tailings                                           344,000    cu.yds.            $1.70       $584,800                    5 development.
                                                                                                                                                              Assumes all urban tailings are excavated and disposed . See cost estimate sheets for rate
         c. Haul, dump and pile, fine tailings at inject site (12 mile rdtrip)        344,000     cu.yds.           $3.11      $1,069,840               CCI development.
         d. Mobilize/move between injection sites                                          21    location      $13,012.00       $273,252                CCI Assumes one move per injection boring (i.e., location) plus one mobilization.
                                                                                                                                                                                                                   3
         e. Injection boring installation                                                  20      boring      $16,000.00       $312,727     Venture Drilling One 10-inch diameter injection boring per 17,600 yd of tailings.
         f. Extraction boring installation                                                 10      boring      $16,000.00       $160,000     Venture Drilling One 10-inch diameter extraction boring per pond location.
         g. Boring Abandonment                                                             30      boring      $10,000.00       $295,455     Venture Drilling Packer installation and cement grout to ground surface.
         h. Inject fine tailings at 200 tons/hour                                     344,000     cu.yds.           $5.76      $1,981,440               CCI See cost estimate detail sheets for rate development.
                                                                                                                                                              Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                              other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         i. Deep till excavated area                                                       61      acres         $911.00           $55,571              CCI average speed used. The appropriate number of moves is included in the unit cost.
         j. Amend soils prior to revegetation                                              61      acres         $320.00           $19,520              CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         k. Revegetate excavated and covered areas                                         61      acres        $1,200.00          $73,200              CCI Land area is disced, seeded and mulched.
         Subtotal Item 4                                                           $4,858,348

         Excavate and Dispose of Near-Stream Fine Tailings in
5.       Underground Mine Workings
                                                                                                                                                           Entire area of piles and bases plus 50-foot buffer zone area. Does not include removal of
         a. Clear, grub, and remove old structures                                        195     acres          $533.50        $104,033             OCC-1 buildings or reinforced structures (i.e., mill foundations, etc.).
         b. Excavate and load fine tailings                                         1,654,000    cu.yds.           $1.70       $2,811,800              CCI Assumes all near-stream tailings are excavated and disposed.

         c. Haul, dump and pile, fine tailings at inject site (12 mile rdtrip)      1,654,000     cu.yds.           $3.11      $5,143,940               CCI See cost estimate detail sheets for rate development.
         d. Mobilize/move between injection sites                                          95    location      $13,012.00      $1,236,140               CCI Assumes one move per injection boring (i.e., location) plus one mobilization.
         e. Injection boring installation                                                  94     boring       $16,000.00      $1,503,636    Venture Drilling   One 10-inch diameter injection boring per 17,600 yd3 of tailings.
         f. Extraction boring installation                                                 12     boring       $16,000.00        $192,000    Venture Drilling   One 10-inch diameter extraction boring per pond location.
         g. Boring Abandonment                                                            106     boring       $10,000.00      $1,059,773    Venture Drilling   Packer installation and cement grout to ground surface.
         h. Inject fine tailings at 200 tons/hour                                   1,654,000    cu.yds.            $5.76      $9,527,040               CCI     See cost estimate detail sheets for rate development.
                                                                                                                                                            Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                            other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         i. Deep till excavated area                                                      195      acres         $911.00        $177,645                CCI average speed used. The appropriate number of moves is included in the unit cost.
         j. Amend soils prior to revegetation                                             195      acres         $320.00         $62,400                CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         k. Revegetate excavated and covered areas                                        195      acres        $1,200.00       $234,000                CCI Land area is disced, seeded and mulched.
         Subtotal Item 5                                                          $22,052,407




                                                                                                                     PAGE 3 OF 6                                                                                                            JULY 2007
     Table C-3
     Alternative 8 Estimated Costs
     Total Source Consolidation, On-Site Disposal and Institutional Controls


Item #                          Item Description                         Est. Quantity         Units   Est. Unit Cost Estimated Cost      Cost Basis                                         Assumptions

                                                                                                                                                    Assumes all upland tailings are covered in place. Assumed that 10% of new washed fines
6.       Repair and Cover Upland Tailings In Place                                                                                                  generated by processing will also be covered but with no increase to covered surface area.
                                                                                                                                                    Entire area of piles and bases plus 50-foot buffer zone area. Does not include removal of
         a. Clear, grub, and remove old structures                                  851       acres         $533.50        $454,009           OCC-1 buildings or reinforced structures (i.e., mill foundations, etc.).
         b. Furnish and load berm material                                       77,848      cu.yds.         $10.24        $797,164             CCI See cost estimate detail sheets for rate development.
         c. Haul, dump, and spread berm material in lifts (14.2 miles
         round trip)                                                           77,848        cu.yds.           $3.41       $265,462               CCI See cost estimate detail sheets for rate development.
         d. Compact clay in lifts in large berms repairs and new )             77,848        cu.yds.           $1.26         $98,088              CCI Assumes 7.4 cubic yards of compacted clay per lineal foot of berm.
         e. Furnish and load cover material                                 2,036,027        cu.yds.          $10.24     $20,848,913              CCI See cost estimate detail sheets for rate development.
         f. Haul, dump, and spread cover material in lifts (14.2 miles
         round trip)                                                        2,036,027        cu.yds.           $3.41      $6,942,851              CCI   See cost estimate detail sheets for rate development.
         g. Compact cover materials over tailings in place                  2,036,027        cu.yds.           $1.26      $2,565,394              CCI   See cost estimate detail sheets for rate development.
         h. Amend soils prior to revegetation                                     851          acres        $320.00        $272,320               CCI   2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         i. Revegetate excavated and covered areas                                851          acres       $1,200.00      $1,021,200              CCI   Land area is disced, seeded and mulched.
         i. Institutional control - deed notice                                    63         parcel        $500.00          $31,550    Eng. Estimate   Assumes 1 parcel (i.e. deed notice) per 10 acres.
         Subtotal Item 6                                                  $33,296,950

         Consolidate and Cover Smelter Wastes, Deep Till Smelter-
7.       Affected Soils
         a. Consolidate smelter wastes on-site                                    1,846      cu.yds.           $2.26           $4,172             CCI Assumes dozer work with no loading or hauling.
                                                                                                                                                      Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
                                                                                                                                                      other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
         b. Deep till smelter affected soils                                         14       acres         $911.00         $12,754               CCI average speed used. The appropriate number of moves is included in the unit cost.
         c. Furnish and load cover material                                      45,173      cu.yds.         $10.24        $462,575               CCI See cost estimate detail sheets for rate development.
         f. Haul, dump, and spread cover material in lifts (14.2 miles
         round trip)                                                             45,173      cu.yds.           $3.41       $154,041             CCI     See cost estimate detail sheets for rate development.
         e. Compact cover materials over smelter wastes in place.                45,173      cu.yds.           $1.26        $56,918             CCI     See cost estimate detail sheets for rate development.
         f. Add biosolids or organic matter                                         280         tons          $30.00         $8,400        Jasper FS    20 tons per acre.
         g. Amend soils prior to revegetation                                        14       acres         $320.00          $4,480             CCI     2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
         h. Revegetate excavated and covered areas                                   14       acres        $1,200.00        $16,800             CCI     Land area is disced, seeded and mulched.
         Subtotal Item 7                                                       $720,140

8.       Rural Residential Yard Soils and Affected Aquifer Wells
         a. Remediate rural residential yards                                        5         yards      $28,000.00       $140,000              EPA Average cost of OU-2 yards completed in 2005.
                                                                                                                                                      Alternative supplied water system is within economically feasible distance to complete
         b. Connect affected households to piped water                                2   Households      $15,000.00          $30,000   Best Estimate connection.
         Subtotal Item 8                                                       $170,000




                                                                                                                PAGE 4 OF 6                                                                                                           JULY 2007
      Table C-3
      Alternative 8 Estimated Costs
      Total Source Consolidation, On-Site Disposal and Institutional Controls


Item #                       Item Description                           Est. Quantity         Units   Est. Unit Cost Estimated Cost     Cost Basis                                         Assumptions
9.     Total Direct Capital Costs                                       $333,457,928

10.       Indirect Capital Costs
          a. Develop and implement institutional controls                             1    lump sum       $500,000        $500,000    Best Estimate
          b. Project management                                                       1    lump sum     $16,672,896     $16,672,896     EPA, 2000 Assume 5% of total direct capital cost
          c. Remedial design                                                          1    lump sum     $16,672,896     $16,672,896     EPA, 2000 Assume 5% of total direct capital cost
          d. Construction oversight and management                                    1    lump sum     $20,007,476     $20,007,476     EPA, 2000 Assume 6% of total direct capital cost
                                                                                                                                                   Assume 2% of total direct capital cost; assumes performance of monitoring (i.e., air,
                                                                                                                                                   groundwater, surface water,) during implementation of the remedy and confirmation
          e. Technical support                                                        1    lump sum      $6,669,159      $6,669,159      EPA, 2000 sampling.
          f. Contingencies                                                            1    lump sum     $66,691,586     $66,691,586      EPA, 2000 Assume 20% of total direct capital cost; 15% scope, 5% bid.
          g. Chat sales compliance, environmental monitoring, and
          oversight                                                                 1      lump sum     $48,181,800     $48,181,800      EPA, 2007 Refer to Appendix E
          Subtotal Indirect Capital Costs                                $175,395,812

11.       Total Capital Costs                                            $508,853,740

12.       Annual Operation and Maintenance Costs
          a. Administer landowner agreements                                           1   lump sum     $100,000.00       $100,000                  Assume 1 FTE plus expenses
          b. Administer institutional controls                                         1   lump sum      $25,000.00        $25,000                  Assume 1/4 FTE in the Ottawa County clerk's office plus expenses.
          c. Administer chat priority and management program                           1   lump sum     $100,000.00       $100,000                  Assume 1 FTE plus expenses
          d. Vegetation management                                                     1   lump sum     $250,000.00       $250,000    Best estimate Assumes management of revegetated areas for 3 years after initial seeding. Goes to zero
          Subtotal Annual O&M Costs                                             $475,000




                                                                                                               PAGE 5 OF 6                                                                                                         JULY 2007
   Table C-3
   Alternative 8 Estimated Costs
   Total Source Consolidation, On-Site Disposal and Institutional Controls


Item #                        Item Description                               Est. Quantity             Units      Est. Unit Cost Estimated Cost       Cost Basis                               Assumptions
13.    Net Present Value Cost Analysis                                         2007               2008               2009             2010            2011          2012          2013        2014        2015        2016
       Direct Capital Costs                                                   $13,284,960        $13,284,960        $13,284,960      $13,284,960     $13,284,960   $13,284,960 $13,284,960 $13,284,960 $13,284,960 $13,284,960
       Indirect Capital Costs                                                  $8,769,791         $8,769,791         $8,769,791       $8,769,791      $8,769,791    $8,769,791 $8,769,791 $8,769,791 $8,769,791 $8,769,791
       Operation and Maintenance Costs                                                                                 $475,000         $475,000        $475,000      $475,000   $475,000    $475,000    $475,000    $475,000
       Total Capital and O&M Costs                                             $22,054,750       $22,054,750        $22,529,750      $22,529,750     $22,529,750   $22,529,750 $22,529,750 $22,529,750 $22,529,750 $22,529,750
       Net Present Value                                                       $20,611,916       $19,263,473        $18,390,987      $17,187,839     $16,063,401   $15,012,524 $14,030,396 $13,112,520 $12,254,691 $11,452,983
       Year                                                                       1                 2                   3               4               5             6             7           8           9          10


        Net Present Value Cost Analysis                                         2017              2018               2019               2020          2021          2022          2023        2024        2025            2026
        Direct Capital Costs                                                   $20,060,833       $20,060,833        $20,060,833        $20,060,833   $20,060,833   $20,060,833 $20,060,833 $20,060,833 $20,060,833 $20,060,833
        Indirect Capital Costs                                                  $8,769,791        $8,769,791         $8,769,791         $8,769,791    $8,769,791    $8,769,791 $8,769,791 $8,769,791 $8,769,791 $8,769,791
        Operation and Maintenance Costs                                          $475,000          $475,000           $475,000           $475,000      $475,000      $475,000    $475,000    $475,000    $475,000    $475,000
        Total Capital and O&M Costs                                            $29,305,624       $29,305,624        $29,305,624        $29,305,624   $29,305,624   $29,305,624 $29,305,624 $29,305,624 $29,305,624 $29,305,624
        Net Present Value                                                      $13,922,891       $13,012,047        $12,160,792        $11,365,226   $10,621,707    $9,926,829 $9,277,410 $8,670,477 $8,103,249 $7,573,130
        Year                                                                     11                12                 13                 14            15            16            17          18          19          20


        Net Present Value Cost Analysis                                         2027               2028               2029              2030          2031          2032         2033        2034         2035        2036        Totals
        Direct Capital Costs                                                                                                                                                                                                   $333,457,928
        Indirect Capital Costs                                                                                                                                                                                                 $175,395,812
        Operation and Maintenance Costs                                           $475,000          $475,000           $225,000           $225,000     $225,000      $225,000    $225,000    $225,000    $225,000     $225,000 $11,300,000
        Total Capital and O&M Costs                                               $475,000          $475,000           $225,000           $225,000     $225,000      $225,000    $225,000    $225,000    $225,000     $225,000 $520,153,740
        Net Present Value                                                         $114,719          $107,214            $47,463            $44,358      $41,456       $38,744     $36,209     $33,840     $31,627      $29,558 $262,539,675
        Year                                                                      21                22                 23                 24           25            26           27          28          29           30


        Total Net Present Value                                               $262,539,675


Notes and Assumptions:
       Direct Capital Costs for Item #'s 1, 2, 4, 5, 7 and 8 are spread evenly over the first 10 years in the Net Present Value calculation.
       Direct Capital Costs for Item #'s 3 and 6 are spread evenly over years 11 through 20 in the Net Present Value calculation.
       Assume indirect capital costs are spread evenly over the 20-year construction timeframe.
       Assume O&M cost start in year 3 and continue for 20 years, then decrease to $225,000.
       The Net Present Value analysis assumes 30 years of O&M at a discount rate of 7 percent.




                                                                                                                             PAGE 6 OF 6                                                                                         JULY 2007
              APPENDIX D

Unit Cost Development
                                                                                                     Appendix D
                                                                                          Unit Cost Development
                                                                     TAR CREEK SUPERFUND SITE, OPERABLE UNIT 4




1.0 Summary
CH2M HILL completed a detailed unit cost evaluation and “ground floor” build-up of the
critical cost components that account for significant percentages of the overall total costs in
the remedial alternatives that were developed and evaluated in the Feasibility Study.

In many cases, lease costs are assumed for construction equipment expected to be needed
for the work, even though the construction contractor might actually buy the equipment
outright, rather than lease. This way of estimating (through leasing) accounts for the
contractor’s costs for equipment insurance, operation, depreciation, and replacement over
the life of the project. These costs are difficult to establish exactly at this stage of the work,
before the remedial design is complete and all details of the work are known. Depreciation
can be especially difficult to gauge accurately. Caterpillar Company literature suggests that
the life span of a piece of heavy construction equipment can vary from 7 to 20 years,
depending on the type of equipment and the relative intensity of its use. Without detailed
knowledge of exact time schedules and conditions of use, the cost estimate will be
somewhat uncertain. However, all of that can be assumed to be built into the lease costs for
equipment, and so lease costs are used for estimating long-term activities.

The estimates summarized in this document are bulk rates, taking advantage of volume
discounts, economies of scale, and efficiency resulting from focused efforts on a large scale.
Significant price increases might result from a piecemeal approach, from slow or small-scale
implementation, or from repeated starts and stops over the course of the work.

Unit costs that were evaluated for addressing source material included excavating, loading
and hauling; deep tilling of soils; excavation of source materials from site streams; injection
of chat and fines into flooded underground mine workings; pushing of chat into subsidence
features or mine shafts; and covering in place. Presented below is a summary outlining the
key cost components, the unit cost estimates that were used in the Feasibility Study cost
estimates, and a listing of the key assumptions and other observations.




TAR CREEK_APPENDIX D UNIT COST DEVELOPMENT       1                                                    MAY 2007
                                                                                                                  Appendix D
                                                                                                       Unit Cost Development
                                                                                  TAR CREEK SUPERFUND SITE, OPERABLE UNIT 4



2.0 Excavation, Loading and Hauling of Chat
This evaluation and cost estimate work-up pertained primarily to the excavation, loading,
and hauling of chat from piles and bases throughout the site. The unit rates developed for
this type of source material may not necessarily apply to other site source materials such as
fine tailings (i.e., flotation tailings) or chat found in site streams.

                                                        Table 2-1

                                      Excavation, Loading and Hauling of Chat

                                             Six- and Twelve-Mile Round Trip

                   Description                         Bid Item       Unit Cost             Attached References

Excavate and Load                                     1010                             Attachment D-1
                                                                    $1.72/yd3

Haul and Dump, 6 Mile Roundtrip                       1020
                                                                    $2.41/yd3


Excavate and Load                                     1040          $1.72/ yd3
Haul and Dump, 12 Mile Roundtrip                      1050
                                                                    $3.11/yd3




Key Assumptions:

•   Includes dozer for placement at haul point (i.e., pile management)

•   Assumes 20-yard trucks are used

•   Includes removal of soil/chat interface at slower production rate


3.0 Deep Tilling of Soils
This evaluation and cost estimate work-up pertained primarily to the deep tilling of soils.
This method is considered for use in addressing native soils after source materials have been
removed from an area and/or on the buffer zone soils surrounding source materials.




TAR CREEK_APPENDIX D UNIT COST DEVELOPMENT                   2                                                     MAY 2007
                                                                                                                 Appendix D
                                                                                                      Unit Cost Development
                                                                                 TAR CREEK SUPERFUND SITE, OPERABLE UNIT 4


                                                          Table 3-1

                                                    Deep Tilling of Soils



               Description                     Bid Item           Unit Cost          Attached References

Deep Tilling                                 1000             $911/acre       Attachment D-2




Key Assumptions:

•   3 MPH average speed for equipment pulling plow and harrow

•   Two D-8 Dozers, one making one pass with a 16-foot-wide moldboard gangplow and the
    other, two passes of a 30-inch disc harrow and spring-tooth harrow pulled in tandem


4.0 Excavation of Source Materials from Site Streams
Work is assumed to be in deep deposits of source materials found in and around
streambeds. In shallow deposits, approximately 2 feet or less, the material is excavated,
removed, and backfilled. If the thickness of the deposit exceeds 2 feet, the upper 2 feet will
be excavated; then the excavation is lined with a 60-mil high-density polyethylene (HDPE)
liner. The liner is secured in anchor trenches, and the liner is covered with 2 feet of
imported, uncontaminated limestone gravel material called a “filter blanket.” In other areas,
the excavation is filled with large rock (riprap) that can resist erosion.

                                                          Table 4-1

                                 Excavation of Source Materials from Site Streams



             Description                      Bid Item            Unit Cost           Attached References

Excavate Chat and Fines                      3000            $17.51/yd3       Attachment D-3
from Stream Bed

Furnish & Load Cover                         5010            $10.24/yd3

Haul & Dump Cover                            5020            $3.41/yd3
Material

Compact Cover Material                       5030            $1.26/yd3



TAR CREEK_APPENDIX D UNIT COST DEVELOPMENT                    3                                                   MAY 2007
                                                                                                             Appendix D
                                                                                                  Unit Cost Development
                                                                             TAR CREEK SUPERFUND SITE, OPERABLE UNIT 4


                                                         Table 4-1

                                 Excavation of Source Materials from Site Streams



             Description                      Bid Item           Unit Cost        Attached References

Furnish and Install Rip-Rap                  6000           $39.11/yd3



Key Assumptions:

•     Slow careful digging required to follow streams and maintain proper depth

•     Added 5% spillage and misplacement volume to purchase price of filter blanket gravel
      volume

•     Locally procured cover materials based on purchase price for clay soils listed in Means
      2007 Work for Miami, Oklahoma

•     Locally procured riprap based on purchase price from a local quarry


5.0 Injection of Source Materials
Source materials include chat and fine tailings.

5.1       Chat
This evaluation and cost estimate work-up pertained primarily to the injection of chat from
piles and bases throughout the site. The estimates are based upon information from the
First and Second Interim Chat Reports (EPA, 2005). Data extracted from the bids received by
the Okalahoma Conservation Commission (OCC) for chat injection work west of
Commerce, Oklahoma were considered.




TAR CREEK_APPENDIX D UNIT COST DEVELOPMENT                   4                                                MAY 2007
                                                                                                                 Appendix D
                                                                                                      Unit Cost Development
                                                                                 TAR CREEK SUPERFUND SITE, OPERABLE UNIT 4


                                                          Table 5-1

                                        Injection of Chat @ 100 Tons per Hour

              Description                      Bid Item           Unit Cost           Attached References

Mobilize/Move Between Locations              2005             $16,193/site    Attachment D-4

Install + Abandon 2 Wells per                2007             $55,470/site
Location

Inject Chat @ 100 Tons/Hour                  2010             $8.91/ yd3



Key Assumptions:

•     Process is conducted as indicated in the conceptual process flow diagram in Attachment
      D-4

•     One injection boring is assumed for each 5,000 yd3 of chat injected, based on EPA pilot
      studies

•     Boring installation cost of $15,000 for 10-inch diameter boring using air rotary with metal
      casing installed until reaching competent bedrock, and abandonment cost of $10,000 each
      (total $25,000 per injection or water extraction boring). (All bare costs without markups)

Note:

This scenario assumes that chat can be injected consistently at a rate of 100 tons per hour.
Pilot studies completed at the Site suggest this rate is achievable.


5.2         Injection of Fines
This evaluation and cost estimate work-up pertained primarily to the injection of fine
tailings and washed fines from millponds throughout the site. The estimates are based
upon information from the First and Second Interim Chat Reports (EPA, 2005). Data
extracted from the bids received by the Okalahoma Conservation Commission (OCC) for
chat injection work west of Commerce, Oklahoma were considered.




TAR CREEK_APPENDIX D UNIT COST DEVELOPMENT                    5                                                   MAY 2007
                                                                                                                 Appendix D
                                                                                                      Unit Cost Development
                                                                                 TAR CREEK SUPERFUND SITE, OPERABLE UNIT 4




                                                          Table 5-2

                                        Injection of Fines @ 200 Tons per Hour

             Description                       Bid Item           Unit Cost           Attached References

Mobilize/Move Between Locations              2405             $13,012/site    Attachment D-5

Install + Abandon Wells                      2407             $27,735/well
Inject Fines @ 200 Tons/Hour                 2410             $5.76/yd3




Key Assumptions:

•   Process is conducted as indicated in the conceptual process flow diagram in Attachment
    D-5

•   One injection boring is assumed for each 17,600 yd3 of fines injected based upon EPA pilot
    studies

•   One extraction well is assumed at each of the 61 fine tailing ponds to be injected into the
    underlying mine workings

•   Boring installation cost of $15,000 for 10-inch diameter boring using air rotary with metal
    casing installed until reaching competent bedrock, and abandonment cost of $10,000 each
    (total $25,000 per injection or water extraction boring). (All bare costs without markup)

Note:

This scenario assumes that fines can be injected consistently at a rate of 200 tons per hour.


6.0 Pushing of Chat into a Subsidence/Mine Shaft Feature
This evaluation and cost estimate work-up pertains to the strategic movement and
placement of chat from piles or bases throughout the Site into subsidence features or open
mineshafts. This evaluation only considers the effort and actions necessary to move chat
material in proximity to a feature (i.e., economically feasible operations) and place it in the
feature. If chat material is not close to a feature, then it may be appropriate to include




TAR CREEK_APPENDIX D UNIT COST DEVELOPMENT                    6                                                   MAY 2007
                                                                                                               Appendix D
                                                                                                    Unit Cost Development
                                                                               TAR CREEK SUPERFUND SITE, OPERABLE UNIT 4


excavation, loading, and hauling costs discussed in Section 2 to bring the material to a
feature. Then, this cost of final placement can be applied. In addition to placement unit
costs, it is assumed that material placed into a feature would require proper covering. The
following text discusses the cost for that application.



                                                      Table 6-1

                              Pushing of Chat into a Subsidence/Mine Shaft Feature

              Description                      Bid Item        Unit Cost           Attached References

Push Chat into Subsidence                    3000             $2.26/yd3    Attachment D-6




Key Assumptions:

•   Assumed a typical subsidence feature capable of receiving 11,000 yd3 of material

•   Assumed push is 200 feet or less

Note:

The quantity of available features, their proximity to chat, and their available capacity are
uncertainties associated with this remedial approach.


7.0 Cover Source Materials In-Place
This evaluation and cost estimate work-up pertains to covering source materials in place. In
general, this cost can also be applied to covering source materials that are placed into a
subsidence feature or covering of a repository.




TAR CREEK_APPENDIX D UNIT COST DEVELOPMENT                7                                                     MAY 2007
                                                                                                                  Appendix D
                                                                                                       Unit Cost Development