Storm Water Quality Handbooks by tbt78273

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									State of California
Department of Transportation




               Storm Water Quality Handbooks

               Project Planning and Design Guide

                Storm Water Pollution Prevention Plan (SWPPP)
                and Water Pollution Control Program (WPCP) Preparation Guide


               Construction Site
               Best Management Practices (BMPs) Guide




                                                        Prepared by

May 2000
Contents
Section 1 – Background
        1.1      Purpose and Scope of this Guide ....................................................................................... 1-1
        1.2      Storm Water Pollutants...................................................................................................... 1-1
        1.3      Regulations and Permits .................................................................................................... 1-1
                 1.3.1         Federal Regulations ............................................................................................ 1-1
                 1.3.2         Caltrans Statewide NPDES Permit..................................................................... 1-2
                                     Permit Requirements.................................................................................... 1-2
                                     Caltrans Statewide Storm Water Management Plan .................................... 1-2
                                     SWPPP/WPCP ............................................................................................. 1-2
        1.4      Permit and SWMP Implementation ................................................................................... 1-3
                                     Regional Workplans..................................................................................... 1-3

Section 2 – Storm Water Quality Considerations during Project Planning
        2.1      Introduction........................................................................................................................ 2-1
        2.2      Defining and Avoiding Potential Impacts.......................................................................... 2-2
                 2.2.1         Defining Potential Impacts ................................................................................. 2-2
                 2.2.2         Options for Avoiding or Reducing Potential Impacts ........................................ 2-2
        2.3      Review Requirements from Environmental Studies to Determine if Additional
                 Project-Specific Controls are Required............................................................................. 2-5
                 2.3.1         Significant, Unavoidable Impacts to Receiving Waters – Special
                               Circumstances for Considering Treatment Controls .......................................... 2-6
                 2.3.2         Discharges of Dredged or Fill Material into Navigable Waters
                               (404 Permit/401 Certification)............................................................................ 2-6
                 2.3.3         California Department of Fish and Game Streambed Alteration
                               Requirements ...................................................................................................... 2-6
                 2.3.4         BMPs Prescribed for 303d Listed Waters (Waste Load Allocations and
                               Watershed Plans) ................................................................................................ 2-6
                 2.3.5         Temporary and On-Going Dewatering............................................................... 2-7
                 2.3.6         Lead Contaminated Soils.................................................................................... 2-7
        2.4      Preliminary Sizing of Permanent Treatment Control Devices........................................... 2-8
        2.5      Planning Level Costs for Construction Site BMPs............................................................ 2-8
                 2.5.1         Estimating Cost for the Preparation of a SWPPP/WPCP ................................... 2-9
                 2.5.2         Estimating Cost for Implementation of Construction Site BMPs....................... 2-9
        2.6      Incorporate Results into Final Report or Scoping Document .......................................... 2-10




       Caltrans Storm Water Quality Handbooks
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Section 3 – Storm Water Quality Considerations during Project Design
           3.1    Delineate Drainage Areas and Define Total Disturbed Area .............................................3-1
           3.2    Review and Update Need to Consider Storm Water Quality Treatment Controls .............3-2
           3.3    Define Climatic Conditions................................................................................................3-3
           3.4    Determine Site Conditions of Drainage Areas ...................................................................3-3
           3.5    Apply General Design Practices and Design Permanent BMPs.........................................3-3
           3.6    Determine Need to Design Construction Site BMPs .........................................................3-5
           3.7    Prepare Storm Water Quality Standard Special Provisions................................................3-5
           3.8    Prepare Storm Water Quality Information Handout for Bid Documents ...........................3-7
           3.9    SWPPP/WPCP Information to RE File..............................................................................3-7
           3.10   Submit NOC to RWQCB ...................................................................................................3-7

Section 4 – Guidance for Selection and Design of Permanent BMPs
           4.1    Permanent Best Management Practices (BMPs)................................................................4-1
           4.2    General Design Practices for Permanent Soil Stabilization ...............................................4-1
                  4.2.1        Soil Stabilization Strategies ................................................................................4-1
                  4.2.2        Protection of Slopes ............................................................................................4-2
                                    Avoiding Existing Slopes .............................................................................4-2
                                    Minimizing Erosion on Slopes .....................................................................4-3
           4.3    General Design Practices for Streambank Erosion Control ...............................................4-6
                  4.3.1        Opportunities for Streambank Erosion Control ..................................................4-6
                                    Hydraulic Control .........................................................................................4-6
                                    Erosion and Sediment Control......................................................................4-6
                                    Hydrologic Control.......................................................................................4-7
           4.4    General Design Practices for Soil Stabilization for Concentrated Flows...........................4-7
           4.5    Preservation of Existing Vegetation and Restabilizing Remaining Disturbed Areas.........4-7
           4.6    General Design Practices for Permanent Treatment Control BMPs ..................................4-8
                  4.6.1        Selecting the Appropriate Treatment Controls....................................................4-9
                  4.6.2        Integrating Treatment Controls with Other Facilities .........................................4-9
                  4.6.3        Detention Strategies ..........................................................................................4-10
                  4.6.4        Incorporating Maintenance Access ...................................................................4-10




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Section 5 – WPCP or SWPPP Information and NOC
       5.1       Information for the WPCP or SWPPP ............................................................................... 5-1
                 5.1.1       Topography Map ................................................................................................ 5-1
                 5.1.2       Soils/Geotechnical Report, Materials Report and/or Other Reports................... 5-2
                                   Toxic History of the Site.............................................................................. 5-2
                                   Nature of Fill Material and Existing Data Describing the Soil .................... 5-2
                                   Pre-Construction Storm Water Quality Control Practices ........................... 5-2
                                   Permanent (Post-construction) Storm Water Quality Control Measures ..... 5-2
                                   Drainage Report ........................................................................................... 5-4
                                   Construction Site Estimates ......................................................................... 5-4
                                   Other Plans/Permits...................................................................................... 5-4
                                   Information/Guidance for Maintenance Staff .............................................. 5-4
       5.2       Preparation and Submittal of NOC .................................................................................... 5-4
       5.3       Storm Water Quality Information Handout for Bid Documents........................................ 5-5
                                   Layout Sheets............................................................................................... 5-5
                                   Explanation of Permanent and Construction Site (Temporary) BMPs ........ 5-6
                                   Other Information ........................................................................................ 5-6
       5.4       Conceptual SWPPP/WPCP................................................................................................ 5-6

Appendices
       Appendix A Notification of Construction
       Appendix B Working Details for Permanent BMPs
       Appendix C Abbreviations, Acronyms, Definition of Terms and References
       Appendix D Cross-reference between the Caltrans Statewide Permit and Statewide SWMP
       Appendix E Sample District NPDES Responsibility Matrix
       Appendix F Information on Treatment Design Storm




       Caltrans Storm Water Quality Handbooks
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Tables
           2-1     Storm Water Related Activities during Project Planning...................................................2-1
           2-2     Project Features and Potential Impacts to be Considered during Project Planning............2-3
           2-3     Options for Avoiding or Reducing Potential Impacts during Project Planning .................2-4
           2-4     Environmental Issues that May Require Permanent and Construction Site BMPs ............2-5
           2-5     Planning Level Costs for Construction Site BMPs ............................................................2-9


           3-1     Storm Water Related Activities during Project Design......................................................3-1
           3-2     Features to Show on Drainage Area Drawings ..................................................................3-2
           3-3     Drainage Area Attributes and their Effect of Storm Water Pollution Controls..................3-4
           3-4     Summary Sheet for Defining Drainage Area Conditions...................................................3-4
           3-5     Rainy Season Dates for Caltrans Districts..........................................................................3-6
                   Check List for Storm Water Quality Activities During Project Design .............................3-8


           5-1     SWPPP Related Documents to be Included in the RE Pending File..................................5-1
           5-2     Computation Sheet for Determining Runoff Coefficients..................................................5-7
           5-2.1   Runoff Coefficients for Undeveloped Areas......................................................................5-8
           5-2.2   Runoff Coefficients for Developed Areas..........................................................................5-9




Figures
           4-1     Decision Tree for Permanent Soil Stabilization Controls ..................................................4-5




                                                                                             Caltrans Storm Water Quality Handbooks
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                                              Section 1
                                             Background

1.1    Purpose and Scope of this Guide
Caltrans has a comprehensive and coordinated statewide effort to prevent pollution in storm water
runoff from Caltrans facilities. In order to reach this goal, Caltrans has taken an integrated approach
that addresses the storm water quality activities of the various functional areas, including planning
and design. Caltrans Statewide Storm Water Management Plan (SWMP) is the policy document that
ties the functional area activities together and describes procedures and practices to address storm
water quality statewide.

The purpose of this Project Planning and Design Guide is to incorporate storm water quality controls
from the SWMP into projects during the planning and design phases. It is important to note that this
document provides only minimum guidelines, and that storm water quality controls other than the
ones presented in this guide, may have to be incorporated on a project-by-project basis to comply
with special requirements from a Regional Water Quality Control Board (RWQCB), specific District
guidelines, or as the result of other studies. Other storm water quality elements that designers may
have to consider are included as part of each District’s Regional Workplan. Other documents have
also been developed to guide the activities of construction and maintenance staff and the
construction contractors. Also, this guide is a “living document” that is subject to change pending
revisions to the Statewide SWMP, the Statewide Permit, or other compliance related documents.

1.2    Storm Water Pollutants
Discharges from storm water drainage systems associated with highways and highway-related
properties, facilities, and activities can contain a variety of pollutants that have the potential to
adversely impact receiving waters. Of primary concern to Caltrans designers are soil erosion and
releases of sediment from exposed or disturbed land areas. Other sources of storm water pollutants
can include exhaust products, brake and tire materials, oil and grease, leaks and spills of fuels, oil,
antifreeze, litter, and other materials.

1.3    Regulations and Permits
1.3.1 Federal Regulations
Federal regulations for controlling discharges of pollutants from municipal separate sewer systems,
construction sites, and industrial activities, were brought under the National Pollutant Discharge
Elimination System (NPDES) permit process by the 1987 amendments to the Clean Water Act
(CWA), and the subsequent 1990 promulgation of federal storm water regulations issued by the U.S.
Environmental Protection Agency (EPA). The EPA regulations require municipal and industrial
storm water discharges to comply with an NPDES permit. In California, the EPA delegated its

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Section 1
Background


authority to issue NPDES permits to the State Water Resources Control Board (SWRCB) and the
nine RWQCBs.

1.3.2 Caltrans Statewide NPDES Permit
The SWRCB issued an NPDES Statewide Storm Water Permit (Permit) to the State of California,
Department of Transportation (Caltrans) in 1999 (Order No. 99-06-DWQ), to regulate storm water
discharges from Caltrans facilities. The Permit requires that Caltrans comply with the requirements
of the General Construction Permit issued by the SWRCB, to regulate discharges from construction
sites that disturb 5 acres or more. The permits cover all Caltrans storm water discharges during and
after construction and from existing facilities and operations. The statewide Permit gives RWQCBs
the option to specify additional requirements they may consider necessary to meet water quality
standards. Copies of the Statewide Permit and the General Permit can be downloaded from the
SWRCB Web site, at http://www.swrcb.ca.gov/html/stormwtr.html.

Permit Requirements
The Permit requires Caltrans to implement a year-round program in all parts of the State to
effectively control storm water and non-storm water discharges. Furthermore, the Permit requires
Caltrans storm water discharges to meet water quality standards through implementation of
permanent and temporary (during construction) Best Management Practices (BMPs) and other
measures. Storm water discharges from Caltrans right-of-way, facilities and activities, are
prohibited, unless the appropriate water quality controls have been included. The discharge of
waste, including soil and sediment, that causes pollution or nuisance, is prohibited. The permanent
BMPs included in the SWMP and this guide, if appropriately designed, constructed and operated,
will normally meet the Permit requirement for post-construction discharges. Caltrans methods to
meet the requirements of the Permit are discussed in more detail throughout this document.

Caltrans Statewide Storm Water Management Plan (SWMP)
The Permit directs Caltrans to implement and maintain an effective SWMP. The Statewide SWMP
is Caltrans’ policy document that describes how Caltrans conducts its storm water management
activities (i.e., procedures and practices), provides descriptions of each of the major management
program elements, discusses the processes used to evaluate and select appropriate BMPs, and
presents key implementation responsibilities and schedules. The SWMP also contains a list of the
BMPs evaluated and selected to manage storm water discharges from Caltrans facilities and
activities. Appendix D of this guide provides a cross-reference between the Permit requirements and
the sections of the SWMP that addressed the requirements.

SWPPP/WPCP
The Storm Water Pollution Prevention Plan (SWPPP) and Water Pollution Control Program (WPCP)
are documents that address water pollution control during construction. The Permit requires that all
storm water discharges associated with construction activity, where clearing, grading, and
excavation results in soil disturbance of at least 2 hectares (5 acres) of total land area, by law must
comply with the provisions of an NPDES Permit and develop and implement an effective SWPPP.
After March 10, 2003, EPA regulations will require a SWPPP for projects with soil disturbance of 1
acre or more – although the SWRCB may impose an earlier date by amending the Statewide Permit

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                                                                                                Section 1
                                                                                              Background


and thus including coverage of projects with soil disturbance of 1 acre or more under the Permit.
Designers are required to include pertinent SWPPP information in the project file.

Construction projects with a disturbed area of less than 2 hectares (5 acres) are not covered under the
Permit at this time and thus do not require a SWPPP. However, Caltrans requires that a WPCP
addressing control measures be prepared and implemented by the construction contractor. Designers
will also be required to include pertinent WPCP information in the project file. In some cases, the
RWQCB may view two (2) or more small projects (less than 5 acres of soil disturbance) in the same
corridor to be parts of a larger common plan of development, thus making the small projects subject
to the requirements of the Permit to develop and implement a SWPPP. The Project Manager should
be aware of other projects in the corridor. If needed, the other projects may be mentioned in the
Notification of Construction (NOC).

1.4    Permit and SWMP Implementation
The Headquarters Environmental Program coordinates implementation of the Statewide SWMP with
each District and with the Headquarters functional areas. The Environmental Program is assisted in
these efforts by the Headquarters Design, Construction and Maintenance Programs. Each District is
responsible for implementing the Statewide SWMP within the District and complying with the
Permit requirements and any District-specific requirements. Appendix E shows a sample draft
Responsibility Matrix that will be developed by each District to show who is responsible for various
activities of storm water quality within the District.

Regional Workplans
It is the Districts responsibility to ensure that storm water quality objectives are met in their areas.
Each District is required to develop a Regional Workplan that defines how the SWMP is to be
implemented, and is specific to the needs in the Region. The workplans will describe the activities
to be undertaken and will address the water bodies in the Region, the impact of the Caltrans
discharge on the water bodies, the BMPs and monitoring program to be implemented in the Region,
and changes that are to be made to the previous year’s program. The workplans will also include
identification of high risk areas, such as locations where spills from Caltrans owned rights-of-way,
activities or facilities can discharge directly to municipal or domestic water supply reservoirs or
ground water percolation facilities, and consideration of appropriate spill containment and spill
prevention control measures for such areas.




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                           Section 2
               Storm Water Quality Considerations
                    during Project Planning

2.1    Introduction
Storm water quality must be considered during project planning (developing the Project Study
Report [PSR], Project Report [PR], Project Scope Summary Report [PSSR], and other scoping
documents) of all transportation facilities. The primary storm water quality objectives during project
planning are to:

   (1) Identify potential storm water quality impacts and develop/evaluate options to avoid, reduce
       or minimize the potential for storm water quality impacts where practical;

   (2) Ensure that the programmed project includes sufficient right-of-way and budget for required
       storm water controls;

   (3) Identify project-specific permanent and temporary BMPs that may be required to mitigate
       impacts.

Table 2-1 summarizes the storm water related activities that should be performed during the
development of the PSR, PR, PSSR and other scoping documents, to meet these objectives. The rest
of Section 2 explains these activities in detail. When questions arise, contact the District Storm
Water Coordinator.

                                                     Table 2-1

                                   Storm Water Related Activities during
                                             Project Planning
                                (PSR, PR, PSSR, Other Scoping Documents)
                    Determine potential storm water quality impacts of the proposed project and
                    develop/evaluate options to avoid or reduce impacts
                    Review requirements from environmental studies to determine if
                    project-specific storm water controls (permanent and temporary) are
                    required
                    Develop preliminary size, location and cost of permanent treatment controls
                    (infiltration and detention devices) – if needed
                    Develop planning-level costs for construction site (temporary) BMPs to be
                    incorporated during project construction
                    Incorporate findings into final report or scoping document




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Section 2
Storm Water Quality Considerations during Project Planning



2.2         Defining and Avoiding Potential Impacts
The project planning phase provides the greatest opportunity to avoid adverse water quality impacts
as alignments and right-of-way requirements are developed and refined. Section 2.2 provides a basic
strategy for identifying and avoiding potential impacts. Avoiding impacts may reduce or eliminate
the need for permanent treatment controls and other mitigation-type BMPs. When the refined
geometric alignment maps are submitted for right-of-way engineering, the alignment should include
sufficient reserved land to construct and maintain all required BMPs at appropriate locations.

2.2.1 Defining Potential Impacts
Table 2-2 identifies many of the project features and potential impacts that should be considered. To
the extent it is available, obtain or develop this information for each project or alternative. The
Project Engineer must confer with other functional units, such as Landscape Architecture,
Hydraulics, Environmental, Materials, Construction, and Maintenance, when necessary. This will
usually be accomplished by submitting layouts/base maps, in conjunction with other information
required by the functional units, to determine impacts and mitigation requirements (i.e., control
measures).

2.2.2 Options for Avoiding or Reducing Potential Impacts
To avoid or reduce potential water quality impacts identified under Section 2.2.1, consider the items
listed in Table 2-3.




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                                                                  Storm Water Quality Considerations during Project Planning


                                                          Table 2-2

                            Project Features and Potential Impacts to be considered
                                            during Project Planning
         Features and Potential Impacts to be Considered                        Reason why they must be considered
Identify which RWQCB will have jurisdiction over the project(s).          Requirements may vary by RWQCB. May impact
Does the RWQCB have any special requirements?                             permanent and temporary control requirements.
Identify receiving waters and all other waters that may affect, or        First step in identifying impacts and potential
may be affected by, the project. Consider aquifers, wells, streams,       control measure requirements.
lakes, reservoirs, wetlands, and waters both fresh and saline.
Consider impacts throughout the project lifecycle, including
construction, maintenance, and operation.
Will construction require work in, above, or directly adjacent to the     Could require additional environmental
water bodies listed above?                                                permits/agreements and control measure
                                                                          requirements.
Are any of the receiving waters or watersheds a source for                Could require additional environmental
domestic water supplies?                                                  permits/agreements and control measure
                                                                          requirements.
Are any sensitive fishery, wildlife, recreational, agricultural, or       Could require additional environmental
industrial aquatic resources located in the vicinity of the project?      permits/agreements and control measure
                                                                          requirements.
Are any of the receiving waters impaired (303d listed)? (Discharges       Supplemental controls may be required to meet
to impaired water bodies may be subject to strict numeric water           further reduce pollutants, meet numeric water
quality standards and prescribed treatment controls.)                     quality standards, waste load allocations or
                                                                          requirements of an adopted watershed plan..
What is Caltrans contribution, expressed as a percentage of total         Used to determine if permanent treatment
flow, to receiving waters that are impaired or "sensitive?"               controls are required.
What is the unit cost for additional right-of-way should it be needed     Used to determine if permanent treatment
for treatment controls?                                                   controls are required.
Will the project increase the potential for downstream erosion by         May need to implement detention devices to
adding impervious surfaces, decreasing the time of concentration,         prevent damage to off-site streambanks or
or redirecting flows?                                                     channels.
Does the project discharge to lined, engineered drainage facilities       Consideration for implementing detention devices
or unlined, natural channels?                                             for streambank protection.
Identify general soil types and vegetation within the project site        Basic information needed for slope design and
                                                                          slope protection plans.
  How difficult will it be to re-establish vegetation following
  construction?
  How long will it take for the new vegetation to establish?
  What are the steepest slopes that should be allowed?
  What vegetation, if any, should be preserved?
Determine the general climate, annual rainfall, and typical seasonal      Basic information needed for slope design and
rainfall patterns for the project area.                                   slope protection plans.
Determine the proposed project slopes, and areas of cut and fill.         Basic information needed for slope design and
                                                                          slope protection plans.
Does the project include contaminated or hazardous soils as               May impact project construction activities and
identified in the initial site assessment (ISA) and environmental         deployment of temporary controls during
documents?                                                                construction.
Will the contractor’s yard be located within the State’s right-of-way     May impact responsibility for, deployment of,
or otherwise be arranged for or provided by Caltrans? If so, what         temporary controls during construction.
are the potential impacts?
Do the local regulatory agencies have seasonal construction               May impact project construction scheduling and
restrictions?                                                             deployment of temporary controls during
                                                                          construction.



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                                                             Table 2-3

                                             Options for Avoiding or Reducing
                                       Potential Impacts during Project Planning
                                                                                Yes   No                 Why
 Can the project be relocated or realigned, while upholding safe design
 standards, to avoid or reduce impacts to receiving waters?
 Can structures and bridges be designed or located to reduce work in
 live streams and minimize construction impacts?
 Can the horizontal and vertical alignments be adjusted, without
 jeopardizing safe design standards, to minimize erosion from slopes by:

      Disturbing existing slopes only when necessary?

      Minimizing cut and fill areas to reduce slope lengths?

      Incorporating retaining walls to reduce steepness of slopes or to
      shorten slopes?
      Acquiring right-of-way easements (such as grading easements) to
      reduce steepness of slopes?
      Avoiding soils or formations that will be particularly difficult to re-
      stabilize?
      Providing cut and fill slopes flat enough to allow re-vegetation and
      limit erosion to pre-construction rates?
      Providing benches or terraces on long cut and fill slopes to reduce
      concentration of flows?

      Rounding and shaping slopes to reduce concentrated flow?

      Collecting concentrated flows in stabilized drains and channels?

      Retaining natural vegetation where feasible?

 Can alternative materials or facilities be utilized to reduce future
 maintenance impacts on water quality (i.e. use of textured concrete in
 lieu of painted materials)?
 Can the project be scheduled or phased to minimize soil-disturbing work
 during the rainy season?
 Can permanent storm water controls (especially basins) and
 conveyance systems be installed early in the construction process to
 provide additional protection and to possibly utilize them in addressing
 construction storm water impacts?




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                                                             Storm Water Quality Considerations during Project Planning



2.3 Review Requirements from Environmental Studies to Determine if
    Additional Project-Specific Controls are Required
During early project planning, storm water activities focused on identifying and avoiding impacts
where practical and, if necessary and cost effective, incorporating permanent treatment BMPs into
the project that may require additional right-of-way. This identification, avoidance and
incorporation process continues in additional detail during the environmental studies phase, to
determine if treatment controls or additional mitigation-type BMPs will be required.

A number of standard permanent (design) and temporary (construction site) BMPs are incorporated
into all projects as discussed further in Sections 3 and 4 of this Guide. However, issues that may be
identified during environmental studies or permit scoping may result in the need for project-specific
permanent or temporary BMPs. Table 2-4 describes some of the typical issues that should be
considered during the environmental studies phase. These issues are discussed further in the
following sections. Much of this information will become available through other technical studies
done during the California Environmental Quality Act/National Environmental Policy Act
(CEQA/NEPA) process. Where special water quality issues are present, the designer shall
coordinate with District Environmental staff and the District Storm Water Coordinator.

                                                        Table 2-4
 Environmental or Permit Issues that May Require                Environmental or Permit Issues that May Require
         Project-Specific Permanent BMPs                      Project-Specific Construction Site (Temporary) BMPs
Significant, unavoidable impacts to receiving waters         Significant, unavoidable impacts to receiving waters
BMPs to meet a prescribed Waste Load Allocation for          Discharges of dredged or fill material into navigable
an impaired (303d listed) water body                         waters (404 Permit/401 Certification)
BMPs prescribed by a Watershed Plan for an impaired          BMPs prescribed by a Fish & Game 1601 Streambed
(303d listed) water body                                     Alteration Agreement
Mitigation measures prescribed by a Fish & Game              BMPs for stockpiling, handling and transporting
1601 Streambed Alteration Agreement                          contaminated soils
                                                             BMPs and local permits for temporary construction
Post-construction dewatering requirements
                                                             dewatering
Variances for lead contaminated soils, emphasizing
                                                             Project-specific needs for District guidelines for specifying
the reuse of soils containing aerially deposited lead
                                                             temporary BMPs
(ADL) due to vehicle emissions
                                                             Potential impacts associated with spills, especially near
Discharges of dredged or fill material into navigable
                                                             municipal or domestic water supply reservoirs or ground
waters (404 Permit/401 Certification)
                                                             water percolation facilities
Potential impacts associated with spills, especially
near municipal or domestic water supply reservoirs or        Specific RWQCB requirements
ground water recharge facilities
Specific RWQCB requirements


It is important to note that if a project is delayed or pulled, permits can expire and must be
re-evaluated, re-issued or renewed. If this occurs, the Project Engineer, Project Manager or the
Office Engineer, is responsible for either re-evaluating the project for permit compliance, renewing
the permit or obtaining a new permit.
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Section 2
Storm Water Quality Considerations during Project Planning




2.3.1 Significant, Unavoidable Impacts To Receiving Waters – Special
      Circumstances for Considering Treatment Controls
Permanent infiltration or detention devices may be required if the CEQA/NEPA process determines
that the project causes significant, unavoidable impacts to receiving waters without incorporation of
such controls in the project. Caltrans considers treatment control devices (i.e., infiltration and
detention basins) for water quality control, only if all of the following special circumstances are met:

    §       Runoff from the completed facility will discharge to significant areas of highly valuable
            habitat in which Federal or State listed aquatic resources have been identified, or will
            discharge to a storm drain that drains directly to such habitat, and;

    §       Caltrans runoff constitutes a substantial portion (more than 10%) of the total flow to such
            habitat.

2.3.2 Discharges of Dredged or Fill Material into Navigable Waters
      (404 Permit/401 Certification)
Projects that discharge dredged or fill materials into navigable waters are required to obtain a 404
permit from the US Army Corps of Engineers, and a 401 water quality certification from the
appropriate RWQCB. Site-specific BMPs may be required for 401 certification to address
discharges during construction and operation.

2.3.3 California Department of Fish & Game Streambed Alteration Requirements
A 1601 Agreement is a negotiated, legally binding contract between a project proponent and the
California Department of Fish and Game containing measures a project must include to avoid or
mitigate adverse impacts to fish and wildlife resources. 1601 agreements are often required for
projects conducted in and around lakes, rivers, or streams.
Although lakes and rivers may be easily identified, the Fish and Game definition of a stream can
include intermittent and ephemeral streams, rivers, creeks, dry washes, sloughs, blue-line streams
(USGS), watercourses with subsurface flows, and other means of water conveyance that supports
aquatic life, riparian vegetation, or stream-dependent terrestrial wildlife. Project-specific BMPs may
be required for asphalt concrete (AC) grindings, chunks and pieces, as described in Project
Development Procedures Manual, Chapter 8.

2.3.4 BMPs Prescribed for 303d Listed Waters (Waste Load Allocations and
      Watershed Plans)
Clean Water Act section 303(d) requires states to identify waters that do not meet State water quality
standards even after pollution point sources have implemented required pollution controls. To
restore a 303(d) listed water body to state water quality standards, states must establish a Total
Maximum Daily Load (TMDL) that allocates pollutant loads among the pollution sources in a
watershed. Caltrans will participate in the development of TMDLs and waste load allocations
(WLAs) that may affect requirements for Caltrans discharges. Caltrans will implement additional

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BMPs if necessary to meet WLAs. Contact the District Storm Water Coordinator to see if Caltrans
has identified technologies capable of providing the required level of pollution control.

Where a TMDL has not been developed for a receiving water that exceeds state water quality
standards and the receiving water is 303(d) listed or otherwise determined to be impaired, Caltrans
will work with and support watershed planning efforts to identify additional controls that may be
necessary to prevent or reduce discharges of the target pollutant from the completed project.

2.3.5 Temporary and On-Going Dewatering
The Statewide Permit requires Caltrans to effectively prohibit non-storm water discharges unless the
discharge is explicitly exempt or covered under a separate NPDES permit. Exempt discharges fall
into two categories: exempt and conditionally exempt. Exempt discharges include diverted stream
flows, springs, rising ground waters, and uncontaminated groundwater infiltration, and are allowed
unless identified as a source of pollution. Conditionally exempt discharges are allowed if they are
identified as not being a source of pollution, appropriate BMPs are developed and implemented, and
the appropriate RWQCB is notified. Monitoring may also be required for some conditionally
exempt discharges.

In the SWMP, Caltrans identified uncontaminated pumped groundwater as being non-polluting, and
identified BMPs for a few other discharges, including irrigation water, discharges from potable
water sources, water line and hydrant flushing, and discharges or flows from emergency fire fighting
activities. Caltrans also proposed that construction site dewatering of coffer dams, utility conduits,
and excavations be considered conditionally exempt with the implementation of the "Removing
Sediment from Dewatering Effluent" BMP. Presence of groundwater will likely be determined
through the Geotechnical Report. The presence of contaminated groundwater or dewatering effluent
may require additional NPDES permits, causing delays to the project. At press time, Caltrans is still
discussing these proposals with the SWRCB as part of the overall SWMP negotiation and approval
process. Until the SWMP is approved and adopted, existing dewatering permits and requirements
are still in effect. Following SWMP adoption, RWQCBs may still require additional monitoring and
reporting, prohibit discharges that are a significant source of pollutants, and issue separate NPDES
permits for discharges beyond the scope of the Caltrans Permit. Check with your District Storm
Water Coordinator for up-to-date information and specific requirements for your project.

2.3.6 Lead Contaminated Soils
On occasion, the environmental review process will identify project soils contaminated with lead.
Usually, the contamination is the result of long-term aerial deposition from vehicle exhaust.
Depending on the project location and the severity of the contamination, remediation requirements
can range from incorporating the contaminated soil into embankment fills to complete removal.
Specific remediation requirements must be provided to the contractor in the project contract
documents (special provisions).

Caltrans has applied for and received variances from the California Department of Toxic Substances
Control (DTSC) for the reuse of some soils that contain lead. Notification that projects involve soils
that are subject to this variance shall be provided to the appropriate RWQCB(s) in writing 30 days

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prior to advertisement for bids to allow a determination by the RWQCB(s) of the need for
development of waste discharge requirements (WDRs). The Project Engineer should contact the
Hazardous Waste Unit to obtain information on disposal of lead contaminated soils.

2.4         Preliminary Sizing for Permanent Treatment Control (Infiltration
            and Detention) Devices
Section 2.3 discussed treatment control device (infiltration and detention basins) requirements for
storm water pollution control as identified by the environmental review process. Infiltration or
detention devices may also be required to provide hydrologic control to prevent increased peak flow
rates erosion in downstream watercourses as a result of increases in magnitude and frequency of
storm flows.

If it is determined that infiltration or detention devices are required, start preliminary design to
determine scope of work, right-of-way need, and cost estimates. The PE should coordinate with
Landscape Architecture to determine aesthetic aspects of basin location and layout, and follow the
respective working details in Appendix B for more detailed design guidelines.

When these permanent treatment control devices are required, consider the following:

    §       Availability of suitable land
    §       Peak discharge rate to downstream watercourses
    §       Maintenance access and costs. The District’s Maintenance Division should be consulted
            when these devices are designed.
    §       Soil conditions appropriate for the BMP. Check with District Materials or Geotechnical units
            for project-specific soil conditions.

The design goal for hydrologic erosion control (streambank erosion control) is to limit the peak
runoff rate for a 2-year storm to the pre-development rate, thus reducing in-stream channel erosion
problems. Note that this design goal is different from, and in addition to, the flood control design
requirements in Chapter 860 of the Highway Design Manual. Also, note that if the project is in the
Lahontan region (Lake Tahoe Hydrologic Unit), the Permit has specific design requirements.
Contact the District Hydraulic Unit for sizing of basins.

See the working details "Infiltration Basin" and "Detention Basin" in Appendix B for additional
implementation guidance. The resulting facility size(s) should be used as a basis for developing cost
estimates and right-of-way requirements for inclusion in the Project Report.


2.5         Planning Level Costs for Construction Site (Temporary) BMPs
The programmed project cost should include estimates for SWPPP or WPCP development and
estimates to implement construction site BMPs during project construction as required by the Permit.
The information provided below are guidelines that will assist designers in estimating the planning
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level costs for the preparation of a SWPPP/WPCP and the costs to implement (i.e., construct,
maintain, and remove) construction site (temporary) BMPs. These cost can then be added to the
overall estimated cost of construction for the project, to come up with the final programming cost as
shown below:

      Total Project Programming Cost     =         Estimated cost of construction

                                             + Estimated cost for SWPPP/WPCP Preparation

                                             + Estimated cost for implementation of Construction Site BMPs



2.5.1 Estimating Cost for the Preparation of a SWPPP/WPCP
For a planning-level estimate, assume the typical preparation cost of a SWPPP to be about $5,000 to
$10,000 ($2,000 to $4,000 for a WPCP), plus $200 per each water pollution control sheet (the
number of water pollution control sheets can be estimated by the using a number equal to the
estimated number of drainage sheets in each construction staging plan set.)

2.5.2 Estimating Cost for Implementation of Construction Site BMPs
Planning-level cost for implementation of construction site (temporary) BMPs can be calculated as a
percentage of total construction costs, depending on project location and type and complexity of
project. In general, higher elevations and higher annual rainfall totals will result in higher
construction site (temporary) BMP costs. Table 2-5 shows various types of projects that may require
implementation of construction site BMPs, and a percentage of the estimated construction cost that
should be added to the construction cost to come up with the total project programming cost.

                                                            Table 2-5

                       Planning-level Cost for Implementation of Construction Site BMPs
                                                                                                      % of Total
                                                  Type of Project                                    Construction
                                                                                                        Cost
          Projects that involve work near 303d listed water body
            Minor work such as resurfacing                                                                3%
            Work that will require structural (treatment) BMPs                                            4%
            New facilities/renovations if TMDLs have been established (includes treatment BMPs)         6%-10%
          Construction of Highway projects
            New project with a large percentage of structure work                                         2%
            Freeway highway widening in rural areas                                                       3%
            Freeway/highway widening in urban areas                                                       4%
            Projects with considerable staging, borrow/fill sites and unbalance projects                  5%
          Landscaping projects
            Projects with irrigation repairs with little ground disturbance                               4%
            Landscape rehabilitation projects where ground disturbance is for irrigation trenches         7%
            and some re-planting work
            Projects with new planting and irrigation that involve large areas of clearing and            10%
            grubbing for new ground cover planting
            Projects (new and rehabilitation) that involve clearing and grubbing for ground cover         15%
            planting that are immediately adjacent to water bodies

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The Project Engineer must also include supplemental funds to cover the 50/50 cost sharing for
maintenance of construction site (temporary) BMPs during construction (see SSP 07-345.) This cost
is estimated to be between 0.5% and 1% of total construction costs.

2.6         Incorporate Results into Final Report or Scoping Document
The information collected and developed during the planning phase will provide the basis for
detailed design during the Plans, Specifications and Estimate (PS&E) phase. All data, decisions, and
assumptions must be carefully documented and included in the final report or scoping document.




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This section presents design guidance for incorporating storm water pollution controls in the Plans,
Specifications and Estimate (PS&E) for any project and performing other storm water related
activities. The primary objectives during this phase are to:

   §   Make a final determination of the need for considering permanent controls and the feasibility
       of including such controls.
   §   Design permanent BMPs
   §   Address the need to include construction site (temporary) BMPs in the bid documents

The storm water related activities to accomplish during design are shown in Table 3-1:

                                                      Table 3-1

                                         Storm Water Related Activities
                                             during Project Design
                    Delineate drainage areas and define total disturbed area

                    Review and update the determination of the need for treatment controls

                    Define climatic conditions of the project

                    Determine site conditions of drainage areas

                    Apply general design practices and design permanent BMPs

                    Determine need to design and specify Construction Site (Temporary) BMPs

                    Prepare Storm Water Quality Standard Special Provisions (SSPs)

                    Prepare Storm Water Quality Information Handout for Bid Documents

                    Develop/collect SWPPP/WPCP information and send to RE file

                    Prepare and submit Notification of Construction


A detailed checklist of these storm water related activities during project design can be found at the
end of this Section.

3.1    Delineate Drainage Areas and Define Total Disturbed Area

(1) Delineate Drainage Areas: Delineate the drainage information shown in Table 3-2, on the
   drawing(s) of the drainage system. Show both pre-project and post-project drainage, if possible,
   on the same drawing; or if necessary for clarity, on separate drawings. Also, this information
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    can be supplied as part of the storm water quality information handout, or can be used to create
    Water Pollution Control Drawings (WPCDs) that may be included in a District-prepared
    Conceptual SWPPP (CSWPPP) (see Section 5.4 of this Guide for information of a CSWPPP.)

                                                         Table 3-2

                                    Features to Show on Drainage Area Drawings
                              Drainage Areas                       Existing and Planned Drainage Facilities

               §   Drainage boundaries & areas to each         §     Curbs/Inlets
                   outfall (on-site and off-site)              §     Underground storm drains
               §   Drainage pattern arrows for overland flow   §     Ditches/swales
                                                               §     Channels
                                                               §     Detention basins and other flow controls
                                                               §     Drainage outfalls from structures (i.e.
                                                                     bridges)



(2) Define Total Disturbed Area: Estimate the total area of soil disturbance expected to result from
    construction activities related to the project. The following are examples of areas that should be
    included in the estimate of land likely to be disturbed by construction activities:
    §       Areas to be cleared and/or grubbed
    §       Areas to be excavated, filled, or otherwise graded
    §       Areas designated for construction staging or storage, if soil is exposed
    §       Areas designated for access/haul roads or borrow/spoil sites, if soil is exposed
    §       Areas of utility relocation

3.2         Review and Update Need to Consider Storm Water Quality
            Treatment Control BMPs
(1) Determine on a drainage area basis the need to consider storm water controls on the project (Use
    the protocol laid out in Section 2.3.)

(2) If it is determined that sediment treatment controls (Lake Tahoe Hydrologic Unit or similar
    conditions, or other special circumstances – See Section 2.3) must be considered, the procedure
    described in Section 2.4 for preliminary sizing of treatment control facilities can be used to
    determine an approximate area required.

(3) Incorporate items identified during the constructability review.




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3.3    Define Climatic Conditions
The following climatic data must be collected to aid in the selection and design of storm water
pollution controls:

(1) Mean Seasonal Rainfall and Evaporation. This information is required if vegetative erosion
    controls are to be considered, to determine whether there is sufficient moisture naturally to
    maintain the vegetation in a sufficiently healthy state to serve their intended purpose.

(2) 2-year storm. This storm, defined by Intensity-Duration-Frequency (IDF) curves, is used to
    check for erosive velocities in earthen channels and in receiving waters. See Chapter 860 of the
    Highway Design Manual (HDM.)

(3) Treatment design storm. This information is needed if infiltration or detention basins are to be
    considered, and is used to determine the volume. See Appendix F.

(4) 20-year, 1-hr storm. This information is needed for projects in the Tahoe Basin.


3.4    Determine Site Conditions of Drainage Areas
Gather additional information about the project site in order to select, locate, and design appropriate
storm water quality controls. Use Table 3-3 to identify physical attributes of site drainage areas that
may affect the selection, siting, and design of many storm water pollution controls. Attributes with
an * are optional depending on the particular controls being considered for application. Required
data can be gathered first, leaving optional data for later in the design process when the specific
control is selected. Table 3-4 shows an example of a worksheet that may be used to summarize
drainage area attributes by drainage area.

3.5    Apply General Design Practices and Design Permanent BMPs
Select and design the specific controls suited to site conditions, as follows:

   §   Soil stabilization. The designer must coordinate with Landscape Architecture and Materials
       on the selection of and design of soil stabilization.

   §   Sediment Treatment Controls (Lake Tahoe Hydrologic Unit or similar conditions, or other
       special circumstances, see Sections 2.3 and 4.6)

   §   Streambank Erosion Controls (see Section 4.2)

Working details for the permanent BMPs approved by Caltrans can be found in Appendix B of this
guide. Section 4.6 contains general design practices for permanent treatment control BMPs.




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                                                           Table 3-3
                   Drainage Area Attributes and their Effect on Storm Water Pollution Controls
                                                                            Effect on Design and Use of Pollution
          Attribute                     Information Source
                                                                                          Controls
 Drainage Area Size            Measured                               Used to select suitable treatment controls and size them

 Slopes                        Topographic Map                        Used to identify slopes that require controls to prevent
                               Aerial Photographs                     erosion. Limits use of certain controls on or adjacent to
                               Field Reconnaissance                   slopes.
                               Contour Grading Plan
 Site permeability             Aerial Photographs                     Use to determine runoff flows and therefore sizing of
 (runoff coefficients)         Satellite Imagery                      many controls. The percentage of the drainage area
                               Field Reconnaissance                   covered by pavement, buildings, concrete, or other
                               GIS Map                                impermeable materials significantly affects the size of
                               Geotechnical Design Report             controls.
 Soil Texture and              Materials Report                       Used to size the surface area of infiltration devices.
 Saturated Soil                Geotechnical Design Report
 Infiltration Rate *           NRCS Soil Survey
 Depth to Seasonal             Well Records                           Limits use of infiltration at sites with shallow
 High Groundwater *            Geotechnical Design Report             groundwater tables. In areas with shallow groundwater
                               Environmental Site Investigations      tables consider detention basins.
                               for Hazardous Wastes
 Existing Vegetation           Aerial Photographs                     Used to identify drainage areas with significant amounts
 /Ground Cover *               Field Reconnaissance                   of unstabilized soil, which limits use of infiltration and
                               Landscape Record Drawings              retention basins.
                               GIS Map
                               Satellite Imagery
 *
 These data are necessary only if treatment controls (i.e. infiltration or retention basins) are being considered.


                                                           Table 3-4

                                Summary Sheet for Defining Drainage Area Conditions

                   Project Name:

     County                                        Route                        KP                           EA

                   Mean Annual Rainfall (mm/yr.): _____           Mean Annual Evaporation (mm/yr.): _____

                Scenario:     Pre-Construction Conditions                            Post-Construction Conditions
                                                        Saturated       Depth to
                         Hydrologic                                                      Slopes in
                                         Predominant       Soil        Seasonal                                     Impervious
     Drainage    Area        Soil                                                        Drainage       Ground
                                             Soil      Infiltration      High                                        Surfaces
      Area ID    (ha)      Group                                                           Area         Cover
                                           Texture         Rate       Groundwater                                      (%)
                         (A, B, C, D)                                                    (% slope)
                                                         (mm/hr)          (m)




 NRCS Survey Maps



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3.6    Determine Need to Design Construction Site (Temporary) BMPs
District procedures and/or project-specific conditions will guide designers in the decision to include
construction site (temporary) BMPs in projects. Some Districts have adopted policies or procedures
requiring designers to incorporate construction site (temporary) BMPs into bidding information
materials or into the PS&E.

Although designing construction site BMPs may not be standard practice in your District,
project-specific conditions may require the designer to incorporate them anyway. Consider
including construction site BMPs in the PS&E; CSWPPP that includes water pollution control
drawings (see Section 5.4 for description of a CSWPPP); or storm water quality information handout
(see Sections 3.8 and 5.3); under any of the following conditions:

   •   There is a need to increase uniformity in contractor bidding
   •   Specific construction site (temporary) BMPs are prescribed by the RWQCB or other
       (non-NPDES) environmental permits or certifications
   •   The CEQA/NEPA process has identified sensitive receiving waters or valuable habitats
       requiring special protection
   •   There are site-specific conditions or sources of pollution that would not be adequately
       addressed by "typical" SWPPP and WPCP deployment strategies.

Consult with Construction when specifying project-specific construction site (temporary) BMPs and
for more specific cost estimation guidelines. For guidance on how to design construction site
(temporary) BMPs, see the Caltrans Storm Water Quality Handbooks - Construction Site Best
Management Practices Guide (presently in development, check with your Storm Water
Coordinator). The PE must also keep in mind that the project may be scheduled or phased to
minimize soil-disturbing activities during the rainy season. In addition, the PE must submit as much
information as possible for constructability review, and incorporate any storm water quality items
identified during such review.


3.7    Prepare Storm Water Quality Standard Special Provisions (SSPs)
Standard Special Provisions (SSPs) must be incorporated into PS&E for all projects, to ensure that
the contract documents clearly set forth the contractor’s responsibilities with respect to preparation
and implementation of the required water pollution control plan. Two Standard Special Provisions
(SSPs) for water pollution control have been developed specifically for this purpose:

   §   SSP 7-340, Water Pollution Control for WPCP projects. This SSP must be used when the
       project will have less than 2 hectares (5 acres) of soil disturbed by construction. After March
       10, 2003, this SSP will only be used for projects less than 0.4 hectares (1 acre).
   §   SSP 7-345, Water Pollution Control for SWPPP projects. This SSP must be used when the
       project will have 2 hectares (5 acres) or more of soil disturbed by construction. After March
       10, 2003, this SSP must be used for all projects greater than 0.4 hectares (1 acre) – although

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            an earlier date may be imposed by the SWRCB by amending the Permit to cover projects
            greater than 0.4 hectares (1 acre).

Caltrans has also developed other SSPs that contain specifications for the implementation of specific
construction site (temporary) BMPs. If a District requires that construction site BMPs are selected
and specified by the designer and shown in the CSWPPP or the PS&E, these SSPs must also be
included in the PS&E package. For additional information on SSPs for construction site (temporary)
BMPs, refer to the Storm Water Quality Handbooks - Construction Site Best Management Practices
Guide. Use of the current version of these SSPs is critical; the designer should download the latest
SSPs from the OE Server.

Rainy Season Dates
The rainy season dates to be used in the storm water quality SSPs are defined as appropriate for the
region, for the applicable RWQCB, or to meet District-specific requirements. Table 3-5 shows the
default dates for each of the Caltrans Districts. The designer should check with the District’s Storm
Water Coordinator for District-specific requirements and make the necessary edits in the SSP.

                                                        Table 3-5

                                      Rainy Season Dates for Caltrans Districts
                                                                                         RAINY SEASON DATES
     DISTRICT                                LOCATION
                                                                                         FROM                THRU
     District 1       All locations                                                October 1           May 1
     District 2       Within the North Coast and Central Valley RWQCBs             October 15          April 15
     District 2       Within the Lahontan RWQCB                                    No designated rainy season dates*
     District 3       All locations                                                October 15          April 15
     District 4       Within the San Francisco Bay RWQCB                           October 1           May 1
     District 4       Outside the San Francisco Bay RWQCB                          October 15          April 15
     District 5       All locations                                                November 1          March 15
     District 6       Within the Central Valley RWQCB                              November 1          March 15
     District 6       Within the Lahontan RWQCB                                    No designated rainy season dates*
     District 7       All locations                                                November 1          March 15
     District 8       Within the Santa Ana and San Diego RWQCBs                    November 1          March 15
     District 8       Within the Lahontan and Colorado River Basin RWQCBs          No designated rainy season dates*
     District 9       Within Mono County                                           October 15          April 15
     District 9       Within Inyo and San Bernardino Counties                      No designated rainy season dates*
     District 10      Within the San Francisco Bay RWQCB                           October 1           May 1
     District 10      Within the Central Valley RWQCB                              October 15          April 15
     District 11      Within the San Diego RWQCB                                   November 1          March 15
     District 11      Within the Colorado River Basin RWQCB                        No designated rainy season dates*
     District 12      All locations                                                November 1          March 15
   * Check with your District’s Storm Water Coordinator for any regional of project-specific requirements.



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3.8     Prepare Storm Water Quality Information Handout for Bid
        Documents
Once the PS&E package is finalized, and if construction site (temporary) BMPs are included in the
PS&E (see Section 3.6), the designer should prepare/develop the Storm Water Quality Information
Handout, which may include the items listed below. This information will be used by the Contractor
to prepare the SWPPP. Section 5.3 of this Guide contains more detail on what these documents may
contain.

   §    Layout sheets showing locations and limits for the BMPs identified in the PS&E
   §    A brief explanation of both the permanent and construction site (temporary) BMPs that will
        be specified
   §    Any additional information the designer feels is necessary for the contractor to bid the project
        accurately and implement during the construction of the project.

   Or

   §    A Conceptual SWPPP prepared by the District if required by the RWQCB or District (See
        Section 5.4).


3.9     SWPPP/WPCP Information to RE File
In addition to the information shown in the project plans, the designer will supply essential
information, developed during the design process, to the Resident Engineer Pending File. This
information will be used by the contractor to prepare the project’s SWPPP or WPCP. The
information can also be used by the RE to review the contractor’s SWPPP. For more details on the
information that needs to be submitted to the RE Pending File, refer to Section 5.

3.10 Submit NOC to RWQCB
When a RWQCB requires a SWPPP (the project will have 5 acres or more of soil disturbed by
construction), a Notification of Construction (NOC) must be submitted to the RWQCB at least 30
days prior to the start of construction. The NOC may be completed by the Project Engineer, Storm
Water Coordinator, Environmental staff, or Project Manager, as determined by District procedure.
The NOC should be submitted to the appropriate RWQCB at the same time the PS&E package is
transmitted to the Office Engineer. A copy of the NOC is in Appendix A.




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                                                      Caltrans
                           Storm Water Quality Handbooks - Project Planning and Design Guide

                                    Check List for Storm Water Quality Activities
                                               During Project Design

            Storm Water Quality Activity during PS&E                     Completed     Date             Name
 Delineate drainage areas
      Drainage Areas
            Drainage boundaries to each outfall
            Drainage area behind each outfall (on-site and off-site)
            Drainage pattern arrows for overland flow
      Existing and Planned Drainage Facilities
            Curbs/Inlets
            Underground storm drains
            Ditches/swales
            Channels
            Detention basins and other flow controls
            Drainage outfalls from structures (i.e. bridges)
 Define Total Disturbed Area
      Areas to be cleared and/or grubbed
      Areas to be excavated, filled, or otherwise graded
      Areas designated for construction staging or storage, if soil is
      exposed
      Areas designated for access/haul roads or borrow/spoil sites, if
      soil is exposed
      Areas of utility relocation
 Review and Update Need to Consider Storm Water Quality
 Treatment Control BMPs
      Determine on a drainage area basis the need to consider storm
      water controls on the project (Use the protocol laid out in
      Section 2.3.) - (Tahoe Basin or similar conditions, or other
      special circumstances)
      If treatment controls must be considered, determine
      approximate area required
      Incorporate items identified during the constructability review
 Define climatic conditions of the project
      Mean Seasonal Rainfall and Evaporation
      2-year storm
      Treatment design storm
      20-year, 1-hour storm
 Determine site conditions of drainage areas
      Complete Table 3-4



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                                                 Caltrans
                      Storm Water Quality Handbooks - Project Planning and Design Guide

                                 Check List for Storm Water Quality Activities
                                            During Project Design

        Storm Water Quality Activity during PS&E                       Completed         Date            Name
Apply general design practices and design permanent BMPs
(PPDG Section 4)
    Soil Stabilization and slope protection
        Avoid existing slopes
        Minimize erosion on slopes – slope design
    Streambank Erosion Control
    Erosion Control for Concentrated Flows
    Preservation of Existing Vegetation and Restabilizing
    Remaining Disturbed Areas
    Permanent Treatment Controls
Determine need to design Construction Site (Temporary) BMPs
   Check for specific District requirements
   Check for specific RWQCB requirements
   Check if the CEQA/NEPA process has identified areas requiring
   special protection
   Check for other site specific conditions or sources of pollution
   not adequately covered by SWPPP and WPCP deployment
   strategies
Prepare Storm Water Quality Standard Special Provisions
   Prepare SSP 07-340 (project will have less than 2 hectares (5
   acres) of soil disturbed by construction)
   Prepare SSP 07-345 (project will have more than 2 hectares (5
   acres) of soil disturbed by construction
   Prepare SSPs for Construction Site (Temporary) BMPs
Incorporate other Storm Water Quality items or comments
identified during the Constructability Review
Prepare SWQ Information Handout for Bid Documents
   Layout sheets with suggested BMP locations
   Brief explanation of permanent and temporary (if any) BMPs
   specified
   Conceptual SWPPP/WPCP
Develop/collect SWPPP/WPCP information and send to RE file
   Develop/collect information on Table 5-1
Prepare and submit Notification of Construction
   Complete NOC
   Submit NOC to RWQCB




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                           Section 4
              Guidance for Selection and Design of
                       Permanent BMPs
This section presents design guidance for selection and design of permanent storm water quality
controls (BMPs) in preparation of PS&E for any project.


4.1    Permanent Best Management Practices (BMPs)
The Caltrans Statewide SWMP listed permanent BMPs that Caltrans has evaluated and selected to
manage sediment in storm water discharges from Caltrans facilities. The listing and working details
for these BMPs are contained in Appendix B. Designers must consider these BMPs for applicability
and incorporation into the PS&E during project design, and should not select BMPs other than those
contained in the SWMP unless they have been evaluated and approved by the Storm Water Advisory
Teams and Headquarters Environmental Program, and design details approved by Headquarters
Project Development Program Managers.

4.2    General Design Practices for Permanent Soil Stabilization (Erosion
       Control)
The goal of an effective erosion control strategy is to maintain natural, pre-construction erosion rates
to the maximum extent possible. In order to accomplish this goal on every project, designers should
develop a strategy for permanently re-stabilizing all disturbed areas of the project by selecting
appropriate BMPs for disturbed areas and drainage systems, that accomplish the following
objectives:

   (a) Preserve existing vegetation to the maximum extent possible.

   (b) Minimize areas disturbed by the project

   (c) Restabilize disturbed areas, according to Landscape Architecture and Maintenance
       recommendations, that are substantially complete for each phase and stage of construction.

   (d) Control or minimize erosion potential of cuts, fills, and drainage patterns

The PS&E must be sufficiently detailed to prescribe construction requirements to implement the
BMPs.

4.2.1 Soil Stabilization (Erosion Control) Strategies
If the need arises, to demonstrate that there will be no net sediment increase for post-development
vs. pre-development conditions, use information on the soils, slopes, vegetation, and climatic
conditions of the project site to estimate the difference in erosion and sedimentation with and

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without the project. This involves using a sediment-discharge relationship (e.g., the Universal Soil
Loss Equation – USLE) to estimate differences in pre-construction and post-construction sediment
yield; and selecting additional erosion control methods that minimize these differences. This process
should be done in coordination with the District Landscape Architect, Geotechnical Engineer,
Materials and the Storm Water Coordinator. Figure 4-1 presents a decision tree for developing an
effective erosion source control design strategy and indicates BMPs to consider for various project
conditions.

4.2.2 Protection of Slopes
Identifying potentially erosive slopes is the first step to ensure their protection. Site investigation of
existing slopes on the project or in the immediate vicinity should be made, including existing
facilities with similar combinations of slope, soil, vegetation and rainfall characteristics, to observe
signs of erosion and effective erosion controls. Rill and gully erosion are the most obvious signs of
erosive slopes. Rill and gully erosion occurs where sheet flow becomes concentrated in small,
defined channels. Rills are typically a few centimeters deep and gullies are much larger. Also,
review the project soils report to determine the maximum steepness for slope stability, considering
both the surface erosion properties of the soils, as well as the structural integrity of the slope.

Impacts on existing slopes should be avoided or minimized to the maximum extent practical. The
following general strategies for minimizing erosion of slopes should be used:

    §       Disturb existing slopes or create new slopes only if necessary

    §       Establish a vegetative cover on the slope(s) or provide other materials to control erosion due
            to rainfall

    §       Minimize the slope steepness/length

    §       Prevent runoff from concentrating, and/or collect concentrated runoff in stabilized
            channels/drains.

Avoiding Existing Slopes: The first goal in project design should be to minimize disturbance of
existing slopes to the maximum extent practical, particularly where the existing slopes have a
well-established vegetative cover. However, in some cases it may be desirable to remove existing
vegetation if the result is a flatter, more stable slope. If the preliminary geometric design of the
project would potentially impact existing slopes (i.e., requiring regrading and/or clearing), determine
if the alignment and/or the geometric cross-section can be changed, or if retaining walls should be
constructed, to minimize the impact on existing slopes. In addition, grading easements should be
considered in order to decrease slope angle and erosion potential. If impacts on existing slopes
cannot be avoided, then the project must include selection and design of permanent soil stabilization
BMPs for slope protection of both disturbed existing slopes and newly created slopes. Staging can
also be used to minimize the impact on existing slopes.




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Minimizing Erosion on Slopes: The procedures and limitations for selection and design of soil
stabilization BMPs for slope protection generally depend on soil type and slope steepness and
length, and are described as follows:

(1) Slopes 1:4 (V:H) or flatter - Project design staff can select and design appropriate BMPs from
    the BMPs described below based upon guidance in this Guide and the working details in
    Appendix B.

(2) 1:4 < Slopes < 1:2 (V:H) - A slope-specific soil stabilization design based upon appropriate
    BMPs from the BMPs described below must be prepared or approved by the District Landscape
    Architect and Storm Water Coordinator.

(3) Slopes 1:2 (V:H) or steeper - Such slopes have the highest potential for erosion. A site-specific
    slope stabilization design must be prepared or approved by the District Landscape Architect. In
    addition, written concurrence with the design must be obtained from District Maintenance
    Division and Storm Water Coordinator.

The BMPs described below must be considered for minimizing erosion on slopes; general guidance
on each BMP is given. More detailed guidance can be found under each individual BMP described
in Appendix B.

Slope Roughening/terracing/rounding
§ Reduce slope steepness and length sufficiently to prevent runoff from concentrating and causing
   rill/gully erosion on long, steep slopes.

§   All slopes should be rounded, with no sharp breaks, as shown in Standard Plan A62A.

§   Terraces or benches should be considered to keep uninterrupted slope heights less than 9.1 m (30
    ft) since the highest amount of erosion occurs at the upstream end of a rill or gully. Some
    erosion control manuals recommend maximum uninterrupted slope heights of 4.6 m (15 ft) if
    soils are very erosive.

§   Runoff from terraces and steps should flow into diversion ditches installed where the terrace
    meets the slope. These diversion ditches should have a cross slope of at least 2%.

§   Mid-slope diversions should be lined on fill slopes.

§   Flatter slopes and terraces establish vegetation more readily, absorb rainfall impact, promote
    infiltration, and reduce runoff.

§   Slope surfaces should be left rough to improve seed germination and plant growth.

§   Design of slopes should be in conformance with Topic 304 of the Highway Design Manual.



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Permanent seeding and planting
§ All disturbed areas shall be planted or stabilized. If work on a slope is substantially complete,
   the slope should be stabilized with permanent controls.

§   Slopes flatter than 1:4 (V:H) and less than 4.6 m (15 ft) high should be designed to be stabilized,
    to prevent formation of rills and gullies.

§   Vegetation in combination with other forms of stabilization should be used on slopes steeper
    than 1:4 (V:H) and longer than 4.6 m (15 ft), in addition to using slope
    roughening/terracing/rounding; ditches, berm, dikes and swales; and overside drains.

§   Grasses and mulches are the most effective and quickest treatment for initial erosion control.
    Trees and shrubs alone are not effective for initial erosion control and should be supplemented
    with appropriate vegetation, mulches, or blankets.

§   The first 12 inches of topsoil (duff) shall be stockpiled and replaced prior to placing permanent
    controls.

Ditches, Berms, Dikes and Swales
§ Top, toe and mid-slope diversion ditches, berms, dikes and swales, should be used to intercept
   runoff and direct it away from critical slopes without allowing it to reach the roadway.
   Typically, mid-slope diversion ditches should have a cross slope of at least 2%, and should be
   concrete or rock lined.

§   Top of slope diversions should be paved along cut slopes where the slope length above the cut is
    greater than 12.2 m (40 ft).

§   Earthen diversion ditches, berms, dikes and swales channelize flow and should be stabilized with
    vegetation or other materials to prevent erosion.

§   Alternatively, drop structures can be placed along the diversion to maintain a grade sufficiently
    mild to prevent erosive velocities, or a paved chute can be placed down the side of the fill before
    the accumulated runoff in the diversion is sufficient to cause erosive velocities.

Overside Drains
§ Overside drains are usually pipes or lined swales that convey runoff from the top of slopes to a
   stable channel/drain at the base of the slope.

§   Size overside drains to convey large, infrequent storms down or around the slope (see Index
    834.4 of the Highway Design Manual for more information on overside drains.)

§   Overside drains in landscaped areas should be concealed by burial or other means.

§   Design top and toe of slope diversion ditches/berms/dikes/swales to direct flow into the drain.

§   Provide for outlet protection/velocity dissipation devices at the outlet of the drain, where needed.
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4.3         General Design Practices for Streambank Erosion Control
The project design must be developed to limit the potential for increased downstream streambank
erosion to the maximum extent practical as a result of future discharges from the project. The major
hydrologic changes which may affect channel stability as a result of changes in the highway
drainage system relate to:

    §       The rate and volume of runoff, due to changes in the land surface,

    §       The sediment load from upstream, due to changes in land surface erosion and upstream
            channel aggradation or degradation,

    §       Hydraulic changes due to stream encroachments or crossings (constructions or expansion), or
            due to changes in the alignment of the channel itself.

Significant Storm Events
Frequent storm events have a large effect on small stream channel stability. When considering storm
water management for channel stability, events with return periods on the order of 2 years can be
significant.

4.3.1 Opportunities for Streambank Erosion Control
In principle, the designer may have control over any of the factors governing sediment transport
capacity, but is commonly constrained by site limitations. These limitations may include factors
such as grade restrictions imposed by the topography of the site, the nature of the native soils and
streambed materials, and hydraulic structures that constrict or force bends in the channel. As a
result, controls intended to limit erosion must be placed in a way that is sensitive to the specific
conditions encountered in the particular site. Additional detailed information and procedures for
design of erosion control for channel and shore protection is found in Chapters 860 and 870 of the
Highway Design Manual.

Hydraulic Control
Hydraulic design for channels within the project site which are materially modified from their
natural state must incorporate appropriate consideration of flow velocities and bed materials. After
evaluating the peak rates of flow, design the channel section and bed materials so that the flow
velocities generated by runoff events will not be sufficient to cause damage to the channel.
Achieving this objective of long-term channel stability may require changes in channel shape, so that
the channel section area is adequate, or may require channel lining, so that the channel itself is
resistant to erosion.

Erosion and Sediment Control
Consider permanent soils stabilization practices set forth in Section 4.2 to reduce sediment loads in
runoff from adjacent sites, and from the project, to pre-project levels both during and after
construction; and to ensure that the chance of significant deposition and blockage in the downstream
channel is minimized.

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Hydrologic Control
The criterion applied to hydrologic control which is targeted at long-term channel stability is as
follows:

(1) Evaluate velocity to ensure no net erosive impact. Runoff generated by the 2-year return period
    storm, calculated for conditions where antecedent moisture conditions are of average dryness,
    shall be controlled by design of the drainage system and storm water BMPs so that the peak flow
    rate for each event after a project is complete does not exceed the peak flow rate generated by the
    same event prior to the project.

(2) To achieve this objective may require the incorporation of a detention or infiltration (retention)
    basin to reduce the peak flow rate. Retention provides the added benefit of reduction in total
    volume of flow, but it will not be possible to incorporate retention (infiltration) in many cases,
    due to physical site constraints, so the minimum criterion is, as stated in (1) above, related to
    peak flow rates.

4.4    General Design Practices for Soil Stabilization for Concentrated
       (Channelized) Flows
Sheet flow runoff will concentrate when flow rates, velocities, and depths are large enough for the
flow regime to become turbulent. The point where flow becomes turbulent and begins to channelize
is difficult to predict, but rarely exceeds a flow path length of 61 m (200 ft) and occurs in much
shorter lengths on steeper, smoother and less porous surfaces. The following BMPs should be
considered to prevent erosion when concentrated flow is expected:

   − Ditches, Berms Dikes and Swales
   − Outlet Protection/Velocity Dissipation Devices

Additional detailed procedures for design of erosion control for channel and shore protection is
found in Chapter 870 of the Highway Design Manual.

4.5    Preservation of Existing Vegetation and Restabilizing Remaining
       Disturbed Areas
Once special conditions of erosion of slopes, channels, and cross drains are addressed, the design
must address stabilization of the remainder of the site by evaluating areas of the site other than
slopes and maximizing the preservation of existing vegetation. Once the design has been
established, and the area of actual construction known, the limits of the construction site must be
established to provide some area for contractor operations, storage, etc. The construction site limits
can be restricted to minimize additional construction period disturbance of existing vegetation,
particularly on areas of the site that would present the greatest challenge to restabilization (e.g.
problematic soil conditions), and sites where floodplains, wetlands, streambanks or perennial
receiving waters with critical resources are on or adjacent to the site and would receive runoff
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directly from the disturbed areas. Areas that will not be disturbed must be clearly marked on the
plans and access limitations should be shown on the plans and described in the Special Provisions.
If preservation of existing vegetation cannot be maximized, the designer must document the
justification for disturbing greater areas of the project site.

Items to consider when preserving existing vegetation and re-stabilizing the remainder of the project
site include:

    §       Preserve existing vegetation to provide erosion and sediment control.

    §       The decision to save existing vegetation should include, at a minimum, the following
            considerations: age and life expectancy, health, aesthetic value, and wildlife benefits of
            vegetation.

    §       Vegetation to be preserved should be shown on the plans.

    §       Soil stabilization (permanent) is required on all disturbed areas.

    §       The use of native plants is appropriate for the project except for highly erosive slopes and
            channels, where denser, deep-rooted species may be required to compensate for the higher,
            more erosive flow velocities in these areas.

    §       Mulches and other forms of physical stabilization (e.g., rock, rip-rap, geotextile materials)
            should be considered for portions of the site where vegetation cannot be easily established or
            where it would require permanent irrigation, increase highway maintenance costs, and/or
            interfere with highway operations.

    §       Stabilizers with rough surfaces and/or pores that store runoff and promote infiltration are
            preferable to paved or other smooth liners that tend to increase runoff and potentially pass
            erosion problems downstream.

4.6         General Design Practices for Permanent Treatment Control BMPs
            (Tahoe Basin or Similar Conditions, or Other Special
            Circumstances)
Where permanent treatment control BMPs are required, they should be used in combination with soil
stabilization BMPs because soil stabilization practices are generally much less expensive to
construct and maintain than treatment controls. Furthermore, if the sediment loads resulting from
erosion within the right-of-way are excessive, these facilities will tend to fill more rapidly and may
subsequently fail to serve their intended purpose and treatment is a more effective method. At the
present time, there are only three treatment control BMPs that Caltrans has conditionally approved
for use on a project-by-project basis; they are: infiltration basins, detention basins and traction sand
trap devices.



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Special Circumstances for Considering Infiltration and Detention Basins
As stated in Section 2.3, Caltrans considers treatment control devices (infiltration and detention
basins) for water quality control, only if all of the following special circumstances are met:

   §   Runoff from the completed facility will discharge to significant areas of highly valuable
       habitat in which Federal or State listed aquatic resources have been identified, or will
       discharge to a storm drain that drains directly to such habitat, and;

   §   Caltrans runoff constitutes a substantial portion (more than 10%) of the total flow to such
       habitat.

Tahoe Basin or Similar Conditions
Traction sand trap devices are only considered for roadways in the following locations where sand is
applied for traction control:

   §   The Lake Tahoe and Truckee River hydrologic units in District 3

   §   Elevations above 7,000 ft in the Mammoth Creek Hydrologic Unit in District 9

   §   The Carson River East Fork and West Fork hydrologic units in District 10

4.6.1 Selecting the Appropriate Treatment Controls
When the need for detention or infiltration basins has been identified during the environmental
review process as described in Section 2.3, and it has been determined which BMP is suitable for
application at this site, the designer must then examine the facility with respect to fitting it into the
right-of-way including convenient access for maintenance, and the cost to construct and maintain the
facility.

Unless the control has been previously identified, and right-of-way reserved for this purpose, the
feasibility of including such control measures at the detailed PS&E stage is limited to what can be
incorporated within the right-of-way defined during development of the final geometric base maps.
One possible exception would be when an opportunity is identified for developing an off-site
joint-use drainage and/or water quality control feature as part of a cooperative agreement with a
local jurisdiction. This would require project-specific negotiations and coordinated design efforts.
If the need to consider an infiltration basin is first determined during the detailed PS&E stage, the
financial feasibility must also be assessed. Selection and design of treatment controls must be
performed in coordination with the Hydraulics Unit.

4.6.2 Integrating Treatment Controls with Other Facilities
In many instances, and especially in areas where available right-of-way is limited, treatment control
BMPs can be integrated into common project features such as medians, shoulders, setbacks, within
interchange areas, landscaped areas, parking areas and unused right-of-ways. Treatment control
BMPs may be considered for open areas within interchange areas and alongside the road, but safety
considerations and access for maintenance must be fully considered when selecting the location.

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In some cases, drainage, flood control and storm water pollution controls can be integrated into a
single facility that achieves all objectives cost-effectively. The design guidelines laid out in the
individual BMPs contained in Appendix B must be carefully followed to ensure that the large storms
used to size the drainage and flood control portion of these sediment basins do not "flush out" the
pollutants already captured by the facility. Alternatively, the large storms may bypass around the
water quality control facility.

Design facilities for siting storm water quality controls consistent with normal Caltrans design and
maintenance practices. Final layout and design of treatment controls must be coordinated with the
Hydraulics Unit, the District Landscape Architect and the Storm Water Coordinator.

4.6.3 Detention Strategies
Combination drainage, flood control and storm water pollution control basins must provide separate
storage volumes and outlet controls for each objective, each sized as if they were separate basins and
then "stacked" in a manner that meets all objectives as noted below:

§   The objective of storm water detention for flood control, sometimes referred to as "peak
    shaving", is to reduce the peak rate of runoff from relatively intense, infrequent design storms
    (e.g., a 10-year storm or larger). Generally, the runoff from smaller storms passes through these
    basins without significantly altering the discharge hydrograph or removing pollutants.

§   Storm water treatment controls employ a different storage strategy; they capture and detain
    almost all runoff from a water quality design storm much smaller than typical flood control
    design storms

4.6.4 Incorporating Maintenance Access
Treatment control BMPs must be periodically maintained in order to be effective. Maintenance
must be consulted to determine maintenance access requirements. These requirements must then be
incorporated into the design.




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5.1 Information for the WPCP or SWPPP
In addition to information shown on the project plans, the project design staff must supply certain
information developed during the design process for use by the contractor via the Resident Engineer
(RE) Pending File. The contractor will use this information to prepare either a WPCP or SWPPP, as
appropriate. Table 5-1 identifies information to be included in the Resident Engineer Pending File
for the contractor to prepare the SWPPP. These items should also be included as part of the
information handout for contract advertisement.

                                                       Table 5-1

                        SWPPP Related Documents to Be Included in the Resident
                                       Engineer Pending File
                       §   Topographic map of the project area
                       §   Soils/geotechnical report, project materials report and/or other
                            reports for description of soils types, nature of fill materials and
                            known buried hazardous or toxic materials
                       §   Pre-construction (Existing) control practices

                       §   Permanent post-construction storm water control measures

                       §   Other plans/permits

                       §   Copy of project drainage report for identifying flow patterns and
                            tributary areas
                       §   Construction site estimates such as area calculations, runoff
                            coefficients and pervious area calculations
                       §   Copy of the submitted Notification of Construction (NOC) for the
                            project


Some of the material listed in Table 5-1 is already required to be in the RE Pending File, but it is
recommended that a second copy of the material be included specifically for SWPPP/WPCP
documentation.

5.1.1 Topography Map
§   Provide a map extending approximately one-quarter mile (400 meters) beyond the property
    boundaries of the construction site showing: the construction site, surface water bodies
    (including known springs and wetlands), known wells, an outline of off-site drainage areas that
    discharge into the construction site, general topography, and the anticipated discharge location(s)
    where the construction site's storm water discharges to a municipal storm drain system or other
    water body. It is recommended that a U.S. Geological Survey (USGS) quad map be used for
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    showing the project site and a one-quarter mile (400 meters) extension beyond the property
    boundaries of the construction site. USGS maps display much of the required information;
    however the map will need to be slightly modified to show anticipated drainage paths (onto and
    off the construction site) and construction site boundaries.

§   The following are additional recommended items that should be provided on the topography
    map:

    − Legend
    − Measurement of the construction site area
    − Flow directions of nearby creeks, streams, and rivers

5.1.2 Soils/Geotechnical Report, Materials Report and/or Other Reports
§   Toxic History of the Site: Include in the WPCP/SWPPP documents package, to the extent
    information is available from the soils/geotechnical report, the project materials report, site
    investigation report developed by the Hazardous Waste Section or other regulatory or
    environmental compliance documentation, a description of all toxic materials known to have
    been treated, stored, disposed, spilled, or leaked in significant quantities onto the construction
    site.

§   The Nature of Fill Material and Existing Data Describing the Soil: Include a copy of the
    project materials report (geotechnical report). The contractor must describe the conditions of the
    fill material and the soil that can be found at the construction site. Fill material should be
    described as whether it is native or non-native, contaminated or uncontaminated, and its
    coverage technique (i.e., native soil coverage, asphalt or concrete coverage, and/or landscape).

§   Pre-construction Storm Water Quality Control Practices: Provide written descriptions of
    existing pre-construction practices, if any, that are already in place to reduce sediment and other
    pollutants in storm water discharges. These permanent control practices may consist of
    sedimentation ponds, oil/water separators, spill containment facilities, etc. If there are no
    pre-construction control practices, then this should be indicated.

§   Permanent (post-construction) Storm Water Quality Control Measures: Provide a written
    listing and narrative descriptions of post-construction permanent BMPs that have been included
    in the project to reduce pollutants in storm water discharges. Narrative descriptions should also
    include operation and maintenance (O&M) procedures for the permanent BMPs, O&M
    short-term and long-term funding, and a statement indicating that the Maintenance Department
    will be responsible for O&M of the post-construction BMPs. The designer must coordinate with
    District Maintenance for development of special O&M procedures. Post-construction BMPs are
    permanent erosion and sediment control measures or other treatment control BMPs that have
    been incorporated into the project plans. They include the minimization of land disturbance,
    minimization of impervious surfaces, treatment of storm water runoff using infiltration or
    detention devices, use of efficient irrigation systems, and appropriately designed and constructed
    energy dissipation devices.

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In some cases, these permanent BMPs will be oriented toward requirements of other agencies,
permit conditions, or other agreements. Any BMP to be included at the request of another agency
should be discussed in the RE Pending File, in order for the Contractor to use this information in
preparing the SWPPP. For example, if the Department of Fish and Game required the
construction of a permanent sedimentation basin, then this basin and its purpose would be
described in this section. In addition, if a local agency were to require an arrangement of K-rail
for the purpose of retaining sediments in a particular area, then the purposes and requirements by
the agency would be described.

The following is sample post-construction requirements standard language, which should be
included in the RE Pending file. This information will then be given to the Contractor for
inclusion in the SWPPP:

“Post-construction (permanent) best management practices (BMPs) have been designed by
Caltrans District ___. The following list describes those permanent post-construction BMPs that
have been incorporated into the project. Details describing the design of each of the BMPs
listed can be found by referring to the plan sheet number listed to the right of the BMP. It is
anticipated that the information provided is to be used by the construction contractor in the
development of the Storm Water Pollution Prevention Plan (SWPPP) for this project, but that no
reduction in service life or operational characteristics shall be incurred to these BMPs by such
use.

                       POST-CONSTRUCTION BMP          PLAN SHEET LOCATION(S)




After construction, projects are covered under the Caltrans Statewide NPDES Permit, Order No.
99-06-DWQ, No. CAS000003. The post-construction management plan, including BMP
operating, maintenance and inspection procedures, are contained in the Caltrans Statewide
Storm Water Management Plan. Any additional requirements are described in the Caltrans
District Regional Workplan submitted to the Regional Water Quality Control Board.

Short-term and long-term operation and maintenance of all post-construction (permanent) storm
water pollution control BMP constructed within the State right-of-way shall be funded by the
District’s Maintenance budget, unless other arrangements are made via a maintenance
agreement. If such agreement has been entered into, a copy of the agreement in included in
Appendix ___.

Use the following paragraph only if needed:
Special operating, maintenance or inspection requirements for the project after construction,
have been developed by Caltrans District ___ and are shown in the Operation and Maintenance
Plan dated _____________________, included in Appendix ___. The contact person for this
maintenance plan is _______(Name and telephone number)______.”


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§   Drainage Report: Include a copy of the drainage report or appropriate information, such as the
    hydrology maps, delineation of drainage boundaries, concentrations of runoff, and runoff
    coefficients.

§   Construction Site Estimates: Provide the following information to the RE Pending File:

    − An estimate of the construction site area in square meters (acres) (see Section 3.1);
    − An estimate of the runoff coefficient of the construction site before and after construction
      (The form shown in Table 5-2 may be used to develop the necessary information for runoff
      coefficients; Tables 5-2.1 and 5-2.2 provide supporting information for the calculation of
      runoff coefficients); and
    − An estimate of the percentage of the area of the construction site that is impervious (e.g.,
      pavement, building, etc.) before and after construction.

§   Other Plans/Permits: Other agencies may have issued permits or have plan requirements for
    the construction of the project or imposed certain conditions. If so, a written description of the
    permit conditions and a copy of the permit must be provided for inclusion in an appendix to the
    SWPPP. Hazardous materials must be handled in accordance with specific laws and regulations
    and disposed of as a hazardous waste. If during the preparation of the PS&E, it is known that
    special permits for accomplishing disposal of hazardous waste is known, then a written
    explanation must be provided to the contractor to be incorporated within this section and it must
    be consistent with other specifications in the contract. In addition, information regarding other
    related permits such as California Fish and Game or U.S. Army Corps of Engineers permits
    should also be included.

§   Information/Guidance for Maintenance Staff: Many of the permanent control measures will
    require on-going inspection and maintenance once construction is completed and the project is
    operational. The design staff should assemble information to be included in the Resident
    Engineer Pending File to be turned over to maintenance division staff upon project close-out.
    This information should include O&M procedures for the permanent BMPs. Some of this
    information can be obtained from the Inspection and Maintenance sections of the BMPs found in
    Appendix B of this Guide.


5.2 Preparation and Submittal of NOC
The Permit requires that a Notification of Construction (NOC) be submitted to the appropriate
RWQCB for projects with soil disturbance of at least 2 hectares (5 acres) of total land area. This
NOC must be submitted at least 30 days prior to the start of construction. A copy of the NOC form
and instructions to complete it can be found in Appendix A of this Handbook. The information
presented below is information that designers should be aware of:

§   The NOC form should be completed by the District Storm Water Coordinator, Environmental
    staff, Project Manager or Project Engineer, as determined by District policy, and submitted to the
    appropriate RWQCB at the same time the PS&E package is transmitted to the Office Engineer.

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§   No fees are to be to submitted to the RWQCB. A copy of the NOC should also be transmitted to
    the District Construction Division.

§   At the time of the first submittal to the RWQCB, the District may elect to leave blank the
    information in Section IV, Construction Field Office, and resubmit a copy of the form with that
    information filled in at the time the RE is assigned. Alternately, the District may wish to fill in a
    contact name of someone other than the RE, such as the Area Senior Construction Engineer or
    Project Manager, who will remain the contact for that project until the NOC is resubmitted with
    the new contact information, or until the Notification of Completion is filed.

§   In some cases, the RWQCB may view two (2) or more small projects (less than 5 acres of soil
    disturbance) in the same corridor as part of a larger common plan of development. The Project
    Manager should be aware of other projects in the corridor. If needed, the other projects may be
    mentioned in the NOC.


5.3 Storm Water Quality Information Handout for Bid Documents
As described in Section 3.8, the designer must determine if some or all of the construction site
(temporary) BMPs will be individually called out in the plans and specifications. This determination
is typically made by either District policy or through consultation with District Construction to
identify which BMPs may be critical to the success of the construction phase water pollution control
program. The Storm Water Quality (SWQ) Information Handout is intended to provide the
contractor with information that substantiates the designers’ generation of quantities for those
individual BMPs as well as show the location of placement of the BMPs. To effectively carry this
out, the SWQ Information Handout may contain:

    §   Layout sheets showing locations and limits for the BMP identified in the PS&E
    §   A brief explanation of both the permanent and construction site (temporary) BMPs that will
        be specified
    §   Any additional information the designer feels is necessary for the contractor to bid the project
        accurately and implement during the construction of the project.

Layout sheets showing suggested BMP locations: The purpose of these sheets is to show the
contractor the designer’s anticipated placement of construction site (temporary) BMPs such as
contractor staging areas, approximate location of concrete washouts, approximate locations for
storage of materials, and preferred locations for vehicle and equipment maintenance. These are not
intended to be highly detailed drawings. Typically, these layouts can be hand-drawn on 200 scale
drawings. Where multiple stages of construction are anticipated, the designer should use the stage
construction sheets to show how deployment of the BMPs is expected to change over time. These
locations and layouts will be, in most cases, subject to the contractors phasing of the work and
timing of operations. As a result, many of the suggested locations will be modified by the contractor
in their SWPPP/WPCP. The layout sheets must also contain a disclaimer stating that they show


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suggested construction site (temporary) BMPs, and that the Contractor is ultimately responsible for
developing a SWPPP that complies with the Permit.

Explanation of Permanent and Construction Site (Temporary) BMPs: This information would
provide brief narrative explanation of the various permanent and construction site (temporary) BMPs
that may be implemented in the project. The designer should identify any existing permanent BMPs
that may be present within the project limits that can be used during construction, as well as identify
any permanent BMPs that should be constructed early for use as a temporary BMP during
construction, such as early application of permanent soil stabilization measures in areas that will no
longer experience soil disturbance during construction.

Other Information: Include any other information that would explain the decisions or thought
process behind the selection and deployment of the BMPs chosen by the designer. Examples include
the designers estimated staging of the project and estimated time of year for those stages; any
scheduling modifications included in the Order of Work specifications that were included to enhance
water pollution control; and any specific BMP deployments that are considered to be critical to the
success of the contractors SWPPP/WPCP.

5.4 Conceptual SWPPP/WPCP
The Caltrans NPDES permit allows any RWQCB to request submission of a SWPPP up to 30 days
prior to the start of construction. In order to not delay the start of construction, the affected District
will typically negotiate a process with the RWQCB to submit a Caltrans prepared “Conceptual
SWPPP” (CSWPPP) about the same time as the PS&E is submitted to Office Engineer.

The CSWPPP should contain all of the elements of a contractor prepared SWPPP, but it will not
replace the contractor’s SWPPP. The term conceptual is used because the designer cannot be
expected to know all aspects of the eventual contractor’s planned order of operations, nor have
knowledge of any delays that may affect the implementation of the SWPPP during construction.
However, when a CSWPPP has been prepared, the designer should strongly consider making that
information available to the contractor, and including much of the information on the project plans
and in the SWQ Information Handout. It should be noted that the RWQCB may have specific
requirements that the Project Engineer must fulfill and coordinate with the RWQCB. Details on the
development and update(s) of the SWPPP and WPCP can be found in the Caltrans Storm Water
Quality Handbooks - SWPPP/WPCP Preparation Guide.




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                                                            Table 5-2

                                           Computation Sheet for Determining
                                                 Runoff Coefficients

            Total Site Area                                   =                           (A)
Existing Site Conditions
                                     1
            Impervious Site Area                              =                           (B)
                                                  2,4
            Impervious Area Runoff Coefficient                =              0.95         (C)
                                 3
            Pervious Site Area                                =                           (D)
                                                        4
            Pervious Site Area Runoff Coefficient             =                           (E)
            Existing Site Area = (B x C) + (D x E)            =
            Runoff Coefficient           A                                                (F)


Proposed Site Conditions (After Construction)
                                     1
            Impervious Site Area                              =                           (G)
                                                 2,4
            Impervious Site Runoff Coefficient                =              0.95         (H)
                                 3
            Pervious Site Area                                =                           ( I)
                                                        4
            Pervious Site Area Runoff Coefficient             =                           ( J)


            Proposed Site Area = (G x H) + (I x J)            =                           (K)
            Runoff Coefficient           A



1
    Includes paved areas, areas covered by buildings, and other impervious surfaces.
2
    Use 0.95 unless lower or higher runoff coefficients can be verified.
3
    Includes areas of vegetation, most unpaved or uncovered soil surfaces, and other pervious areas.
4
    See Table 5-2.1 and 5-2.2 for runoff coefficients.




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                                                              Table 5-2.1

                                           Runoff Coefficients for Undeveloped Areas
                                                       Watershed Types
                                      Extreme                      High                   Normal                     Low
 Relief                               0.28 -0.35                0.20 - 0.28             0.14 -0.20                0.08 - 0.14

                                Steep, rugged terrain     Hilly, with average     Rolling, with average     Relatively flat land,
                                with average slopes       slopes of 10 to 30%     slopes of 5 to 10%        with average slopes
                                above 30%                                                                   of 0 to 5%
 Soil Infiltration                    0.12 - 0.16               0.08 - 0.12            0.06 - 0.08                0.04 - 0.06

                                No effective soil         Slow to take up         Normal; well drained      High; deep sand or
                                cover, either rock or     water, clay or          light or medium           other soil that takes
                                thin soil mantle of       shallow loam soils of   textured soils, sandy     up water readily,
                                negligible infiltration   low infiltration        loams, silt and silt      very light well
                                capacity                  capacity, imperfectly   loams                     drained soils
                                                          or poorly drained
 Vegetal Cover                        0.12 - 0.16               0.08 - 0.12            0.06 - 0.08                0.04 - 0.06

                                No effective plant        Poor to fair; clean     Fair to good; about       Good to excellent;
                                cover, bare or very       cultivation crops, or   50% of area in good       about 90% of
                                sparse cover              poor natural cover,     grassland or              drainage area in
                                                          less than 20% of        woodland, not more        good grassland,
                                                          drainage area over      than 50% of area in       woodland or
                                                          good cover              cultivated crops          equivalent cover
 Surface Storage                      0.10 - 0.12               0.08 - 0.10            0.06 - 0.08                0.04 - 0.06

                                Negligible surface        Low; well defined       Normal; considerable      High; surface
                                depression few and        system of small         surface depression        storage, high;
                                shallow; drainage-        drainageways; no        storage; lakes and        drainage system not
                                ways steep and            ponds or marshes        pond marshes              sharply defined;
                                small, no marshes                                                           large flood plain
                                                                                                            storage or large
                                                                                                            number of ponds or
                                                                                                            marshes
 Given:     An undeveloped watershed consisting of:                               Solution:
                     1) rolling terrain with average slopes of 5%,                     Relief                    0.14
                     2) clay type soils,                                               Soil Infiltration         0.08
                     3) good grassland area, and                                       Vegetal Cover             0.04
                     4) normal surface depressions.                                    Surface Storage           0.06
                                                                                                      C=         0.32
 Find:      The runoff coefficient, C, for the above watershed


 Reference: Caltrans Highway Design Manual, July 1995




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                                                      Table 5-2.2

                                       Runoff Coefficients for Developed Areas
                   Type of Drainage Area                                  Runoff Coefficient
Business:
     Downtown areas                                                              0.70 - 0.95
     Neighborhood areas                                                          0.50 - 0.70


Residential:
     Single-family areas                                                         0.30 - 0.50
     Multi-units, detached                                                       0.40 - 0.60
     Multi-units, attached                                                       0.60 - 0.75


Suburban                                                                         0.25 - 0.40

Apartment dwelling areas                                                         0.50 - 0.70

Industrial:
     Light areas                                                                 0.50 - 0.80
     Heavy areas                                                                 0.60 - 0.90


Parks, cemeteries:                                                               0.10 - 0.25

Playgrounds:                                                                     0.20 - 0.40

Railroad yard areas:                                                             0.20 - 0.40

Unimproved areas:                                                                0.10 - 0.30

Lawns:
     Sandy soil, flat, 2%                                                        0.05 - 0.10
     Sandy soil, average, 2-7%                                                   0.10 - 0.15
     Sandy soil, steep, 7%                                                       0.15 - 0.20
     Heavy soil, flat, 2%                                                        0.13 - 0.17
     Heavy soil, average, 2-7%                                                   0.18 - 0.25
     Heavy soil, steep, 7%                                                       0.25 - 0.35


Streets:
     Asphaltic                                                                   0.70 - 0.95
     Concrete                                                                    0.80 - 0.95
     Brick                                                                       0.70 - 0.85
     Drives and walks                                                            0.75 - 0.85


Roofs:                                                                           0.75 - 0.95

Reference: Caltrans Highway Design Manual, July 1995




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                                 Appendix A
                         Notification of Construction

                                                                                             4/10/2000
                             CALTRANS STATEWIDE NPDES PERMIT

                               Order No. 99-06 DWQ, NPDES CAS000003

                           Notification Of Construction (NOC) Instructions


The Permit requires that a Notification of Construction (NOC) for construction projects covered by
the Permit be submitted to the appropriate Regional Water Quality Control Board (RWQCB) at least
30 days prior to the start of construction. In some cases, the RWQCB may view two or more smaller
projects in the same corridor as part of a larger common plan of development. The Project Manager
should be aware of other projects in the corridor. If needed, these projects should be mentioned in
section V. Construction Site Information.

Typically, most of the information on the form is completed by the District Storm Water
Coordinator, Environmental staff, Project Manager or Project Engineer. That individual also
submits the NOC to the appropriate RWQCB(s) at the same time the PS&E package is transmitted
to the Office Engineer. No fees are to be to submitted to the RWQCBs. A copy should also be
transmitted to the District Construction Division.

At the time of the first submittal to the RWQCB, the District may elect to leave blank the
information in Section IV. Construction Field Office and resubmit a copy of the form with that
information filled in at the time the Resident Engineer (RE) is assigned. Alternately, the District
may wish to fill in a contact name of someone other than the RE, such as the Area Senior
Construction Engineer or Project Manager, who will remain the contact for that project until the
NOC is resubmitted with the new contact information, or until the Notice of Completion of
Construction (NCC) is filed.

The form may be filled in electronically or by printing legibly.

I. IDENTIFICATION
Provide a brief project descriptive name, a “nickname.” When the NOC is first submitted to the
RWQCB, check the First Submittal box. For subsequent changes of information, including contact
information, enter the amendment number.

Enter the Contract Number. Use the construction phase EA.



         Caltrans Storm Water Quality Handbooks
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         May 2000                                                                                      1
Appendix A
Notification of Construction


Enter the date that the NOC is first submitted to the Regional Water Quality Control Board
(RWQCB), or date of subsequent submittals.

Provide a “to scale” or "to approximate scale" drawing of the construction site and the immediate
surrounding area. Limit the map to an 8.5” x 11” or 11" x 17" size. At a minimum, the map must
show the site perimeter, the geographic features surrounding the site, general topography, and
location of the construction project in relation to surface waters and named streets, roads,
intersections, or landmarks. Do not submit a drawing unless it meets the above size limits.

Enter the city, if applicable, or N/A if not within city limits. Enter the county or counties, route
number, post mile and kilometer post. Also enter the tentative start and end dates.

Enter a tentative date the Storm Water Pollution Prevention Plan (SWPPP) will be available.

II. CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD(S)
Check the box of the RWQCB(s) that has jurisdiction over the area that the project is in.

III.CALTRANS DISTRICT
Enter the name and address of the Caltrans District individual responsible for submittal of the NOC
to the RWQCB. Typically that individual is the Project Engineer, Project Manager, the District
Storm Water Coordinator, or Environmental Program staff.

IV.    CONSTRUCTION FIELD OFFICE
Enter Caltrans field office information, if known, and Construction Contact person information. As
discussed above, the District may elect to use the contact information for the RE after the project has
been assigned, or another individual, such as the Area Senior or Project Manager. If the
Construction Contact information changes, then the District should resubmit a revised form to the
RWQCB(s). Provide the physical address of the field office, or a description of the physical location
of the field office if no physical address is available and a location map.

V. CONSTRUCTION SITE INFORMATION
Provide a brief narrative description of the work. You can attach a checklist of permanent and/or
temporary BMPs if needed, or required by a RWQCB. A checklist of construction BMPs can also
be attached later as an amendment after the SWPPP is completed.

Check the box or boxes to indicate any additional required approvals, permits or certifications.
Some examples are: variance from the Department of Toxics Substances Control (DTSC) for reuse
of soil containing lead, dredge or fill operations requiring Army Corps of Engineers 404 certification
and/or Clean Water Act 401 certification, streambed alteration requiring Department of Fish and
Game 1601 permit and non-storm water discharges requiring separate waste discharge requirements.
Describe the condition and whether the approval, permit or certification has been issued. If the
project involves soils subject to the DTSC variance, notify the appropriate RWQCB(s) to determine
if separate waste discharge requirements must be issued. The RWQCBs have up to 120 days to issue
waste discharge requirements, so the RWQCBs should be notified early on in the process.

                                                                         Caltrans Storm Water Quality Handbooks
Appendix A                                                               Project Planning and Design Guide
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                                                                                                    Appendix A
                                                                                   Notification of Construction




Indicate the total size in acres and hectares, of the construction project. Also indicate the size of the
disturbed soil area. Disturbed soil area is defined in the Storm Water Management Plan as “areas of
exposed, erodible soil, including stockpiles, that are within the construction limits and that result
from construction activities.”

Identify the name of the surface receiving water body for the storm water discharge. Indicate
whether the project is in or immediately adjacent to the receiving water. If the storm water is
infiltrated, check the box for infiltration basin, and identify the basin’s location. If the discharge is
to a separate storm sewer system, such as a collection system operated by a municipality, flood
control district, utility, or similar entity, check the box for municipal/other system and the name of
the system owner.

VI.   CERTIFICATIONS
The permit requires that all reports and information requested by the SWRCB or RWQCBs be
signed by an Executive Officer, Executive Director or a duly authorized representative if the
authorization is made in writing. If a District elects to delegate signature authority to staff, a model
letter that submits a list of authorized names or positions to a RWQCB is attached that can be used
for this purpose. If signature authority is delegated to staff, a copy of that delegation letter should be
sent to the Storm Water Manager at Headquarters.



NOC FORM
The Notification of Construction (NOC) can be found at Caltrans Electronic Forms System Web
Site. Go to the Caltrans Onramp, click on Resources, then Caltrans Electronic Forms System
(CEFS), then Forms. The NOC may be located by entering the form name, number (CEM-2002) or
looking under the Construction heading. The most current version of the form will be at that site.




         Caltrans Storm Water Quality Handbooks
         Project Planning and Design Guide                                                          Appendix A
         May 2000                                                                                            3
                                           Model Letter


District Letterhead



To:    Regional Water Quality Control Board
       Address




                Authorized Representative(s) to Sign Storm Water

                                Notification of Construction

In compliance with the State of California Department of Transportation (Caltrans) NPDES Permit
for Storm Water Discharges, Order No. 99-06-DWQ Section M. 10. b, I hereby authorize the
following individuals/positions to sign the Notification of Construction to the Regional Water
Quality Control Board as required by Sections H. 8. a. and d. The individuals/positions authorized
to sign that document have the responsibility for the overall operation of the regulated facility or
environmental matters.

List individuals and/or positions




District Director Signature Block

Date


Cc: Ranny Eckstrom, Storm Water Project Manager, Caltrans Headquarters
State of California – Department of Transportation (Caltrans)                             CP-CEM-2002                                                                  4/10/2000

                                                    NOTIFICATION OF CONSTRUCTION
IN COMPLIANCE WITH CALTRANS STATEWIDE NPDES STORM WATER PERMIT Order No. 99-06 DWQ, NPDES No. CAS000003

I. IDENTIFICATION-Attach Vicinity Map, ½ size copy of Title Sheet
 Project                                                            Check One:                                                  Contract Number              Date MM/DD/YY
                                                                      First Submittal     or         Amendment No. __           EA

  City(if applicable)                          County                                                            Tentative Start Date           Tentative End Date


 Route                  Post Mile                                                  Kilometer Post                                               Tentative Date SWPPP Available


II. CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARDS
   Region 1, North Coast                    Region 5, Central Valley                           Region 6, Lahontan                                  Region 7, Colorado River
   Region 2, San Francisco Bay                Sacramento                                         South Lake Tahoe                                  Region 8, Santa Ana
   Region 3, Central Coast                    Fresno                                             Victorville                                       Region 9, San Diego
   Region 4, Los Angeles                      Redding

III. CALTRANS DISTRICT
 Name/Number                                                                                   Project Contact

 Address                                                                                       Position Title

 City                                                                  Zip                     Phone
                                                                                               (       )
IV. CONSTRUCTION FIELD OFFICE- Attach Location Map
 Street Address                                                                                Construction Contact

 Physical Location if Different than address above                                             Position Title

 City                               State                                    Zip                Phone
                                                                                                (          )

V. CONSTRUCTION SITE INFORMATION




 Description and Type of Work




 Additional related required approvals:           DTSC Variance         CWA 404/401                 DFG 1601            NPDES/WDRs          Other
 Describe:



 Total Construction Area:                 Acres                         Hectares          Total Disturbed Area:                         Acres                   Hectares

 Receiving Water Name:                                                                    Project In Or Adjacent to Receiving Water?:                     Yes                 No
 Project Discharges to?:      Groundwater Infiltration            Basin Location:                                  Municipal/Other System Name:

VI. CERTIFICATION
 I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure
 that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those
 persons directly responsible for gathering the information, the information submitted is true, accurate, and complete to the best of my knowledge and belief. I am
 aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment of knowing violations.


 Signature: ________________________________________________                                            Date:

 Print/Type Name:                                                                                       Title:
                         Appendix B
              Working Details for Permanent BMPs

Caltrans Permanent Best Management Practices (BMPs)
The Caltrans Statewide SWMP established the following lists of permanent erosion control and
treatment control BMPs that may be incorporated into projects during project design:

Erosion Control (Soil Stabilization) BMPs:
These are permanent BMPs selected by Caltrans to prevent soil from being dislodged by rainfall and
resulting surface flows. These BMPs are approved for consideration and implementation statewide
on all projects.

                                               Erosion Control BMPs
                          Preservation of Existing Vegetation
                          Concentrated Flow Conveyance Systems
                                 Ditches, Berms, Dikes and Swales
                                 Overside Drains
                                 Flared Culvert End Sections
                                 Outlet Protection/Velocity Dissipation Devices
                          Slope/Surface Protection Systems
                                 Vegetated Surfaces
                                     Slope Roughening/Terracing/Rounding
                                     Mulching
                                     Permanent Seeding and Planting
                                 Hard Surfaces


Treatment Control BMPs:
These are permanent BMPs selected by Caltrans to remove sediment from storm water discharges.
Treatment controls are approved for consideration for all projects but should only be implemented
when the CEQA/NEPA process identifies discharges that have potential to significantly affect the
environment. See each BMP for specific criteria and regional restrictions:

                                             Treatment Control BMPs
                          Infiltration (Retention) Basin
                          Detention Basin
                          Traction Sand Trap Devices*
                          * Only approved for specific Regions. See BMP.




         Caltrans Storm Water Quality Handbooks
         Project Planning and Design Guide                                                 Appendix B
         May 2000                                                                                   1
                Preservation of Existing Vegetation




                                                                         BMP Objectives

                                                                  M   Soil Stabilizati on
                                                                  F   Sediment Control
                                                                  F   Tracki ng Co ntrol
                                                                  F   Wind Erosion Control
                                                                  F   Non-Storm Water


Definition and Preservation of existing vegetation is the process of identifying and protecting
     Purpose desirable vegetation in any areas subject to land-disturbing activities.

                    The primary function of preservation of existing vegetation is to maintain an
                    effective form of erosion (soil stabilization) and sediment control, as well as
                    watershed protection, landscape beautification, dust control, pollution control, and
                    shade.

 Appropriate This technique is applicable to all types of sites. Areas where preserving
 Applications vegetation can be particularly beneficial are floodplains, wetlands, streambanks,
                    steep slopes, and other areas where erosion control would be difficult to establish,
                    install, and maintain, or areas where there are critical resources downstream.

                    Preservation of existing vegetation should be practiced in the following locations:

                       Areas on a site where no construction activity is planned or will occur at a
                        later date

                       Sensitive areas where natural vegetation exists and should be preserved, such
                        as on steep slopes, watercourses, and building sites in wooded areas

                       Within and as a buffer to areas where federal, state, or local government
                        regulations require preservation, such as delineated wetlands, vernal pools,
                        marshes, etc.

   Limitations Protection of existing vegetation requires planning, and may constrict the area
                    available for construction activities. Additionally, if land costs are high, it may not
                    be practical to preserve areas of existing vegetation for a given project unless

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   May 2000                                                                                                 1 of 7
                           Preservation of Existing Vegetation
                               required by regulation. In this case, it may be appropriate to evaluate the existing
                               vegetation for species type for re-vegetation in landscaping plans.

  Design Guidance                  Preservation of vegetation on a site should be planned before any site
                                    disturbance begins. Preservation requires good site management to
                                    minimize the impact of construction activities on existing vegetation, which
                                    may adversely affect their growth.

                               Planning
                                  The following planning steps should be taken to preserve existing vegetation:

                                   Decisions on which vegetation to save should be based on the following
                                    considerations:

                                      -   Life expectancy and present age of vegetation
                                      -   Health and disease susceptibility
                                      -   Aesthetic values
                                      -   Comfort relative to site temperature variations and wind
                                      -   Wildlife benefits
                                      -   Adaptability to the proposed project
                                      -   Survival needs of the vegetation (i.e. whether this vegetation is at risk of
                                          extinction)
                                      -   Relationship to other vegetation, (i.e. whether this vegetation supports
                                          the existence of the surrounding vegetation)

                                   Review existing vegetation in early spring to identify seasonal plant species.

                                   All vegetation to be retained should be identified and delineated in the
                                    contract documents and marked in the field prior to the start of adjacent soil
                                    disturbing activities.

                                   Critical areas, such as floodplains, steep slopes, and wetlands, should be left
                                    in their natural condition unless disturbance is unavoidable.

                                   Minimize disturbed areas by locating temporary roadways and roadways to
                                    be used by maintenance, to avoid stands of trees and shrubs, and to follow
                                    existing contours to reduce cutting and filling.

                                   Locate multiple utilities in the same trench to minimize trenching.
                                    Excavations should be outside the drip line of trees.

                                   Plans for tree preservation should:
                                      -   Avoid compaction of the soil within the drip line of a tree that can block
                                          off air and water from the roots. Therefore, construction material

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             Preservation of Existing Vegetation

                                storage and crew and vehicle paths should be noted on the site plan and
                                located where they will not cause root compaction, and to avoid nicking
                                or scarring of the tree trunk.

                        -       Maintain the grade around vegetation to be preserved – raising the grade
                                can suffocate roots, and lowering the grade may expose roots. In paved
                                areas, there should be at least 1.5 m (5 ft) of ungraded ground beyond
                                the drip line.

                        -       Avoid changes in soil chemistry that can result from refuse of chemicals
                                deposited on the soil surface.

                        -       Soil stabilization measures should be located at the limits of clearing to
                                prevent sediment deposition within the area where vegetation is being
                                preserved.

                    When removing vegetation, consider impacts (such as increased exposure to
                     rain and wind damage) to the adjacent vegetation that will be preserved.

                 Tree and Vegetation Marking and Protection
                    During a pre-construction conference, vegetation preservation and protection
                     measures for that project should be reviewed with the contractor and any
                     subcontractors.

                    Responsibility for removal of all vegetation protection devices should be
                     clearly identified as the Contractors.

                    Several types of protective devices may be used, and all personnel should be
                     instructed to honor these devices. Within 12 m (40 ft) of a proposed
                     building or excavation, however, retained trees should be protected by
                     fencing. The following are alternatives for tree and vegetation protection:

                            −    A standard snow fence on steel posts set 1.8 m (6 ft) apart and at a
                                 height of 1 m (3 ft), may be placed at clearing limits.

                            −    Plastic fencing of 1 m (3 ft) wide orange polypropylene webbing that
                                 is fully stabilized against ultraviolet light, with openings not larger
                                 than 50 mm by 50 mm, shall be used at clearing limits. The fence
                                 posts shall be either wood or metal at the Contractor’s option and shall
                                 be suitable for the purpose intended. The posts spacing and depth shall
                                 be adequate to completely support the fence in an upright position.

                            −    An earth berm may be constructed according to specifications, but
                                 only if its presence does not conflict with drainage patterns. The base
                                 of the berm on the tree or vegetation side shall be located at the
                                 clearing limits.

Caltrans Storm Water Quality Handbooks
Project Planning and Design Guide                                              Preservation of Existing Vegetation
May 2000                                                                                                    3 of 7
                           Preservation of Existing Vegetation
                                        −   Additional trees between the trunks of retained trees and the clearing
                                            limits may be left standing as protection. Trees in this buffer zone
                                            should be a maximum of 1.8 m (6 ft) apart so that equipment and
                                            material cannot pass. These trees should be re-examined before
                                            construction is completed to check for and ensure survival or be
                                            removed.

                               Grade Protection
                                   If the ground level must be raised around an existing tree or tree group, a tree
                                    well can be constructed. A professional arborist should be consulted if a tree
                                    well appears to be warranted or desired. A well may be created around the
                                    tree slightly beyond the drip line to retain the natural soil in the area of the
                                    feeder roots.

                                   If the grade is being lowered, trees can be protected by constructing a
                                    surrounding wall of large stones, brick, or block, and backfilled. Fertilizer
                                    and water should be applied thoroughly and drainage provided so that water
                                    does not accumulate.

                                   It is best to perform the construction activities in the tree’s vicinity during
                                    the tree’s dormant period.

                                   If necessary, a tree wall shall be constructed using the following procedures:

                                        −   Remove vegetation and organic matter from beneath the retained
                                            tree(s) to at least 1 m (3 ft) beyond the drip line, loosening the soil to at
                                            least 75 mm (3 in) in depth without damaging roots.

                                        −   Apply fertilizer to the root area according to label instructions.

                                        −   Construct a dry well to allow for trunk growth. Provide 300 mm (12
                                            in) between the trunk and the wall for older, slow-growing trees, and
                                            600 mm (24 in) for younger trees.

                                        −   The well should be just above the level of the proposed fill, and the
                                            wall should taper away from the trunk by 80 mm/m (1 in/ft) of wall.

                                        −   The well wall should be constructed of large stone, brick, building tile,
                                            concrete blocks, or cinder blocks, with openings left in the wall for the
                                            flow of air and water. Mortar should be used only near the top of the
                                            well and above the porous fill.

                                        −   Drain lines beginning at the lowest point inside the well should be
                                            built extending outward from the trunk in a radial pattern with the
                                            trunk as the hub. They should be made of 100 mm (4 in), high-quality
                                            drain tiles, sloping away from the well at a rate of 10 mm/m (0.125
                                            in/ft). A circumferential line of tiles should be located beneath the drip
                                            line; vertical tiles or pipes should be placed over the intersections of

                                                                                     Caltrans Storm Water Quality Handbooks
Preservation of Existing Vegetation                                                  Project Planning and Design Guide
4 of 7                                                                               May 2000
             Preservation of Existing Vegetation

                               the two tile systems for fills greater than 600 mm (24 in) in depth, held
                               in place with stone fill. All tile joints should be tight. Drainage may
                               be improved by extending a few radial tiles beyond each intersection
                               and slope sharply downward. Coarse gravel may be substituted for tile
                               in areas where water drainage is not a problem. Stones, crushed rock,
                               and gravel may be added instead of vertical tiles or pipes, so the upper
                               level of these porous materials slopes toward the surface near the drip
                               line.

                           −   Tar paper or an approved equivalent should be placed over the tile or
                               pipe joint to prevent clogging, and a large stone placed around and
                               over drain tiles or pipes for protection.

                           −   Layer 50 mm (2 in) to 150 mm (6 in) of stone over the entire area
                               under the tree from the well outward at least to the drip line. For fills
                               up to 600 m (24 in) deep, a layer 200 mm (8 in) to 300 mm (12 in)
                               should be adequate. Deeper fills require thicker layers of stone to be
                               built to a maximum of 750 mm (30 in).

                           −   A layer of 20 mm (0.75 in) to 25 mm (1 in) stone covered by straw,
                               fiberglass mat, or filter fabric should be used to prevent soil clogging
                               between stones. Do not use cinders as fill material.

                           −   Complete filling with porous soil (to sustain vegetation) until the
                               desired grade is reached.

                           −   Crushed stone should be placed inside the dry well over the openings
                               of the radial tiles to prevent clogging of the drain lines. Vertical tiles
                               should also be filled with crushed rock and covered with a screen.

                           −   The area between the trunk and the well wall should be covered by an
                               iron grate or filled with a 50-50 mixture of crushed charcoal and sand
                               to prevent anyone from falling into the well or to prevent leaves,
                               debris, rodents, or mosquitoes from accumulating.

                           −   One-half of these systems may be constructed if the grade is being
                               raised on only one side of the tree(s).

                 Trenching and Tunneling
                    Trenches should be built as far away from tree trunks as possible, at a
                     minimum outside of the drip line, to reduce the amount of root damage.
                     Those trenches built should avoid large roots or root concentrations by
                     curving the trench or by tunneling under large roots and concentrated root
                     areas. Tunneling is more expensive at first, but results in less soil
                     disturbance and impacts of the root system; this cost may offset the cost of
                     tree removal and replacement if the tree should die. Therefore, tunneling is


Caltrans Storm Water Quality Handbooks
Project Planning and Design Guide                                             Preservation of Existing Vegetation
May 2000                                                                                                   5 of 7
                           Preservation of Existing Vegetation
                                      nearly always preferable over trenching.

                                   The tunnel should be at least 450 mm (18 in) below the ground surface, and
                                    not below the tree center to minimize impact on the roots.

                                   Roots should not be left exposed to air; they should be covered with soil as
                                    soon as possible, protected, and kept moistened with wet burlap or peat moss
                                    until the tunnel can be built.

                                   The ends of damaged or cut roots should be cut off smoothly and protected
                                    by painting them with a tree-wound dressing.

                                   Trenches and tunnels should be filled as soon as possible. Careful filling and
                                    tamping will eliminate air spaces in the soil.

                                   To induce and develop root growth, peat moss should be added to the fill
                                    material.

                                   The tree should be mulched and fertilized to conserve moisture, and to
                                    stimulate new root growth.

                                   Remove any trees intended for retention if those trees are damaged seriously
                                    enough to affect their survival. If replacement is desired, the new tree
                                    should be of similar species, and of at least 50 mm (2 in) caliper.

  Maintenance and                  During construction, the limits of disturbance should remain clearly marked
        Inspection                  at all times. The contractor should be required to maintain existing
                                    vegetation in conformance with the requirements of the contract. Because
                                    protected trees may be destroyed by carelessness during the final cleanup
                                    and landscaping, fences and barriers should be removed last, after all other
                                    cleanup.

                                   If damage to protected trees still occurs, maintenance guidelines described
                                    below should be followed:

                                   Soil that has been compacted over a tree’s root zone should be aerated by
                                    punching holes 300 mm (12 in) deep with an iron bar, possibly #4 rebar, and
                                    moving the bar back and forth until the soil is loosened. Holes should be
                                    placed 450 mm (18 in) apart throughout the area of compacted soil under the
                                    tree crown.

                                   Any damage to the crown, trunk, or root system of a retained tree during
                                    maintenance should be repaired immediately.

                                   Damaged roots should be immediately cut clean, and moist soil or soil
                                    amendments shall be placed around the cut root.

                                   If bark damage occurs, all loosened bark should be cut back into the
                                                                                  Caltrans Storm Water Quality Handbooks
Preservation of Existing Vegetation                                               Project Planning and Design Guide
6 of 7                                                                            May 2000
             Preservation of Existing Vegetation

                        undamaged area, with the cut tapered at the top and bottom, and drainage
                        provided at the base of the wood. Cutting of the undamaged area should be
                        as limited as is possible.

                    Serious tree injuries should be attended to by an arborist.




Caltrans Storm Water Quality Handbooks
Project Planning and Design Guide                                        Preservation of Existing Vegetation
May 2000                                                                                              7 of 7
                   Ditches, Berms, Dikes and Swales




                                                                       BMP Objectives

                                                                M Soil Stabilization
                                                                F Sediment
                                                                F Tracking Control
                                                                F Wind Erosion
                                                                F Non-Storm Water


Definition and Ditches, berms, dikes, and drainage swales are devices used to intercept, divert,
     Purpose and convey surface runoff, generally sheet flow, and direct it to an overside (or
                     slope) drain or stabilized watercourse. The primary function of ditches, berms,
                     dikes, and swales, is to prevent erosion and reduce pollutant loading.

 Appropriate Ditches, berms, dikes and swales are typically implemented:
 Applications
                        At the top of slopes to divert run-on from adjacent slopes.

                        At the bottom and mid-slope locations to intercept sheet flow and convey
                         concentrated flows

                        At other locations to convey runoff to overside drains, stabilized
                         watercourses, drainage pipes and channels.

                        To intercept runoff from paved surfaces.

                        Along roadways and facilities.

   Limitations          Care must be applied to correctly size and locate earth dikes, drainage
                         swales and lined ditches. Excessively steep, unlined dikes and swales are
                         subject to erosion and gully formation.

                        Non-stabilized tributary areas will reduce the effectiveness of these
                         measures due to high sediment runoff.

                        These measures may cause water to pond onto inappropriate areas (e.g.,
                         active traffic lanes, material storage areas, etc.) if not properly sized.


  Caltrans Storm Water Quality Handbooks
  Project Planning and Design Guide                                          Ditches, Berms, Dikes and Swales
  May 2000                                                                                              1 of 3
                             Ditches, Berms, Dikes and Swales
                                    Altering existing waterways or clearing existing vegetation may require
                                     permits from the California Department of Fish & Game, or the U.S. Army
                                     Corps of Engineers.

   Design Guidance                  Select design flow and safety factor based on careful evaluation of the risk
                                     due to erosion of the measure, over topping, flow backups, or wash out.

                                    Examine the site for run-on from off-site sources. These off-site flows shall
                                     be diverted from the sites’ right of way.

                                    Select flow velocity limit of unlined conveyance systems based on soil
                                     types and drainage flow patterns for each project site. Establish a
                                     maximum flow velocity for using earth dikes and swales, above which a
                                     lined ditch must be used (see Highway Design Manual Table 862.2).
                                     Consider use of riprap, engineering fabric, vegetation, or concrete.

                                    Consider outlet protection where localized scour is anticipated.

                                    Consider order of work provisions early in the construction process in order
                                     to effectively install and utilize permanent ditches, berms, dikes, and
                                     swales.

                                    A sediment trapping device should be used in conjunction with
                                     conveyances where sediment laden water is expected.

                                    Typical ditches, berms, dikes and swales are shown in Figures 1 and 2.

           References               California Department of Transportation Highway Design Manual, Chapter
                                     830, Roadway Drainage.

                                    1999 Standard Plan A62A, A87, D94A and D94B, pp. 118 and 127, State
                                     of California- Department of Transportation Standard Plans (July 1999).




                                                                                  Caltrans Storm Water Quality Handbooks
Ditches, Berms, Dikes and Swales                                                  Project Planning and Design Guide
2 of 3                                                                            May 2000
                 Ditches, Berms, Dikes and Swales




                                            Figure 1
                                         Figure 1




              TYPICAL EARTH DIKE / DIVERSION BERM



                                           Figure 2


Caltrans Storm Water Quality Handbooks
Project Planning and Design Guide                      Ditches, Berms, Dikes and Swales
May 2000                                                                          3 of 3
                                                                    Overside Drains




                                                                          BMP Objectives

                                                                    M Soil Stabilizati on
                                                                    F Sediment Control
                                                                    F Tracki ng Co ntrol
                                                                    F Wind Erosion Control
                                                                    F Non-Storm Water



   Definition and Overside drains are pipes, flumes, or asphalt concrete drains used to protect
        Purpose slopes against erosion. They collect surface runoff from the roadbed, the tops of
                       cuts, or from benches in cut or fill slopes, and convey it down the slope.

    Appropriate Overside drains are typically used at sites where slopes may be eroded by surface
    Applications runoff.

      Limitations          May reduce the time of concentration (as compared to flatter, more
                            naturalized conveyance facilities) for storm water runoff and contribute to
                            increased peak runoff rates.

                           When a downdrain is not to be placed in a trench, and if directed by the
                            Engineer or specified, the downdrain shall be securely anchored to the slope
                            of the ground with an anchor assembly as directed by the Engineer.

Design Guidance            Overside drains should be positioned at the lower end of the slope.

                           Pipe downdrains are metal pipes adaptable to any slope. They should be
                            considered where side slopes are 1:4 or steeper and buried when practical.

                           Flume downdrains are rectangular corrugated metal flumes with a tapered
                            entrance. They are best adapted to slopes that are 1:2 or flatter.

                           Paved spillways are recommended on side slopes flatter than 1:4. On
                            steeper slopes, a pipe should be used.

                           Overside drains are typically spaced at 100 m to 150 m intervals.


     Caltrans Storm Water Quality Handbooks
     Project Planning and Design Guide                                                         Overside Drains
     May 2000                                                                                            1 of 2
                                                                  Overside Drains
                         Overside drain materials shall conform to section 69-1.02 of the Caltrans
                          Standard Specifications.

                         Severe erosion may result when overside drains fail by over topping,
                          piping, or pipe separation.

                         Entrance tapers and tapered inlets shall be installed in such a manner as to
                          function properly and efficiently and shall be placed as to retain the material
                          in the dike and prevent water from percolating under or around them. The
                          seal between the entrance of the overside drain and the surrounding material
                          shall be watertight.

   Maintenance and       Make sure water is not ponding onto inappropriate areas (e.g., active traffic
         Inspection       lanes, material storage areas, etc.).

           References    California Department of Transportation Highway Design Manual, Chapter
                          830, Roadway Drainage; section 834.4, Overside Drains.

                         Section 69: Overside Drains, p. 505, State of California Department of
                          Transportation Standard Specifications (July 1999)

                         1999 Standard Plan D87A thru D87D, p. 118, State of California-
                          Department of Transportation Standard Plans (July 1999)




                                                                        Caltrans Storm Water Quality Handbooks
Overside Drains                                                         Project Planning and Design Guide
2 of 2                                                                  May 2000
                                         Flared Culvert End Sections




                                                                          BMP Objectives

                                                                   M   Soil Stabilizati on
                                                                   F   Sediment Control
                                                                   F   Tracki ng Co ntrol
                                                                   F   Wind Erosion Control
                                                                   F   Non-Storm Water




   Definition and Flared culvert end sections are devices placed at the inlets and outlets of pipes and
        Purpose channels to improve hydraulic operation, retain the embankment near pipe
                        conveyances, and to help prevent scour and minimize erosion at inlets and outlets.

    Appropriate            Outlets of overside drains and culverts.
    Applications
                           Inlets of culverts.

                           Often used with outlet protection and energy dissipation devices.

      Limitations Primarily for hydraulic efficiency, with some limited erosion control benefits.

Design Guidance            Common and preferred device for end treatment for small to medium sized
                            culverts.

                           Consider the need for outlet protection and energy dissipation devices.

                           Rock slope protections or flared end sections can be constructed at inlets to
                            protect from scouring.

                           Use Caltrans Standard Plans D94A and D94B

     References            Section 70-1.02C, Flared End Sections, p. 510, State of California
                            Department of Transportation Standard Specifications (July 1999)

                           1999 Standard Plan D94A and D94B, pp. 118 and 127, State of California-
                            Department of Transportation Standard Plans (July 1999).



      Caltrans Storm Water Quality Handbooks
      Project Planning and Design Guide                                               Flared Culvert End Sections
      May 2000                                                                                             1 of 1
                                                 Outlet Protection/
                                      Velocity Dissipation Devices




                                                                          BMP Objectives

                                                                   M Soil Stabilizati on
                                                                   F Sediment Control
                                                                   F Tracki ng Co ntrol
                                                                   F Wind Erosion Control
                                                                   F Non-Storm Water




   Definition and Outlet protection/velocity dissipation devices are physical mechanisms placed at
        Purpose the outlets of pipes and channels to prevent scour and reduce the velocity and/or
                       energy of storm water discharges.

    Appropriate            Where localized scouring is anticipated, such as outlets of pipes, drains,
    Applications            culverts, slope drains, diversion ditches, swales, conduits or channels.
                           Outlets subject to short, intense flows of water, such as from flash floods.
                           Where lined channels or ditches discharge to unlined conveyances.

     Limitations/          Loose riprap may have stones washed away during high flows.
     Precautions           Grouted riprap may break up in areas of freeze and thaw.
                           If there is not adequate drainage and water builds up behind grouted riprap,
                            it may cause the grouted riprap to break up due to the resulting hydrostatic
                            pressure.

Design Guidance            There are many types of energy dissipaters; rock, which is represented in
                            Figure 1, is one common type. However, note that this is only one example
                            and the District Hydraulics Engineer must be contacted for region-specific
                            requirements.

                           Common device for outlet protection is a structurally lined apron, lined with
                            riprap, grouted riprap or concrete apron. Also see BMP for Flared Culvert
                            End Sections.


     Caltrans Storm Water Quality Handbooks
     Project Planning and Design Guide                                 Outlet Protection/Velocity Dissipation Devices
     May 2000                                                                                                   1 of 5
                                                              Outlet Protection/
                                                   Velocity Dissipation Devices
                                    Apron length is related to outlet flow rate and tailwater level.

                                    For proper operation of apron:

                                         -       Align apron with receiving stream and keep straight throughout its
                                                 length. If a curve is needed to fit site conditions, place it in upper
                                                 section of apron.

                                         -       If size of apron riprap is 300 mm (12 in) or larger, protect underlying
                                                 filter fabric with 100 mm (4 in) minimum gravel blanket to prevent loss
                                                 of soil material beneath riprap.

                                    For outlets located at the top of a slope, the areas receiving the discharge
                                     should have additional erosion protection from the re-concentrated, high
                                     velocity flow that is leaving the structural apron.




                                                                                          Caltrans Storm Water Quality Handbooks
Outlet Protection/Velocity Dissipation Devices                                            Project Planning and Design Guide
2 of 5                                                                                    May 2000
                                                    Outlet Protection/
                                         Velocity Dissipation Devices




                                                                                      Figure 1


    Pipe Diameter                   Discharge           Apron Length, La                Rip Rap
                                        3
         mm                            m /s                    m                   D50 Diameter Min
                                                                                          mm
         300                          0.14                       3                        100
                                      0.28                       4                        150
         450                          0.28                       3                        150
                                      0.57                       5                        200
                                      0.85                       7                        300
                                      1.13                       8                        400
         600                          0.85                       5                        200
                                      1.13                       8                        200
                                      1.42                       8                        300
                                      1.70                       9                        400
                     For larger or higher flows, consult a Registered Civil Engineer
Source: USDA – SCS




        Caltrans Storm Water Quality Handbooks
        Project Planning and Design Guide                            Outlet Protection/Velocity Dissipation Devices
        May 2000                                                                                              3 of 5
                                                            Outlet Protection/
                                                 Velocity Dissipation Devices
                           ROCK ENERGY DISSIPATER AT CULVERT OUTLET

    From Caltrans District 1 (circa 1980), revisions by James A. Racin, P.E. (916-227-7017) 20 Aug. 1999:
               length, metric table (rock size, trench depth, RSP-fabric), determining rock size.

Design Notes:

          1. Determine rock size based on culvert outlet velocity.

               A. 1st trial rock size by N.K. Berry’s equation (1948), see USBR EM-25:

                                                     d = 0.0126 V2

                    Where: d = diameter (ft), V = velocity (fps), specific gravity = 2.65

               B. Compare to Caltrans Bank & Shore Equation 1. With 1:1.5 (V:H) (if H>1.5, size will be
                  small) and specific gravity = 2.65

                                                   W = 0.0000568 V6

                    Equation 1 gives rock size on bank, usually smaller than size from Berry equation for bedload
                    movement along channel bottom.

               C. Also compare above rock sizes to HEC-14 chart, Figure II-C-1, on page II-9 (1975),
                  originally form Searcy (1967).

               D. Select final rock size based on engineering judgment and field experience at similar sites.

     2. When downstream channel requires rock bank protection, compare dissipater rock size to bank rock
        size.

     3. Adjust length (increase or decrease) based on site-specific constraints.




                                                                                 Caltrans Storm Water Quality Handbooks
Outlet Protection/Velocity Dissipation Devices                                   Project Planning and Design Guide
4 of 5                                                                           May 2000
                                                     Outlet Protection/
                                          Velocity Dissipation Devices




Construction note: Length, width, depth dimensions are approximate, (squared-off excavation not required).

                                             Z Trench Depth Range    Type of RSP-fabric
                 Rock Size RSP-class
                                                     (mm)           Non-woven or Woven
                     Backing No. 2                 250 – 400                A or B
                     Backing No. 1                 300 – 450                A or B
                          Light                    450 – 600                   B
                          ¼T                       750 - 900                   B
                          ½T                       900-1100                    B
                           1T                     1200 – 1500                  B




         Caltrans Storm Water Quality Handbooks
         Project Planning and Design Guide                             Outlet Protection/Velocity Dissipation Devices
         May 2000                                                                                               5 of 5
         Slope Roughening/Terracing/Rounding




                                                                       BMP Objectives

                                                                 M Soil Stabilizati on
                                                                 F Sediment Control
                                                                 F Tracking Co ntrol
                                                                 F Wind Erosion Control
                                                                 F Non-Storm Water




Definition and Roughening, terracing and rounding are techniques used for creating unevenness
     Purpose on bare soil through the construction of furrows, terraces, serrations, stair-steps, or
                    track-marks on the soil surface to increase the effectiveness of temporary and
                    permanent soil stabilization (erosion control) practices. Roughening, terracing and
                    rounding should be used as a permanent measures to prepare a slope to receive
                    permanent vegetation.

                    Slope roughening or terracing reduces erosion potential by decreasing runoff
                    velocities, reducing the length of sheet flow, trapping sediment, and increasing
                    infiltration of water into the soil. Slope rounding is a design technique used to
                    minimize the formation of concentrated flows.

 Appropriate           Use on all embankments or cut slopes prior to the application of temporary
 Applications           soil stabilization or permanent seeding.

                       Where seeding, planting, and mulching to stabilize exposed soils will benefit
                        from surface roughening, such as graded areas with smooth, hard surfaces.

                       Where the slope length needs to be shortened by terracing. Terracing is
                        usually permanent and should be designed under the direction of and
                        approved by the Materials Department based on site conditions. Terraces
                        must be designed with adequate drainage and stabilized outlets for the flow.

   Limitations         Roughening may increase grading costs and result in sloughing in certain
                        soil types.

                       Stair-step grading may not be practical for sandy, steep, or shallow soils,
   Caltrans Storm Water Quality Handbooks
   Project Planning and Design Guide                                      Slope Roughening/Terracing/Rounding
   May 2000                                                                                             1 of 6
                 Slope Roughening/Terracing/Rounding
                                      because these soils with low-stability could easily fail under windy or rainy
                                      conditions, resulting in the disappearance of the grading effects.

                               Roughening alone as a temporary erosion control or surface preparation
                                measure is of limited effectiveness in intense rainfall events.

  Design Guidance There are different methods for achieving a roughened soil surface, and the
                            selection of an appropriate method depends upon the type of slope. Roughening
                            methods include stair-step grading or furrowing, which must be done across the
                            slope and along the contour. Tracking, by contrast, must be done up and down the
                            slope. Factors to be considered in choosing a method are slope steepness, mowing
                            requirements, soil type, and whether the slope is formed by cutting or filling.

                            Roughening
                               Use stair-step grading or furrows (groove cuts) on slopes that are steeper
                                than 1:3 (V:H). See Figures 4, 5 and 6.

                               Use stair-step grading on erodible material which is soft enough to be ripped
                                by a bulldozer. Slopes consisting of soft rock with some subsoil are
                                particularly suited to stair-step grading.

                               Make the vertical cut distance less than the horizontal distance, with
                                individual vertical cuts no more than 600 mm (24 in) high in soft materials
                                or no more than 1 m (3 ft) high in rocky materials. Slightly slope the
                                horizontal position of the "step" in towards the slope.

                               The face of the slope should consist of loose, uncompacted fill 100 mm (4
                                in) to 150 mm (6 in) deep, from stockpiled topsoil of initial grading.

                               Slopes that will be maintained by mowing should be no steeper than 1:3
                                (V:H).

                               To roughen these areas, create shallow grooves by normal tilling, disking,
                                harrowing, or use a cultipacker-seeder. Make the final pass of any such
                                tillage on the contour.

                               Make grooves formed by such implements close together, less than 250 mm
                                (10 in) apart and not less than 25 mm (1 in) deep.

                               Limit roughening with tracked machinery to soils with a sandy textural
                                component to avoid undue compaction of the soil surface. See Figure 3.

                                Operate tracked machinery up and down the slope to leave horizontal
                                 depressions in the soil. Do not backblade during the final grading operation.




                                                                                Caltrans Storm Water Quality Handbooks
Slope Roughening/Terracing/Rounding                                             Project Planning and Design Guide
2 of 6                                                                          May 2000
             Slope Roughening/Terracing/Rounding

                        Terracing
                           Terraces or benches should be designed to be compatible with the
                            geotechnical features of the site. Benches should be at least 6 m wide and
                            sloped to form a valley of at least 0.3 m deep with the low point a minimum
                            of 1.5 m from the toe of the upper slope. Access for maintenance equipment
                            should be provided to the lowest bench, and if feasible to all higher benches.
                            For highly erosive soils, and steeper slopes, the Landscape Architect and the
                            Geotechnical Engineer should be consulted.

                           Runoff from terraces and benches should be conducted in lined diversion
                            ditches installed where the terrace meets the slope.

                           See Figure 7.

                        Rounding
                           The tops and toes of all cut slopes where the material is not solid rock should
                            be rounded, both in plan and profile, and should match the adjacent existing
                            conditions. A layer of earth overlying a rock cut also should be rounded.
                            See Figures 1 & 2.

Maintenance and Periodically check the seeded or planted slopes for rills and washes, particularly
      Inspection after significant storm events, greater than 1.2 mm (0.5 in). Fill these areas slightly
                        above the original grade, then re-seed and mulch as soon as possible. Avoid use of
                        heavy equipment or machinery as it can damage a newly revegetated slope.




                       FIGURE 1                                        FIGURE 2

                                        SLOPE ROUNDING



       Caltrans Storm Water Quality Handbooks
       Project Planning and Design Guide                                     Slope Roughening/Terracing/Rounding
       May 2000                                                                                            3 of 6
                 Slope Roughening/Terracing/Rounding




                                      mulch,


FIGURE 3




 FIGURE 4




                                               Caltrans Storm Water Quality Handbooks
Slope Roughening/Terracing/Rounding            Project Planning and Design Guide
4 of 6                                         May 2000
      Slope Roughening/Terracing/Rounding




                                         FIGURE 5




Caltrans Storm Water Quality Handbooks
Project Planning and Design Guide                   Slope Roughening/Terracing/Rounding
May 2000                                                                          5 of 6
                 Slope Roughening/Terracing/Rounding




                                      FIGURE 6




                                      FIGURE 7




                                                 Caltrans Storm Water Quality Handbooks
Slope Roughening/Terracing/Rounding              Project Planning and Design Guide
6 of 6                                           May 2000
                                                                                    Mulching




                                                                        BMP Objectives

                                                                 M   Soil Stabilizati on
                                                                 F   Sediment Control
                                                                 F   Tracki ng Control
                                                                 M   Wind Erosion Control
                                                                 F   Non-Storm Water


Definition and Mulching is the process of applying loose bulk materials to the soil surface as a
     Purpose permanent or temporary cover. Common types of mulch are: straw, wood/bark
                     chips, and green material.

                     The primary function of mulching is to reduce erosion by protecting bare soil from
                     rainfall impact, increasing infiltration, and reducing runoff. Mulches are also
                     generally used to compliment seeding and vegetation establishment techniques, by
                     serving as protection for the soil before the seeds and vegetation have had a chance
                     to grow and establish, although some mulches like aggregates and wood/bark chips
                     have been used in lieu of long-term established vegetation.

 Appropriate Mulching is considered an erosion control (soil stabilization) alternative in the
 Applications following situations:

                        As a stand-alone temporary surface cover on disturbed areas until soils can
                         be prepared for revegetation and permanent vegetative cover can be
                         established.

                        As short term, non-vegetative ground cover on slopes to reduce rainfall
                         impact, decrease the velocity of sheet flow, settle out sediment and reduce
                         wind erosion.

                        As long term, non-vegetative ground cover around established plants, such
                         as trees or shrubs, and on flat to minor slopes not otherwise protected from
                         erosion due to wind and rain.



   Caltrans Storm Water Quality Handbooks
   Project Planning and Design Guide                                                               Mulching
   May 2000                                                                                          1 of 5
                                                                                     Mulching
           Limitations Straw
                      There is a potential for introduction of weed-seed and unwanted plant material in
                      sensitive areas, however rice straw can be used in sensitive areas. Most critical
                      limitation is that where straw blowers are used to apply mulch, areas for treatment
                      must be within 45 m (150 ft) of a road or surface capable of supporting vehicular
                      traffic.

                      Wood/Bark Chips
                      Primarily used in areas as a temporary ground cover around trees, shrubs and
                      landscape plantings. Erosion control effectiveness is unknown, but is considered
                      poor. Chips are difficult if not impossible to anchor on steepened slopes and may
                      be blown by high winds. Shredded products tend to hold together better than
                      chips, and stay on slopes better and are less subject to wind erosion. However,
                      shredded bark has been known to catch fire from cigarettes discarded from vehicle
                      windows. In addition, they do not withstand concentrated flows and are prone to
                      sheet erosion. Note: Caltrans has used shredded wood/bark materials on slopes up
                      to 1:2 (V:H) with reported success. However, until material properties can be
                      standardized and formal field trials completed, use of wood/bark chips and
                      shredded materials on steep slopes should be limited to non-critical applications
                      and where backup measures can be readily deployed.

                      Green Material
                      Green material is not always commercially available and quality is variable. There
                      is a potential for the presence of unwanted weeds and other plant materials.
                      Delivery system is primarily by manual labor, although pneumatic application
                      equipment is available. Erosion control effectiveness is generally unpredictable
                      and should be considered poor unless oversprayed with a tackifying agent.
                      Depending on the material, it might require additional fertilizer inputs, thus
                      increasing costs. Note: Caltrans has used green material on slopes up to 1:2 (V:H)
                      with reported success. However, until material properties can be standardized, use
                      of green material on steep slopes should be limited to non-critical application and
                      where backup measures can be readily deployed.

  Design Guidance Mulch Selection
                      There are many types of mulches, and selection of the appropriate type should be
                      based on the type of application and site conditions. The following criteria should
                      be considered in selection of the appropriate mulch:

                         Cost
                            -   Material cost
                            -   Preparation cost
                            -   Installation cost
                            -   Add-ons

                                                                         Caltrans Storm Water Quality Handbooks
Mulching                                                                 Project Planning and Design Guide
2 of 5                                                                   May 2000
                                                                               Mulching

                     Effectiveness
                         -    Reduction of erosion
                         -    Reduction of flow velocity
                         -    Reduction of runoff

                     Acceptability
                         -    Environmental compatibility
                         -    Institutional/regulatory acceptability
                         -    Visual impact

                     Vegetation Enhancement
                         -    Native plant compatibility
                         -    Germination rate
                         -    Growth rate
                         -    Moisture retention
                         -    Temperature modification
                         -    Open space/coverage
                         -    Nutrient uptake

                     Installation
                         -    Durability
                         -    Longevity
                         -    Ease of installation
                         -    Safety

                     Operation and Maintenance
                         -    Maintenance frequency
                         -    Need for fertilization
                         -    Need for temporary irrigation

                  Application Procedures
                  Prior to application, after existing vegetation has been removed, roughen
                  embankment and fill areas by rolling with a crimping or punching type roller or by
                  track walking. Track walking should only be used where rolling is impractical.

                  The construction-application procedures for mulches vary significantly depending
                  upon the type of mulching method specified. Three (3) methods are highlighted
                  here:

                     Straw: Loose straw is the most common mulch material used in conjunction
                      with direct seeding of soil. Mulching is the generally the second part of a


Caltrans Storm Water Quality Handbooks
Project Planning and Design Guide                                                             Mulching
May 2000                                                                                        3 of 5
                                                                         Mulching
              multi-step process which should be implemented as follows:

              -    Apply seed and fertilizer to the bare soil.

              -    Apply loose straw over the top of the seed/fertilizer at a rate of 1,500 –
                   2,000 lb./acre (681 - 908 kg/acre), either by machine or by hand
                   distribution.

              -    The straw must be evenly distributed on the soil surface.

              -    Anchor the straw in place by using a tackifier, netting, or "punch" it into
                   the soil mechanically.

              Methods for holding the mulch in place depend upon the slope steepness,
              accessibility, soil conditions and longevity. "Punching" straw into the soil is
              the best way to anchor it in place:

              -    On small areas, a spade or shovel can be used.

              -    On slopes with soils which are stable enough and of sufficient gradient
                   to safely support construction equipment without contributing to
                   compaction and instability problems, straw can be "punched" into the
                   ground using a knife-blade roller or a straight bladed coulter, known
                   commercially as a "crimper" or “sheepsfoot”.

              -    On small areas and/or steepened slopes, straw can also be held in place
                   using plastic netting. The netting should be held in place using 11
                   gauge wire staples, geotextile pins or wooden stakes (as described in the
                   “Geotextiles, Mats/Plastic Covers and Erosion Control Blankets” BMP
                   shown in the Storm Water Quality Handbooks - Construction Site Best
                   Management Practices Guide.)

              -    Where slopes are too steep to support construction equipment or areas
                   of application too large to allow cost-effective use of nettings, straw
                   should be held in place using any number of tackifiers which act to glue
                   the straw together and to the soil surface. The tackifiers should be
                   selected on the basis of their longevity and ability to hold the fibers in
                   place until vegetation is established through the mulch.

            Green Material: This type of mulch is produced by recycling of vegetation,
             such as grass, shredded shrubs and trees. Green material can be spread by
             hand, however pneumatic methods are available. Mulch should be
             composted to kill weed seeds.

              -    It can be used as a temporary ground cover.

              -    The green material should be evenly distributed on site to a depth of not
                   more than 100 mm (4 in).


                                                             Caltrans Storm Water Quality Handbooks
Mulching                                                     Project Planning and Design Guide
4 of 5                                                       May 2000
                                                                                        Mulching

                               -    Anchoring green material in place with a tackifier is necessary on steep
                                    slopes.

                           Wood/Bark Chips: Suitable for ground cover in ornamental or revegetated
                            plantings.

                               -    Wood/bark chips are not suitable for steep slopes. Shredded wood/bark
                                    is conditionally suitable; see note under limitations.

                               -    Can be spread by hand (however pneumatic methods are available).

                               -    The mulch should be evenly distributed across the soil surface to a depth
                                    of 50 mm (2 in) to 75 mm (3 in).

                          Note: Avoid mulch over-spray onto the traveled way, sidewalks, lined drainage
                          channels, and existing vegetation.

Maintenance and Regardless of the mulching technique selected, the key consideration in
      Inspection maintenance and inspection is that the mulch needs to last long enough to achieve
                        erosion-control objectives. Mulches applied to temporarily stabilized seeded areas
                        must last as long as it takes for vegetation to develop and provide permanent,
                        erosion-resistant cover. If the mulch is applied as a stand-alone erosion control
                        method over disturbed areas (without seed), it should last the length of time the site
                        will remain barren or until final re-grading and revegetation. Conversely, if the
                        mulch is utilized as part of a revegetation strategy, then a balance should be struck
                        between the degradation of the mulch and the emergence of vegetation over time.

                        Where vegetation is the ultimate cover, maintenance and inspection should focus
                        on the quality and diversity of vegetation establishment through the mulch. Where
                        vegetation is not the ultimate cover, such as ornamental and landscape applications
                        of bark or wood chips, inspection and maintenance should focus on longevity and
                        integrity of the mulch.




      Caltrans Storm Water Quality Handbooks
      Project Planning and Design Guide                                                                Mulching
      May 2000                                                                                           5 of 5
                            Permanent Seeding and Planting




                                                                            BMP Objectives

                                                                      M Soil Stabilizati on
                                                                      F Sediment Control
                                                                      F Tracking Control
                                                                      F Wind Erosion Control
                                                                      F Non-Storm Water




   Definition and Permanent seeding and planting is the process of establishing a permanent
        Purpose perennial vegetative cover on areas that have been disturbed by construction. The
                        primary functions of permanent seeding and planting are to: improve long-term
                        aesthetics, reduce erosion by slowing runoff velocities, enhance infiltration and
                        transpiration, trap sediment and other particulates, protect soil from raindrop
                        impact, and provide habitat for wildlife.

     Appropriate           Permanent seeding and planting must be established on areas of disturbed
     Applications           soil that are complete or nearly complete and that can support the selected
                            vegetation.

                           Permanent seeding and planting is appropriate in most areas that are
                            susceptible to erosion by wind or water and have sufficient rainfall or
                            temporary irrigation to establish and maintain the selected plant materials.
                            Applications include all areas of the site disturbed by construction, cut and
                            fill areas, slopes, spoil piles, waterways, buffer strips, and stream banks.

       Limitations         If the site is susceptible to erosion, additional control measures may be
                            necessary during the establishment of vegetation.

Design Guidance Permanent vegetation may require temporary irrigation where the natural rainfall is
                        insufficient to establish and/or maintain the selected plant materials. The site
                        should first be evaluated to select the appropriate vegetation and planting strategy.
                        The site evaluation should consider: soil type and condition; site topography;
                        climate and season; types of vegetation suited to the site; maintenance concerns; as
                        well as water, fertilizer, and herbicide requirements.

       Caltrans Storm Water Quality Handbooks
       Project Planning and Design Guide                                           Permanent Seeding and Planting
       May 2000                                                                                            1 of 2
                                  Permanent Seeding and Planting
                            The subsequent steps should be followed for implementation:

                                  When feasible, strip and stockpile topsoil during construction. Use
                                   stockpiled materials in the surface preparation prior to seeding operations.

                                  Apply fertilizer or other soil amendments as indicated by a soil test. Review
                                   SSPs 20-03 and 20-04 for appropriate application of materials.

                                  Plant the seed using broadcast seeding, seed drilling, or hydraulic application
                                   of seed.

                                  After planting of seed, apply a protective mulch, erosion control blanket, or
                                   other protective cover, to keep the seed in place and to cover and moderate
                                   the soil moisture and temperature until the seed germinates and grows.

                                  Schedule seeding and planting to occur when soil temperature and moisture
                                   will optimize seed germination and plant growth.

                                  Follow-up applications should be made to cover weak spots or other
                                   disturbances.

  Maintenance and                 All seeded areas should be inspected for failures and re-seeded, fertilized,
        Inspection                 and mulched within the planting season.




                                                                                  Caltrans Storm Water Quality Handbooks
Permanent Seeding and Planting                                                    Project Planning and Design Guide
2 of 2                                                                            May 2000
                                                                        Hard Surfaces




                                                                         BMP Objectives

                                                                    M Soil Stabilizati on
                                                                    F Sediment Control
                                                                    F Tracki ng Co ntrol
                                                                    F Wind Erosion Control
                                                                    F Non-Storm Water




   Definition and Hard surfaces consist of placing concrete, rock, or rock and mortar slope
        Purpose protection.

     Appropriate           Areas where vegetation would not provide adequate erosion protection.
     Applications

       Limitations         Aesthetics
                           Increases runoff peaks and velocities

Design Guidance Design of hard surface slope protection must be coordinated with the District
                        Landscape Architect, Materials, Maintenance and other interested units.

                        Rock Slope Protection
                           Rock slope protection consists of placing revetment type rock courses in
                            layers.

                           Loose, sharp, or extraneous material must be removed from the slope prior to
                            placement of rock slope protection.

                           Underlayment fabric must be placed loosely over the surface so the fabric
                            conforms to the surface without damage. Equipment or vehicles should not
                            be driven directly on the fabric.

                           A footing trench should be excavated along the toe of slope.

                           Local surface irregularities should not vary from the planned slope by more
                            than 0.3 m as measured at right angles to the slope.


      Caltrans Storm Water Quality Handbooks
      Project Planning and Design Guide                                                           Hard Surfaces
      May 2000                                                                                            1 of 2
                                                                      Hard Surfaces
                       Rock and Mortar Slope Protection
                         As a minimum, the top 1/3 of the rocks must be exposed.

                         If the rocks are to be grouted in place with concrete, the rocks should be
                          cleaned of any adhering dirt or clay and then moistened. The concrete
                          should be placed with buckets, chutes, tubes, pneumatic equipment, or other
                          mechanical means and then spaded and rodded into place to ensure adequate
                          penetration. After the concrete has been placed, the rocks should be
                          thoroughly brushed so that their top surfaces are exposed.

                       Concrete Slope Protection
                         Concrete slope protection consists of constructing portland concrete cement
                          or shotcrete slope paving under the ends of bridges and at other locations.

                         Foundation areas should be evenly graded and thoroughly compacted, with
                          moisture sufficient to allow a firm foundation and to prevent absorption of
                          water from the concrete or mortar.

                         Work should be scheduled so that the work (including placing, finishing, and
                          application of curing compound) between timber borders in started and
                          completed in the same day. There should not be any construction joints
                          between timber spacers.

          References     Section 72-5, Concrete-Rock Slope Protection, p. 520, State of California
                          Department of Transportation Standard Specifications (July 1999)

                         Section 72-6, Slope Paving, p. 523, State of California Department of
                          Transportation Standard Specifications (July 1999)

                         1999 Standard Plan D101, p. 145, State of California- Department of
                          Transportation Standard Plans (July 1999).

                         California Bank and Shore Rock Slope Protection Design. Caltrans Study
                          No. F90TL03 (June 1996).




                                                                       Caltrans Storm Water Quality Handbooks
Hard Surfaces                                                          Project Planning and Design Guide
2 of 2                                                                 May 2000
                                                               Infiltration Basin




                                                                        BMP Objectives

                                                                 ● Sediment
                                                                 F
                                                                  M Oil and Grease
                                                                  M Metals and Toxics
                                                                  F Nutrients
                                                                  M Bacteria and Viruses
                                                                  M Highly Effective
                                                                  F Low Effectiveness



Definition and An infiltration basin is a device designed to remove pollutants from surface
     Purpose discharges by capturing the runoff volume from the water quality design storm
                    and infiltrating it prior to the next significant storm event. The primary functions
                    of infiltration basins are to remove pollutants from storm water runoff where soil
                    conditions are suitable, and to recharge or replenish the ground water. In
                    addition, infiltration basins can significantly reduce total annual surface runoff
                    volume, which can reduce streambank erosion and other adverse impacts to
                    stream habitats from transportation facility runoff.

 Appropriate Consider infiltration basins for use when:
 Applications
                           Runoff from the completed facility will discharge to significant areas of
                             highly valuable habitat in which Federal or State listed aquatic resources
                             have been identified; and
                         Caltrans runoff will constitute a substantial portion (more than 10 percent)
                            of the total flows to such habitat
                        Infiltration basins should be considered only when underlying soils are
                         highly permeable and depth to groundwater is sufficient to allow infiltration
                         and where groundwater pollution is not an anticipated concern.

                        Infiltration basins are effective when a high level of particulate and
                         dissolved pollutant removal is required. Pollutants are removed by filtering
                         through the soil mantle. If properly designed, very little pollution travels
                         more than 500 mm (20 in) below the basin bottom.

                        Infiltration basins are usually most effective for drainage areas less than 2
                         ha (5 ac) where soil is porous, unless multiple basins are considered.


  Caltrans Storm Water Quality Handbooks
  Project Planning and Design Guide                                                         Infiltration Basin
  May 2000                                                                                               1 of 8
                                                                         Infiltration Basin
                                Infiltration basins can be used in combination with detention basins for
                                 peak flow management. This type of facility is useful to provide flood
                                 control storage and significant water quality benefits by infiltrating the
                                 "first flush" (i.e., initial part of runoff where a large portion of the total
                                 pollutant load is concentrated in a relatively small portion of the total runoff
                                 volume).

                                Typical highway applications include: within interchange areas; elongated
                                 basins in the median; or dedicated areas on the right-of-way.

               Limitations      Infiltration basins can be effectively used only where the soil is porous and
                                 can infiltrate the required quantity of storm water within 24 to 48 hours.

                                Infiltration basins require a minimum invert to groundwater separation of
                                 1.2 meters (4 ft.) using the seasonally high (wet-weather) groundwater
                                 elevation.

                                Very coarse gravel soils provide low removal of dissolved pollutants which
                                 can increase risk of ground water contamination.

                                Infiltration basins may not be suitable adjacent to drinking water wells,
                                 foundations, septic tanks, drain fields, unstable slopes, or on fill sites or
                                 steep slope areas due to potential seepage problems.

                                Infiltration basins may not be appropriate where there is significant
                                 potential for hazardous chemical spills.

                                Infiltration basins usually fail if they receive high sediment loads.
                                 Therefore, infiltration basins should not be used until upstream drainage
                                 area is stabilized.

                                Maintenance needs of infiltration basins are high because frequent
                                 inspection is required.

                                Infiltration basins require special care during construction to maintain
                                 permeability. Heavy equipment and machinery that will cause compaction
                                 and reduce permeability should not be allowed to travel over the area.

    Design Guidance Design of infiltration basins must be coordinated with the District Hydraulics
                             Division. A typical resource used in the design of infiltration basins is HEC-22.

                             The physical suitability of the infiltration basin site should be evaluated for the
                             following general design criteria:

                                Infiltration basins shall be designed to capture, store and treat (infiltrate) the
                                 Water Quality Volume preferably as an off-line device. The Water Quality
                                 Volume is the volume of runoff produced by the equivalent of, at a

                                                                                 Caltrans Storm Water Quality Handbooks
Infiltration Basin                                                               Project Planning and Design Guide
2 of 8                                                                           May 2000
                                                              Infiltration Basin

                         minimum, the treatment design storm event. Additional storage volume
                         may be required for locations where an off-line device is infeasible due to
                         physical or hydraulic constraints.

                      Infiltration basins shall be located down gradient from the highway
                       pavement to avoid infiltration to the pavement structural section and
                       subgrade.

                      Infiltration basins may require energy dissipation devices to minimize scour
                       potential.

                      Infiltration basins require an extensive geotechnical exploration to
                       determine the subsurface profile and the hydraulic conductivity of the in
                       situ soils. The exploration should perform field permeability tests in lieu of
                       laboratory permeability tests. The presence of fine-grained materials can
                       significantly reduce permeability.

                      A minimum of one soils log should be required for each 465 m2 (5,000 ft2)
                       of infiltration basin area (plan view) and in no case less than three soils logs
                       per basin. Each soils log should extend a minimum of 3 m (9 ft) in depth
                       below the bottom of the proposed basin, in order to extend below the
                       ground water level. Historical well records and geotechnical investigations
                       must also be evaluated to establish potential ground water levels.

                      Soil Suitability: Coarse soils with low ratio of organic materials should be
                       used. Soils with 30 percent or greater clay content or 40 percent or greater
                       silt/clay content should not be used. Infiltration basins should not utilize fill
                       material nor be placed over fill soils, though fill material is acceptable for
                       berms surrounding the basin.

                      Depth of Water Table: The invert of infiltration basins should be located at
                       least 1.2 m (4 ft) above the seasonally high (wet-weather) groundwater
                       elevation.

                      Infiltration basins shall have an overflow outlet to limit the risk of
                       overtopping the device.

                      Proximity to Drinking Water Wells, Septic Tanks, Drain Fields, Building
                       Foundations: The proximity of infiltration basins to other structures and
                       facilities must be taken into account due to constituents in storm water and
                       possible disruption/damage to other structures.

                         -     Provide a minimum clearance of 30 m (100 ft) between infiltration
                               basins and drinking water wells, septic tanks, drain fields, and springs
                               used for public water supplies.


Caltrans Storm Water Quality Handbooks
Project Planning and Design Guide                                                           Infiltration Basin
May 2000                                                                                                 3 of 8
                                                              Infiltration Basin
                         -    Infiltration basins should be located at least 6 m (20 ft) downslope and
                              30 m (100 ft) upslope from building foundations.

                         -    Consult state and local health services department’s criteria and project
                              geotechnical engineer for further requirements.

                      Land Slope: Infiltration basins can be located on slopes of up to 15 percent.
                       Use of infiltration basins on steeper grades increase the chance of water
                       seepage from the subgrade to lower areas of the site and reduces the amount
                       of water which actually infiltrates.

                      Pre-construction soil infiltration rate should be between 7.6 mm/hr (0.3
                       in/hr) and 100 mm/hr (4 in/hr), as determined by the project
                       materials/geotechnical engineer.

                      The infiltration basin site should have a maximum clay content of 30
                       percent and a minimum cation exchange capacity of 5 meq, which shall be
                       determined by the project geotechnical engineer.

                      Bedrock, or an impervious soil layer, shall be no closer than 1.2 m (4 ft)
                       from the invert of the basin.

                      Upon completion of the initial excavation, the side slopes of the infiltration
                       basin, in addition to any embankments and the downstream outlets, should
                       be stabilized to prevent siltation of the basin. When all areas contributing
                       runoff to the sediment basin have been stabilized, and after removal of all
                       accumulated sediments, the excavation of the basin to finished grade should
                       proceed. The basin inlet should be designed to help prevent erosion.
                       Erosion should be controlled by installing outlet protection/velocity
                       dissipation devices (See “Outlet Protection/Velocity Dissipation Devices”
                       BMP in this Guide.)

                      Impact on local ground water, including recharge potential and water
                       quality, should be examined.

                      Infiltration Basin Sizing: The degree of treatment achieved by an
                       infiltration basin is a function of the volume of storm water that is captured
                       and infiltrated over time. Determine the design capture volume required
                       using guidance under “Volume” below. Using the infiltration rate of the
                       soil for a saturated condition (as determined by the project geotechnical
                       engineer), determine the area of the basin bottom to infiltrate the capture
                       volume in 24 hours, i.e.

                                                    AR = V
                                                             24 × I sat




                                                                          Caltrans Storm Water Quality Handbooks
Infiltration Basin                                                        Project Planning and Design Guide
4 of 8                                                                    May 2000
                                                                Infiltration Basin

                  where                  AR =     basin infiltration area required, m2
                                         V =      design storm volume, m3
                                         Isat =   Saturated soil infiltration rate, m/hr
                                         24 =     Required time for the basin to empty, hrs

                      Infiltration/retention times longer than 48 hours should not be considered to
                       minimize the potential for mosquito breeding.

                      Incorporate bypass or overflow for large events or build detention storage
                       on top of the infiltration basin.

                      Volume: Caltrans has adopted a maximum design goal of sizing detention
                       basins to capture the entire runoff from a treatment design storm event
                       (water quality design storm). Determine the treatment design storm event
                       for either the closest rain gauge to the project site, or the average of the
                       closest 2-3 gauges, particularly where there is a significant elevation
                       difference between the closest gauge and the project site. The runoff
                       produced by this storm based upon the characteristics of the project
                       drainage area after completion of the project should then be calculated and
                       the resulting volume used as a maximum design target.

                  The basic data requirements for a design analysis are:
                                 − the inflow peak discharge and hydrograph;
                                 − the (allowable) infiltration rate; and
                                 − the basin stage-storage relationship
                  The design process consists of establishing the inflow/storage/outflow
                  relationship and adjusting the storage volume and outflow characteristics until the
                  design objectives are met. In most cases, the inflow is fixed by upstream
                  conditions, and the outflow is fixed by the design goals. The purpose of the
                  analysis then is to determine the appropriate basin type, storage volume and outlet
                  configuration. In many cases for roadway drainage design, the storage volume
                  and basin type may be fixed, and the analysis determines the size of the outlet.
                  Infiltration basins with volumes smaller than that which can store treatment
                  design storm event may be considered under the following circumstances:
                         (1) Sufficient right-of-way is not available, or cannot be feasibly obtained
                              to accommodate the volume.

                          (2) A site-specific MEP analysis is conducted in consultation with
                              Headquarters Environmental Program staff.

                  Under the above circumstances, the minimum storage volume recommended is
                  that which would capture at least 80 percent of all runoff from the project
                  drainage area.

Caltrans Storm Water Quality Handbooks
Project Planning and Design Guide                                                             Infiltration Basin
May 2000                                                                                                   5 of 8
                                                                       Infiltration Basin
                          Other water quality capture volumes which would allow capture of greater than
                          80 percent of all runoff up to the treatment design storm event can be considered
                          if right-of-way is available or if the site specific analysis indicates a greater level
                          of capture is justified based upon an MEP analysis.
                              Dedicated access to the basin bottom should be provided for maintenance
                                 vehicles.

                             Basins may be lined with a 150 mm (6 in) to 300 mm (12 in) layer of filter
                              material such as coarse sand to prevent the buildup of impervious deposits
                              on the natural soil surface. To increase the permeability of clayey soils, a
                              150 mm (6 in) layer of coarse organic material may be specified; but trying
                              to increase permeability is not recommended.

                             If possible, the infiltration basin sides and bottom should be stabilized.
                              Stabilizing with vegetation or non-vegetative measures on the sides of the
                              basin minimizes erosion and controls dust; whereas the bottom of the basin
                              is vegetated to reduce tendency to clog with fine solids. Whenever
                              possible, native vegetation that requires less intensive maintenance and is
                              less likely to become a nuisance should be used. The planting design
                              should consider access to high maintenance areas such as inlet and outlet
                              structures. Also, a stabilized buffer strip at least 6 m (20 ft) wide should be
                              provided around the basin to protect against erosion and sloughing.

              Special        Special precautions must be taken to the work sequence, techniques, and the
          Construction        equipment employed to protect the natural infiltration rate. Light
        Considerations        equipment and construction procedures that minimize compaction should be
                              used. The basin area should be flagged off while heavy equipment is in the
                              area.

                             Storm water should not be allowed to enter the infiltration basin until all
                              construction is completed and the contributing drainage area to the basin is
                              adequately stabilized. If this prohibition is not feasible in particular
                              situations, do not excavate the facility to the final grade until after all
                              construction is complete upstream.

                             If native soils are very pervious, incorporate materials into confining levee
                              to control seepage.

    Maintenance and The primary objective of maintenance/inspection activities is to ensure that the
          Inspection infiltration facility continues to perform as designed and to substantially lengthen
                          the required time interval between major rehabilitation.

                             Side slopes should be maintained as needed to promote dense vegetative
                              cover with extensive root growth which enhances infiltration though the
                              slope surface, prevents erosion and consequent sedimentation of the basin
                              floor, and prevents invasive weed growth.


                                                                               Caltrans Storm Water Quality Handbooks
Infiltration Basin                                                             Project Planning and Design Guide
6 of 8                                                                         May 2000
                                                         Infiltration Basin

References            Urban Drainage Design Manual, Hydraulic Engineering Circular No. 22 –
                       HEC22, U.S. Department of Transportation, Federal Highway
                       Administration, 1996. Publication No. FHWA-SA-96-078

                      Retention, Detention and Overland Flow for Pollutant Removal from
                       Highway Stormwater Runoff. Volume 2. Design Guidelines. U.S.
                       Department of Transportation, Federal Highway Administration, 1996.
                       Publication No. FHWA-SA-96-096.

                      Urban Runoff Quality Management, ASCE/WEF, 1998

                      Caltrans Highway Design Manual, Chapter 810.




Caltrans Storm Water Quality Handbooks
Project Planning and Design Guide                                                   Infiltration Basin
May 2000                                                                                         7 of 8
                                                 Infiltration Basin




                     FIGURE 1 – INFILTRATION BASIN SCHEMATIC




                                                       Caltrans Storm Water Quality Handbooks
Infiltration Basin                                     Project Planning and Design Guide
8 of 8                                                 May 2000
                                                                   Detention Basin




                                                                             BMP Objectives

                                                                      M   Sediment
                                                                      F   Oil and Grease
                                                                      F   Metals and Toxics
                                                                      F   Nutrients
                                                                      F   Bacteria and Viruses
                                                                      M Highly Effective
                                                                      F Low Effectiveness



Definition and A detention basin is a permanent device formed by excavating and/or constructing
     Purpose an embankment so that runoff from the water quality design storm is temporarily
                     detained under quiescent conditions, allowing sediment and particulates to settle
                     out before the runoff is discharged.

 Appropriate Consider detention basins for use when:
 Applications        1. Runoff from the completed facility will discharge to significant
                                    areas of highly valuable habitat in which Federal or State listed
                                    aquatic resources have been identified; and,
                               2. Caltrans runoff will constitute a substantial portion (more than
                                  10 percent) of the total flows to such habitat
                        Detention basins are used upstream of receiving waters to remove sediment
                         or other pollutants from storm water runoff from highways, roads, parking
                         lots and rest areas, and maintenance areas.

                        Detention basins can be used where less permeable soils and/or restrictive
                         subsurface conditions prevent the use of infiltration basins for pollutant
                         removal.

                        Detention basins can be designed and constructed in conjunction with flood
                         control basins to reduce peak storm water flow rates for drainage areas
                         where the hydraulic capacity of receiving waters is limited (e.g., 2, 5, 10,
                         100-yr storms).

                        Usual highway placement locations are cloverleaves and dedicated areas in
                         the right-of-way.


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             Limitations     The quality of the runoff and the intent of the basin should be considered.
                              If the basin is being considered for highly soluble pollutant removal such as
                              nutrients, then an infiltration basin is preferred.

                             Detention basins require a large surface area (0.5 to 3% of the contributing
                              drainage area) to permit settling of sediment. Space may be limited for a
                              particular a site.

                             Detention basins are not typically practical for small drainage areas because
                              the necessary outflow control requires small outlets that clog rapidly.

                             If upstream erosion is not properly controlled, detention basins can be
                              maintenance intensive with respect to sediment removal, nuisance odors,
                              and insects (i.e., mosquitoes), etc.

                             Detention basins require a differential elevation between inlets and outlets
                              and thus, may be limited by terrain.

   Design Guidance Coordinate design of detention basins with the district’s Hydraulics Division for
                           the use of spreadsheets and computer programs such as HY-22. The following
                           are presented as guidelines for designing detention basins:

                           General Guidance
                             A small permanent pool area can be integrated into the facility if desired
                              (see Figure 3). The pool can be an aesthetic enhancement and can
                              submerge first flush sediment loads that are washed into the basin. If the
                              permanent pool dries up during the summer, this is not a problem.

                             Access: A permanent area should be provided around the perimeter of the
                              impoundment to allow maintenance. Provisions should also be made for
                              emptying the basin as necessary for maintenance procedures.

                             Volume: Caltrans has adopted a maximum design goal of sizing detention
                              basins to capture the entire runoff from a treatment design storm event.
                              Determine the treatment design storm event for either the closest rain gauge
                              to the project site, or the average of the closest 2-3 gauges, particularly
                              where there is a significant elevation difference between the closest gauge
                              and the project site. The runoff produced by this storm based upon the
                              characteristics of the project drainage area after completion of the project
                              should then be calculated and the resulting volume used as a maximum
                              design target.

                                The basic data requirements for a design analysis are:
                                      − the inflow peak discharge and hydrograph;
                                      − the (allowable) outflow peak discharge;
                                      − the basin stage-storage relationship; and

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                                 − the outlet stage-discharge relationship.

                          The design process consists of establishing the inflow/storage/outflow
                          relationship and adjusting the storage volume and outflow characteristics
                          until the design objectives are met. In most cases, the inflow is fixed by
                          upstream conditions, and the outflow is fixed by the design goals. The
                          purpose of the analysis then is to determine the appropriate basin type,
                          storage volume and outlet configuration. In many cases for roadway
                          drainage design, the storage volume and basin type may be fixed, and the
                          analysis determines the size of the outlet. Figure 1 is a graphical
                          representation of the storage volume required for on-line detention, off-line
                          detention, and infiltration basins.

                          The inflow peak discharge and hydrograph are obtained through
                          hydrologic analysis of the upstream watershed. Hydrologic analysis is
                          discussed in detail the FHWA publication "Practical Highway Hydrology",
                          Highway Drainage Series #2, and Hydraulic Engineering Circular #22
                          (HEC22). A thorough discussion is also found in the Caltrans Highway
                          Design Manual, Chapter 810. The peak discharge is obtained by
                          developing a rainfall-runoff relationship and applying a design storm to
                          determine a peak flow rate. The Rational Method is one very common and
                          well-documented method of determining peak discharge rates. Peak
                          discharges also can be obtained by statistical analysis of past flows, unit
                          hydrograph analysis, regional relationships or other methods. Hydrographs
                          can be obtained from unit hydrograph analysis, synthetic hydrograph
                          methods or the use of physically-based computer models such as the United
                          States Soil Conservation Service TR-20 program, subsystem HYDRA in
                          HYDRAIN, or the U.S. Army Corps of Engineers HEC-1 program.

                          The outflow peak discharge usually is determined by the design objectives.
                          It may be desired to maintain outflow discharge at existing levels, at the
                          capacity of an existing or proposed downstream structure, or at another
                          discharge determined by local conditions. There may be a range of
                          acceptable outflow discharges depending on the magnitude of the inflow
                          discharge.

                          The basin stage-storage relationship is determined from the topography of
                          the storage basin. The relationship is represented by a table of ponding
                          depth in meters versus total ponding volume in cubic meters. For design of
                          storage basins, determination of basin topography may be a trial-and-error
                          procedure. A preliminary estimate of the total volume required can be
                          made using the procedure described below.

                          The outlet stage-discharge relationship is determined from the hydraulic
                          characteristics of the outlet. The relationship is represented by a table of
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                                                             Detention Basin
                  ponding depth in meters versus total outflow discharge in cubic meters per
                  second. Determination of the outlet configuration may be a trial-and-error
                  process. If the outfall type and dimensions are known, it can be a simple
                  matter of a direct hydraulic analysis to determine an outlet stage-discharge
                  relationship (performance curve).

                  Storage Indication Method (On-Line Basins)
                  The Storage Indication Method is used for routing of flow through on-line
                  detention basins. This method is based upon the equation:

                                                        ∆S
                                           I - O =                                       Equation 1
                                                        ∆t
                  where:
                    I      =    inflow rate, in m3/s,
                    O      =    outflow rate, in m3/s,
                    S      =    the change in the storage volume, in cubic meters,
                    ∆t     =    elapsed time, in seconds.

                  Equation 1 states that inflow minus outflow is equal to the change in
                  storage. The equation can be rearranged for a finite time period as:

                         (I1 + I2 )   +
                                          æ S1  O ö
                                               - 1 =
                                                     æ S2  O ö
                                                          + 2                            Equation 2
                            2             è ∆t   2ø  è ∆t   2 ø
                  where:
                    I1          =     inflow rate at the start of the time period, in m3/s,
                    I2          =     inflow rate at the end of the time period, in m3/s,
                    O1     =    outflow rate at the start of the time period, in m3/s,
                    O2     =    outflow rate at the end of the time period, in m3/s,
                    S1     =    storage volume at the start of the time period, in cubic meters,
                    S2     =    storage volume at the end of the time period, in cubic meters,
                    ∆t     =    duration of the time period, in seconds.

                  This equation, in conjunction with an inflow hydrograph and the
                  relationship between storage and outflow, can be used to route flows
                  through a detention basin.

                  The Storage Indication Method is described in detail in many hydrologic
                  texts. The application of the method in the design of on-line detention
                  basins for which the outflow discharge is known is described below. It is
                  assumed that an inflow hydrograph is available prior to beginning the
                  procedure.


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                          Step 1     Preliminary Volume Estimate. A preliminary estimate of the
                          storage volume can be made by superimposing an assumed outflow
                          hydrograph on the inflow hydrograph as shown in Figure 1 and estimating
                          the volume represented by the difference between the two up to the time
                          that inflow equals outflow. This volume is shown labeled as “storage” on
                          Figure 1. The outflow hydrograph is assumed to begin at the same time as
                          the inflow hydrograph, and peak at a point on the falling limb of the inflow
                          hydrograph.

                          If the inflow and outflow hydrographs are triangular as shown in Figure 1,
                          the preliminary volume estimate can be represented by:

                                                    é    æ Op ö ù
                                           V s = Vi ê1 - ç    ÷ú                 Equation 3
                                                    ë    è Ip ø û

                          where:
                             VS     =    estimate of required storage volume, in cubic meters,
                             Vi     =    total inflow volume, in cubic meters,
                             Op     =    peak outflow rate, in m3/s,
                             Ip     =    peak inflow rate, in m3/s.

                          Step 2    Prepare a preliminary detention basin configuration based upon
                          the preliminary volume estimate. Develop a stage-storage relationship for
                          the assumed basin configuration.

                          Step 3     Choose an initial outflow configuration based on engineering
                          judgment and develop a stage-outflow relationship. The stage-outflow
                          relationship can be estimated using mathematical equations for orifice or
                          weir flow, or approximated from Federal Highway Administration (FHWA)
                          nomographs for culvert design (FHWA Hydraulic Design Series #5).

                          Step 4     The common parameter in the stage-storage (step 2) and stage-
                          outflow relationships (step 3) is stage. Therefore, merge the two
                          relationships to construct a storage-outflow relationship.




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                                     STORAGE              INFLOW




                         DISCHARGE
                                                                 OUTFLOW




                                                      TIME
                                      ON-LINE DETENTION BASIN

                                      STORAGE
                         DISCHARGE                        INFLOW


                                                                 OUTFLOW




                                                      TIME
                                      OFF-LINE DETENTION BASIN
                                       STORAGE




                                                          INFLOW
                         DISCHARGE




                                                                      OUTFLOW




                                                      TIME
                                                 INFILTRATION BASIN
                                                 RETENTION BASIN

                                     INFLOW/OUTFLOW HYDROGRAPHS


                                                                                                  Figure 1
                  Note: For water quality purposes and to capture the “first-flush”, an off-
                  line detention basin would be configured to have and inflow-outflow
                  hydrograph similar to the one shown for an infiltration basin.


                  Step 5   Select a routing time interval (∆t). For the initial estimate and for
                  convenience, this value may be one tenth of the rise time of the inflow
                  hydrograph. The inflow hydrograph will be "discretized" using this time
                  increment.

                  Step 6      Using the storage-outflow relationship and the chosen time
                  interval, establish a relationship between outflow (O) and the quantity
                  [(S/∆t) + (O/2)] in Equation 2. Prepare a working table and working curve
                  of this relationship. It may be convenient to plot the working curve on
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                          logarithmic graph paper due to the wide range of values that generally must
                          be represented.

                          An "equal-values" line refers to the locus of points on the working curve
                          where [(S/∆t) + (O/2)] equals the outflow (O). Check the working curve to
                          ensure that it does not exceed the "equal-values" line at any point on the
                          curve. If it does exceed the "equal-values" line, the routing time interval ∆t,
                          is too large. Reduce the routing time and repeat Steps 5 and 6. A small
                          routing time is not a particular problem if computer calculations are to be
                          made. The interest in having a larger time step (up to about one-tenth of the
                          time to rise on the inflow hydrograph) is to minimize manual calculations.

                          Step 7    Perform the routing by computing outflow for each time step
                          from Equation 2 and the relationship between outflow and [(S/∆t) + (O/2)].
                          A routing tabulation is useful to track the routing computations. For
                          convenience, the routing table should have columns for:

                                         −   the time steps;
                                         −   the inflow hydrograph;
                                         −   the quantity [(S/∆t) - (O/2)];
                                         −   the quantity [(S/∆t) + (O/2)]; and
                                         −   outflow.

                          Reservoir stage and storage volume could be included in the table, but they
                          are not necessary to the routing computations.

                          The routing procedure is as follows: (Subscript 1 represents a value for the
                          previous time step and subscript 2 represents a value for the current time
                          step.)

                          Steps 1 through 7 are graphically illustrated by the flowchart shown as
                          Figure 2.

                          Step 8    As the final step, a graphical representation of the inflow and
                          outflow hydrographs should be prepared.




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                                                                       Detention Basin
                                                                   Begin




                                    S     O
                             With      +                No                            Yes
                                    ∆t    2                    First time step?              Assume Outflow = Inflow
                           as an argument in the
                            working curve, find
                               Outflow (O)




                                                   No                                       S    O       S    O
                            Last time step?                                                    +   - O =    -
                                                                                            ∆t   2       ∆t   2



                              Yes
                                                        STORAGE INDICATION
                                                        METHOD FLOWCHART
                                Finish                                                       Advance all subscripts
                                                                                               for next time step.




                                                                                (I1 + I2 )   æ S1    Oö æ S2  O ö
                                                             Use equation 4-2,             +      - 1 =      + 2
                                                                                    2        è ∆t    2ø è ∆t   2 ø
                                                                                            S2    O2
                                                             to calculate a new value of       +
                                                                                           ∆t     2


                                                                                                                Figure 2

                   Detention Time: Detention basins require longer detention times to provide
                    the opportunity for sediment particles in the runoff to settle out of the water
                    column. Detention facility studies indicate that effective detention basins
                    should be designed for a detention time of 24 hours for average conditions
                    rather than full-basin conditions. In California, a 24-hour average detention
                    time for the full range of storms up to and including the water quality
                    design storm (determined from Table 1) is generally achieved with a
                    full-basin drawdown time of at least 40 hours, where the drawdown time is
                    the time required for a full basin to empty. The maximum design goal is to
                    achieve a 48-hour drawdown for a full basin. Detention times longer than
                    48 hours should not be considered to minimize the potential for mosquito
                    breeding.

                      The design analysis must then be scheduled to determine if the facility takes
                      at least 24 hours to drain when half full. For basins sized to capture the
                      treatment design storm event, an outlet sized to draw down the basin in 48
                      hours will very likely result in detention times of less than 24 hours for the
                      half full condition and smaller storms. For such conditions, a two-step
                      outlet should be designed. It is recommended that the lower outlet be sized
                      to drain the water quality volume in 40 hours. The second outlet is placed
                      at the mid-water elevation and is sized in combination with the lower orifice
                      to drain the entire facility in 48 hours. Another approach is to install the
                      outlet about 300 mm (12 in) above the bottom of the pond (essentially
                      enlarging the micropool area). This lower area will normally dry up
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                          between storms and will capture much of the volume of small storms,
                          improving pollutant removal (see Figure 3).

                          Detention basins shall have three discharge stages. They are:

                               (1) the Water Quality Volume,
                               (2) the primary flood control outlet, and
                               (3) a secondary outlet to limit the risk of overtopping the device.

                      Basin Geometry: The configuration of the basin, as well as the location of
                       the associated facilities (inlet, outlet structures, baffles, etc.), will
                       significantly impact the desired function of the basin. In order to enhance
                       pollutant removal, the hydraulic flow length of the basin should be
                       maximized. Typically the length to width ratio of the basin should be on
                       the order of 3:1 or greater. Typical pond depths range from 1.2 m (4 ft) to
                       1.8 m (6 ft). Figure 3 is an idealized detention basin layout.

                      Basin Side Slopes: Embankment slopes should be stable and gentle enough
                       to limit rill erosion and facilitate maintenance access and needs. Although
                       limited by the stability of the soil, typically, basin slopes should be 1:4
                       (V:H) or flatter. Steeper slopes may require that the facility be fenced for
                       safety. Embankment slopes should be compacted and stabilization of
                       slopes provided to assist in preventing erosion. Height limitations should
                       be in accordance with the Highway Design Manual, Index 829.9.

                      Basin sizes, volumes and berm/dam heights must be in conformance with
                       the Division of Dam Safety requirements.

                      Inlets: Inlet structures should be designed to dissipate flow energy at the
                       inlet point to limit erosion and promote particle sedimentation. They should
                       be located as far as possible from the outlet structure to maximize the
                       hydraulic flow length. A forebay, designed upstream of the basin, can be
                       provided to remove large particles.

                      Invert Depth to Groundwater: Detention devices should have an
                       impermeable liner at locations where the invert to seasonally high (wet
                       weather) groundwater separation is less than 1.5 meters. This will reduce
                       maintenance access problems and minimize establishment of wetland plant
                       species.

                      Aesthetics: The aesthetics of the site are also a consideration. Vegetation
                       should be selected carefully to enhance the appearance of the basins. If a
                       detention pond is designed to empty completely following a rainfall event,
                       appropriate ground cover should be provided.

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                     Maintenance Considerations: Maintenance procedures should also be
                      considered during the planning stages. Basins should be located such that
                      safe and easy access for maintenance is provided. Debris in empty basins
                      may be unsightly and require more frequent maintenance. In some areas,
                      mosquitoes and other insects may require additional maintenance.

                     Safety: Safety is a major consideration when planning detention basins.
                      Basins should be located where failure would not cause loss of life or
                      property damage. Basins which maintain either temporary or permanent
                      pools of water should be fenced to limit public access. The size of the
                      basins may require approval from the State Division of Safety of Dams.

                  Basin Outlet Guidance
                  Proper hydraulic design of the outlet is critical to achieving good performance of
                  the detention basin. The two most common outlet problems that occur are: (1) the
                  capacity of the outlet is too great resulting in only partial filling of the basin and
                  drawdown time less than designed for; and (2) the outlet clogs because it is not
                  adequately protected against trash and debris. To avoid these problems, the
                  following outlet types are recommended for use: (1) a single orifice outlet with or
                  without the protection of a riser pipe, and (2) perforated riser. A V-notch weir
                  can also be used, but is not recommended. The V-notch weir will not clog, but it
                  is difficult to maintain small release rates at low heads. The perforated riser, if
                  properly designed and gravel packed, gives much better control and is
                  recommended over the V-notch weir. Design guidance for single orifice and
                  perforated riser outlets follow:

                  Flow Control Using a Single Orifice: The outlet control orifice should be sized
                  using the following equation:

                                2 A( H − Ho) 0.5 (7 x10 −5 ) A( H − Ho) 0.5
                           a=                     =
                                3600CT (2 g ) 0.5            CT

                  where:           a = area of orifice (ft2) (1 ft2 = 0.0929m2)
                                   A = average surface area of the pond (ft2)
                                   C = orifice coefficient
                                   T = drawdown time of full pond (hrs.)
                                   G = gravity (32.2 ft./s2)
                                   H = elevation when the pond is full (ft)
                                   Ho = final elevation when pond is empty (ft)

                  With a drawdown time of 40 hours, the equation becomes:

                                        (1.75 x10 −6 ) A( H − Ho) 0.5
                                   a=
                                                      C

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                   Assuming an average release rate at one half the pond depth, (a common
                   approach in several design manuals) may lead to considerable error if the pond
                   has a significant variation of surface area with depth which may result in basins
                   with relatively small areas and sideslopes less than 1:3. If this is true, do not use
                   Equation (2); consult HEC-22 for the design of detention facilities.

                   Care must be taken in the selection of "C"; 0.60 is most often recommended and
                   used. However, based on actual tests, GKY (1989), “Outlet Hydraulics of
                   Extended Detention Facilities for Northern Virginia Planning District
                   Commission” recommends the following:

                       C = 0.66 for thin materials; where the thickness is equal to or less
                           than the orifice diameter

                       C = 0.80 when the material is thicker than the orifice diameter

                   Drilling the orifice into an outlet structure that is made of concrete can result in
                   considerable impact on the coefficient, as does the beveling of the edge.

                   Three alternative outlet structures that use single orifice outlets are suggested
                   (Figures 4, 5 and 6). The concrete block structure is appropriate for large ponds.
                   The riser pipe is suggested for small to large ponds to prevent orifice clogging.
                   Hole size and placement is not critical in this case because the orifice will control
                   the discharge rate. Placing the outlet control in the berm or in a manhole located
                   downstream of the facility is most suitable for small ponds as along as other
                   outlets/spillways are provided for storms larger than the water quality design
                   storm. For small facilities, place the control orifice in the outlet manhole
                   downstream of the filter as shown in Figure 5, Riser Pipe; or use a "T-pipe" as
                   shown in Figure 6, Control Manhole, to submerge the orifice.

                   Flow Control Using the Perforated Riser: For outlet control using the perforated
                   riser as the outflow control. This design incorporates flow control for the small
                   storms in the perforated riser but also, provides an overflow outlet for large
                   storms. If properly designed, the facility can be used for both water quality and
                   drainage control by: (1) sizing the perforated riser as indicated for water quality
                   control; (2) sizing the outlet pipe to control peak outflow rate from the 2-year
                   storm; and (3) using a spillway in the pond berm to control the discharge from
                   larger storms up to the 100-year storm.

                   Recommendations regarding the design of a perforated riser pipe are shown in
                   Table 1. To prevent clogging of the bottom orifices of the riser pipe, wrap the
                   bottom three rows of orifices with filter fabric per Section 88 of Standard
                   Specifications and a cone of 25 mm (1 in) to 75 mm (3 in) rock.


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                                                                    Detention Basin
             Special During construction of detention basins it is important to keep the following in
         Construction mind:
       Considerations
                             Sediment should be removed from temporary basins which are to be used
                              for permanent detention basins.

                             Temporary BMPs including sediment basins and traps, diversion channels
                              and dikes, should be maintained until permanent BMPs are complete and
                              operable.

                             The fill material used in embankments should be compacted to at least 95%
                              of the maximum density obtained form compaction tests performed by the
                              Modified Proctor method of ASTM D698.

                             Seepage through embankments may cause embankment failure.
                              Consideration must be given to permeability of embankments.

   Maintenance and           Vegetation should be maintained as needed including periodic removal of
         Inspection           aquatic plants that may potentially impact nutrients in the water.

                             Vector controls should be implemented as needed. Varying water depths
                              every few days may help control some vectors.

            References       Urban Drainage Design Manual, Hydraulic Engineering Circular No. 22 –
                              HEC22, U.S. Department of Transportation, Federal Highway
                              Administration, 1996. Publication No. FHWA-SA-96-078

                             Retention, Detention and Overland Flow for Pollutant Removal from
                              Highway Stormwater Runoff. Volume 2. Design Guidelines. U.S.
                              Department of Transportation, Federal Highway Administration, 1996.
                              Publication No. FHWA-SA-96-096.

                             Urban Runoff Quality Management, ASCE/WEF, 1998

                             Caltrans Highway Design Manual, Chapter 810.




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                          Figure 3- Detention Basin Schematic


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                  Detention Basin




                               Figure 4




                              Figure 5




                               Figure 6




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                                                 Figure 7




                                                  Table 1




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                                     Traction Sand Trap Devices




                                                                        BMP Objectives

                                                                 M   Sediment
                                                                 F   Oil and Grease
                                                                 F   Metals and Toxics
                                                                 F   Nutri ents
                                                                 F   Bacteria a nd Viruses
                                                                 M Highly Effective
                                                                 F Low Effectiven ess




Definition and A traction sand trap is a device that allows traction sand to settle out of highway
     Purpose storm water runoff. It must provide sufficient storage volume to retain the settled
                    sand until the traction sand trap is cleaned. A traction sand trap is a permanent
                    control measure that may be a stand-alone device, or may be incorporated as part
                    of another storm water facility such as a detention basin.

                    Caltrans routinely applies sand on snowy or icy roadways, primarily in
                    mountainous areas, to provide additional traction for vehicles. The main purpose
                    of sand traps is to recapture this sand from storm water runoff, thereby reducing
                    traction sand discharges to receiving waters and habitats. Traction sand traps are
                    not efficient at removing fine sediments (silts, clays) or other pollutants and
                    should not be considered for this purpose.

                    Typically, a traction sand trap device is a drainage inlet that has been modified to
                    capture and retain traction sand. Typical modifications include increasing the
                    depth of the inlet so that there is a settling/storage area below the invert of the
                    outlet pipe, linking multiple inlets for increased storage volume, and adding weep
                    holes to allow the storage volume to drain.

 Appropriate Consider traction sand trap devices for roadways in the following locations where
 Applications sand is applied for traction control:

                        The Lake Tahoe and Truckee River hydrologic units in District 3.
                        Elevations above 7,000 ft in the Mammoth Creek Hydrologic Unit in
                         District 9.
                        The Carson River East Fork and West Fork hydrologic units in District 10.


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                                            Traction Sand Trap Devices
            Limitations Traction sand trap devices:

                               Have a tributary area limited to that of a single inlet location.

                               Provide relatively little traction sand storage volume.

                               May result in traction sand discharges during high flow conditions as a
                                result of limited volume, turbulent conditions, or insufficient settling time.

                               Are difficult to design for a particular removal efficiency.

                               Require the use of a vacuum truck for cleaning.

   Design Guidance Volume for Sand Storage.

                             The volume required to store traction sand is calculated by starting with the
                             estimated amount of traction sand spread in a given area and applying reduction
                             factors to account for sand that has been recovered by other means or that cannot
                             be captured. The equation is:

                                                            V = (S x R x L x E)/F
                             Where:

                             V=       The total volume of traction sand that must be stored (m3).
                             S=       The estimated volume of sand applied (m3/yr).
                             R=       a reduction factor to account for sand recovered by roadway sweeping.
                             L=       A factor to account for other miscellaneous losses/accumulations.
                             E=       An estimated recovery efficiency.
                             F=       The number of times the trap will be cleaned (times/yr.) (see below)
                             S:       Typical sand application rates range from 47 m3/lane/km/yr for areas with
                                      average application rates to 95 m3/lane/km/yr for areas with high
                                      application rates. To estimate the total volume of traction sand applied,
                                      select an appropriate application rate from the range listed above, and
                                      multiply it by the total number of lanes (e.g., one lane in each direction
                                      equals two lanes) and the length of highway tributary to the sand trap.
                                      Because some areas track sand usage by post mile, a more accurate
                                      estimate may be obtained by consulting with District maintenance staff.
                                      In any event, consider the following guidelines when estimating the
                                      volume of sand that is spread annually in the tributary area:

                             Exposure: Roadways on north facing slopes generally require more traction sand
                             than similar south facing slopes. The surrounding vegetation may also
                             significantly affect exposure and traction sand application.

                             Roadway grade: steeper grades generally receive more traction sand.
                                                                                Caltrans Storm Water Quality Handbooks
Traction Sand Trap Devices                                                      Project Planning and Design Guide
2 of 6                                                                          May 2000
                                   Traction Sand Trap Devices

                  Other climatic and geographic factors, such as elevation, will affect the traction
                  sand application rate for a specific area.

                  Other sources of similar material: Adjacent cut slopes and other non-paved
                  tributary areas may contribute similar-sized sediment or other debris that will be
                  retained in the trap.

                  R:        This is a reduction factor to account for traction sand that is recovered
                            through roadway sweeping. Estimate a value between 1.0 (no roadway
                            sweeping) and 0.6 (aggressive winter roadway sweeping) based on
                            interviews with District maintenance staff. If actual sweeping records are
                            available, these may provide a more accurate estimate.

                  L:        This is a factor to account for traction sand that has been carried into or
                            out of the tributary area by miscellaneous means such as wind (smaller
                            particles), sand thrown out of the tributary area by snow clearing
                            equipment, and sand splashed or carried by vehicles. Estimate an
                            appropriate value in the range of 0.8 (high losses from known sources
                            such as snow blowers) to 1.2 (high accumulation from known sources).
                            Use a factor of 1.0 for no miscellaneous losses/accumulations.

                  E:        This reduction factor is provided to account for traction sand that passes
                            through the sand trap without settling out. Because of particle size
                            limitations, settling inefficiencies, and other factors, it may not be
                            realistic or practicable to recover all of the traction sand that reaches the
                            sand trap. Until empirical information is obtained from pilot studies, a
                            value of 1.0 should be used for this factor.

                  F:        This is the number of times the sand trap will be cleaned each season.
                            Usually, the value for F is 1 as most basins are cleaned once per year,
                            usually in the summer. If obtaining the required storage volume is
                            difficult, it may be possible to implement mid-season cleaning (F greater
                            than 1), but District maintenance staff should be consulted to make sure
                            this is practicable. Mid-season cleaning requirements will also likely
                            affect trap design, as maintenance equipment will have to access the trap
                            under wet or snowy conditions.

                  Traction Sand Inlet Trap Design.
                  Conceptual traction sand trap devices are shown in Figures 1 – 3. Typical
                  modifications from a standard Caltrans inlet include increasing the depth of the
                  inlet so that there is a settling/storage area below the invert of the outlet pipe,
                  linking multiple inlets at one location for increased sand storage volume, and
                  adding weep holes to the bottom to allow the storage area to drain. The primary

Caltrans Storm Water Quality Handbooks
Project Planning and Design Guide                                                   Traction Sand Trap Devices
May 2000                                                                                                 3 of 6
                                            Traction Sand Trap Devices
                             design considerations for modifying a standard inlet into a traction sand trap
                             device are sand storage volume, inlet depth, inlet drainage, and maintenance
                             access.

                             Inlet Depth: Once the required storage volume has been determined, divide the
                             required volume by the inlet’s cross sectional area (plan view) to calculate the
                             required depth of the inlet’s traction sand storage area. The storage area should
                             start at least 0.3 m below the invert of the inlet’s outlet pipe and extend no more
                             than 3 m below the inlet grate (or road surface). If the inlet is any deeper than
                             that, a vacuum truck will have difficulty removing the traction sand from the
                             bottom of the basin. Additionally, the bottom of the inlet should be at least a few
                             meters above the ground water table. If the required storage volume cannot be
                             met under these criteria, consider using double inlets or non-standard inlets,
                             adding more inlets, using a different treatment control, or supplementing the
                             traction sand inlets with additional down-stream controls.

                             Inlet Drainage: Because the bottom of a traction sand inlet is below the inlet’s
                             outlet pipe, additional drainage holes must be provided to prevent standing water
                             and associated problems (e.g., mosquito breeding). The design infiltration rate
                             should be limited to 50 percent of that indicated in the soils report. This would
                             provide a factor of safety and allow for accumulation of fines that, over time, will
                             reduce the infiltration rate. If the surrounding soils do not provide sufficient
                             permeability to draw down the inlet within 48 hours, it may be necessary to select
                             a different treatment control. Any traction sand inlet with drainage holes must be
                             designed t prevent damage to the adjacent roadway subgrade. Typical mitigation
                             measures include locating inlets only on the down-gradient side of the roadway,
                             locating the top inlet drainage hole below the roadway subgrade, and providing
                             additional drainage pathways (such as a leach line) to guide water away from the
                             subgrade. Locating traction sand inlets on the high side of a super elevated
                             section should be avoided.

                             Maintenance Access: Vacuum trucks are typically used to remove accumulated
                             traction sand from the inlets. Providing a pullout area for the vacuum truck not
                             only provides an additional measure of safety for the cleaning crew, but may also
                             save time and money by avoiding land closures. At a minimum, the pullout area
                             should be about 10 m long and about 3 m wide and be located so the inlet is near
                             the front of the truck. (Also see “Inlet Depth,” above.) See Standard Plans for
                             maintenance vehicle pull out. Consult with District maintenance staff to see if
                             inlet location markers are required.




                                                                                Caltrans Storm Water Quality Handbooks
Traction Sand Trap Devices                                                      Project Planning and Design Guide
4 of 6                                                                          May 2000
                                   Traction Sand Trap Devices




                                         FIGURE 1




                                         FIGURE 2


Caltrans Storm Water Quality Handbooks
Project Planning and Design Guide                   Traction Sand Trap Devices
May 2000                                                                 5 of 6
                             Traction Sand Trap Devices




                               FIGURE 3




                                          Caltrans Storm Water Quality Handbooks
Traction Sand Trap Devices                Project Planning and Design Guide
6 of 6                                    May 2000
                            Appendix C
                     Abbreviations, Acronyms,
                Definition of Terms and References

Abbreviations                                      NPDES   National Pollutant Discharge
                                                           Elimination System
ac             acre
                                                   PE      Project Engineer
cy             cubic yards
                                                   PM      Project Manager
ft             feet
                                                   PR      Project Report
gal            gallon
                                                   PS&E    Plans, Specifications & Estimates
gpm            gallons per minute
                                                   PR      Project Report
ha             hectares
                                                   PSR     Project Study Report
hr             hour
                                                   PSSR    Project Scope Summary Report
in             inches
                                                   RE      Resident Engineer
lf             linear feet
                                                   RWQCB   California Regional Water Quality
l              liter
                                                           Control Board
m              meter
                                                   SSP     Standard Special Provisions
mm             millimeter
                                                   SWMP    Statewide Storm Water
s              second
                                                           Management Plan
                                                   SWPPP   Storm Water Pollution Prevention
Acronyms                                                   Plan
BMP             Best Management Practice           SWQ     Storm Water Quality
CEQA           California Environmental Quality    SWRCB   California State Water Resources
               Act                                         Control Board
CSWPPP         Conceptual SWPPP                    TMDL    Total Maximum Daily Load
CWA            Clean Water Act                     WDID    Waste Discharge Identification
EPA            Environmental Protection Agency             Number
NEPA           National Environmental Policy Act   WLA     Waste Load Allocations
NOC             Notification of Construction       WPCDs   Water Pollution Control Drawings
                                                   WPCP    Water Pollution Control Program




         Caltrans Storm Water Quality Handbooks
         Project Planning and Design Guide                                          Appendix C
         May 2000                                                                            1
Appendix C
Abbreviations, Acronyms, Definition of Terms and References




Definition of Terms
Active Construction Area: The area where the contractor intends to be actively involved in soil disturbing
work during the ensuing 21 day period during the rainy season. This may include areas where soils have been
disturbed as well as areas where soil disturbance has not yet occurred.

Best Management Practice (BMP): Any program, technology, process, siting criteria, operating method,
measure, or device that controls, prevents, removes, or reduces pollution.

Clean Water Act (CWA): The Federal Water Pollution Control Act enacted in 1972 by Public Law 92-500
and amended by the Water Quality Act of 1987. The Clean Water Act prohibits the discharge of pollutants to
Waters of the United States unless said discharge is in accordance with an NPDES permit. The 1987
amendments include guidelines for regulating municipal, industrial, and construction storm water discharges
under the NPDES program.

Construction Activity: Includes clearing, grading, or excavation and contractor activities that result in soil
disturbance.

Construction Site: The area involved in a construction project as a whole.

Contamination: An impairment of the quality of the waters of the state by waste to a degree that creates a
hazard to the public health through poisoning or through the spread of disease including any equivalent effect
resulting from the disposal of waste, whether or not waters of the state are affected.

Contractor: Party responsible for carrying out the contract per plans and specifications. The Standard
Specifications and Special Provisions contain storm water protection requirements the contractor must
address.

Desert Areas: Areas within the Colorado River Basin RWQCB and the North and South Lahontan RWQCB
jurisdictions (excluding the Mono and Antelope areas, East and West Walker River, East and West Carson
River, and the Truckee and Little Truckee River).

Discharge: Any release, spill, leak, pump, flow, escape, dumping, or disposal of any liquid, semi-solid or
solid substance.

Disturbed Areas: Areas that have been purposefully cleared, grubbed, excavated, or graded by the
contractor; ground surface that has been disrupted by construction activities, including construction
access/roads, producing significant areas of exposed soil and soil piles. Staging and storage sites are
considered as part of the total disturbed land area, if they are located on erosible soil within state right-of-way.

Environmental Protection Agency (EPA): Agency that issued the regulations to control pollutants in storm
water runoff discharges (The Clean Water Act and NPDES permit requirements).

Erosion: The wearing away of land surface primarily by wind or water. Erosion occurs naturally as a result
of weather or runoff but can be intensified by clearing, grading, or excavation of the land surface.

                                                                                Caltrans Storm Water Quality Handbooks
Appendix C                                                                      Project Planning and Design Guide
2                                                                               May 2000
                                                                                                         Appendix C
                                                        Abbreviations, Acronyms, Definition of Terms and References




Exempt Construction Activities: Activities exempt from the Permit, including routine maintenance to
maintain original line and grade, hydraulic capacity, or original purpose of the facility; and emergency
construction activities required to protect public health and safety. Local permits may not exempt these
activities.

Existing vegetation: Any vegetated area that has not already been cleared and grubbed.

Fair Weather Prediction: When there is no precipitation in the forecast between the current calendar day
and the next working day. The National Weather Service NOAA Weather Radio forecast shall be used. The
contractor may propose an alternative forecast for use if approved by the Engineer.

Feasible: Economically achievable or cost-effective measures which reflect a reasonable degree of pollutant
reduction achievable through the application of available nonpoint pollution control practices, technologies,
processes, site criteria, operating methods, or other alternatives.

Good Housekeeping: A common practice related to the storage, use, or cleanup of materials, performed in a
manner that minimizes the discharge of pollutants.

Local permit: An NPDES storm water permit issued to a District by the RWQCB having jurisdiction over
the job site. Requirements of the local permit are generally similar to, but supersede the requirements of the
General Permit. The District Storm Water Coordinator should be consulted to identify and to incorporate
variances between the local permit and General Permit.

National Pollutant Discharge Elimination System (NPDES) Permit: The national program for issuing,
modifying, revoking and reissuing, terminating, monitoring and enforcing Permits under the Clean Water Act.
A permit issued pursuant to the Clean Water Act that requires the discharge of pollutants to Waters of the
United States from storm water be controlled.

Non-active Construction Area: Any area not considered to be an active construction area. Active
construction areas become nonactive construction areas whenever construction activities are expected to be
discontinued for a period of 21 or more days during the rainy season.

Non-Storm Water Discharge: Any discharge to a storm drain system or receiving water that is not
composed entirely of storm water.

Notification of Construction (NOC): A formal notification submitted by Caltrans to the appropriate
Regional Water Quality Control Board (RWQCB) at least 30 days prior to the start of a construction project
that will result in the disturbance of two hectares (five acres) of soil. Information on the tentative start date,
tentative duration, location of construction, description of project, estimated number of affected acres, and the
name and phone number of the Resident Engineer is provided.

Notice of Completion of Construction (NCC): A formal notice submitted by Caltrans to the appropriate
Regional Water Quality Control Board (RWQCB) upon completion of the construction and stabilization of a
site, for Permit site terminating coverage under the permit. The NCC is filed by the RE.


          Caltrans Storm Water Quality Handbooks
          Project Planning and Design Guide                                                              Appendix C
          May 2000                                                                                                3
Appendix C
Abbreviations, Acronyms, Definition of Terms and References


Permanent BMP: BMPs that are installed during construction and designed to provide long-term storm
water quality protection following a project’s completion.

Permit: The NPDES Permit for Stormwater Discharges from the State of California Department of
Transportation (Caltrans) Properties, Facilities and Activities – Order No. 99-06-DWQ.

Project Engineer (PE): Caltrans staff responsible for preparation of Plans, Specifications, and Estimate
(PS&E) documents otherwise known as "contract plans" or "bid documents."

Project Manager (PM): Caltrans staff responsible for "shepherding" a project through the project planning
and development process, verifying that all requirements, including storm water protection, are met.

Pollution: The man-made or man-induced alteration of the chemical, physical, biological, and radiological
integrity of water. An alteration of the quality of the water of the state by waste to a degree which
unreasonably affects either the waters for beneficial uses or facilities that serve these beneficial uses.

Receiving Waters: All surface water bodies within the permit area.

Regional Water Quality Control Board (RWQCB): California agencies that implement and enforce Clean
Water Act Section 402(p) NPDES permit requirements, and are issuers and administrators of these permits as
delegated by EPA. There are nine regional boards working with the State Water Resources Control Board.

Regional Work Plan: A plan that describes how the various programs will be implemented by the Districts
in each region.

Resident Engineer (RE): The Caltrans representative charged with administration of construction contracts.
The RE decides questions regarding acceptability of material furnished and work performed. The RE has
"contractual authority" to direct the contractor and impose sanctions if the contractor fails to take prompt and
appropriate action to correct deficiencies. The following contractual sanctions can be imposed by the RE: (a)
withholding payments (or portions of payments), (b) suspending work, (c) bringing in a separate contractor to
complete work items (the contractor is billed for such costs), (d) assessing liquidated damages including
passing along fines for permit violations, (e) initiating cancellation of the construction contract.

Sediment: Organic or inorganic material that is carried by or suspended in water and that settles out to form
deposits in the storm drain system or receiving waters.

State Water Resources Control Board (SWRCB): California agency that implements and enforces Clean
Water Act Section 402(p) NPDES permit requirements, is issuer and administrator of these permits as
delegated by EPA. Works with the nine Regional Water Quality Control Boards.

Storm Drain System: Streets, gutters, inlets, conduits, natural or artificial drains, channels and watercourses,
or other facilities that are owned, operated, maintained and used for the purpose of collecting, storing,
transporting, or disposing of storm water.

Storm Water: Rainfall runoff, snow melt runoff, and surface runoff and drainage. It excludes infiltration
and runoff from agricultural land.

                                                                              Caltrans Storm Water Quality Handbooks
Appendix C                                                                    Project Planning and Design Guide
4                                                                             May 2000
                                                                                                          Appendix C
                                                         Abbreviations, Acronyms, Definition of Terms and References




Storm Water Inspector: Caltrans staff member who provides support to the Resident Engineer.
Coordinates activities and correspondence related to WPCP and SWPPP review and implementation.

Storm Water Pollution Prevention Plan (SWPPP): A plan required by the Permit that includes site
map(s), an identification of construction/contractor activities that could cause pollutants in the storm water,
and a description of measures or practices to control these pollutants. It must be prepared and approved
before construction begins. A SWPPP prepared in accordance with the Special Provisions and the Handbooks
will satisfy Standard Specifications Section 7-1.01G - Water Pollution, requirement for preparation of a
program to control water pollution.

Temporary Construction Site BMPs: BMPs that are required only temporarily to address a short-term
storm water contamination threat. For example, silt fences are located near the base of newly graded slopes
that have a substantial area of exposed soil. Then, during rainfall, the silt fences filter and collect sediment
from runoff flowing off the slope.

Total Maximum Daily Loads (TMDL): The maximum amount of a pollutant that a waterbody can
assimilate and still meet ambient water quality standards. TMDLs are established for water quality-limited
segments, which are defined as “any segment where it is known that water quality does not meet applicable
water quality standards, and/or is not expected to meet applicable water quality standards, even after the
application of technology-based effluent limitations…” (40 CFR 130.2(j)). TMDLs are implemented through
waste load allocations (WLA) applied to point sources and load allocations (LA) applied to nonpoint sources.

Water Pollution Control Program (WPCP): A program that must be prepared and implemented by the
construction contractor under Standard Specifications Section 7-1.01G - Water Pollution, for projects that
disturb less than 5 acres (2 hectares) of land.

Waste Discharge Identification Number (WDID): The unique project number issued by the SWRCB upon
receipt of the notice of intent (NOI).

Waste Load Allocations (WLA): The maximum load of pollutants each discharger of waste is allowed to
release into a particular waterway. Discharge limits are usually required for each specific water quality
criterion being, or expected to be, violated. Also, the portion of a stream’s total assimilation capacity
assigned to an individual discharge.

Rainy Season: The dates of the rainy season shall be as specified: use dates in the local permit if a local
permit is applicable to the project site and rainy season dates are specified therein; or, if the local permit does
not specify rainy season dates and/or in areas of the state not subject to a local permit, the rainy season dates
shall be determined using Table 3-5 of this Guide.




          Caltrans Storm Water Quality Handbooks
          Project Planning and Design Guide                                                               Appendix C
          May 2000                                                                                                 5
Appendix C
Abbreviations, Acronyms, Definition of Terms and References



References
California Bank and Shore Rock Slope Protection Design. Caltrans Study No. F90TL03 (June 1996)

California Storm Water Best Management Practices Handbooks, March 1993

Design and Construction of Urban Stormwater Management Systems, ASCE Manual and Report on
Engineering Practice No. 77/WEF Manual of Practice No. FD-20, 1992

Highway Drainage Guidelines, Volume III, Guidelines for Erosion and Sediment Control in Highway
Construction, American Association of State Highway and Transportation Officials (AASHTO), 1992

Retention, Detention, and Overland Flow for Pollutant Removal from Highway Stormwater Runoff, Volume
II, Design Guidelines, U.S. Department of Transportation, Federal Highway Administration, Publication No,
FHWA-RD-96-096, November 1996

State of California Department of Transportation Highway Design Manual

State of California Department of Transportation Standard Plans, July 1999

State of California Department of Transportation Standard Specifications, July 1999

Stormwater Management for Transportation Facilities, National Cooperative Highway Research Program,
Synthesis of Highway Practice 174, Transportation research Board, National Research Council, 1993

Urban Drainage Design Manual, Hydraulic Engineering Circular No. 22 – HEC22, U.S. Department of
Transportation, 1996

Urban Runoff Quality Management, ASCE Manual and Report on Engineering Practice No. 87/WEF Manual
of Practice No. 23, 1998




                                                                             Caltrans Storm Water Quality Handbooks
Appendix C                                                                   Project Planning and Design Guide
6                                                                            May 2000
                             Appendix D
                    Cross Reference between the
                  Caltrans Statewide Permit and the
                      Caltrans Statewide SWMP

                  Caltrans Statewide Permit vs. Caltrans Statewide SWMP
                                     Cross Reference
      Permit
#                                                Requirement                                  SWMP Reference
     Reference

1    Fact Sheet      Storm Water System Management – Assess need for IC/ID                  Sect. 4.2 & App. C – D
     (I.1.C.2.)      investigation or enhanced BMP program where inlets contain             Family
                     excessive material on a regular basis.
2    Fact Sheet      Accidental Spills – Spill notification to MS4s (compliance problem)    Sect. 4.3.3 & BMP D5a –
                     and RWQCB (potential impact on receiving water)                        Emergency Response &
                                                                                            Clean-up Practices
3    Fact Sheet      Illicit Connection/Illegal Discharge (IC/ID) Detection - Train field   Sect. 5.2.1
                     maintenance personnel to recognize IC/IDs and respond to them.

4    Fact Sheet      Method for receiving and responding to public complaints               Sect. 2.8
5    Fact Sheet      Program Evaluation and Monitoring – Coming year monitoring plan        Sect. 6.2.2.1
     (K.2.a)                                                                                Sect. 6.2.2.7 & separate
                                                                                            report
6    Fact Sheet      Characterization of representative discharges and possible beach       Sect. 6.2.2.1
                     closure areas
7    Fact Sheet      Evaluation of effectiveness of maintenance activity control measures   Sect. 6.2.2.4
                                                                                            Sect. 6.3.2.2
8    Fact Sheet      Evaluation of effectiveness of maintenance facility pollution          Sect. 6.3.2.2
                     prevention plans
9    Fact Sheet      Evaluation of effectiveness of construction erosion prevention and     Sect. 6.2.2.5
                     control measures                                                       Sect. 6.3.2.1
10   Fact Sheet      Evaluation of effectiveness of permanent control measures              Sect. 6.2.2.6
11   Fact Sheet      Evaluation of effectiveness of highway operation control measures      Sect. 6.2.2.4
                                                                                            Sect. 6.3.2.2, and
                                                                                            Appendix B.2.9
12   Fact Sheet      Annual program audit                                                   Sect. 6.3.2
13   Fact Sheet      Region Specific Concerns – Lahontan RWQCB requirements                 Sect. 7
     (L.1.)
14   Fact Sheet      Annual Report – Submit annual report                                   Sect. 6.4.1




        Caltrans Storm Water Quality Handbooks
        Project Planning and Design Guide                                                                   Appendix D
        May 2000                                                                                                     1
Appendix D
Cross Reference between
the Caltrans Statewide Permit and the Caltrans SWMP


                   Caltrans Statewide Permit vs. Caltrans Statewide SWMP
                                      Cross Reference
         Permit
  #                                              Requirement                                       SWMP Reference
        Reference

  15    B.3           Conditionally exempted non-storm water discharges – Develop               Sect. 4.5.1
                      appropriate control measures
  16    B.4           Conditionally exempted non-storm water discharges – Procedures            Sect. 4.5.1
                      for notifying the SWRCB of these discharges
  17    B.4           Conditionally exempted non-storm water discharges - Procedures            Sect. 6.3
                      for monitoring and record management
  18    B.7           Examine (IC/ID) results for elevated pollutants, follow-up as             Sect. 4.4.5
                      appropriate.
  19    B.8           Investigate need for BMPs for fire fighting and emergency activities.     Sect. 4.5.1
  20    B.9           Submit a Comprehensive Non-storm Water Report as part of the              Section 4.5.1
                      Annual Report.                                                            Section 6.4.1
  21    C-1.3.a       Municipal WQS exceedance - Notify and submit a report to the              Sect. 2.12
                      appropriate RWQCB.
  22    C-2.3.a       Construction WQS exceedance – Notification of RWQCB and report            Sect. 2.11
                                                                                                Sect. 2.12
  23    F.3           MEP analysis of structural controls for new construction or major         Sect. 2.4.2 (Category IB)
                      reconstruction                                                            and Appendix B
  24    F.3.a         Include list of appropriate control measures                              Appendix C
  25    F.3.b         Effective operation and maintenance program for BMPs                      Sect. 4 and Appendix C
  26    F.3.c         Spill containment                                                         Sect. 4.4.5 and Appendix
                                                                                                C
  27    F.3.d         Development and implementation of program to improve pollutant            Sect. 2.4.2 (Category IA)
                      removal landscape design                                                  and Sect. 6.2.2.5
  28    F.3.e         A description of how these BMPs will be developed, constructed and        Sect. 2.4
                      maintained
  29    F.3.f         A BMP Selection Report                                                    Sect. 2.4 and Appendix B
  30    F.3.f         The process shall include a mechanism for public input and review         Sect. 2.8
                      during the BMP selection process
  31    F.3.g         New Technology Report                                                     Sect. 2.4.4.2
                                                                                                Sect. 6.2.2.6
  32    F.4.a         Storm Water Drainage System Retrofitting                                  Sect. 4.7
  33    G.1.a         Coordination with MS4 Permittees                                          Sect. 2.6
  34    G.1.b         A Municipal Coordination Plan                                             Sect. 2.6
  35    G.2.a         Establish and maintain adequate legal authority.                          Sect. 2.9
  36    G.2.b         Analysis of the Adequacy of Legal Authority                               Sect. 2.9
  37    G.3.b         Fiscal Analysis                                                           Sect. 2.10



                                                                                      Caltrans Storm Water Quality Handbooks
Appendix D                                                                            Project Planning and Design Guide
2                                                                                     May 2000
                                                                                                            Appendix D
                                                                                             Cross Reference between
                                                                  the Caltrans Statewide Permit and the Caltrans SWMP


                 Caltrans Statewide Permit vs. Caltrans Statewide SWMP
                                    Cross Reference
      Permit
#                                                Requirement                                    SWMP Reference
     Reference

38   G.4             Policies to resolve conflicts between implementation of the storm        Sect. 2.4.4.2
                     water program and current standard practices and policies                Sect. 6.3
39   G.5             Inspection Program                                                       Sect. 6.3
40   H.1.a          Review of construction site plans by others                               Sect. 2.6.2
41   H.1.b          Requirement of structural and nonstructural BMP implementation as         Sect. 2.6.2
                    part of activities done by others
42   H.1.c          Site inspections and enforcement of work done by others                   Sect. 2.6.2
43   H.1.d           Education of construction site operators                                 Sect. 5.3
44   H.3             Follow Lahontan RWQCB erosion control guidelines. [Note: there           Sect. 7.4
                     appear to be various versions of these guidelines, with seemingly no
                     official versions.]
45   H.4             Plan, site, and develop roads and highways in a manner that              Sect. 2.4
                     protects water quality, beneficial uses of water and minimizes           Sect. 3.5
                     erosion and sedimentation and site, design, and maintain bridge
                     structures so that sensitive and valuable aquatic ecosystems and
                     areas providing water quality benefits are protected.
46   H.6             Limit the application, generation, and migration of toxic substances     Sect. 3.4
                     from construction sites.
47   H.7             Maintain erosion and sediment control BMPs during the interim            Sect. 4.4.2
                     period between completion of construction and final landscaping
                     activities.
48   H.8.a           Submit Notification of Construction be at least 30 days prior to the     Sect. 3.4
                     start of construction.
49   H.8.b           Involve RWQCB staff in the planning stages for projects that may         Sect. 3.5
                     have a significant potential water quality impact.
50   H.8.b           The SWPPP shall contain a BMP program for any mobile operations          Sect. 2.3.3.3
                     used at construction project.
51   I.1.a           Implement runoff management programs and systems for existing            Sect. 4
                     bridges and roadways.
52   I.1.a           Identify road segments with slopes that are prone to erosion and         Sect. 4.4.2
                     discharge of sediment and stabilize these slopes to the extent
                     possible.
53   b.(1)           Enhance use of appropriate native and adapted vegetation to              Sect. 4.4.2
                     prevent erosion and remove pollutants in runoff.                         Sect. 6.2.2.5
54   b.(2)           Apply herbicides such that herbicide runoff minimized or eliminated.     Sect. 4.4.4
                                                                                              Sect. 6.2.2.1
                                                                                              Sect. 6.2.2.7
55   b.(3)           Apply nutrients without causing significant nutrient runoff to surface   Sect. 4.4.4
                     water.

        Caltrans Storm Water Quality Handbooks
        Project Planning and Design Guide                                                                     Appendix D
        May 2000                                                                                                       3
Appendix D
Cross Reference between
the Caltrans Statewide Permit and the Caltrans SWMP


                    Caltrans Statewide Permit vs. Caltrans Statewide SWMP
                                       Cross Reference
         Permit
  #                                                 Requirement                                   SWMP Reference
        Reference

  56    b.(4)         Continue to implement existing vegetation control management             Sect. 4.4.4
                      plans, and integrating them into over all statewide plan.
  57    c.(1)         Remove all waste from those inlets that pose a significant threat to     Sect. 4.4.2
                      water quality on an annual basis prior to the winter season each
                      year.
  58    c.(2)         Drain inlets which contain significant materials must be considered      Sect. 4.4.2
                      for an IC/ID investigation and for an enhanced BMP program
                      focused on reducing the sources of the material found.
  59    1.2.a.(1)     Follow Office of Emergency Services procedure for reporting              Sect. 4.4.3
                      highway spills
  60    a.(2)         Spill Notification – Notify                                              Sect. 4.4.3
  61    a.(3)         Spill Notification – Report                                              Sect. 4.4.3
  62    b.(1)         Procedures for receiving and investigating public complaints             Sect. 2.8
  63    b.(1)         Post numbers for reporting complaints to Caltrans in places where        Sect. 4.4.3
                      illegal dumping is found to be a problem.
  64    b.(2)&(3)     Develop procedures to conduct investigations of every IC/ID to           Sect. 4.4.2
                      identify the source.
  65    b.(4)         Track all reports of IC/IDs and the action taken on them.                Sect. 4.4.2
  66    I.3.a         Prepare Maintenance FPPPs for all maintenance facilities.                Sect. 4.8
  67    J.            Continue participation in areas where Caltrans is already                Sect. 5.4
                      participating in an areawide Public Education Program.
  68    J.1.a         Implement the education program specified in the SWMP for                Sect. 5.2
                      Caltrans employees.
  69    J.1.b         Provide frequent educational reminders to employees to reinforce         Sect. 5.2.5
                      the training.
  70    J.2.a         Implement the education program specified in the SWMP for                Sect. 5.3
                      construction contractors.
  71    J.2.b         Provide outreach to contractors to raise their awareness of the          Sect. 5.3.2
                      problems and causes of storm water pollution and to reinforce their
                      training.
  72    J.3.b.(1)     Conduct research on public behavior that affects the quality of          Sect. 5.4
                      Caltrans runoff.
  73    K.I           Develop a characterization plan to identify and describe existing        Sect. 6.2
                      major discharges and points of discharge.
  74    K.I           For discharges containing pollutants, Caltrans shall investigate the     Sect. 4.4.2
                      source of the pollutants and as appropriate, eliminate the IC/ID or      Sect. 6.2
                      implement BMP programs. The characterization plan shall identify
                      procedures for notifying the appropriate RWQCB.
  75    K.I           Plan for Characterization Studies                                        Sect. 6.2


                                                                                     Caltrans Storm Water Quality Handbooks
Appendix D                                                                           Project Planning and Design Guide
4                                                                                    May 2000
                                                                                                            Appendix D
                                                                                             Cross Reference between
                                                                  the Caltrans Statewide Permit and the Caltrans SWMP


                  Caltrans Statewide Permit vs. Caltrans Statewide SWMP
                                     Cross Reference
      Permit
#                                                 Requirement                                   SWMP Reference
     Reference

76   K.2                              Monitoring Strategy Report Update                       Sect. 6.2
77   K.2.a            Monitoring and Reporting Program                                        Sect. 6.2
78   K.3              Plan to notify RWQCBs about noncompliance                               Sect. 2.11
79   K.3.c.(1)        Conduct periodic inspections at maintenance facilities.                 Sect. 4.8
                                                                                              Sect. 6.3
80   K.3.c.(2)        Report maintenance facility noncompliance to the RWQCB per              Sect. 2.11
                      K.3.a.
81   K.3.d.           Perform annual self-audit of the storm water program.                   Sect. 6.3
82   K.3.d.           Outline of the proposed audit (compliance review plans)                 Sect. 6.3.2
83   K4               Annual Report                                                           Sect. 6.4.1
84   L                Location specific requirements – Lahontan Region                        Sect. 7
85   M.1              Ensure that all personnel whose decisions or activities could affect    Sect. 5.2
                      storm water quality are familiar with Permit contents.
86   M.4              Properly operate and maintain at all times any facilities and systems   Sect. 2.3.3.3
                      of treatment and control.                                               Sect. 4.4.6
87   M.6              Comply with the Standard Provisions for NPDES Permits at 40 CFR
                      122.41 and 40 CFR 122.42(c).
                      •   Notice of Changes to Facilities                                     Sect. 3.4
                      •   Report of anticipated non-compliance(s)                             Sect. 2.11.1




         Caltrans Storm Water Quality Handbooks
         Project Planning and Design Guide                                                                    Appendix D
         May 2000                                                                                                      5
                    Appendix E
Sample District NPDES Program Responsibility Matrix

                                                                                                                                                                          SWQ Handbook
                                     Task Assignments as per the Storm                                                                                                      Reference:




                                                                             Planning SWC
                                     Water Quality (SWQ) Handbooks




                                                                                                     Construction

                                                                                                     Construction
                                                                             Management




                                                                                                                                 Right of Way



                                                                                                                                                          Maintenance
                                                                             Design PSR
                                                                                                                                                                        P = Project Planning &




                                                                                                                    Contractor
                                                                                                                                                                            Design Guide
     Project                         C = Concurrence                                                                                                                    C = Construction Site




                                                                                                                                                Permits
                                                                             Project
                                     R = Responsible




                                                                                            Design
Milestone                                                                                                                                                                   BMPs Guide




                                                                             SWC




                                                                                                     SWC
                                     A = Assist                                                                                                                         M = Maintenance Guide




                                                                             PSR




                                                                                                     RE
                                     O = Oversight                                                                                                                      S = Statewide Permit
                                                                                                                                                                        G = General Permit
                                 1            Develop Initial Assessment of R    A
             Project Planning




                                             treatment controls during PSR
                                 2 Impacts to receiving waters                   R

                                 3 Involve RWQCB staff in planning               R
                                   stages for projects that may have a
                                   significant potential water quality
                                   impact
                                 4 Identifying necessary Permanent BMPs          A          R               A

                                 5 Consider Temporary Critical Controls &        A          R               A
                                   Scheduling
                                 6 Preliminary sizing of Treatment and                      R
                                   Streambank Erosion controls
                                 7 Determination and R/W layout for                         R                                                             C
                                   permanent treatment controls
                                 8 Design of permanent treatment                 A          R                                                             C
                                   controls, streambank erosion & critical
             Project Design




                                   temporary controls
                                 9 WPCP/ SWPPP Determination,                    A          R
                                   Incorporate appropriate Special
                                   Provisions
                                10 Incorporation of other water quality          A          R
                                   features as required of CEQA, NEPA,
                                   Fed, State or local permit into PS&E
                                11 Prepare Notification of Construction              A      R
                                   (NOC)
                                12 Submit NOC to Planning 35 days                    R      A
                                   before Construction
                                13 File NOC 30 days prior to construction        R
                                   with Regional Board
                                14 Update NOC with RE name change                                    R                                                                  G-C.18
      Contract is is Ready
Contract

                    to List




                                15 File updated NOC with Regional Board          R                   A      A                                                           G-C.18

                                16 Review project files and PS&E. confirm        A          A        R
       Awarded




                                   correct SSPs are in PS & E

                                17 Conduct Pre-Construction meeting                         A        R      A




                  Caltrans Storm Water Quality Handbooks
                  Project Planning and Design Guide                                                                                                                                 Appendix E
                  May 2000                                                                                                                                                                   1
Appendix E
Sample District NPDES Program Responsibility Matrix




                                                                                                                                                                                 SWQ Handbook
                                          Task Assignments as per the Storm                                                                                                        Reference:




                                                                                    Planning SWC
                                          Water Quality (SWQ) Handbooks




                                                                                                            Construction

                                                                                                            Construction
                                                                                    Management




                                                                                                                                        Right of Way



                                                                                                                                                                 Maintenance
                                                                                    Design PSR
                                                                                                                                                                               P = Project Planning &




                                                                                                                           Contractor
       Project                            C = Concurrence                                                                                                                          Design Guide
                                                                                                                                                                               C = Construction Site




                                                                                                                                                       Permits
    Milestone




                                                                                    Project
                                          R = Responsible




                                                                                                   Design
                                                                                                                                                                                   BMPs Guide




                                                                                    SWC




                                                                                                            SWC
                                          A = Assist                                                                                                                           M = Maintenance Guide




                                                                                    PSR




                                                                                                            RE
                                          O = Oversight                                                                                                                        S = Statewide Permit
                                                                                                                                                                               G = General Permit
                                      18 Provide contractor with appropriate            A                   R      A
                                         information/ documents for
                                         WPCP/SWPPP
     Contract is




                                      19 Prepare WPCP or SWPPP for RE                                       A      A       R
      Awarded




                                         review

                                      20 Review WPCP or SWPPP                           A                   R      C

                                      21 Request changes in WPCP/SWPPP                  A                   R      A
                                         based on reviews

                                      22 Revise WPCP/SWPPP to meet                                                         R
                                         standards

                                      23 Approve WPCP or SWPPP prior to                 C                   R      C
                                         construction (by RWQCB’s request 30
                                         days prior to construction for sensitive
                                         projects)
                                      24 Implement WPCP / SWPPP                         O                   R      A       R

                                      25 Ensure permits from other agencies are         A                   R              R
                                         adhered to including Reporting,
                                         Certifications, and record keeping
         Project is in Construction




                                      26 Maintain RE files and SWPPP/ WPCP                                  R      O
                                         with Amendments
                                      27 Maintain Contractor files                                          O      O       R

                                      28 Comply with the requirements of the            O                   R      A       R
                                         SSP’s, Project Plans, NPDES Permit
                                         and Construction General Permit
                                      29 Require amendments of the WPCP/                O                   R      A       R
                                         SWPPP as necessary to meet the
                                         SSP’s, Plans, NPDES and General
                                         Construction Permit
                                      30 Designate assigned staff to act as                                 R
                                         Storm Water Inspector

                                      31 Inspect projects for compliance with           O                   R      A       R
                                         WPCP / SWPPP & SSP
                                      32 Observe, report and direct cleanup of          O                   R
                                         illegal dumping or illicit connections
                                         detected on construction sites


                                      33 Review inspection results from Storm           A,                  R      A
                                         Water Inspector and Contractor                 O

                                      34 Prepare Notice of Noncompliance                A                   R      A,      R
                                                                                                                   C



                                                                                                                                        Caltrans Storm Water Quality Handbooks
Appendix E                                                                                                                              Project Planning and Design Guide
2                                                                                                                                       May 2000
                                                                                                                                                                 Appendix E
                                                                                                                            Sample District NPDES Program Responsibility Matrix




                                                                                                                                                                                                 SWQ Handbook
                                                          Task Assignments as per the Storm                                                                                                        Reference:




                                                                                                    Planning SWC
                                                          Water Quality (SWQ) Handbooks




                                                                                                                            Construction

                                                                                                                            Construction
                                                                                                    Management




                                                                                                                                                        Right of Way



                                                                                                                                                                                 Maintenance
                                                                                                    Design PSR
                                                                                                                                                                                               P = Project Planning &




                                                                                                                                           Contractor
                                                                                                                                                                                                   Design Guide
          Project                                         C = Concurrence                                                                                                                      C = Construction Site




                                                                                                                                                                       Permits
                                                                                                    Project
                                                          R = Responsible




                                                                                                                   Design
                                                                                                                                                                                                   BMPs Guide
Milestone




                                                                                                    SWC




                                                                                                                            SWC
                                                          A = Assist                                                                                                                           M = Maintenance Guide




                                                                                                    PSR




                                                                                                                            RE
                                                          O = Oversight                                                                                                                        S = Statewide Permit
                                                                                                                                                                                               G = General Permit
                                                      35 File Notice of Noncompliance with              R                          A                                                           S-K.3.a
                                                         Regional Board verbally w/n 5 working
                                                         days, w/ written follow up w/n 30 days
                                                         of Noncompliance discovery
                                                      36 Notify Storm Water Coordinator of              A                   R              R                                                   S- I.2.a(3)
                                                         discharge causing or contributing to an
                                                         exceedance of an applicable Water
                         Project is in Construction




                                                         Quality Standards (WQS)
                                                      37 Notify RWQCB by telephone w/n 48               R                          A
                                                         hours of discharge discovery and a
                                                         written report to RWQCB w/n 14 days
                                                         of discharge discovery
                                                      38 Take actions against the contractor for        A                   R      A
                                                         failure to comply with the requirements
                                                         of WPCP/ SWPPP, SSP
                                                      39 Prepare Notice of Completion: with         O                       R      A                                             C             G-7.1
                                                         70% coverage of vegetation or
                                                         equivalent measures
                                                      40 Pre-completion walk-thru with                      R               A                                                    C
                                                         maintenance and Storm Water
                                                         Coordinator
                                                      41 File Notice of Completion with RWQCB           R                                                                                      S- H.8.d

                                                      42 Pass Project files to Maintenance                  O      A        R                                                    C

                                                      43 Prepare Annual Certification                   O                   R      O       R

                                                      44 Keep Records of all inspectors,                                    R
                                                         compliance certifications, and non-
                                                         compliance reporting for a least three
                                                         (3) years
                                                      45 Maintain Storm Water Drainage                                                                                           R             M-1.7
Maintenance Operations
                                Highways




                                                         System & Pumping Facilities
                                                      46 Perform Highway Surveillance                   O                                                                        R             M-1.8
                                                         Activities; Receive Notification of
                                                         accidental spills or threat of discharge
                                                         and report it to planning Storm Water
                                                         Coordinator, Maintain IC/ ID file
                                                      47 Prepare and approve a Facility                 C                                                                        R
                                                         Pollution Prevention Plan (FPPP)
                                Yards




                                                      48 Maintenance Yard compliance during             O                                                                        R
                                                         operation, non-compliance filing and
                                                         reporting to Regional Board




                                      Caltrans Storm Water Quality Handbooks
                                      Project Planning and Design Guide                                                                                                                                      Appendix E
                                      May 2000                                                                                                                                                                        3
Appendix E
Sample District NPDES Program Responsibility Matrix




                                                                                                                                                             SWQ Handbook
                        Task Assignments as per the Storm                                                                                                      Reference:




                                                                Planning SWC
                        Water Quality (SWQ) Handbooks




                                                                                        Construction

                                                                                        Construction
                                                                Management




                                                                                                                    Right of Way



                                                                                                                                             Maintenance
                                                                Design PSR
                                                                                                                                                           P = Project Planning &




                                                                                                       Contractor
      Project           C = Concurrence                                                                                                                        Design Guide
                                                                                                                                                           C = Construction Site




                                                                                                                                   Permits
   Milestone




                                                                Project
                        R = Responsible




                                                                               Design
                                                                                                                                                               BMPs Guide




                                                                SWC




                                                                                        SWC
                        A = Assist                                                                                                                         M = Maintenance Guide




                                                                PSR




                                                                                        RE
                        O = Oversight                                                                                                                      S = Statewide Permit
                                                                                                                                                           G = General Permit
                    49 Submit Encroachment Permit                   A                                                              R
   of Way Permits




                       Application for Review of Water
                       Pollution Control Provisions
                    50 Review Encroachment Permit                   R                                                              A
                       Application and Review Water Pollution
                       Control Provisions.

                    51 Submit Airspace Lease/ Demolition            A                                               R
    Right




                       Application for Review of Water
                       Pollution Control Provisions
                    52 Review Airspace Lease/ Demolition            R                                               A
                       Application for Review of Water
                       Pollution Control Provisions




                                                                                                                    Caltrans Storm Water Quality Handbooks
Appendix E                                                                                                          Project Planning and Design Guide
4                                                                                                                   May 2000
                                    Appendix F
                              Treatment Design Storm


This information is presently under development and it will be distributed as soon as it is completed.




         Caltrans Storm Water Quality Handbooks
         Project Planning and Design Guide                                                    Appendix F
         May 2000                                                                                      1

								
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