Benchmarking Report Minnesota Pollution Control Agency

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					 Benchmarking Report: Site-Specific
Approaches for Lake Nutrient TMDLs



                                                     FINAL REPORT




                                                       Prepared for:
                    Minnesota Pollution Control Agency



                                                      June 26, 2006


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  Limno-Tech, Inc.
  Excellence in Environmental Solutions Since 1975
  Houlton, WI Office
  Headquarters in Ann Arbor, MI
Benchmarking Report:
Site-Specific Approaches to Lake Nutrient TMDLs                                                                      June 26, 2006




                                            TABLE OF CONTENTS


1. PROJECT BACKGROUND .................................................................................................1

2. RESEARCH APPROACH ....................................................................................................2
     2.1 PROCESS FOR SELECTING BENCHMARKING STATES .................................... 2
     2.2 STATES SURVEYED AND CONTACT INFORMATION ....................................... 2
     2.3 SURVEY QUESTIONS ............................................................................................... 3
     2.4 BENCHMARKING INTERVIEW PROCESS ............................................................ 4

3. BENCHMARKING RESULTS ............................................................................................5
     3.1 BENCHMARKING INTERVIEW RESPONSES ....................................................... 5
     3.2 GENERAL FINDINGS ................................................................................................ 9
     3.3 OPTIONS FOR SITE-SPECIFIC APPROACHES BEING USED BY STATES ..... 12
         3.3.1 SITE-SPECIFIC CRITERIA ..................................................................................... 13
         3.3.2 NATURAL BACKGROUND AND REFERENCE REACH ............................................. 22
         3.3.3 REFINE BENEFICIAL USE ..................................................................................... 24
         3.3.4 UAA – CHANGE BENEFICIAL USE....................................................................... 25
         3.3.5 VARIANCE ........................................................................................................... 29
         3.3.6 NON-DEGRADATION ........................................................................................... 30
         3.3.7 TMDL COMPONENTS – MARGIN OF SAFETY, RESERVE CAPACITY, AND
                 IMPLEMENTATION ............................................................................................ 31
     3.4 SUMMARY OF TMDL STORMWATER POLICIES AND APPROACHES ......... 41
         3.4.1 OVERVIEW OF EPA STORMWATER APPROACH ................................................... 41
     3.5 BENCHMARKING STATES’ APPROACHES........................................................ 42
         3.5.1 SMALL MS4 PERMITS ......................................................................................... 42
         3.5.2 CONSTRUCTION GENERAL PERMITS .................................................................... 43
         3.5.3 SPECIFIC TMDL AND STORMWATER PERMIT EXAMPLES .................................... 44

4. CONCLUSIONS..................................................................................................................47




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Site-Specific Approaches to Lake Nutrient TMDLs                                                                        June 26, 2006




                                                   LIST OF TABLES
Table 1: Summary of Benchmarking Interview Responses for Questions Related to the Water
       Resource.........................................................................................................................6
Table 2: Summary of Benchmarking Interview Responses for Questions Related to Site-
       Specific Approaches in the Context of TMDLs ............................................................7
Table 3: Summary of Benchmarking Interview Responses for Questions Related to
       Watersheds Draining to the Waterbodies with Site-Specific Approaches.....................8
Table 4: Arizona’s Matrix for Implementation of the Narrative Nutrient Standards in Lakes
       and Reservoirs..............................................................................................................15
Table 5: Maine’s Secchi, Chlorophyll a, and Phosphorus Endpoints for the Narrative Nutrient
       Standard .......................................................................................................................18
Table 6: Maine’s Acceptable Increases in Lake Phosphorus Concentration by Water Quality
       Category.......................................................................................................................36
Table 7: Summary of Small MS4 (upper) and Construction (lower) general permits from
       benchmarking states pertaining to stormwater and TMDLs........................................44




                                             LIST OF APPENDICES
Appendix A           Contact List for Benchmarking Interviews
Appendix B           List of TMDL Websites for Benchmarking States
Appendix C           Benchmarking Interview Notes
Appendix D           State Nutrient Criteria Approaches
Appendix E           Example TMDLs
Appendix F           TMDL Language from Benchmarking State Stormwater Permits
Appendix G           Example NPDES Stormwater Permits
Appendix H           Other References




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Benchmarking Report:
Site-Specific Approaches to Lake Nutrient TMDLs                                      June 26, 2006




                                  EXECUTIVE SUMMARY
The Minnesota Pollution Control Agency (MPCA) is in the process of writing protocols for
Total Maximum Daily Load (TMDL) development for lakes impaired by nutrients. A
primary issue of concern deals with lakes that are not likely to meet existing or proposed
nutrient standards despite extraordinary efforts to meet load reduction targets. In these
instances, the TMDL equation can’t be solved through the wasteload allocation (WLA) and
load allocation (LA), since the necessary reductions are unachievable through current
technologies or practices. In these instances, the primary question for the MPCA is: Should
site-specific approaches be applied to balance the TMDL equation? Another key issue is
development of site-specific approaches to the water quality standard to address situations
where the attainable water quality is “better” than the standard and there is a desire to protect
the lake to that higher level. Site-specific approaches being considered are: site-specific
standards or criteria, use classification changes supported by use attainability analyses
(UAAs), and variances. MPCA plans on issuing guidance to address this issue in the summer
of 2006.
The purpose of the work summarized in this report was to assist the MPCA in researching
how states nationwide are addressing issues related to difficult to achieve or unattainable
nutrient TMDLs for lakes. To accomplish this task, Limno-Tech, Inc. (LTI) conducted
benchmarking interviews of ten states across the country, in addition to Minnesota, using an
interview questionnaire developed by MPCA. Information developed from this research will
be used by MPCA in development of site-specific approaches to be included in the protocols
for lake nutrient TMDLs. The ten benchmarking states are: Arizona, California, Maine,
Maryland, Michigan, Montana, New York, Vermont, Virginia, and Washington. These ten
states were selected because they were identified to have been either: 1) working on lake
nutrient TMDLs and therefore had the greatest likelihood of having considered site-specific
approaches; or 2) were known to be using or developing site-specific approaches.
Several key findings related to the use of site-specific approaches to address unattainable
TMDLs resulted from the benchmarking interviews. These are:
    •   Use of site-specific approaches to “balance the TMDL equation” is limited for a
        variety of reasons, but examples of several types of site-specific approaches do exist.
        In general, the benchmarking states are in the early stages of considering and using
        site-specific approaches to resolve situations where attaining goals of the TMDLs will
        be difficult if not unattainable. Montana is the single state that has explicitly
        identified an approach for dealing with unattainable TMDLs. Montana Department of
        Environmental Quality (DEQ) is proposing a standardized variance procedure on the
        basis of economic hardship to implement TMDLs for phosphorus in streams.
        Maryland is considering the use of “maximum practicable reduction” best
        management practices (BMPs) scenarios and adaptive implementation for difficult to
        achieve bacteria TMDLs. However, this approach is in its infancy. Several other
        states, Arizona (site-specific criteria), California (UAAs and variances), and
        Maryland (UAAs), have used site-specific approaches in difficult TMDL situations,
        but these have been on a case-by-case/unique instance basis. Virginia DEQ
        recognizes a future need for site-specific approaches to deal with difficult to achieve


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Benchmarking Report:
Site-Specific Approaches to Lake Nutrient TMDLs                                     June 26, 2006



        lake nutrient TMDLs, but is taking the approach of waiting until after implementation
        of controls to determine next steps.
    •   Site-specific criteria are being used or proposed by some states on routine or case-
        by-case bases, but generally not specifically for “difficult to achieve” TMDL
        situations. However, the nutrient criteria approaches in use or proposed by several
        states incorporate flexibility in setting nutrient criteria such that the need for site-
        specific approaches for use in difficult TMDL situations might be reduced. Arizona is
        the only state that indicated use of site-specific criteria in difficult to achieve TMDL
        situations. Maryland is developing an approach for setting site-specific adjustments
        to bacteria endpoints based on “maximum practicable reduction” scenarios for Best
        Management Practices (BMPs), but the approach has not yet been implemented.
        The nutrient criteria frameworks in Arizona, California, Michigan, Maine, and
        Washington incorporate flexibility in setting nutrient criteria for lakes. Arizona uses
        a matrix of threshold values that vary by beneficial use and lake class to implement
        its narrative nutrient standard. California, Michigan, and Washington, have or are
        proposing approaches that will result in site-specific nutrient criteria or targets for
        lakes and reservoirs. Maine’s nutrient criteria approach is based on trophic change
        risk categories.
    •   States occasionally use site-specific approaches that result in more protective
        standards or criteria or proactive waterbody management. Of the benchmarking
        states, New York and Maryland indicated use of such approaches. New York
        developed a nutrient TMDL for the New York City water supply watershed that
        included phosphorus criteria that were more protective than the numeric target for the
        state’s narrative standard for seven of the nineteen reservoirs in the watershed.
        Maryland has used the site-specific approach of requiring implementation of a
        watershed protection plan to protect a reservoir from further degradation when its
        status was borderline impaired. Rather than writing a TMDL for the reservoir, the
        state documented the impairment in what it termed a “Water Quality Analysis.”
    •   Variances are being used in TMDL situations by two of the states surveyed. Of the
        benchmarking states, California and Montana are the only states using or proposing
        to use variances in TMDL situations. California has used variances on a case-by-case
        basis; however, information was not received regarding specifics of when UAAs are
        used in California.. Montana is proposing an approach to unattainable phosphorus
        TMDLs in streams using variances on the basis of substantial and widespread
        economic hardship. Variances are Montana’s preferred approach in part due to the
        retention of existing designated uses.
    •   While over 100 Use Attainability Analysis (UAA) efforts have been considered or
        undertaken nationwide, examples of the use of UAAs are limited among the states
        surveyed. Of the benchmarking states, Maryland and California have used UAAs in
        TMDL situations. Maryland pursued a UAA in one instance for a nutrient-impaired
        lake. The justification made by Maryland Department of Environment for pursuing
        the beneficial use change in lieu of completing a TMDL was acceptable to EPA. The
        UAA itself has not yet been completed. California has used UAAs on a case-by-case


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Benchmarking Report:
Site-Specific Approaches to Lake Nutrient TMDLs                                   June 26, 2006



        basis; however, information was not received regarding specifics of when UAAs are
        used in California.
    •   Experience with site-specific approaches for agricultural TMDLs is virtually
        nonexistent. None of the benchmarking states have experience in dealing with site-
        specific approaches for agricultural watersheds. Arizona indicated that agricultural
        sources would potentially be treated as point sources in such a situation. Washington
        indicated that the focus would be different for implementation in agricultural
        watersheds, given the predominance of nonpoint sources vs. point sources. Illinois
        has developed numerous lake nutrient TMDLs in agricultural watersheds. Some of
        these have resulted in needed load reductions of 80% and higher and could be
        considered unachievable. Illinois EPA is allowing adaptive management in TMDL
        implementation to deal with these difficult to achieve TMDL situations. Though it is
        not aimed at site-specific approaches, Maine Department of Environmental
        Protection has had a cooperative arrangement with the Maine Association of
        Conservation Districts to develop TMDLs in agricultural watersheds since 2000.
    •   While TMDLs have addressed stormwater, the bridge of addressing TMDLs in
        specific stormwater permit instances has not been crossed. Many of the
        benchmarking states (Maine, Maryland, Michigan, Washington) indicated that
        stormwater from MS4s is being included in TMDLs as wasteload allocations. Phase 2
        MS4 permits are in draft form in New York and Washington, and implementation of
        the small MS4 program has just begun in Vermont. The majority of benchmarking
        states have either not had occasion to deal with TMDL requirements in MS4 permits,
        have not yet begun to deal with them, or have just begun to deal with them. Virginia
        is currently in the process of coordinating how to put TMDL requirements into
        stormwater permits. New York’s draft MS4 permits include more specific
        requirements for implementation of the six minimum measures for small MS4s. Most
        states have not yet dealt with construction stormwater TMDL issues. However,
        Vermont is now using individual permits for construction in impaired watersheds.
    •   Issues related to defining Maximum Extent Practicable (MEP) and considering Best
        Available Technology (BAT) have not been addressed in detail. The single state with
        comments on the question regarding whether states are considering BAT as separate
        from MEP was from Maryland. Maryland Department of Environment considers
        BAT to be equivalent to MEP. A few states indicated that they have no specific
        definition of MEP, while New York indicated that its new MS4 permits define MEP
        with more specific controls required in impaired watersheds.
    •   Implementation of BMPs does not fall within the purview of TMDL program staff. In
        many instances, implementation and tracking of BMPs is the responsibility of other
        departments, programs, or even agencies within the states. This may account for the
        lack of consideration or response from the benchmarking states on the questions
        related to implementation of BMPs prior to determination of TMDLs being
        unattainable. As with TMDL stormwater issues, coordination between multiple
        program areas may also add to the complexity of addressing TMDL implementation .



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Site-Specific Approaches to Lake Nutrient TMDLs                                     June 26, 2006



    •   Margin of Safety (MOS) is not being used as a tool for addressing difficult to achieve
        TMDLs by most of the benchmarking states. However, Maryland is proposing an
        approach to dealing with unattainable bacteria TMDLs that would rely on adaptive
        management to address uncertainty within the TMDL, rather than the typical MOS. In
        typical TMDL situations, the benchmarking states are using a mixed set of
        approaches for addressing MOS in TMDLs. Maine uses an implicit MOS approach
        for lake nutrient TMDLs. Some states are using explicit approaches routinely (Illinois
        and Virginia). Several of the benchmarking states do not have a standardized
        approach and determine which type of MOS, implicit or explicit, to use on a case by
        case basis (Arizona, California, and Michigan). Washington defines MOS using
        “science-based numbers” that result from data analyses and modeling results, as
        opposed to selecting an arbitrary explicit MOS.
    •   Reserve capacity for future development is being used in TMDLs by several of the
        benchmarking states. Benchmarking states using reserve capacity for future growth in
        typical TMDL situations include California, Illinois, Maine, and Virginia. Several
        states indicted that they do not set aside reserve capacity in TMDLs. These states
        include Arizona, Maryland, Michigan, Vermont, and Washington. Michigan has
        decided not to include consideration for future growth in TMDLs due to public
        objections to its inclusion in one TMDL instance. In an example on the opposite end
        of the spectrum from inclusion of reserve capacity in TMDLs, Washington imposed
        a building moratorium to restrict future growth following development of a TMDL
        for a lake in one instance.
    •   TMDL implementation approaches are being used by some states to address difficult
        to achieve TMDLs. Illinois is incorporating adaptive management into
        implementation plans for agricultural nutrient TMDLs. Maryland is also planning to
        use adaptive management within a proposed approach to dealing with unattainable
        bacterial TMDLs. Virginia is incorporating long implementation time frames into
        TMDLs for lakes with high internal loading.
As represented by the benchmarking states, site-specific approaches, including site-specific
criteria, UAAs, variances, and the TMDL components of margin of safety and
implementation, are being used for lake nutrient TMDLs across the country. However, the
use of these approaches for both unattainable and more protective TMDLs is on a case-by-
case basis; most states do not have guidance, checklists, or set frameworks for identifying
when site-specific approaches are necessary and how to apply them.
The decision by a state to use a certain type of site-specific approach, or conversely not to
use a certain approach, is affected by a number of complex factors, including state water
quality standards and other regulations, public acceptance, available financial resources,
prioritization of water quality issues (i.e., types of waterbodies or impairments), and
coordination between agency program areas.
Based on the benchmarking research, Minnesota is clearly on the forefront in considering
site-specific approaches and guidance for developing more protective TMDLs and to address
otherwise unattainable TMDLs.



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Benchmarking Report:
Site-Specific Approaches to Lake Nutrient TMDLs                                      June 26, 2006




                             1. PROJECT BACKGROUND
The Minnesota Pollution Control Agency (MPCA) is in the process of writing protocols for
Total Maximum Daily Load (TMDL) development for lakes impaired by nutrients. A
primary issue of concern deals with lakes that are not likely to meet existing or proposed
nutrient standards despite extraordinary efforts to meet load reduction targets. In these
instances, the TMDL equation can’t be solved through the wasteload allocation (WLA) and
load allocation (LA), since the necessary reductions are unachievable through current
technologies or practices. In these instances, the primary question for the MPCA is: Should
site-specific approaches be applied to balance the TMDL equation? Another key issue is
development of site-specific approaches to the water quality standard to address situations
where the attainable water quality is “better” than the standard and there is a desire to protect
a lake to that higher level. Site-specific approaches being considered are: site-specific
standards or criteria, use classification changes supported by use attainability analyses
(UAAs), and variances.

MPCA plans on issuing guidance to address this issue in the summer of 2006. The model
being used for such guidance is the Regional Guidance on Submittal Requirements for Lake
and Reservoir Nutrient TMDLs, U.S. EPA, New England Region, Office of Ecosystem
Protection (http://www.epa.gov/ne/eco/tmdl/guidance.html). MPCA would like to modify
and augment this guidance to make it appropriate to Minnesota and add a section to this
guidance addressing site-specific approaches.
The purpose of the work summarized in this report was to assist the MPCA in researching
how states nationwide are addressing issues related to difficult to achieve or unattainable
nutrient TMDLs for lakes. To accomplish this task, Limno-Tech, Inc. (LTI) conducted
benchmarking interviews of ten states across the country that were identified to be the
furthest along in related TMDL projects and consideration of this issue. Benchmarking was
conducted using an interview questionnaire developed by MPCA. Information developed
from this research will be used by MPCA in development of site-specific approaches to be
included in the protocols for lake nutrient TMDLs.
Section 2 of this report presents the Research Approach. Benchmarking Results are presented
in Section 3.




Limno-Tech, Inc.                                                                           Page 1
Benchmarking Report:
Site-Specific Approaches to Lake Nutrient TMDLs                                    June 26, 2006




                              2. RESEARCH APPROACH
The primary method used to conduct research into the issues related to the use of site-specific
approaches for nutrient TMDLs in lakes was benchmarking interviews of state agency staff
nationwide. Collection of pertinent documentation (state rules, policies, TMDL and permit
examples, etc.) was also conducted. Information on state stormwater policies and approaches
related to TMDLs was also summarized based on a review of small MS4 and construction
permits from each of the benchmarking states. Selection of the states for benchmarking, the
survey questions, and interview process are described in this section.

2.1 PROCESS FOR SELECTING BENCHMARKING STATES
To narrow the field of states considered for benchmarking, contacts were made with TMDL
and/or water quality standards (WQS) program staff at the 10 U.S. Environmental Protection
Agency (EPA) regions. These EPA staff were asked to identify states that were developing
nutrient TMDLs for lakes, as well as states that were dealing with site-specific issues related
to nutrients in lakes. In addition to contacting the 10 EPA regions, state TMDL coordinators
in Wisconsin, Iowa, North Dakota, North Carolina, and Florida were contacted directly.
The list of states dealing with nutrient TMDLs for lakes developed from these contacts was
prioritized and provided to MPCA for their review and selection of the states to be contacted
for benchmarking. During the selection process, MPCA also considered information
presented by state agency staff at the Nutrient Criteria 2006 conference in Dallas, Texas
based on conference notes provided by Steve Heiskary of MPCA’s Environmental Analysis
and Outcomes Division.
With regard to the Region 5 states of Michigan, Wisconsin, Indiana, Illinois, and Ohio, the
Region 5 WQS coordinator indicated that Michigan was the state of interest due to its work
in both lake nutrient TMDLs and developing site-specific standards. Lisa Schultz from the
Wisconsin Department of Natural Resources Bureau of Watershed Management indicated
that Wisconsin has done numerous lake nutrient TMDLs, but that the state was not using site-
specific approaches. Illinois is also completing nutrient TMDLs for lakes and reservoirs, but
as with Wisconsin, site-specific approaches are not being used. While Illinois was not
selected for a benchmarking interview, information on how lake nutrient TMDLs in
agricultural areas are handled in Illinois is provided in Section 3 based on LTI’s experience
in developing TMDLs for Illinois EPA.
Select information was also collected from other states, including Colorado, Kansas, and
Oregon, on UAAs, reference reach approaches, and stormwater permitting approaches.

2.2 STATES SURVEYED AND CONTACT INFORMATION
Benchmarking interviews were completed for a total of 11 states. The states interviewed
were:
    •   Arizona
    •   California
    •   Maine
    •   Maryland


Limno-Tech, Inc.                                                                          Page 2
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Site-Specific Approaches to Lake Nutrient TMDLs                                   June 26, 2006



    •   Michigan
    •   Minnesota
    •   Montana
    •   New York
    •   Vermont
    •   Virginia
    •   Washington
Partial interviews were conducted for California, Montana, and New York. California’s
TMDL approach is not standardized across its nine regional water boards. The California
interview was conducted with a staff person at the state water board. Attempts to obtain
follow up information from recommended contacts at the regional boards were unsuccessful.
In Montana’s case, a staff member in water quality standards was interviewed, but the TMDL
coordinator was unresponsive. New York was not identified as a benchmarking state during
the screening process described in Section 2.1. However, the New York Department of
Environmental Conservation was contacted regarding a specific TMDL example. During this
conversation, some of the subjects covered by the questionnaire were discussed, and the
resulting responses were included in the benchmarking results presented in Section 3.
Multiple attempts were also made to set up interviews with Utah and Florida but were
unsuccessful.
The list of interviewees at the state agencies and their contact information is presented in
Appendix A. The list in Appendix A also includes contacts that were attempted but
unsuccessful. Links to TMDL websites for each of the benchmarking states are provided in
Appendix B.

2.3 SURVEY QUESTIONS
The benchmarking interviews were conducted using a questionnaire containing a list of
survey questions developed and provided by the lake protocols team of MPCA. The survey
questions were organized in three general categories:
    1. Questions related to the water resource (lake). Questions in this category pertained to
       types of site-specific approaches being used, beneficial uses, and information needed
       to justify site-specific approaches.
    2. General questions related to site-specific approaches in the context of TMDLs. These
       questions pertained to obstacles in pursuing site-specific approaches, including the
       topics of public involvement, agricultural sources, future development, margin of
       safety, internal loading, and BMPs.
    3. Questions related to watersheds draining to the waterbodies (lakes) with site-specific
       approaches. These questions were targeted at stormwater issues, including how
       stormwater is addressed in TMDLs, how TMDLs are addressed in stormwater
       permits, and other issues such as defining Maximum Extent Practicable (MEP).
The full question list can be viewed in the benchmarking interview notes found in Appendix
C and in the matrix summarizing states’ responses in Section 3.1.



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Benchmarking Report:
Site-Specific Approaches to Lake Nutrient TMDLs                                    June 26, 2006



2.4 BENCHMARKING INTERVIEW PROCESS
Benchmarking interviews were arranged by contacting the state agencies via phone. The
questionnaire was emailed to interviewees in advance of the interview. In general,
interviewees contacted agency staff in other program areas (i.e., standards, TMDLs,
stormwater) prior to the scheduled interview to get responses for questions in areas outside
their purview or included these staff in the interview conference calls.




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Benchmarking Report:
Site-Specific Approaches to Lake Nutrient TMDLs                                  June 26, 2006




                            3. BENCHMARKING RESULTS
Benchmarking interview responses, general findings from the interview, a review of site-
specific approaches being used by the benchmarking states, and a review of TMDL
stormwater policies and approaches are presented in this section.

3.1 BENCHMARKING INTERVIEW RESPONSES
The responses of the 11 benchmarking interviews were compiled and summarized in a
standardized format in order to compare responses from each state. A matrix of questions and
state responses was then developed for each of the three categories of survey questions (see
Section 2.3), as presented in Tables 1 through 3. Interview notes from each of the 11
benchmarking states are provided in Appendix C.

Though Illinois EPA was not interviewed for this project, the state is included in the
matrices. The responses for Illinois in Tables 1 through 3 are based on LTI’s experience
developing TMDLs in the state under contract with Illinois EPA. Interview notes from a
discussion with an LTI staff member responsible for developing TMDLs in Illinois is
included in Appendix C.




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Benchmarking Report:
Site-Specific Approaches to Lake Nutrient TMDLs                                                                                                                                                                                                                                                                                                       June 26, 2006




                                                                                                    Table 1: Summary of Benchmarking Interview Responses for Questions Related to the Water Resource

Question                                                              Minnesota                     Arizona                    California                   Illinois1                    Maine                   Maryland                 Michigan               Montana5              New York             Vermont                Virginia           Washington
                                                                       Region 5                     Region 9                   Region 9                     Region 5                    Region 1                 Region 3                 Region 5               Region 8              Region 2             Region 1               Region 3            Region 10
Have you used, are you currently using, or are you
considering the use of, site-specific approaches to
“balance the equation” for TMDLs that would                                                                                                                                                                 Have used (unique
                                                                                                                                                                                                                                                      2                                                                                           8
otherwise be unattainable?                                            Considering                     Using                       Using                         No                          No                 instances)               Considering             Considering               No                    No               Considering              No
  1. How do you determine when a site-specific
  approach is appropriate or when a TMDL is                                                                                                                                                                                          Each lake will have                                                                       Decision during
  unachievable?                                                      Undetermined            Case by case basis          Case by case basis                    N/A                         N/A              Case by case basis       site-specific criteria    Undetermined        Case by case basis          N/A            TMDL development            N/A
  Do you have a ‘checklist’ for evaluating the need
  for a site-specific approach?                                             No                          No                          No                          No                          No                       No                       No                     No                   No                    No                    No                  No
  2. What policies/processes are you using (or
  considering) to address site-specific water
  quality standards?                                                                                                                                                                                                                                                                 Undetermined                               Undetermined
                                                                                                                                                                                                                         3
                                Site-specific criteria                       X                           X                           X                                                       X                       X                         X                                                               N/A                                         X
                                                                                                                                                                                                                       4                                                                                         6
                                               UAAs                          X                                                       X                                                                               X
                                          Variances                          X                                                       X                                                                                                                                X
  Through the TMDL process, rule making, public
  forum?
                                                                                                                                                                                                                         3                                                                                                                8
                                     TMDL process                                                                                    X                                                                               X                                                               Undetermined              N/A                    X
                                        Rulemaking                           X                           X                                                                                   X                                                 X                      X                                                                                    X
                                       Public forum
    Are your beneficial uses ranked by order of                                                                                                                                                             Yes - in practice, not
    priority or importance?                                                 No                          No                          No                         Yes                          No                       rule                     No                     No                                         No                    No                  No
    Does your process for evaluating the
    maintenance of a beneficial use differ
    between uses?                                                    Undetermined                       No                          No                         Yes                          No                      Yes                       No                     No                                         No                    No                  No
    Are you setting “minimum” WQ parameter
                                                                                                                                                                                                                                                                                                                     7                        9
    values for maintaining Beneficial Uses?                          Undetermined                      Yes                         Yes                          No                          No                       No                       No                     No              Undetermined              Yes                   Yes                  No
                                                                                                 Data analysis,
     How do you the determine "minimum"                                                            literature,                                                                                                                                                                                                                Reference lake data
     thresholds?                                                     Undetermined                benchmarking             Literature and data                  N/A                         N/A                      N/A                      N/A                     N/A             Undetermined         Undetermined                set                 N/A

                                                                                                                                                                                                                                        Standardized;
                                                                                                                                                                                                                                     Minimal information:
                                                                                                                                                                                                                                        surface conc.,
3. How much and what type of information is                                                                                                                                                                                            vertical profiles,
needed to justify a site-specific approach?                          Undetermined              Context specific              Standardized                      N/A                         N/A                   Unknown              mean depth, color         Standardized                                   N/A                   N/A                  N/A
Is the consideration for site-specific status driven
by locally affected jurisdictions or by state                                                                                                                                                                                                                                                            Locally affected
resource managers?                                                   Undetermined                State (to date)                   Both                        N/A                         N/A                      N/A                      Both                   Both                                   jurisdictions             N/A                  N/A
Would you allow a party outside your agency to
collect and compile data to establish a defensible
site-specific approach?                                              Undetermined                      Yes                         Yes                         Yes                         Yes                      Yes                      Yes                    Yes                                        Yes                   Yes                  Yes

                                                                                                 Within TMDL                                             Not in TMDL                                    Not in TMDL                                                                                                              Not in TMDL            Not in TMDL
                                                                                              equation as part of          No standardized                 equation;               Within TMDL       equation; sometimes                Not in TMDL                                                       Within TMDL         equation; Address in equation; Sometimes
4. How are you addressing internal loading in the                                               LA; Address in             approach across              Incorporated in         equation as separate   incorporated in                equation; Case by                                                 equation as part of   implementation time     incorporated in
context of balancing the TMDL equation?                              Undetermined              implementation              regional boards                 modeling                 component             modeling                       case basis           Not yet dealt with                               LA                    frame               modeling

Gray shading indicates response not recorded during interview or response not received from follow up contacts.
Footnotes:
1. Reponses for Illinois are based on LTI experience in developing lake nutrient TMDLs for the Illinois EPA. Illinois EPA was not interviewed for this project.
2. Michigan's nutrient criteria rules are currently under development.
3. Response pertains to bacteria. Considering an approach to bacteria TMDLs that outlines possibility of doing a risk-based adjustment of the fecal bacteria endpoint.
4. A UAA for a lake was pursued by the state in one unique case.
5. Reponses pertain primarily to draft nutrient criteria for rivers and streams in MT. MT does not yet have lake nutrient criteria.
6. UAAs cannot be done in Vermont, because uses are established by the state legislature.
7. A matrix with different thresholds will be developed.
8. Virginia's approach is to wait until after TMDL implementation to decide whether a site-specific approach is necessary. Currently, implementation is not yet far enough along to have dealt with this.
9. Virginia's nutrient criteria are currently in draft form.




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                                                                      Table 2: Summary of Benchmarking Interview Responses for Questions Related to Site-Specific Approaches in the Context of TMDLs

Question                                                               Minnesota                     Arizona                    California                   Illinois1             Maine               Maryland              Michigan            Montana3        New York               Vermont             Virginia           Washington
                                                                        Region 5                     Region 9                   Region 9                     Region 5             Region 1             Region 3              Region 5            Region 8        Region 2               Region 1            Region 3            Region 10

What opportunities or obstacles did you encounter
when applying a site-specific approach?
 1. Public involvement in the TMDL process is
 very important and is a requirement for
 developing TMDLs.
         When site-specific approaches are used,
    do you address public participation any
    differently?                                                     Undetermined                        No                          No                           N/A               N/A                   N/A                    No                                                        N/A                 N/A                  N/A
         Are there key outcome-related
    messages that you use to explain why site-
    specific approaches are needed and what                                                      Reasons why
    their benefits are to the public?                                Undetermined             approach is needed                     No                           N/A               N/A                   N/A                    No                                                        N/A                 N/A                  N/A
 2. How are site-specific approaches handled for
 lakes impacted primarily by agricultural                                                    Potentially treated as                                                                                                       Same as for other                                                                                  Different focus for
 sources?                                                            Undetermined               point sources                                                     N/A               N/A                   N/A                 TMDLs                                                        N/A                 N/A            implementation
 3. In urban settings there often is a demand for                                                                           No standardized
 further watershed development. Are you                                                                                     approach across
                                                                                                                                                                                                                                   2                                                                                                     4
 addressing this demand for development?                                    Yes                          No                 regional boards                       Yes               Yes                   No                    No                                                         No                  Yes                  No
 Are you calculating and setting a reserve
 capacity to allow for this?                                                Yes                          No                    Sometimes                          Yes               Yes                   No                     No                                                        No                  Yes                  No

                                                                                                                                                                                                  For bacterial TMDLs,
                                                                                                                                                                                                  will use a maximum
                                                                                                                                                                                                  practicable reduction
                                                                                                                            No standardized                                                           approach and                                                                                      Explicit at 10% - no
                                                                                                                            approach across                                Set goal that is 2 ppb        adaptive         No standardized                                                               complex situations Using science-based
  4. How are you addressing margin of safety?                        Undetermined                Project specific           regional boards              Explicit at 10%     more protective          management             approach                                                 Undetermined             so far           numbers
Do you consider whether enough BMPs and
pollution reduction opportunities have been
implemented within the watershed before
pursuing a site-specific approach to balance the
equation?                                                            Undetermined                       Yes                                                       N/A               N/A                   Yes                   N/A                                                        Yes                 Yes                  N/A
                                                                                                                                                                                                                                                                                        Universal       Cost-effective and
If so, what standard or threshold (e.g. practicable,                                         Threshold is context                                                                                                                                                                     implementation     reasonable per
reasonable, prudent and feasible) do you apply?                      Undetermined                  specific                                                       N/A               N/A               Practicable               N/A                                                      expected          standards                N/A
                                                                                              Situation specific;
What factors or characteristics do you review in                                                would include                                                                                                                                                                                                Tracking
your evaluation of the adequacy of BMPs and                                                     effectiveness                                                                                     Outside of scope of                                                                 Not quantifying   implementation and    Not quantifying
pollution reduction opportunities implemented?                       Undetermined                 monitoring                                                      N/A               N/A            TMDL program                 N/A                                                    reductions           monitoring          reductions

                                                                                                                                                                                                 Piney Run Reservoir -
                                                                                                                                                                                                 Wrote a water quality Major reasons for
                                                                                                                                                                                                     analysis with     choosing site-specific               New York City Water
                                                                                                                                                                                                      watershed         criteria for each lake                Supply Reservoir
                                                                                                                                                                                                 management instead          is the natural                   Watershed TMDL
                                                                                                Lakeside Lake,                                                                                   of a TMDL. Working variability in types of                     (2000): more
                                                                                             Tuscon: site-specific                                                                                   with county to           lakes within                     restrictive site-
                                                                                                DO and ortho-P                                                                                      prevent further       ecoregions of the                  specific criteria, but
                                                                                              levels; limits on TP                                                                               degradation; UAA for state. Ecoregions                     TMDL was pollitically
What “real world” examples are available to                                                   and chl a, chlorine,                                                                                Edgewater Village       were too large a                    driven and not a
support a site-specific approach?                                                                  and NH3                                                                          N/A                   Lake                   scale.                          typical case

Gray shading indicates response not recorded during interview or response not received from follow up contacts.
Footnotes:
1. Reponses for Illinois are based on LTI experience in developing lake nutrient TMDLs for the Illinois EPA. Illinois EPA was not interviewed for this project.
2. Michigan DEQ included reserve capacity in one TMDL. There were major public objections to this approach. Subsequently, DEQ is no longer including reserve capacity in TMDLs.
3. Multiple attempts to contact the TMDL leader for Montana DEQ were unsuccessful.
4. Conversely, Washington imposed a building moratorium for one lake TMDL.




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                                                  Table 3: Summary of Benchmarking Interview Responses for Questions Related to Watersheds Draining to the Waterbodies with Site-Specific Approaches

Question                                                               Minnesota                     Arizona                    California                   Illinois1         Maine                Maryland               Michigan           Montana2        New York                Vermont                Virginia               Washington
                                                                        Region 5                     Region 9                   Region 9                     Region 5         Region 1              Region 3               Region 5           Region 8        Region 2                Region 1               Region 3                 Region 10
                                                                                                                                                                                                                                                                                                                                Phase 2 permits are
                                                                                                                                                                                                                                                                                                                                  currently in draft
                                                                                                                                                                                                                                                                                                                                    form. Include
                                                                    Haven't had occasion                                                                                                                                                                                                                                         reopener clauses
                                                                       to get into these                                                                                                                                                                                                                                         related to TMDLs.
                                                                       issues for small                                                                                                            Haven't really                                                                                                               Have been told that
                                                                      MS4s; Would not                                                                                                              crossed these                                         Permits in draft form;                                                    Phase 1 and 2
1. How are you addressing MS4 Stormwater limits                     allow discharge if no                                                                                                       bridges yet; MS4s                                        Stormwater has been                                                      permittees must
in nutrient TMDLs and how are you incorporating Stormwater in WLA;       allocation is                                                                                                          included in WLAs,                                        included in LA; More                                                     have WLAs, but
these limits (BMPs) into SWPPPS (WLA             SWPPPs must be available; If allocation                                                                                                            non-Phase 2                                          specific requirements                                                    permittees aren't
                                                                                                                                                                                                                                                                                                        Use landuse-based
determination, MEP and BAT requirements,         modified wihtin 18  is available, would                                                                                                         communities also                                           for 6 Minimum                                                         held to WLAs in
                                                                                                                                                                                                                                                                                    Have not been        loading allocation;
compliance schedules, etc.)?                       mos of TMDL          need SWPPP                                                                                                             included in TMDLs                                            Measures (MM)                                                              permits.
                                                                                                                                                                                                                                                                                      dealing with     currently coordinating
                                                                                                                                                                                                     MEP is not
                                                                                                                                                                                                                                                                                   stormater/TMDL          how to put into
2. How are you defining Maximum Extent                                                                                                                                                         specifically defined;                                        Providing more
                                                                                                                                                                                                                                                                                   issues yet. MS4            permits
Practicable (MEP) in MS4 permits, especially in                                               Generic definition of                                                                            use 15% reduction                                           specific approach
                                                                                                                                                                                                                                                                                  implementation is
the context of potentially unachievable nutrient                                                MEP; context                                                                                       as number for     Just starting to think                and guidance for
                                                                                                                                                                                                                                                                                    just underway.
TMDLs?                                                               Undetermined                  specific                                                                                       implementability   about these issues;                  implementing 6MM
3. Are you considering best available technology                                                                                                                                                 Same from MD's      Stormwater included                                                                                           Permits specify
                                                                                                                                                                         Haven't really gotten
(BAT) as separate from MEP?                                          Undetermined                        No              Not yet addressed in                                                       perspective            in WLAs                                                                                                  specific TMDL
                                                                                                                                                                          into these issues;
                                                                                                                             a statewide                                                                                                                                                                                           implementation
                                                                                                                                                                          MS4s included in
4. For Stormwater NPDES discharges to currently                                                                               approach.                                                                                                                                                                                         requirements (BMPs,
                                                                                                                                                                                 WLAs
impaired waterbodies, are you requiring MEP,                                                                                                                                                                                                                                                                                       source controls,
best available technology (BAT), variances, or                                                                                                                                                                                                                                                                                       monitoring,
adaptive TMDL implementation?                                        Undetermined                      MEP                                                                                        Undetermined                                                   MEP                                                               schedules, etc).
Are you allowing ‘compliance schedules’ over                                                                                                                                                                                                                                                            Yes, for MS4s. No,
multiple permit cycles? What about wastewater                                                                                                                                                                                                                                                             for wastewater
NPDES sources?                                                              Yes                  Undetermined                                                                                     Undetermined                                                                                                NPDES.
                                                                                                                                                                                                                                                                                  Yes. Construction
                                                                                                                                                                                                                                                                                  had been covered
                                                                                                                                                                                                                                                                                   under a general
                                                                                                                                                                                                                                                                                  permit. Individual
5. Are there any special considerations given to                                                                                                                                                                                                                                   permits are now                              Construction is not
NPDES Construction Stormwater Permit projects                                                                                                                                                                                                             Haven't dealt with      used for impaired    Not for nutrients, only    being defined
that discharge to currently impaired waters?                                Yes                   No example.                                                                                           No                                                construction yet.            waters.             for sediment        seperately in TMDLs
                                                                                                                                                                                                                       Want to use site-
                                                                                                                                                                                                                       specific process.
6. What policies/processes are you using (or                                                                                                                                                                            Most likely will
considering) to address site-specific needs                                                                                                                                                                              incorporate
relating to permitted sources?                                       Undetermined                       N/A                                                                                            None              stormwater.                                                 See above.             See above.              See above.

Gray shading indicates response not recorded during interview or response not received from follow up contacts.
Footnotes:
1. Reponses for Illinois are based on LTI experience in developing lake nutrient TMDLs for the Illinois EPA. Illinois EPA was not interviewed for this project.




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3.2 GENERAL FINDINGS
Several key findings related to the use of site-specific approaches to address unattainable
TMDLs resulted from the benchmarking interviews (refer to Tables 1 through 3). These
findings are intended to provide an overview of the status of the use of site-specific
approaches throughout the country, as represented by the benchmarking states. These are:
    •   Use of site-specific approaches to “balance the TMDL equation” is limited for a
        variety of reasons, but examples of several types of site-specific approaches do exist.
        In general, the benchmarking states are in the early stages of considering and using
        site-specific approaches to resolve situations where attaining goals of the TMDLs will
        be difficult if not unattainable. Montana is the single state that has explicitly
        identified an approach for dealing with unattainable TMDLs. Montana Department of
        Environmental Quality (DEQ) is proposing a standardized variance procedure on the
        basis of economic hardship to implement TMDLs for phosphorus in streams.
        Maryland is considering the use of “maximum practicable reduction” best
        management practices (BMPs) scenarios and adaptive implementation for difficult to
        achieve bacteria TMDLs. However, this approach is in its infancy. Several other
        states, Arizona (site-specific criteria), California (UAAs and variances), and
        Maryland (UAAs), have used site-specific approaches in difficult TMDL situations,
        but these have been on a case-by-case/unique instance basis. Virginia DEQ
        recognizes a future need for site-specific approaches to deal with difficult to achieve
        lake nutrient TMDLs, but is taking the approach of waiting until after implementation
        of controls to determine next steps.
    •   Site-specific criteria are being used or proposed by some states on routine or case-
        by-case bases, but generally not specifically for “difficult to achieve” TMDL
        situations. However, the nutrient criteria approaches in use or proposed by several
        states incorporate flexibility in setting nutrient criteria such that the need for site-
        specific approaches for use in difficult TMDL situations might be reduced. Arizona is
        the only state that indicated use of site-specific criteria in difficult to achieve TMDL
        situations. Maryland is developing an approach for setting site-specific adjustments
        to bacteria endpoints based on “maximum practicable reduction” scenarios for Best
        Management Practices (BMPs), but the approach has not yet been implemented.
        The nutrient criteria frameworks in Arizona, California, Michigan, Maine, and
        Washington incorporate flexibility in setting nutrient criteria for lakes. Arizona uses
        a matrix of threshold values that vary by beneficial use and lake class to implement
        its narrative nutrient standard. California, Michigan, and Washington, have or are
        proposing approaches that will result in site-specific nutrient criteria or targets for
        lakes and reservoirs. Maine’s nutrient criteria approach is based on trophic change
        risk categories.
    •   States occasionally use site-specific approaches that result in more protective
        standards or criteria or proactive waterbody management. Of the benchmarking
        states, New York and Maryland indicated use of such approaches. New York
        developed a nutrient TMDL for the New York City water supply watershed that


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        included phosphorus criteria that were more protective than the numeric target for the
        state’s narrative standard for seven of the nineteen reservoirs in the watershed.
        Maryland has used the site-specific approach of requiring implementation of a
        watershed protection plan to protect a reservoir from further degradation when its
        status was borderline impaired. Rather than writing a TMDL for the reservoir, the
        state documented the impairment in what it termed a “Water Quality Analysis.”
    •   Variances are being used in TMDL situations by two of the states surveyed. Of the
        benchmarking states, California and Montana are the only states using or proposing
        to use variances in TMDL situations. California has used variances on a case-by-case
        basis; however, information was not received regarding specifics of when UAAs are
        used in California.. Montana is proposing an approach to unattainable phosphorus
        TMDLs in streams using variances on the basis of substantial and widespread
        economic hardship. Variances are Montana’s preferred approach in part due to the
        retention of existing designated uses.
    •   While over 100 Use Attainability Analysis (UAA) efforts have been considered or
        undertaken nationwide, examples of the use of UAAs are limited among the states
        surveyed. Of the benchmarking states, Maryland and California have used UAAs in
        TMDL situations. Maryland pursued a UAA in one instance for a nutrient-impaired
        lake. The justification made by Maryland Department of Environment for pursuing
        the beneficial use change in lieu of completing a TMDL was acceptable to EPA. The
        UAA itself has not yet been completed. California has used UAAs on a case-by-case
        basis; however, information was not received regarding specifics of when UAAs are
        used in California.
    •   Experience with site-specific approaches for agricultural TMDLs is virtually
        nonexistent. None of the benchmarking states have experience in dealing with site-
        specific approaches for agricultural watersheds. Arizona indicated that agricultural
        sources would potentially be treated as point sources in such a situation. Washington
        indicated that the focus would be different for implementation in agricultural
        watersheds, given the predominance of nonpoint sources vs. point sources. Illinois
        has developed numerous lake nutrient TMDLs in agricultural watersheds. Some of
        these have resulted in needed load reductions of 80% and higher and could be
        considered unachievable. Illinois EPA is allowing adaptive management in TMDL
        implementation to deal with these difficult to achieve TMDL situations. Though it is
        not aimed at site-specific approaches, Maine Department of Environmental
        Protection has had a cooperative arrangement with the Maine Association of
        Conservation Districts to develop TMDLs in agricultural watersheds since 2000.
    •   While TMDLs have addressed stormwater, the bridge of addressing TMDLs in
        specific stormwater permit instances has not been crossed. Many of the
        benchmarking states (Maine, Maryland, Michigan, Washington) indicated that
        stormwater from MS4s is being included in TMDLs as wasteload allocations. Phase 2
        MS4 permits are in draft form in New York and Washington, and implementation of
        the small MS4 program has just begun in Vermont. The majority of benchmarking
        states have either not had occasion to deal with TMDL requirements in MS4 permits,


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        have not yet begun to deal with them, or have just begun to deal with them. Virginia
        is currently in the process of coordinating how to put TMDL requirements into
        stormwater permits. New York’s draft MS4 permits include more specific
        requirements for implementation of the six minimum measures for small MS4s. Most
        states have not yet dealt with construction stormwater TMDL issues. However,
        Vermont is now using individual permits for construction in impaired watersheds.
    •   Issues related to defining Maximum Extent Practicable (MEP) and considering Best
        Available Technology (BAT) have not been addressed in detail. The single state with
        comments on the question regarding whether states are considering BAT as separate
        from MEP was from Maryland. Maryland Department of Environment considers
        BAT to be equivalent to MEP. A few states indicated that they have no specific
        definition of MEP, while New York indicated that its new MS4 permits define MEP
        with more specific controls required in impaired watersheds.
    •   Implementation of BMPs does not fall within the purview of TMDL program staff. In
        many instances, implementation and tracking of BMPs is the responsibility of other
        departments, programs, or even agencies within the states. This may account for the
        lack of consideration or response from the benchmarking states on the questions
        related to implementation of BMPs prior to determination of TMDLs being
        unattainable. As with TMDL stormwater issues, coordination between multiple
        program areas may also add to the complexity of addressing TMDL implementation .
    •   Margin of Safety (MOS) is not being used as a tool for addressing difficult to achieve
        TMDLs by most of the benchmarking states. However, Maryland is proposing an
        approach to dealing with unattainable bacteria TMDLs that would rely on adaptive
        management to address uncertainty within the TMDL, rather than the typical MOS. In
        typical TMDL situations, the benchmarking states are using a mixed set of
        approaches for addressing MOS in TMDLs. Maine uses an implicit MOS approach
        for lake nutrient TMDLs. Some states are using explicit approaches routinely (Illinois
        and Virginia). Several of the benchmarking states do not have a standardized
        approach and determine which type of MOS, implicit or explicit, to use on a case by
        case basis (Arizona, California, and Michigan). Washington defines MOS using
        “science-based numbers” that result from data analyses and modeling results, as
        opposed to selecting an arbitrary explicit MOS.
    •   Reserve capacity for future development is being used in TMDLs by several of the
        benchmarking states. Benchmarking states using reserve capacity for future growth in
        typical TMDL situations include California, Illinois, Maine, and Virginia. Several
        states indicted that they do not set aside reserve capacity in TMDLs. These states
        include Arizona, Maryland, Michigan, Vermont, and Washington. Michigan has
        decided not to include consideration for future growth in TMDLs due to public
        objections to its inclusion in one TMDL instance. In an example on the opposite end
        of the spectrum from inclusion of reserve capacity in TMDLs, Washington imposed
        a building moratorium to restrict future growth following development of a TMDL
        for a lake in one instance.



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    •   TMDL implementation approaches are being used by some states to address difficult
        to achieve TMDLs. Illinois is incorporating adaptive management into
        implementation plans for agricultural nutrient TMDLs. Maryland is also planning to
        use adaptive management within a proposed approach to dealing with unattainable
        bacterial TMDLs. Virginia is incorporating long implementation time frames into
        TMDLs for lakes with high internal loading.

3.3 OPTIONS FOR SITE-SPECIFIC APPROACHES BEING USED BY STATES
In general, the benchmarking states are in the early stages of considering and using site-
specific approaches to resolve situations where attaining TMDL goals will be difficult if not
unattainable. This section describes the limited instances where such approaches are being
used and presents examples of TMDLs and permits incorporating these approaches.
Approaches that result in more protective endpoints are also included, where they exist.
The information presented in this section is intended for use in the site-specific approach
section of the lake nutrient TMDLs protocols document. The approaches are organized as
they appear in the draft outline of the site-specific approach section and include:
    •   Site-Specific Criteria
    •   Natural Background and Reference Reach
    •   Refine Use
    •   UAA – Change Use
    •   Variance
    •   Non-Degradation
    •   TMDL Components: Margin of Safety, Reserve Capacity, and Implementation

The following conventions for the terms “standard”, “criterion”, and “target”, “threshold”, or
“goal” are used in this section:
        “Standard” is used when referring to the combination of the designated beneficial use
        and numeric criterion for a specific constituent. Water quality standards are required
        by federal regulations to be comprised of three components: 1) designated uses (40
        CFR 131.10), 2) criteria to protect uses (40 CFR 131.11), and 3) a nondegradation
        policy (40 CFR 131.12).
        “Criterion” is used to refer to the numeric level or concentration of a constituent that
        supports a particular use (based on 40 CFR 131.3).
        “Target”, “threshold”, or “goal” refer to the numeric level of a constituent developed
        for application of a narrative standard (as opposed to a numeric standard).
The definitions above are different than MPCA convention for these terms. However, these
definitions are consistent with definitions in the federal water quality regulations and those
used by many states surveyed for this report.




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3.3.1 Site-Specific Criteria
Use of site-specific aquatic life water quality criteria that reflect site-specific conditions is
allowed under the Clean Water Act as specified in the Federal water quality standards
regulation at 40 CFR 313.11(b)(1)(ii). The approach is intended to allow for criteria that
come closer to protecting aquatic life at a specific location than the national or statewide
criteria. The rationale for use of site-specific criteria should be based on differences in
physical and chemical characteristics of the waterbody(ies) in question, species sensitivity, or
a combination of the two as compared to those used to develop the national aquatic life
criteria (U.S. EPA, 1994).
The Water Quality Standards Handbook (U.S. EPA, 1994) contains three procedures for
calculating site-specific criteria, based on these types of differences:
    1. Recalculation considers differences between the sensitivities of the aquatic organisms
       used to develop national criteria and the site-specific sensitivities of organisms;
    2. Water-Effect Ratio considers differences between the toxicities of the chemical in
       laboratory dilution water and in site water; and
    3. Resident Species considers both kinds of differences.
Site-specific criteria are subject to review by U.S. EPA.
Of the benchmarking states, Arizona is the only state that indicated use of site-specific
criteria in difficult to achieve TMDL situations. However, the nutrient criteria approaches
used or being proposed in several of the benchmarking states (Arizona, California,
Michigan, Washington, and Maine) afford flexibility in setting appropriate nutrient criteria
such that there may be less of a need for site-specific approaches to address difficult TMDLs.
Therefore, in addition to presenting examples of the use of site-specific criteria, this section
also describes the nutrient criteria approaches from the benchmarking states that incorporate
such flexibility. Flexibility is incorporated in different ways within the various states’
approaches, including through the use of criteria specific to the combination of different
classes of lakes and beneficial uses, criteria based on trophic change risk categories, and
calculation of site-specific criteria for each waterbody.
Arizona uses a matrix of threshold values that vary by beneficial use and lake class to
implement its narrative nutrient standard. Three other states, California, Michigan, and
Washington, have or are proposing approaches that will result in site-specific nutrient
criteria or targets for each individual lake or reservoir. Maine’s nutrient criteria approach is
based on trophic change risk categories. Maryland is developing an approach for setting
site-specific adjustments to bacteria endpoints based on “maximum practicable reduction”
scenarios for Best Management Practices (BMPs). While New York does not use site-
specific criteria on a routine basis, the state does have a unique example of a TMDL
developed using site-specific criteria that are more protective. Each of these approaches or
examples is described below. An example of use of site-specific criteria in Colorado for
Denver International Airport is also provided. Montana, Vermont, and Virginia do not
utilize site-specific criteria within their nutrient criteria approaches or to deal with difficult to
achieve TMDLs.



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Arizona
Arizona has developed an implementation procedure (ADEQ, 2005; included in Appendix D)
for its narrative nutrient standard that is based on threshold values for specific beneficial uses
and lake classes. While site-specific criteria are not determined within Arizona’s nutrient
standard implementation procedure, the approach results in more refined determination of
appropriate nutrient criteria using the combination of beneficial uses and lake classes.
Arizona’s matrix of threshold values is provided in Table 4.
Threshold values are used in the matrix for the following parameters: chlorophyll-a, secchi
depth, total nitrogen, total Kjeldahl nitrogen (TKN), total phosphorus, percent blue-green
algae, and total count of blue-green algae. The lake classes were selected based on statistical
analysis of lake and watershed characteristics from 70 lakes and reservoirs in the state, and
include the classes of deep, shallow, igneous-based, sedimentary, and urban. The threshold
values were determined based on data from a subset of 50 lakes and reservoirs in the state
and using available literature and other state policies.
Concentrations of any single parameter in the matrix exceeding the threshold values for a
specific beneficial use and lake class do not automatically indicate use impairment or
violation of the nutrient standard. Exceedances of the narrative nutrient standard in lakes are
determined in one of four ways (ADEQ, 2005):
    1. The mean chlorophyll-a result is at or above the upper value in the target range for
       chlorophyll-a for the lake category prescribed in Table 4.
    2. The mean chlorophyll-a result is within the target range for chlorophyll-a for the lake
       category prescribed in Table 4 and the mean blue-green algae result is at or above 20,000 per
       milliliter or the mean blue-green algae count is 50 percent or more of the total algae count.
    3. The mean chlorophyll-a result is within the prescribed range for the lake category and there is
       other evidence of nutrient-related impairments. ADEQ will consider the following factors
       when applying this weight-of-evidence approach:
            a. Exceedances of dissolved oxygen or pH standards;
            b. Fish kills or other aquatic organism mortality attributed to exceedances of dissolved
               oxygen or pH, or to ammonia or algal toxicity;
            c. Secchi depth is below the lower threshold value for the lake category;
            d. The concentration of total phosphorus, total nitrogen, or TKN exceed the upper value
               in the range prescribed for the lake category in Table 4.
    4. The mean chlorophyll-a result is below the prescribed range for the lake category but the lake
       is a shallow lake with a mean depth of less than 4 meters and submerged aquatic vegetation
       covers more than 50% of the aerial extent of the lake bottom and there is a greater than 5
       milligram per liter swing in diel (24-hr) dissolved oxygen concentration measured within the
       photic zone.




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        Table 4: Arizona’s Matrix for Implementation of the Narrative Nutrient Standards in Lakes and Reservoirs.




FBC = Full Body Contact
PBC = Partial Body Contact
A&W = Aquatic and Wildlife
top m = top meter of the water column
Source: Arizona Department of Environmental Quality. October 2005. Narrative Nutrient Standard for Lakes & Reservoirs Implementation Procedures.



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Arizona also uses site-specific criteria for lakes and reservoirs for difficult to achieve or
unattainable TMDL situations. Site-specific criteria have been used in Arizona in situations
where the waterbody characteristics are unique (such as particularly shallow reservoirs with
water level issues) or in situations where anthropogenic activities have severely altered
natural conditions. The TMDL for Lakeside Lake in Tucson, AZ (ADEQ with PBS&J, 2005)
is an example of the latter. The TMDL was developed using site-specific dissolved oxygen
and ortho-phosphorus levels and limits on total phosphorus and chlorophyll a, pH, and
ammonia. Following is an excerpt from the goals section of the TMDL:
        Due to assessed water quality standards violations and the requirement for a NPDES
        permit, a Load Analysis Model was constructed to 1) test a management strategy that
        was expected to gain a better understanding of seasonal constraints to the ecosystem,
        2) test the ability of a newly installed aeration system in mitigating water quality
        standards exceedances, 3) effectively build monitoring and management plans for the
        lake and watershed, and 4) evaluate the need to consider site-specific, seasonal, or
        designated use criteria changes. Generally, changes in standards or the
        establishment of site-specific standards are the result of ongoing science-based
        investigations or changes in toxicity criteria from EPA. Changes in designated uses
        and standards are part of the surface water standards triennial review process and
        are subject to public review. Standards are not changed to bring the waterbody into
        compliance, but must be based on existing uses, technical and economic feasibility,
        and natural conditions (40 C.F.R. 131.10). [emphasis added]
        The LSL TMDL has incorporated data collected post-installation of the new aerator
        (2002-2003). The TMDL refines the load analysis model and establishes numeric
        load reductions for nitrate, ammonia, and phosphorus. Target endpoints will be
        measured in the lake itself and shall: 1) not exceed a threshold of 50 ug/L
        chlorophyll-a during peak growing season (April-October), and 2) meet the DO, pH,
        and ammonia numeric criteria for a warm water fishery. The implementation plan
        will be an NPDES permit condition and will require active management of LSL to
        meet these endpoints.
The Lakeside Lake TMDL is included in Appendix E.

California
California has developed a framework of secondary indicator targets for beneficial uses using
a beneficial risk-based approach. The preliminary numeric targets or “beneficial use risk
category boundaries” were developed using literature sources and elicitation from the state’s
Regional Water Quality Control Boards. The secondary indicator targets can be converted to
site-specific nutrient concentration targets for assessment, permitting, and TMDLs using
standardized simple models. Nutrient concentration targets derived from secondary indicators
will be considered acceptable if they are not lower than background levels in that region. The
lake model framework is based on the U.S. Army Core of Engineers BATHTUB model that
has been coded in a spreadsheet format. Depending on the use, complexity of the system,
data availability, and economic impact of the decision, more detailed and site-specific tools
might be necessary.




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This beneficial risk-based framework will be applied in approximately 200 nutrient TMDLs
for lakes and streams throughout the state. The data collected during TMDL development
will potentially be used to develop a set of statewide nutrient-related criteria in the future.
California’s proposed approach is described in a presentation given by Dena McCann of the
State Water Quality Control Board at the Nutrient Criteria 2006 conference (McCann, 2006).
This presentation is included in Appendix D.

Colorado
Denver International Airport (DIA) successfully changed Colorado regulations for dissolved
oxygen criteria in their five receiving waters in 2004. DIA was not able to meet water quality
standards for dissolved oxygen in their receiving waters due to their use of de-icing
compounds. The rationale for the DIA’s request for site-specific criteria came from a
receiving water study. This study showed that natural conditions or a combination of natural
and irreversible human-induced conditions present in the receiving waters precluded
attainment of the existing dissolved oxygen criteria. DIA had advanced treatment of
stormwater in place on-site, including recycling and reduction programs. The State agreed
that these treatments satisfied Colorado’s regulatory requirements for implementation of all
best practical, available, and economically achievable technology for the control of aircraft
deicing fluids. These actions were sufficient to create revisions in the state water quality
classifications for the DIA receiving waters; the proponent’s rationale document is attached
to this document in Appendix H.

Maine
Maine’s nutrient criteria approach is based on “the recognition of stable or decreasing
trophic state for any given lake statewide - recognizing that minor increases in phosphorus
levels may occur without any violation in water quality standards (i.e., increased trophic
state)” (Maine DEP, 2002; included in Appendix D).
Numeric endpoints for the state’s narrative nutrient standard vary based on trophic change
risk, as shown in Table 5.




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 Table 5: Maine’s Secchi, Chlorophyll a, and Phosphorus Endpoints for the Narrative
                                 Nutrient Standard




        Source: Maine Department of Environmental Protection (DEP). February 1, 2002. Nutrient Criteria
        Adoption Plan.


Accompanying the endpoints is a set of allowable phosphorus increases that result in
unperceivable changes in lake trophic state. Maine’s incremental phosphorus criteria
methodology is used to manage new non-point (watershed) total phosphorus loadings to
lakes in order to avoid any perceivable increase in lake trophic state. Use of the methodology
in this manner is described in Section 3.3.7.b.

Maryland
Maryland Department of Environment (MDE) is evaluating the possibility of using a risk-
based (human versus animal sources) adjustment of TMDL endpoints for bacteria. The
approach would be used in only the most obviously unattainable situations (such as 98% load
reductions needed). The approach is based on defining a “maximum practicable reduction”
scenario for bacteria load reductions. The scenario is developed by identifying the suite of
BMPs that could be implemented in the watershed and applying expected removal
efficiencies for the BMPs to identify the maximum load reduction that could be practicably
achieved. Required TMDL load reductions would then be compared to the maximum
practicable reduction to see if an endpoint adjustment is necessary.
Documentation of this is not publicly available, but should be ready for public review soon.
MDE worked closely with EPA Region 3 on this approach.



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Michigan
Michigan’s proposed nutrient criteria approach will result in site-specific criteria being set
for each lake assessed. This approach is not in response to unattainable TMDLs, but rather
was developed as a way to address spatial variability in lake types across the state. Therefore,
it allows for development of more protective criteria. The nutrient criteria set using the
approach can be used to develop a loading analysis to set load allocations, wasteload
allocations, and margins of safety for TMDLs.
Michigan DEQ is developing a set of threshold total phosphorus levels through stressor
response analysis to identify biological change points for food trophic levels for use in the
approach. The steps to setting nutrient criteria for a lake using the proposed approach are: 1)
predict the natural concentration of the lake under pre-development (no urban or agricultural
land uses) conditions, 2) evaluate where the predicted natural concentration falls within the
threshold levels, and 3) set goals using the predicted natural concentration in empirical
models to establish loading capacity. In step 2, the options are to set the criterion at the
specific predicted concentration or use the threshold level. If monitoring indicates that the
predicted level is higher than monitoring data, anti-degradation rules would apply and the
target will be set at the monitored level.
During development of the process, Michigan DEQ identified the key factors affecting
phosphorus levels in Michigan lakes as mean depth, agriculture and urban land uses, and
percent of geological outwash. In reservoirs, these factors were mean depth, forest cover, and
color. Information needs to develop the site-specific criteria are thought to be minimal. Mean
depth and color are required for the models. Surface concentrations and vertical profiles
(parameters are as of yet undefined) are needed for verification. The minimum information
required for the analysis will be outlined in state rules. Outside party data would be allowed
and is desired to limit financial burden on the Michigan DEQ to establish the site-specific
approach.
Documentation of Michigan’s approach is not currently publicly available.

New York
A unique example of the use of site-specific criteria that are more protective comes from the
state of New York.
Nineteen water supply reservoirs for New York City were listed on New York’s 303(d) list
as being impaired by point and nonpoint sources for phosphorus. Seven of the reservoirs are
considered source waters and the remaining 12 reservoirs are considered upstream reservoirs
(not a direct source of unfiltered water for the distribution system). TMDLs for the reservoirs
were developed in a phased approach, with Phase I TMDLs completed in 1997 and Phase II
TMDLs completed in 2000. Phase II was used to refine the analyses and modeling conducted
in Phase I. The New York State Department of Environmental Conservation (NYSDEC) and
New York City Department of Environmental Protection (NYCDEP) collaborated on
development of the TMDLs.
The numeric phosphorus target used for the state’s narrative standard in the Phase I TMDLs
was 20 ug/L, which is an aesthetic guidance value for recreation. In the Phase II TMDLs,


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NYCDEP desired to identify a more protective numeric target for the drinking water uses.
NYCDEP used a “weight of evidence approach” to determining what it felt were appropriate
targets. NYSDEC agreed that 15 ug/L was an appropriate target for protection of the source
water reservoirs, but determined that there was not a technically defensible basis established
for lowering the target for the upstream reservoirs.
Following is an excerpt from the Phase II TMDLs (included in Appendix E):
        NYSDEC has determined that NYCDEP has demonstrated a link between
        phosphorus concentrations, algal growth and certain indicators of use impairments
        such as taste & odor complaints. Therefore, there is technical justification to support
        using the 15 ug/L value for phosphorus as a site-specific interpretation of the
        narrative standard to protect the drinking water use in the source water reservoirs
        listed above. DEP’s weight of evidence approach demonstrates that 15 ug/L of
        phosphorus is adequate to protect source water reservoirs.
        Based upon current information, the NYSDEC is unable to establish technically
        defensible site-specific objectives for phosphorus for the protection of drinking water
        in the remaining 12 (upstream) reservoirs. The reason for this is that an adequate link
        has not been made between upstream water quality and water quality in the
        downstream source waters. This link must consider many complex factors such as the
        distance to the downstream source water reservoirs, additional time for processes
        such as phosphorus uptake, settling, die-off of algae and oxygenation of water as it
        travels between reservoirs. These chemical, physical and biological processes
        significantly affect water quality and directly influence the appropriate phosphorus
        values necessary to protect the drinking water use in the downstream source water
        reservoirs. Since this link is not a part of the Phase II analysis, it is not appropriate to
        apply 15 ug/L, as the numeric interpretation of the narrative standard to these
        reservoirs because they are not source water reservoirs, and do not serve as a direct
        supply of drinking water to the distribution system. The 20 ug/L existing guidance
        value for recreational use will serve as the basis for the Phase II TMDLs for these 12
        upstream reservoirs.
It should be noted that the TMDLs for the New York City water supply reservoirs cannot be
considered a typical example of a site-specific approach that might be undertaken in the state,
according to Ron Entringer of NYSDEC.

Washington
Washington’s existing water quality standards outline ranges of values for phosphorus
concentration based on trophic state and ecoregion and include an approach for setting lake-
specific phosphorus criteria within these bounds. There are some regions of the state that do
not have defined phosphorus ranges; in these areas individual lake-specific studies must be
completed to establish site-specific criteria.
Each ecoegion also has defined phosphorus “action values”. Phosphorus concentrations
above these values trigger a lake-specific study to determine appropriate criteria that are
protective of beneficial uses. Criteria can be established at or above the action values in these
instances. If the criteria determined to be appropriate in the study are also found to be
unachievable, the rules allow for setting less stringent phosphorus criteria in accordance with
Clean Water Act requirements for designation of uses (Water Quality Standards Regulation


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40 CFR 131.10; see further discussion in Section 3.3.4) if the beneficial use the criterion is
intended to protect is not an existing use.
Washington’s nutrient criteria and the associated rule language are included in Appendix D.


References – Site-Specific Criteria
United States Environmental Protection Agency (U.S. EPA). 1994. Water Quality Standards
    Handbook: Second Addition. EPA-823-B-94-005.
Arizona
    Arizona Department of Environmental Quality with PBS&J (ADEQ). June 16, 2005. Lakeside
         Lake TMDL Nutrients & Associated Parameters. Open File Report 05-03. Included in
         Appendix E.
    Arizona Department of Environmental Quality Water Quality Division (ADEQ with PBS&J).
         October, 2005. Narrative Nutrient Standard for Lakes & Reservoirs Implementation
         Procedures. Included in Appendix D.
California
    McCann, Dena et al. 2006. Technical Approach to Develop Nutrient Numeric Endpoints for CA.
        Presented at Nutrient Criteria 2006. February 6 to 8, 2006. Dallas, TX. Included in
        Appendix D.
Colorado
     The City and County of Denver Department of Aviation, Denver International Airport.
         Proponent’s Prehearing Statement of Denver International Airport. In The Matter of
         Revisions to Water Quality Classifications, Standards and Designations For Multiple
         Segments in the South Platte River Basin, Laramie River Basin, Republican River Basin
         and Smokey Hill River Basin, Regulation #38 (5 Ccr 1002-38). Included in Appendix H.
Maine
    Maine Department of Environmental Protection (DEP). February 1, 2002. Nutrient Criteria
       Adoption Plan. Included in Appendix D.
    Stephen J. Silva, Director, EPA’s Maine Program. United States Environmental Protection
        Agency, New England. Letter to David Courtemanch, Maine Department of Environmental
        Protection. March 3, 2003. Re: Maine Nutrient Criteria Adoption Plan submitted February
        1, 2002. Included in Appendix D.
Maryland
    Documentation of Maryland’s proposed site-specific bacteria TMDL approach is not yet publicly
    available. Maryland Department of Environment contact: Tim Rule, (410) 537-3688,
    trule@mde.state.md.us.
Michigan
     Documentation of Michigan’s proposed approach is targeted to be available in the summer of
     2006. Michigan DEQ contact: Sylvia Heaton, (517) 373-1320, heatons@michigan.gov
     Empirical lake model equations are included in the following presentation:



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           Holden, Sarah. Michigan Department of Environmental Quality. February 2006. “Nutrient
                Criteria Development for Michigan’s Surface Waters – An Update” Presentation
                given at the 5th Annual Surface Water Monitoring and Standards (SWiMS) Meeting.
                Chicago, IL. January 31-February 2, 2006. Accessed April 25, 2004.
                http://www.epa.gov/r5water/wqb/presentations/holden.pdf.
New York
    New York State Department of Environmental Conservation. June 2000. Phase II Phosphorus
        Total Maximum Daily Loads for Reservoirs in the New York City Water Supply
        Watershed (Delaware, Dutchess, Greene, Putnam, Schoharie, Sullivan, Ulster, and
        Westchester Counties). Included in Appendix E.
Washington
    Washington Administrative Code. WAC 173-201A-230. Establishing lake nutrient criteria.
       Available online from: http://apps.leg.wa.gov/wac/default.aspx?cite=173-201A-230.
       Included in Appendix D.

3.3.2 Natural Background and Reference Reach
The term “natural background” is used in the water quality arena in two contexts. The term is
used in TMDL loading assessments when referring to the natural (as opposed to human-
caused) nonpoint source load in a watershed (40 CFR 130.2). In the context of this report,
“natural background” refers to the concentration in a lake under specific reference conditions
that is used to set a water quality criterion or target.
The natural background approach is based on setting watershed land uses to a specified
reference condition and determining what in-lake nutrient concentrations would occur. In
many instances, natural background is defined as land use conditions prior to both urban and
agricultural development or at a point in time approximately 200 years ago corresponding to
pre-European settlement.
Three different definitions of reference conditions arise from its application in biological
assessments (Larsen, 2003), where use of the approach is routine:
    •   Minimally Disturbed Condition: Condition in the absence of significant human
        disturbance (e.g., “natural”, “pristine”, or “undisturbed”)
    •   Least Disturbed Condition: Found in conjunction with the best available physical,
        chemical, and biological habitat given today’s state of the landscape
    •   Best Attainable Condition: Condition is equivalent to the ecological condition of
        (hypothetical) least disturbed sites where the best possible management practices are
        in use
Some states are now recognizing that use of a “Best Attainable Condition” approach is more
appropriate than the other definitions for defining reference conditions in highly
disturbed/altered watersheds. Colorado (CDHE, 2002) has developed what they term the
“Expected Condition” approach. These conditions reflect more than only minimal impact,
including those impacts associated with historical and dominant land and water use activities.
To identify the modified concept, the term "expected condition" has been used to distinguish



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it from the EPA term. Colorado’s definition of “Expected Condition” can be summarized as
(WQCD, 2004):

     “Expected condition is the condition of a waterbody resulting from the best biological,
     physical and chemical conditions attainable (considering past, present and future beneficial
     uses) given reasonable and appropriate land, soil and water quality management practices
     and avoiding material injury to water rights. Where feasible, the expected condition for a
     waterbody, or group of water bodies, will be determined based on the best conditions that
     can be attained by an aggregate of similar waterbodies within a regionally partitioned
     framework (i.e. ecoregions, elevation, and stream size).”

Similarly, Montana defines the term “reference condition” as (Montana DEQ, 2004):
     “the condition of a waterbody capable of supporting its present and future beneficial uses
     when all reasonable land, soil, and water conservation practices have been applied. In other
     words, reference condition reflects a waterbody’s greatest potential for water quality given
     historic land use activities.”
Michigan is the single benchmarking state that considers natural background in a site-
specific approach related to nutrient criteria. Michigan’s proposed nutrient criteria approach,
which was described in Section 3.3.1, is based on calculation of natural lake conditions prior
to development and can be considered a “natural background” approach. As mentioned
above, the Michigan approach would result in phosphorus criteria being set for each
individual lake assessed.
The reference reach approach is similar to the natural background approach and is based on
comparing water quality conditions in a waterbody to those in a set of reference waterbodies
that have been determined in some fashion (such as through statistical analysis of water
quality data) to represent reference conditions using one of the definitions described above.
The reference waterbodies are chosen based on geographical or other appropriate similarities.
The ecoregion approach to setting nutrient criteria utilizes some aspects of the reference
reach approach. None of the benchmarking states utilized a reference reach approach, other
than states that are using or proposing ecoregion-based nutrient criteria (Montana and
Washington).


References - Natural Background and Reference Reach
Larsen, P. 2003. Basic Reference Condition and Classification Techniques. Reference Condition and
     the Role of Classification. National Biological Assessment and Criteria Workshop. Coeur
     d’Alene, ID.
Colorado
     Colorado Department of Public Health and Environment (CDPHE). 2002. Implementation
          Guidance for Determining Sediment Deposition Impacts to Aquatic Life in Streams and
          Rivers. Commission Policy 98-1. Revised June 2002.
     Colorado WQCD, 2004. Colorado’s Expected Condition Concept and Approach. Accessed May
          20, 2006. http://www.cwqf.org/Workgroups/Aquatic_Life/
          EC%20Concept%20&%20Approach%20Draft%20Paper%20101804.pdf.


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Michigan
     Documentation of Michigan’s proposed approach is targeted to be available in the next few
     months. Michigan DEQ contact: Sylvia Heaton, (517) 373-1320, heatons@michigan.gov
     Empirical lake model equations are included in the following presentation:
           Holden, Sarah. Michigan Department of Environmental Quality. February 2006. “Nutrient
                Criteria Development for Michigan’s Surface Waters – An Update” Presentation
                given at the 5th Annual Surface Water Monitoring and Standards (SWiMS) Meeting.
                Chicago, IL. January 31-February 2, 2006. Accessed April 25, 2004.
                http://www.epa.gov/r5water/wqb/presentations/holden.pdf.
Montana
     Montana Department of Environmental Quality (DEQ). 2004. Water quality integrated report
         for Montana 2004. November 24, 2004. http://nris.state.mt.us/wis/environet/2004
         Home.html

3.3.3 Refine Beneficial Use
States are required to adopt beneficial use categories to protect public water supplies; fish,
shellfish and wildlife; recreation; and agricultural, industrial, and other purposes including
navigation (40 CFR 131.10(a)). Federal water quality standards regulations also allow for
states to develop subcategories of uses and associated water quality criteria that are more
refined (49 CFR 131.10(c)). Sub-categories of aquatic life uses can be based on habitat
differences (e.g., warmwater vs. coldwater), community structure and function (e.g. species
richness), community characteristics (e.g. important fish species present), or unique,
valuable, or sensitive species or habitats (U.S. EPA, 1994). Sub-categories of beneficial uses
are commonly termed “tiered uses”.
States that have tiered uses for which nutrient criteria or targets have been set may have more
flexibility in their nutrient criteria approaches, since the criteria/targets set for the refined
uses may more closely represent appropriate water quality conditions for waterbodies in each
category. Use of refined uses as a site-specific approach is similar to the UAA (discussed in
Section 3.3.4). A UAA may or may not be required when a change in subcategory of
beneficial use is sought. Lack of tiered beneficial uses can limit the use of UAAs, since there
may be no appropriate use category to assign to a waterbody when a change in existing
designated uses is sought.
Use of refined beneficial uses was not described as a site-specific approach employed by any
of the benchmarking states.


References – Refine Beneficial Use
     United States Environmental Protection Agency (U.S. EPA). 1994. Water Quality Standards
         Handbook: Second Addition. EPA-823-B-94-005.




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3.3.4 UAA – Change Beneficial Use
Federal water quality standards regulations (40 CFR 131.10) allow for a process to change a
designated beneficial use, called a use attainability analysis (UAA). A UAA is a process
whereby states or stakeholders may make a case for reclassification of a waterbody. Through
this process, states or other stakeholder groups may either “upgrade” a beneficial use to a
higher protection than the existing designated use, or “downgrade” a use if the designated use
is not an “existing use” and the designated use is not attainable. To downgrade a designated
use, states/stakeholders must demonstrate that attaining the designated use is not feasible
because of one or more of the following conditions (40 CFR 131.10(g)):

        1. Naturally occurring pollutant concentrations prevent the attainment of the use; or
        2. Natural, ephemeral, intermittent, or low flow conditions or water levels prevent the
           attainment of the use, unless these conditions may be compensated for by the
           discharge of sufficient volume of discharges without violating state water
           conservation requirements to enable uses to be met; or
        3. Human caused conditions or sources of pollution prevent the attainment of the use
           and cannot be remedied or would cause more environmental damage to correct
           than to leave in place; or
        4. Dams, diversions, or other types of hydrologic modifications preclude the
           attainment of the use, and it is not feasible to restore the waterbody to its original
           condition or to operate such modification in a way that would result in the
           attainment of the use; or
        5. Physical conditions related to the natural features of the water body, such as the
           lack of a proper substrate, cover, flow, depth, pools, riffles, and the like, unrelated
           to water quality, preclude attainment of aquatic life protection uses; or
        6. Controls more stringent than those required by sections 301(b) [secondary
           treatment for publicly owned treatment works] and 306 [new source performance
           standards for industries] of the Act would result in substantial and widespread
           economic and social impact.

Once a group completes a documented UAA, the state water quality regulators must
determine if the beneficial use change is in compliance with state and federal laws. This
process also includes a period for public review and comment. If a state believes a beneficial
use change will comply with state and federal regulations, the request is then forwarded to
the EPA. The EPA reviews changes in beneficial uses to ensure that public health and
welfare are still protected and that the beneficial use serves the purposes of the Clean Water
Act. The EPA then approves (or disapproves) a change in designated beneficial use for the
waterbody of interest.

California makes a distinction in water quality guidance between UAAs and site-specific
criteria. Although both of these processes may seem to achieve the same result (a change in
the water quality standards for a given waterbody), they are separate processes and each is
appropriate in different circumstances. A UAA may generally be considered in situations
when a designated use and/or associated water quality criteria appear to be inappropriate or
the use does not exist, when a use does not appear to be attainable, or when meeting the use


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would likely result in substantial and widespread economic and social impact (40 CFR
131.10(g)). In other words, there is substantial evidence for a use itself to be evaluated, rather
than a criterion. On the other hand, site-specific criteria are usually considered when a
numeric criterion, rather than an appropriate use, is questioned (California State Water
Resources Control Board, 2005). Refinements to the set criteria may be appropriate if the
water quality standard was based on inappropriate (e.g., poor or few) data (California State
Water Resources Control Board, 2005). Because these two processes so often coincide with
TMDLs and they can be difficult to sort out, California issued TMDL guidance (California
State Water Resources Control Board, 2005) that dedicated an appendix to UAAs and site-
specific criteria. This appendix is attached in Appendix H.

Furthermore, a UAA must include an evaluation of both the uses (or activities) actually
occurring in the water and whether the water quality supports the use. Two statements in the
Federal regulations which implement the Clean Water Act provide the boundaries for
considering existing uses and attainable uses:
    •   40 CFR 131.3(e) defines existing uses as “…those uses actually attained in the water
        body on or after November 28, 1975, whether or not they are included in the water
        quality standards”, and
    •   40 CFR 131.10(d) states that “At a minimum, uses are deemed attainable if they can
        be achieved by the imposition of effluent limits required under sections 301(b) and
        306 of the Act and cost-effective and reasonable best management practices for
        nonpoint source control.”
These provisions, and the flexibility allowed to states regarding the definition of beneficial
uses, leave ambiguity in the definition and relationship between existing use and attained
uses.
The U.S. EPA recognizes the challenges created by the ambiguity and holds the position that
any determination of existing use is specific to the water body. The 1994 U.S. EPA Water
Quality Standards Handbook describes multiple options for determining existing uses,
including the following quote from the preamble to the water quality standards regulation
"...even though it may not make sense to encourage use of a stream for swimming because of
the flow, depth or velocity of the water, the States and EPA must recognize that swimming
and/or wading may occur anyway. In order protect public health, States must set criteria to
reflect recreational uses if it appears that recreation will in fact occur in the stream." More
recently, in a 2005 administrative order granting a summary determination in favor of the
U.S. EPA on issues related to existing uses, the EPA Administrator affirmed the multi-factor,
site-specific nature of existing use determinations by holding that the presence of fishing in a
water cannot serve as the only evidence to upgrade the beneficial use designation of a river
(U.S. EPA, 2005). Therefore, UAAs must address actual uses, other potentially limiting
factors, and whether water quality supports the uses or can support the uses with appropriate
pollution controls or reasonable best management practices.
The UAA process can be simple and occur over a short timescale or can be complex and part
of a lengthy process. There is no set methodology for UAAs; rather, the process was left



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open-ended by the EPA so it could be tailored to fit the needs of specific waterbodies. This
means, however, that the process lacks a solid and easily accomplished protocol, and
sometimes this is a difficult hurdle in beginning a UAA. In addition, the public review
process can intimidate states from downgrading a beneficial use, even if it actually serves the
community well to do so. There is also the perception that UAAs are difficult to accomplish
without promotion and assistance from regional EPA entities.
In fact, some of the benchmarking states have not pursued changes in beneficial use via a
UAA because of the perceived difficulty of the process and public perception of
downgrading designated uses. Virginia DEQ, due to major public dissent in developing a
secondary contact recreation use, anticipates that it would be difficult to conduct successful
UAAs in their state. Similarly, UAAs have not been done yet in Maryland as a response to
difficult to achieve TMDL situations. Tim Rule of the Maryland Department of Environment
indicated that the burden of proof for changing a use would be very high and the state would
need to be highly involved. Other benchmarking states are not pursuing UAAs for different
reasons. Montana DEQ has decided not to pursue UAAs because the state is interested in
retaining original beneficial uses as goals. UAAs cannot be conducted in Vermont, due to
beneficial uses being established by the state legislature. In other cases, such as in
Washington, UAAs are allowed by state rules, but no UAAs have been implemented in a
lake TMDL situation.
Despite the reluctance on the part of some states, UAAs have been conducted nationwide and
designated use changes approved. In March of 2006, over 100 UAA efforts around the
country were cataloged by an independent research team. These efforts include situations
where UAAs are being considered; are under development; have been conducted and were
approved or disapproved; and were started but abandoned. UAA efforts in Kansas,
Maryland, and Washington are described below.
The State of Kansas has verified or changed several designated uses by using a one-day
assessment approach and relatively simple worksheet. The goals of these UAA efforts were
to provide defensible information on the existing and attainable beneficial uses of classified
waterbodies. Similar, but separate UAA protocols exist for assessing aquatic life, recreation,
food procurement, and water supply uses. First, researchers gather and review all applicable
files, databases, and maps for the waterbody. In this process, all known beneficial uses,
aquatic and semi-aquatic species associated with the waterbody are identified. The existing
use designations are reviewed to ensure that they currently support documented existing uses
or aquatic life. If necessary, a site visit is then conducted to verify obvious uses or lack of
uses. For example, evidence of a boat ramp and fishing dock indicated recreational use, while
lack of shoreline access to a lake or pond justified no recreational contact. The results of the
background search and site visit are then recorded on standard forms and submitted to the
State, then EPA for approval. The Kansas State UAA protocols and an example UAA are
attached in Appendix H.
An example of a nutrient-related UAA in Maryland arose as a need from the 303(d) listing
process, however this example is a unique instance related primarily to the improper
assignment of beneficial uses. Edgewater Village Lake (Lake Serene), Maryland, is a
residential, man-made lake constructed as a stormwater detention basin to improve



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downstream water quality. Edgewater Village Lake was assigned a drinking water use as
part of a watershed-wide designation. Edgewater Village Lake is not currently nor has ever
been used for drinking water. The lake is impaired for nutrients, and a 92% reduction in
phosphorus loading would be required to meet the existing drinking water use. Therefore,
Maryland Department of Environment submitted a letter to the EPA stating the drinking
water use was inappropriate, because the beneficial use did not exist and it would be
extremely difficult and costly to achieve the water quality standards for drinking water. This
letter referred to the water quality analysis done by the state during the beginning of the
TMDL process to rationalize a change in designated uses. The EPA has responded to the
Maryland request and agreed that the beneficial use was addressed appropriately and can be
changed. The State has not yet begun the UAA that will make this change in designated use
formal.

A UAA effort was undertaken but later abandoned to address dissolved oxygen impairment
in the Spokane River, Washington. A draft TMDL was developed by Washington
Department of Ecology in 2004 requiring significant phosphorus reductions to meet
dissolved oxygen standards. A group of dischargers had filed a petition with the state for a
UAA. This petition was withdrawn in 2005 and the dischargers and the state are currently
working together to develop an acceptable implementation plan for the TMDL. One of the
reasons for withdrawing the UAA petition was the long time frame (years) for the state to go
through the rule making process for the designated use change. Following is an excerpt from
the project website (http://client-ross.com/spokane-river/index.htm) discussing the current
direction of activities:

        In February 2005, public and private dischargers subject to the TMDL (the
        Petitioners) reached agreement with the Washington State Department of Ecology to
        withdraw their Petition for Rule Making concerning a proposed Use Attainability
        Analysis (UAA) and to begin a dialogue about how an acceptable Spokane River
        TMDL Implementation Plan might be developed. This allows productive discussion
        about how to best achieve the needed water quality requirements while meeting local
        needs. The Draft TMDL and the UAA will be reviewed in the context of planned
        future actions and the expected resulting improvements in river quality.
        A wide range of parties, including local governments, the State of Idaho, the Spokane
        Tribe of Indians, environmental groups, power companies, as well as Ecology and the
        dischargers, are participating in Full Group discussions that are focused on
        identifying specific pound-for-pound phosphorus reduction methods. The discussion
        is called the Spokane River TMDL Collaboration. Four workgroups have been
        created–Technology, Wastewater Flows & Loading, Reuse & Conservation, and
        Non-Point Sources–to discuss and recommend to the Full Group how both points
        sources (dischargers) and non-point sources (runoff, septic tanks, etc.) of pollution
        can be effectively managed to reduce pounds of phosphorus reaching the river.
        The Department of Ecology will make the ultimate decision whether the
        implementation strategy will meet the requirements of the TMDL. The final draft
        TMDL and implementation strategy will be subject to public review and comment.
        Ecology will then finalize the TMDL and submit it to the U.S. Environmental
        Protection Agency for its approval.


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References - UAA
     United States Environmental Protection Agency (U.S. EPA). 1994. Water Quality Standards
         Handbook: Second Addition. EPA-823-B-94-005.
     United States Environmental Protection Agency (U.S. EPA). 2005. In the Matter of Buckeye
         Florida, L.P. Accessed April 26, 2006. http://www.epa.gov/oalj/orders/0307.htm.
California
     California State Water Resources Control Board. March 2005. Draft State of California S.B. 469
          TMDL Guidance A Process for Addressing Impaired Waters in California. Appendix
          included in Appendix H.
Kansas
     Kansas Department of Health & Environment. Use Attainability Analysis Protocols. Included in
         Appendix H.
Maryland
   The letter to EPA Region 3 from Maryland Department of Environment regarding the
   inappropriate use for Edgewater Villa Lake is not available electronically. It could be obtained
   from Tim Rule, (410) 537-3688, trule@mde.state.md.us.

Washington
      Spokane River TMDL Collaboration website: http://client-ross.com/spokane-river/index.htm

3.3.5 Variance
Variances are recommended for use by states when it is believed that the original water
quality standards are eventually attainable (U.S. EPA, 1994). A variance application must
prove that attaining designated uses is not feasible based on one of the six conditions given in
the water quality standards regulations at 40 CFR 131.10(g), as presented previously in
Section 3.3.4. Development of supporting information for a variance is similar to that
required for UAAs, and as with UAAs, variances are subject to U.S. EPA approval.
Variances differ from UAAs in the following ways: 1) variances are both discharger and
pollutant specific, 2) are time-limited, and 3) do not forego the currently designated use (U.S.
EPA, 1994).
Of the benchmarking states, only California and Montana indicated using variances to
address unattainable TMDLs. California has used variances on a case-by-case basis, but the
specifics are not available for this report. Montana is proposing using variances in a more
routine approach to addressing low nutrient criteria for phosphorus in its streams.

Montana
Montana DEQ is proposing a standardized variance procedure on the basis of economic
hardship to implement TMDLs for phosphorus in streams. The variance procedure is being
developed to address the low phosphorus criteria for streams that are resulting from the
state’s nutrient criteria development approach. The state desires to let science drive the
development of nutrient criteria. Therefore, if the scientific approach results in low nutrient
criteria values, the state will come up with an implementation procedure to deal with current



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realities that hinder meeting low criteria. The approach described below is for streams, but
the procedures are anticipated to be the same for Montana lakes.
In developing the variance-based site-specific approach, Montana considered options that
might be applicable under state law and the CWA. Montana state law requires that the
economics of wastewater treatment be considered in setting requirements for permittees. The
CWA allows for three approaches to address unattainable water quality standards: 1) removal
of uses (UAAs), 2) use site-specific standards, and 3) use variances. The variance approach
was most desirable to Montana because it allows for retention of the original water quality
use classifications and standards, because variances only apply to specific parameters, and
because there is a time-based review (every permit cycle or with triennial water quality
standards review). Montana’s rationale on the chosen variance approach is that if standards
are difficult to achieve, communities only pay for what they can afford now, and in the
future, cheaper treatment options can be implemented without having removed uses. The
basis of decision for the variance is substantial and widespread economic hardship per EPA
40 CFR 131.13.
For the variance, Montana is working on developing a standardized model to be applied to
communities on a case-by-case basis. The model will use basic economic information to
identify wastewater treatment levels a community can afford relative to water quality
standards and waste treatment cost. Montana DEQ is currently working out the details on
information requirements for the analysis. The variance procedures will be driven by a
combination of the state and the local affected communities. Montana DEQ plans to bring the
nutrient criteria and the implementation plan (economic hardship variance) to their board as a
package.


References - Variance
United States Environmental Protection Agency (U.S. EPA). 1994. Water Quality Standards
    Handbook: Second Addition. EPA-823-B-94-005.
Montana
    Documentation of Montana’s proposed nutrient criteria and the associated implementation
    approach including use of the variance is not currently publicly available. Montana DEQ contact:
    Mike Suplee, (406) 444-0831, msuplee@mt.gov.

3.3.6 Non-Degradation
The regulatory requirements governing water quality standards can be found in 40 CFR 131.
State water quality standards must include designated uses (Section 131.10), criteria that
protect the designated uses (Section 131.11), and a non-degradation policy that protects
existing uses and high quality water resources (Section 131.12). Non-degradation policies are
intended to protect both 1) existing beneficial uses and 2) achieved water quality that is better
than that necessary to protect beneficial uses. The Federal non-degradation policy (40 CFR
131.12), also commonly referred to as anti-degradation, is based on a three-tiered system,
with Tier 1 protecting existing uses, Tier 2 protecting water quality that exceeds the
fishable/swimmable goals of the Clean Water Act, and Tier 3 protecting Outstanding
National Resource Waters (U.S. EPA, 1994).


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As a site-specific approach, a non-degradation policy can allow states to recognize and
protect water quality that is “better” than that required by water quality standards by
providing justification for setting site-specific criteria that are more protective than the
statewide or ecoregion criteria and allowing for requirement of additional reasonable control
measures. A non-degradation review occurs at the time of permit application for new and
expanded discharges. Non-degradation also factors into TMDL situations if a permittee
ceases discharge. The newly available wasteload allocation may be apportioned to other
discharges following non-degradation requirements.
This approach was not described as being used by any of the benchmarking states, though it
does factor into development of site-specific nutrient criteria in Michigan. See description of
Michigan’s approach in Section 3.2.2.

3.3.7 TMDL Components – Margin of Safety, Reserve Capacity, and
       Implementation
Options within the TMDL framework for dealing with difficult to achieve or unattainable
TMDLs include various methods for addressing margin of safety (MOS), reserve capacity for
future growth, and adaptive management or long time frames in implementation. Approaches
used by the benchmarking states to deal with these TMDL components are summarized in
the following sections.

3.3.7.a Margin of Safety
A Margin of Safety (MOS) is a required element of a TMDL (40 CFR 130.33(b)(7)) and is
designed to account for uncertainty in TMDL calculations. The MOS can be expressed
explicitly as unallocated assimilative capacity or can be incorporated implicitly in the TMDL
through the use of conservative assumptions when calculating the allowable load (U.S. EPA,
1991).
An independent research project conducted in 2002 (Freedman et al, 2002) reviewed 176
TMDLs from across the country. MOS was found to be selected largely on an arbitrary basis,
largely due to absence of guidance in how to define a MOS and practical difficulties in
defining TMDL uncertainty.
The 2002 study presented methods for improved MOS determinations. The final step in the
revised MOS approach presented in the study was consideration of the feasibility of
implementing the calculated MOS. Following is an excerpt from the study (Freedman et al,
2002):
        The final step of the revised Margin of Safety approach requires a decision regarding
        whether the MOS can be feasibly implemented. While it is recognized that this is
        primarily a policy decision, it is appropriate to describe some of the factors that
        determine implementation feasibility. These factors include:
           •   Magnitude of the MOS: The magnitude of the MOS itself will play a
               primary role in its acceptance. An MOS that accounts for 80% of the
               total allowable load will be more likely to be challenged than an MOS
               that accounts for 20% of the total allowable load.




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           •   Additional Cost: Another important factor in determining the feasibility
               of the MOS is the additional cost of implementation relative to a less
               conservative MOS. Marginal costs of treatment generally increase as the
               level of treatment increases; a significant increase in marginal cost for an
               uncertain benefit may argue for reconsideration of the MOS.
           •   Site-Specific Considerations: This factor is designed to consider the
               importance of protecting an individual site. The policy decision may be
               made to ensure that certain waters are ensured of near-term compliance
               regardless of cost; while other waters may appropriately allow a lower
               degree of certainty when the degree of potential harm is less or the
               economic considerations of a large MOS are considered.
Since site-specific approaches to deal with unattainable TMDLs are being used in only a few
instances, the responses pertaining to the question “how are you addressing margin of
safety?” were primarily related to the states’ approaches to dealing with MOS in typical
TMDL situations. The benchmarking states are using a mixed set of approaches for
addressing MOS in TMDLs. Some are using explicit approaches routinely (Illinois and
Virginia). Several of the benchmarking states do not have a standardized approach and
determine which type of MOS, implicit or explicit, to use on a case by case basis (Arizona,
California, and Michigan). Washington defines MOS using “science-based numbers” that
result from data analyses and modeling results, as opposed to selecting an arbitrary explicit
MOS. Two interesting examples of states’ approaches to addressing MOS come from Maine
and Maryland.

Maine
Maine uses an implicit approach to addressing MOS for lake nutrient TMDLs. One of the
routinely used components of the implicit MOS is to set an in-lake phosphorus target that is 2
ppb more protective than the concentration indicated in the statewide lake database that is
protective from nuisance algal blooms. An example application of this approach is for the
Sabattus Pond TMDL for phosphorus (included in Appendix E) completed by Maine
Department of Environmental Protection in 2004:
        MARGIN OF SAFETY (MOS): An implicit margin of safety was incorporated into
        the Sabattus Pond TMDL through the conservative selection of the numeric water
        quality target, as well as the selection of relatively conservative phosphorus export
        loading coefficients for cultural pollution sources (Table 4). Based on both Sabattus
        Pond historical records and a summary of statewide Maine lakes water quality data
        for non-colored (< 26 SPU) lakes - the target of 15 ppb (1,155 kg TP/yr in Sabattus
        Pond) represents a highly conservative goal to assure attainment of Maine DEP water
        quality goals of non-sustained and non-repeated blue-green summer-time algae
        blooms due to NPS pollution or cultural eutrophication and stable or decreasing
        trophic state. The statewide data base for non-colored Maine lakes indicate that
        summer nuisance algae blooms (growth of algae which causes Secchi disk
        transparency to be less than 2 meters) are more likely to occur at 18 ppb or above. A
        range of 15 to 17 ppb (1,155 to 1,308 kg TP/yr in Sabattus Pond) is unlikely to result
        in nuisance algae blooms. The difference between the in-lake target of 15 ppb and 17
        ppb (153 kg) represents a 11.7 (12%) percent implicit margin of safety for Sabattus
        Pond. A nonquantified margin of safety for attainment of state water quality goals is



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        also provided by the inherently conservative methods used by Maine DEP to estimate
        future growth in the Sabattus Pond watershed.

Maryland
Maryland’s proposed approach to dealing with unattainable bacteria TMDLs (see discussion
in Section 3.3.1) addresses MOS through iterative implementation (or adaptive management)
of BMPs determined to provide the maximum practicable bacterial load reductions. In this
type of approach, the MOS set at the outset of the TMDL is less than the MOS that would
normally be determined to be appropriate using typical implicit or explicit approaches.
Uncertainty in the TMDL is then addressed through adaptive management (cycle of
implementation of controls, monitoring for effectiveness, and revision of control approach).


References – MOS
Freedman, et al. 2002. Navigating the TMDL Process: Evaluations and Improvements. WERF
    Report: (Project 00-WSM-1).
United States Environmental Protection Agency (U.S. EPA) 1991. Guidance for Water Quality-Based
     Decisions: The TMDL Process. EPA Office of Water: Washington, DC. Accessed May 20,
     2006. http://www.epa.gov/OWOW/tmdl/decisions/dec1c.html .
Maine
   Maine Department of Environmental Protection and Maine Association of Conservation
        Districts. August 12, 2004. Sabattus Pond PCAP-TMDL Report. Maine DEPLW 2004 –
        0649. Included in Appendix E.
Maryland
   Documentation of Maryland’s proposed site-specific bacteria TMDL approach is not yet publicly
   available. Maryland Department of Environment contact: Tim Rule, (410) 537-3688,
   trule@mde.state.md.us.

3.3.7.b Reserve Capacity
Reserve capacity for future growth is a component of the TMDL allocation scheme.
Allocation is the distribution of available loading capacity in a given water body among point
sources (referred to as wasteload allocation, WLA), nonpoint sources (referred to as load
allocation, LA), margin of safety (MOS), natural background, future growth, and any other
categories of pollutant sources (Freedman et al, 2002). Load allocation can range from a
trivial TMDL component to a high-stakes component with significant financial implications.
Within current regulations (40 CFR 130.2) future point and nonpoint sources are included
with existing point and nonpoint sources within the definitions of WLA and LA,
respectively. U.S. EPA guidance (U.S. EPA, 1999) states that TMDLs “may allow for future
growth by including a separate allocation for this purpose or by allocating acceptable
wasteloads and loads in a way that incorporates growth.”
Allocation methods that allow for future growth would potentially lower current allowable
discharge loads by setting aside a portion of the TMDL for future discharges, while
allocation methods that do not include reserve capacity could restrict future growth entirely.



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As is the case with margin of safety as described in the preceding section, reserve capacity
for future development has not been dealt with by the benchmarking states in unattainable
TMDLs. Therefore, the descriptions of states’ approaches in this section are based on the use
of these approaches in typical TMDL situations and can be considered examples of the
various approaches states are using to address future growth in TMDLs.
Several of the benchmarking states indicated that they do not set aside reserve capacity in
TMDLs. These states include Arizona, Maryland, Michigan, Vermont, and Washington.
Michigan has decided not to include consideration for future growth in TMDLs due to public
objections to its inclusion in one TMDL instance. In an example on the opposite end of the
spectrum from inclusion of reserve capacity in TMDLs, Washington imposed a building
moratorium to restrict future growth following development of a TMDL for a lake in one
instance.
States using reserve capacity for future growth in TMDLs include California, Illinois,
Maine, and Virginia. California does not have a standardized approach across its nine
regional water boards for dealing with the issue. Descriptions of how reserve capacity is used
in Illinois, Maine, and Virginia follow.

Illinois
Illinois considers future growth in TMDLs for developing watersheds. An example of
consideration of the affects of future growth on point and nonpoint sources comes from the
TMDL for chloride and dissolved oxygen for the East Branch of the DuPage River (Illinois
EPA, 2004; included in Appendix E):


        6.2 Future Growth
        Future growth may have an impact on TMDL allocation scenarios in two ways:
           •   Modified point source loads
           •   Modified nonpoint source loads
        A change in point source loads may occur due to an increase (or decrease when there
        is a declining population) in population densities in existing clusters or development
        of new clusters. The summer low-flow condition was found to be the critical
        condition for the DO impairment. Therefore, point source contribution has the most
        significant impact on instream DO concentration. Change of population served by the
        point sources will affect the point source discharge. An analysis of projected
        population data (NIPC, 2002) shows that the population of DuPage County will have
        increased by 26 percent from 1990 to 2020. Accordingly, all point source discharges
        under the summer low-flow condition were increased by 26 percent and the DO was
        simulated using the QUAL2E model. A comparison of the model result for increased
        point source discharge with that of existing point source discharge shows slightly
        improved in-stream DO concentration.
        Future growth will also affect nonpoint source pollution by changing land use
        coverage in the watersheds. For example, agricultural areas converted to residential
        land will have an impact on water quality in the impaired segments. The chloride and
        conductivity TMDL allocations require consideration of land use changes, especially


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        conversion to road. Increased chloride load due to future growth in the watersheds
        was estimated assuming that all agricultural areas in the existing GIS coverage of
        land use would be converted to residential areas. Using GIS data of current road
        density it was estimated that up to 15 miles of new roads might be constructed in the
        process of land use change. The new land use data was incorporated in developing
        TMDL allocations for chloride.
In this TMDL, the point source wasteload allocation was increased by 26% to account
for future growth and future development was considered in developing nonpoint
source load allocations. The specific percentage that the load allocation was increased
to account for projected development was not specified.

Maine
Maine’s watershed reserve capacity analysis is not specific to the state’s TMDL program.
The state stormwater and site location of development laws (06-096 Code of Maine Rules
chapter 500; included in Appendix H) trigger the analysis within a watershed based on
development. Therefore, the rules apply to both unimpaired as well as impaired watersheds.
The threshold for the reserve capacity analysis is a project disturbing one acre or more and
resulting in either: 1) one acre or more of impervious area or five acres of developed area, or
2) 20,000 square feet of new imperious area or five acres of new development (for lakes in
the “most at risk” category).

The phosphorus standard applies only in lake watersheds and is described in the rule (06-096
CMR 500 section 4B(2)(b)):

        Description of phosphorus standards. An allowable per-acre phosphorus allocation
        for each lake most at risk will be determined by the department. The department’s
        determination is based upon current water quality, potential for internal recycling of
        phosphorus, potential as a cold-water fishery, volume and flushing rate, and projected
        growth in the watershed. This allocation will be used to determine phosphorus
        allocations for a project unless the applicant proposes an alternative per-acre
        phosphorus allocation that is approved by the department. If the project is a road in a
        subdivision, only 50% of the parcel's allocation may be applied to the road unless
        phosphorus export from both the road and the lots is subject to this chapter, in which
        case the entire allocation for the parcel may be applied.

The allowable increase in phosphorus load is determined using Maine’s Allowable
Numerical Incremental Change-Based Methodology. This methodology forms the basis of
the state’s nutrient criteria plan (Maine DEP, 2002; included in Appendix D) accepted by
EPA (Silva, 2003; included in Appendix D). The methodology is based on the amount in-
lake phosphorus concentrations can increase without a perceivable change in trophic state.
The range of allowable increase is 0.5 to 1.25 ppb and varies based on lake water quality
categories, shown in Table 6.




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  Table 6: Maine’s Acceptable Increases in Lake Phosphorus Concentration by Water
                                  Quality Category
                   Water Quality Category                Lake Protection Level (ppb)
                                                     High                        Medium
                   Outstanding                                0.5                      1.0

                   Good                                       1.0                      1.5

                   Moderate/Stable                            1.0                     1.25

                   Moderate/Sensitive                        0.75                      1.0

                   Poor/Restorable                                      0.2-0.5
        Excerpted from: Nutrient Criteria Adoption Plan, Maine Department of Environmental Protection, February 1, 2002.


Once the appropriate allowable increase in phosphorus concentration is determined for a
lake, empirical models are used to calculate watershed loads associated with the increased in-
lake concentration. The increase in watersheds loads is then allocated across undeveloped
portions of the watershed on a per acre basis. A developer proposing a new development
must then use this allocation and appropriate site export coefficients and BMP removal
efficiencies to model phosphorus loads from the proposed project. Within the TMDL
framework, the phosphorus load for future development is included in the non-point source
load allocation (LA).

Maine encourages municipalities to adopt ordinances based on the state law for new
development of areas less than one acre. Of approximately 450 towns in Maine, 350 have
lakes. Two hundred of these have numerous lakes, and 60 to 70 of these have adopted such
ordinances (per Jeff Dennis, Maine DEP). This methodology has been in use in Maine since
1980.

Virginia
Virginia DEQ addresses future watershed growth in TMDLs by using watershed buildout
scenarios to develop required load reductions. In one example from a TMDL for benthic
impairments in streams (VDEQ and VDECR, 2003; included in Appendix E), future
increases in nonpoint source runoff from municipal separate storm sewer systems (MS4s)
were considered using projected land use changes within defined urban development areas
and commercial centers. Several buildout scenarios (25%, 50%, 100% buildout) were
evaluated, and the 25% buildout scenario was determined to be most appropriate for use in
TMDL allocations as it was thought to best approximate growth conditions in the watershed.
Increased loading from other permitted point sources was evaluated by using permitted
capacities, rather than actual operating flows. Required load reductions and associated
TMDL allocations were based on the 25% buildout scenario.




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References – Reserve Capacity
Freedman, et al. 2002. Navigating the TMDL Process: Evaluations and Improvements. WERF
    Report: (Project 00-WSM-1).
United States Environmental Protection Agency (U.S. EPA). 1999. Draft Guidance for Water
     Quality-based Decisions: The TMDL Process (Second Edition) EPA 841-D-99-001. August.
Illinois
    Illinois Environmental Protection Agency. October 2004. Total Maximum Daily Loads for the
         East Branch of the DuPage River, Illinois. Prepared by CH2MHill. Included in Appendix E.
Maine
    Maine Department of Environmental Protection. Stormwater Management Rules. 06-096 Code
       of Maine Rules Chapter 500. Included in Appendix H.
    Maine Department of Environmental Protection. February 1, 2002. Nutrient Criteria Adoption
       Plan. Included in Appendix D.
    Stephen J. Silva, Director, EPA’s Maine Program. United States Environmental Protection
        Agency, New England. Letter to David Courtemanch, Maine Department of Environmental
        Protection. March 3, 2003. Re: Maine Nutrient Criteria Adoption Plan submitted February
        1, 2002. Included in Appendix D.
Virginia
    Virginia Department of Environmental Quality and Virginia Department of Conservation and
        Recreation (VDEQ and VDECR). February 2003. Opequon Watershed TMDLs for Benthic
        Impairments: Abrams Creek and Lower Opequon Creek, Frederick and Clarke Counties,
        Virginia. Revised October 2003. Prepared by: Department of Biological Systems
        Engineering, Virginia Tech. Included in Appendix E.

3.3.7.c Implementation
Implementation of TMDL requirements is necessary to attain water quality standards.
However, the Clean Water Act does not establish any new implementation authorities for
TMDLs beyond those that exist elsewhere in state, local, tribal, or federal law. Point sources,
therefore, implement the wasteload allocations within TMDLs through enforceable water
quality-based discharge limits in NPDES permits authorized under Section 402 of the CWA.
Federal regulations require that effluent limits in NPDES permits for point sources be
consistent with wasteload allocations in a U.S. EPA-approved TMDL (40 CFR
122.44(d)(1)(vii)).
A 1997 U.S. EPA policy memorandum “New Policies for Establishing and Implementing
TMDLs” directs EPA regions to work in partnership with states and tribes to develop
implementation plans for nonpoint sources. The memorandum states that the implementation
plan should include: 1) reasonable assurances that the nonpoint source load allocations will
be achieved; 2) a public participation process; and 3) recognition of other watershed
management processes (e.g., the continuing planning process). U.S. EPA does not require
development of nonpoint source implementation plans and does not review the plans for
approval.



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Some of the benchmarking states are using various approaches within TMDL
implementation plans to address unachievable TMDLs. Examples from Illinois, Maryland,
and Virginia are described below. Maine’s approach to developing and implementing
agricultural TMDLs is also included in this section, though it is not used specifically for
unachievable TMDL situations.

Illinois
Illinois has conducted numerous lake nutrient TMDLs. The statewide phosphorous criterion
(0.05 mg/L) is the stated goal for every TMDL. To date, TMDLs for lakes are being
completed primarily in agriculturally dominated watersheds, where point source discharges
directly to lakes are either nonexistent or insignificant (such as shower facilities from state
parks or water treatment plant flush water). Some TMDLs for rivers and streams being
completed in the agricultural watersheds in Illinois do include point sources such as small
wastewater treatment systems (typically seasonal discharges), combined sewer overflows,
and other point sources. The technical approach used to develop lake nutrient TMDLs in
Illinois is to use the BATHTUB model to compare assimilative capacity to current loads
(including sediment/internal loading). Because significant phosphorous loading reductions
are known to be needed, the decision has been made to focus resources on implementation
rather than on collecting additional data and developing more refined models.
Although there is no set cut off for unachievability, several of the TMDLs are resulting in
80%+ reduction in phosphorus loading necessary to meet the TMDL goal and are likely
unachievable. An example of such a situation is the phosphorus TMDL for Lake Glen Shoals
in the Glen Shoals/Hillsboro watershed (Illinois EPA, 2005; included in Appendix E). To
implement these TMDLs, adaptive management is being used to deal with phosphorus
loading at the local level. Illinois EPA had originally planned to convene a panel of
community experts to help prioritize watershed activities. The panel would select from a
menu of management techniques to help reduce phosphorus and incorporating the choices
into the TMDL implementation plans. However, this approach has not yet been used in
practice. Implementation plans are, however, being written to include the menu of
management activities. Several such implementation plans have recently been submitted to
EPA for review, but are not yet publicly available.

Maine
Though it is not aimed at site-specific approaches, Maine Department of Environmental
Protection (DEP) has had an interesting cooperative arrangement with the Maine Association
of Conservation Districts (MACD) since 2000 to develop TMDLs in agricultural watersheds.
MACD and individual soil and water conservation districts work with farmers throughout the
TMDL process under the guidance that the program is voluntary and not regulatory. If the
farmers are willing to help the state develop loads, etc. for the TMDL, they receive program
help for implementation of the TMDL.

The following is an excerpt from a paper presented by David Halliwell of Maine DEP at the
Water Environment Federation Specialty Conference TMDL 2003. It gives an example of




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one lesson learned during development of an agricultural lake TMDL from the partnership
with MACD:

        The amount of watershed assessment required to develop a TMDL for this very
        complicated water resource necessitated soliciting help and a new and promising
        relationship with the Maine Association of Conservation Districts (MACD) was
        initiated under Maine DEP 319-contract in early summer 2000. A routine TMDL
        developmental approach was applied to Sebasticook Lake and a typical 50-page draft
        report was publicly reviewed in the fall of 2000. Following a much larger than
        anticipated public response, the final EPA review report was 84 pages long, with no
        less than 34 additional pages of documented public comments, inclusive of Maine
        DEP/ MACD responses.

        Notably, on the basis of updated land use information provided by farmers and the
        Penobscot County SWCD/NRCS offices, the total phosphorus load attributed simply
        to agricultural practices was reduced from a high of 70 percent of the watershed
        nutrient load to less than 50 percent. Based on this experience, it was apparent that a
        preliminary review phase of lake TMDL drafts by select stakeholders needed to be
        incorporated into the new developmental process early on - prior to formally posting
        on the Maine DEP web-page, advertising in newspapers, and officially submitting to
        US-EPA via the public review process (emphasis added). Sister state agencies,
        including the Department's of both Forestry and Agriculture, also reviewed the
        Sebasticook Lake public review draft and asked to be included in future TMDL lake
        and watershed preliminary stakeholder reviews. The Sebasticook Lake TMDL was
        finally EPA-approved in early March 2001. (Halliwell, 2003)


Maryland
Maryland’s proposed approach to dealing with unattainable bacteria TMDLs (see discussion
in Section 3.3.1) allows for iterative implementation (or adaptive management) of an
identified set of BMPs determined to provide the maximum practicable bacterial load
reductions.
Maryland has used the site-specific approach of requiring implementation of a watershed
protection plan to protect a reservoir from further degradation when its status was threatened
but not impaired. The example is for the Piney Run Reservoir, and impoundment owned by
Carroll County, MD. The reservoir was listed on the 1998 303(d) list as impaired for
sediments and nutrients. This example focuses on the nutrient impairment. Rather than
completing a TMDL, the state wrote a “Water Quality Analysis” for the impairment
(included in Appendix E). Following is an excerpt from the MDE website describing the
state’s approach:


        Piney Run Reservoir thus currently meets its designated use. However, the reservoir
        is borderline between mesotrophic and eutrophic status with respect to nutrient
        supply, biological productivity, water clarity, and oxygen depletion in the
        hypolimnion.



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        Because the data fall just within the State’s water quality standards and the watershed
        is located in a rapidly developing area, Maryland Department of the Environment
        (MDE) will require that Carroll County develop a Watershed Protection Plan (WPP),
        otherwise MDE will develop a TMDL to assure the necessary protections. The WPP
        is to protect the quality of the water supply source, manage a recreational water
        resource, and monitor the effects of changes in the watershed that might generate
        new pollutant sources. MDE believes such a plan is needed to ensure that there is no
        additional degradation of water quality that could threaten the reservoir, and will
        protect water quality sooner and more effectively than a TMDL. Barring the receipt
        of any contradictory data, this report will be used to remove Piney Run Reservoir
        from the 303(d) list on the understanding that a WPP will be completed. Although
        the waters of Piney Run Reservoir do not display signs of eutrophication caused by
        excessive nutrients, the State reserves the right to require additional pollution
        controls in the watershed if evidence suggests that nutrients from the basin are
        contributing to downstream water quality problems.

Virginia
Virginia DEQ is currently working on TMDLs for nutrient impaired lakes that are listed
based on dissolved oxygen violations. To address situations where internal nutrient cycling in
lakes precludes attainment of the TMDL endpoints, Virginia has decided to take the approach
of incorporating long implementation time frames into TMDL implementation plans. Internal
loading is not included in load allocations in Virginia. Other site-specific approaches will be
evaluated following the implementation phase, if implemented controls are not successful in
meeting TMDL goals.

References - Implementation

Illinois
    Illinois EPA TMDL Program contact: Bruce Yurdin, (217) 782-3362,
    Bruce.Yurdin@epa.state.il.us

  Illinois Environmental Protection Agency (EPA). August 2005. DRAFT TMDL Glenn
      Shoals/Hillsboro Watershed Lake Glenn Shoals (ROL), Old Lake Hillsboro (ROT). Included
      in Appendix E.
Maine
  There is no documentation of Maine’s approach to developing agricultural TMDLs with the
  Maine Association of Conservation Districts. The Maine Association of Conversation Districts
  TMDL program contact: Forrest Bell (207) 650-7597.

   Halliwell, David. 2003. The Evolution of Maine Lake TMDL’s and Phosphorus Control Action
      Plans. With Forrest Bell and Jodi Michaud-Federle, Maine Association of Conservation
      Districts. Paper presented at Water Environment Federation TMDL 2003 Conference.
      November 16-19, 2003. Chicago, IL. Included in Appendix H.

Maryland
    Documentation of Maryland’s proposed site-specific bacteria TMDL approach is not yet
    publicly available. Maryland Department of Environment contact: Tim Rule, (410) 537-3688,
    trule@mde.state.md.us.


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      Maryland Department of the Environment (no date) Water Quality Analyses (WQA) with EPA
         Concurrence of MDE's Findings. Accessed April 20, 2006. http://www.mde.state.md.us/
         Programs/WaterPrograms/TMDL/ApprovedFinalTMDL/WQA_final_pineyrun_eutro.asp)

      Maryland Department of the Environment. September 2004. The Water Quality Analysis of
         Eutrophication for Piney Run Reservoir, Carroll County, MD. Included in Appendix E.

Virginia
      Since Virginia DEQ is currently working on TMDLs for lakes, an example implementation
      plan using the described approach is not available. The Virginia DEQ contact is Jutta
      Schneider, (804) 698-4099, jschneider@deq.virginia.gov.

3.4 SUMMARY OF TMDL STORMWATER POLICIES AND APPROACHES
The information presented in this section is based on the benchmarking interview results
presented in Section 3.1, a review of small MS4 and construction general stormwater permits
for the benchmarking states, and LTI knowledge of a unique TMDL stormwater permit in
Oregon.
Summaries of TMDL related language and requirements in small MS4 and construction
general stormwater permits from the benchmarking states, as well as specific TMDL and
stormwater permit examples are included. TMDL related language was excerpted by LTI
from the states’ permits and is provided in Appendix F. Web links to the permits are also
included in the appendix.

3.4.1 Overview of EPA Stormwater Approach
EPA mandates control of storm water discharges through its National Pollutant Discharge
Elimination System (NPDES). The NPDES program was implemented in two phases. Phase I
of the NPDES program was implemented nationally in 1990 to address stormwater runoff
from medium and large municipal separate storm sewer systems (MS4s) and several
categories of industrial activity, including construction activities that disturb five or more
acres of land. Phase II of the NPDES Program, implemented in 1999, addresses smaller
sources of stormwater runoff, including small municipal separate storm sewer systems
(MS4s) and small construction activities that disturb one to five acres of land. Because the
Phase II rules were passed fairly recently (in 1999), most state programs are still in their
infancy. Some states do not yet have final small MS4 and small construction permits nor
have they been through development of any TMDLs addressing stormwater from these
permitted sources. Many state programs are currently working out the lines of
communication between TMDL and stormwater program staff.
The EPA recommends that for NPDES-regulated municipal and small construction storm
water discharges, effluent limits should be expressed as best management practices (BMPs)
or other similar requirements, rather than as numeric effluent limits (EPA, 2002). EPA
policy states,




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    “because storm water discharges are due to storm events that are highly variable in frequency
    and duration and are not easily characterized, only in rare cases will it be feasible or
    appropriate to establish numeric limits for municipal and small construction storm water
    discharges. The variability in the system and minimal data generally available make it
    difficult to determine with precision or certainty actual and projected loadings for individual
    dischargers or groups of dischargers. Therefore, EPA believes that in these situations, permit
    limits typically can be expressed as BMPs, and that numeric limits will be used only in rare
    instances.”

3.5 BENCHMARKING STATES’ APPROACHES
In the benchmarking states, stormwater TMDL issues have not yet been fully addressed. The
majority of benchmarking states have either not had occasion to deal with TMDL
requirements in MS4 permits, have not yet begun to deal with them, or have just begun to
deal with them. Phase 2 MS4 permits are in draft form in New York and Washington, and
implementation of the small MS4 program has just begun in Vermont. However, several
states did indicate that stormwater from MS4s is being included in TMDLs in the wasteload
allocations (Maine, Maryland, Michigan, and Washington).
While many states are considering stormwater separately in TMDLs within either wasteload
or load allocations, most states have not yet dealt with how to incorporate TMDL
requirements within stormwater permits. The necessary coordination between TMDL and
stormwater program areas within the state agencies adds to the complexity of addressing this
issue. Virginia is currently in the process of coordinating how best to incorporate TMDL
requirements into permits. New York’s draft MS4 permits include more specific
requirements for implementation of the six minimum measures for small MS4s.
Federal rules require stormwater to be controlled to the “maximum extent practicable” or
MEP. The single state with comments on the question regarding whether states are
considering best available technology (BAT) as separate from MEP was from Maryland.
Maryland Department of Environment considers BAT to be equivalent to MEP (Maryland’s
definitions of BAT and MEP were not provided). A few states indicated that they have no
specific definition of MEP, while New York indicated that its new MS4 permits define MEP
with more specific controls required in impaired watersheds.
The following sections present a summary of TMDL language in the benchmarking states
small MS4 and construction general stormwater permits. This language is included, along
with web links to the permits, in Appendix F.

3.5.1 Small MS4 Permits
All but two of the benchmarking states address TMDLs in their small MS4 permits (Table 7).
California does not address the issue in their permits, but this task is relegated to the TMDL
development process. Maryland is the other state that does not deal with impaired
waterbodies in their small MS4 permit. Similar to the construction permits, the most common
tactic for incorporating small MS4 flows is through WLA in the TMDLs, and unless the
TMDL states otherwise, these permits must meet the WLA. BMPs are necessities in
Arizona, Minnesota, and California. Arizona and Washington require monitoring for
pollutants causing impairments (Table 7). In Arizona, both the discharge and receiving


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waters must be monitored. Washington approaches monitoring differently for each TMDL.
In fact, the Washington permit lists each TMDL in the state and specific requirements for
MS4s discharging to those areas. Michigan’s small MS4 permit allows for iterative
approaches to dealing with stormwater released into impaired waterbodies (Table 7). New
York will soon be publishing stormwater permits that outline heightened requirements for
implementation of the six minimum measures for small MS4s. The state is also working on a
stormwater manual for phosphorus (Refer to state stormwater permit excerpts in Appendix
F).

3.5.2 Construction General Permits
A review of benchmarking states’ general construction and small MS4 permits revealed that
states are still struggling with control of construction stormwater discharges to their impaired
waterbodies. Construction permits tend to be less advanced in dealing with TMDLs for all
the benchmarking states than the MS4 permits. Three of the benchmarking states’ permits do
not address TMDLs in their construction general permits (Table 7). The majority of the
states call for inclusion of the construction runoff in the WLA of TMDLs, unless a TMDL
states that it is not necessary. Only Arizona calls for BMPs specifically to control
construction stormwater loading consistent with TMDL provisions, while California,
Vermont and Washington are the only states that require water quality monitoring for
pollutants listed as causes of impairments for the receiving water (Table 7) in their
construction permits. The monitoring requirements vary by state. For example, in California
discharge monitoring only is required, while in Vermont and Washington both receiving
water and discharge monitoring are required (Appendix F). Vermont and Washington also
require monitoring only for certain types of impairment (e.g., sediment, pH). (Refer to state
stormwater permit excerpts in Appendix F.)




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  Table 7: Summary of Small MS4 (upper) and Construction (lower) general permits
           from benchmarking states pertaining to stormwater and TMDLs.



                                  Presumptive BMPs




                                                     Iterative approach
                                                     303(d) Pollutants
                Included in WLA




                                                     Monitoring for

State                                                                     Other
Small MS4
Arizona            X                 X                X
California                           X                                    TMDLs not fully addressed in permit1
Maine              X
Maryland                                                                  TMDLs not addressed in permit
Michigan                                                           X
Minnesota          X
Montana            X
New York                                                                  Must be consistent with TMDL
Vermont            X                                                      Must be consistent with TMDL
Virginia                                                                  May need to create an implementation plan to meet TMDL goals
Washington         X                                  X                   Requirements vary by TMDL
Construction
Arizona                              X
California         X                                  X
Maine              X
Maryland                                                                  TMDLs not addressed in permit
Michigan                                                                  TMDLs not addressed in permit
Minnesota          X                 X
Montana                                                                   TMDLs not addressed in permit
New York                                                                  Specific SWMP requirements
Vermont                                               X                   Site inspection every 14 days
Virginia           X                                                      Must be consistent with TMDL
Washington         X                                  X
Notes:
    1.   California addresses these issues in their TMDL Guidance.

3.5.3 Specific TMDL and Stormwater Permit Examples
Although most states have incorporated TMDL provisions into their general permits, most
states have not yet had occasion to deal with specific instances of TMDLs and stormwater
permits. Very few examples of TMDLs that deal directly with stormwater arose from the
benchmarking interviews. Some of this may be due to the fact that the EPA calls for BMPs
only, and cautions against numeric targets. Another part of this issue is the infancy of the
Phase II stormwater program. An example of a lake TMDL for phosphorus from Maine that
incorporates stormwater from a small MS4 is provided below. An example of a stormwater



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permit dealing with TMDLs is also provided from Clean Water Services, Oregon. Oregon
was not interviewed for this project. The example from Oregon was included based on LTI’s
knowledge of the permit from working with Clean Water Services. It is unique to the state.

Maine
The Sabattus Pond TMDL for phosphorus (included in Appendix E) completed by Maine
Department of Environmental Protection in 2004, provides an example of a WLA for
stormwater from a small MS4:


    “WASTE LOAD ALLOCATIONS (WLAs): The town of Sabattus is a regulated
    urbanized area that is directly subject to Maine’s National Pollution Discharge
    Elimination System (NPDES) Phase II Stormwater Program. With the assumption that all
    urban runoff is occurring in regulated areas, the WLA for the Sabattus Pond Watershed is
    derived from the (GIS calculated and field verified) TP export percentage from selected
    developed urban-type sub-categories (See Table 4, page 30 - developed selected shoreline
    and non-shoreline sub-totals). The WLA is the sum of the following existing estimated
    loads (62 + 131 kg TP/yr) or 193 kg TP/yr.”

Oregon
Clean Water Services (CWS) is the public wastewater and surface water management utility
for urban residential parts of the Tualatin River Watershed, Oregon. The utility had their
NPDES permit approved in 2004, with several clearly-defined methods for dealing with
TMDLs in their MS4 discharges. These methods were defined in the stormwater
management plan (SWMP) and Monitoring Program and include the following measures of
progress towards TMDL goals: performance measures, BMPs, benchmarks, monitoring
triggers, narrative conditions, and an evaluation of the effectiveness of the SWMP. The
permit (included in Appendix G) states that the SWMP is part of the permit, and,

    “The SWMP and associated Monitoring Program include best management practices
    (BMPs), monitoring triggers, narrative conditions, adaptive management and other
    elements designed to reduce the introduction of pollutants into waters of the State from
    the MS4 to the maximum extent practicable (MEP). The SWMP also includes evaluation
    and reporting requirements designed to measure the effectiveness of the BMPs and other
    programs.”

References – TMDL Stormwater Policies and Approaches
United States Environmental Protection Agency (U.S. EPA). 2002. Establishing Total Maximum
    Daily Load (TMDL) Wasteload Allocations (WLAs) for Storm Water Sources and NPDES
    Permit Requirements Based on Those WLAs.
Appendix F. TMDL related stormwater language excerpted by LTI from each of the benchmarking
    states construction and small MS4 general stormwater permits.




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Maine
    Maine Department of Environmental Protection and Maine Association of Conservation
       Districts. August 12, 2004. Sabattus Pond PCAP-TMDL Report. Maine DEPLW 2004 –
       0649. Included in Appendix E.
Oregon
     Clean Water Services website: http://www.cleanwaterservices.org/
     Oregon Department of Environmental Quality. National Pollutant Discharge Elimination System
         Watershed-Based Waste Discharge Permit. Expiration Date: 1/31/09. Permit Numbers:
         101141, 101142, 101143, 101144 & MS4. Issued to: Clean Water Services, 2550 SW
         Hillsboro Highway, Hillsboro, OR 97123 Included in Appendix G.




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                                     4. CONCLUSIONS
As represented by the benchmarking states, site-specific approaches, including site-specific
criteria, UAAs, variances, and the TMDL components of margin of safety and
implementation, are being used for lake nutrient TMDLs across the country. However, the
use of these approaches for both unattainable and more protective TMDLs is on a case-by-
case basis; most states do not have guidance, checklists, or set frameworks for identifying
when site-specific approaches are necessary and how to apply them.
The decision by a state to use a certain type of site-specific approach, or conversely not to
use a certain approach, is affected by a number of complex factors, including state
regulations, public acceptance, available financial resources, prioritization of water quality
issues (i.e., types of waterbodies or impairments), and coordination between agency program
areas.
Based on the benchmarking research, Minnesota is clearly on the forefront of considerations
for site-specific approaches and in developing guidance for more protective TMDLs or
addressing otherwise unattainable TMDLs.




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                                         APPENDICES
            Appendices A through H are provided in the accompanying CD-ROM.




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