&EPA
United States
Environmental Protection
Agency !
Office of Water
(4203M)
EPA-833-R-01-002
JULY 31, 2001
Guidance: Coordinating GSO
Long-Term Planning With
Water Quality Standards Reviews
-------
United States Office of Water EPA-833-R-01-002
Environmental Protection (4203M) JULY 31,2001
Agency
&EPA
GUIDANCE:
COORDINATING CSO LONG-TERM PLANNING
WITH
WATER QUALITY STANDARDS REVIEWS
-------
NOTICE
The Guidance: Coordinating CSO Long-Term Planning with Water Quality Standards
Reviews is designed to address questions on integrating development of CSO long-term control
plans (LTCPs) with water quality standards reviews. These questions have been raised since the
1994 publication of the CSO Control Policy, and EPA is responding to them by expanding on its
existing guidance.
The guidance included in this document cannot impose legally binding requirements on
EPA, states, tribes, or the regulated community. It cannot substitute for Clean Water Act (CWA)
requirements, EPA's regulations, or the obligations imposed by consent decrees or enforcement
orders. Further, this guidance might not apply to a particular situation based upon the
circumstances.
-------
FOREWORD
EPA issued the Combined Sewer Overflow (CSO) Control Policy in April 1994 (59 FR
18688). To date, EPA has released seven guidance documents and worked with stakeholders to
foster implementation of the Policy. EPA continues to affirm the Policy's key themes, such as
providing clear levels of control, using a flexible permitting approach, allowing phased
implementation of CSO controls based on a community's financial capability, and reviewing and
revising, as appropriate, water quality standards. In practice, many challenges remain, and
implementation of the Policy has not met some initial expectations.
The CSO Policy calls for the development of a long-term control plan (LTCP) which
includes measures that provide for compliance with the Clean Water Act, including attainment of
water quality standards. LTCP development that is consistent with the CSO Policy is key to the
success of local CSO control efforts. The CSO Policy provides that" [d]Development of the long-
term plan should be coordinated with the review and appropriate revision of water quality
standards (WQS) and implementation procedures on CSO-impacted receiving waters to ensure
that the long-term controls will be sufficient to meet water quality standards"'' (59 FR 18694). In
the seven years since EPA issued the CSO Control Policy, implementation of this principle has
not progressed as quickly as expected.
Given local resource constraints, CSO communities need clear guidance on how they
should implement the CSO control and other wet weather water pollution control programs to
attain water quality standards. Water quality standards reviews are an important step in
integrating the development and implementation of affordable, well-designed and operated CSO
control programs with the requirements of the Clean Water Act (CWA). However, the Agency
recognizes that State and Interstate Water Pollution Control Directors will need to set priorities
for water quality standards reviews based on a number of factors, including court-mandated total
maximum daily load (TMDL) analyses. EPA plans to actively participate in and facilitate the
process wherever possible.
As part of EPA's FY 1999 Appropriation, Congress directed EPA to develop guidance on
the conduct of water quality standards and designated use reviews for CSO receiving waters.
Congress further urged EPA to provide technical and financial assistance to states and EPA
Regions to conduct these reviews. In response, EPA hosted three stakeholder listening sessions
in the spring of 1999 and an experts workshop on September 24, 1999. The purpose of these
meetings was to obtain participants' views on the impediments to implementing the water
quality-based provisions in the CSO Policy, and actions that EPA should take. In December
2000, Congress enacted CWA amendment 402(q)(2) requiring publication of the guidance by
July 31, 2001, after public review and comment. The Guidance: Coordinating CSO Long-Term
Planning with Water Quality Standards Reviews addresses many of the stakeholder concerns.
The objective of this guidance is to lay a strong foundation for integrating CSO long-term
control planning with water quality standards reviews. Agreement among CSO communities,
states, and EPA on the data to be collected and the analyses to be conducted to support the long-
-------
term control plan development and water quality standards reviews can facilitate water quality
standards reviews for CSO-receiving waters.
The guidance describes the process for integrating LTCP development and
implementation with the water quality standards review. This process is the essence of EPA's
commitment to facilitating the review and revision, as appropriate, of water quality standards for
CSO-impacted receiving waters. Integrating CSO long-term control planning with water quality
standards reviews requires greater coordination among CSO communities, states, EPA, and the
public. Although this coordination is an intensive process, it provides greater assurance that
CSO communities will implement affordable CSO control programs that support the attainment
of appropriate water quality standards.
As outlined in the guidance, EPA will continue to implement the CSO Control Policy
through its existing statutory and regulatory authorities. The principal mechanisms are the
National Pollutant Discharge Elimination System (NPDES) permit program and the water quality
standards program. NPDES authorities are and will continue to be responsible for implementing
the CSO Control Policy. EPA commits to working with State and Interstate Water Pollution
Control Directors to implement all aspects of the CSO Control Policy, including the integration
of LTCP development with the review and revision, as appropriate, of water quality standards.
MichaellB. Cook, Director Diane C Regas Geoffrey H. rubbs, Director
Office of WastewatenManagement Acting Assistant Administrator Office of Science and Technology
Date: 7 31 O\ Date: g/2./O/ Date: 7/>//fu
r __,^ f '
11
-------
TABLE OF CONTENTS
FOREWORD i
GLOSSARY vi
I. INTRODUCTION 1
1. Why is EPA developing this guidance? 1
2. What is EPA's goal? 2
3. What is included in this guidance? 3
A. Existing program framework 3
B. Reviewing and revising, as appropriate, water quality standards 5
C. Integrating CSO LTCP development and implementation with
water quality standards reviews 6
D. The watershed approach 8
II. EXISTING PROGRAM FRAMEWORK 9
1. CSO Program Framework 9
A. What is the statutory authority for controlling CSOs? 9
B. What are the technology-based requirements for
controlling CSOs? 9
C. What are the water quality-based requirements for
controlling CSOs? 9
D. What options are available in developing an LTCP that meets the
intent of the water quality-based provisions of the CSO Control
Policy? 10
E. How do CSO LTCP monitoring and modeling activities support
water quality standards reviews? 12
2. Water Quality Standards Program Framework 14
A. Who is responsible for water quality standards? 14
B. How does a state develop and adopt water quality standards? 15
C. How do states classify their uses? 16
D. How do states protect recreational uses, particularly in
urban areas? 16
E. What are the appropriate criteria for protecting primary contact
recreation? 18
F. Where are the bacteria criteria applied? 21
G. How do states protect aquatic life uses? 21
H. How have some states developed more refined aquatic life uses? ... 22
I. Why are refined aquatic life uses important in the urban
environment? 23
in
-------
J. What steps are necessary to develop a system of tiered aquatic life
uses and subcategories for urban systems? 24
K. What is the process for assigning subcategories of uses to
individual water bodies? 25
III. REVIEWING AND REVISING WATER QUALITY STANDARDS 28
1. How often are water quality standards reviewed? 28
2. What type of water quality standards revisions are possible? 28
3. What type of analysis is required to remove or lower the level of
protection for a use? 29
4. What bases may be appropriate for determining that a use is not
attainable in CSO receiving waters? 30
5. Are there ways to simplify the VAA process? 32
6. What is a variance and when is it appropriate? 34
IV. INTEGRATING CSO LTCP DEVELOPMENT AND IMPLEMENTATION WITH
WATER QUALITY STANDARDS REVIEWS 36
1. How do you integrate the development of CSO LTCPs by communities
and the review of water quality standards by states? 36
2. How have states reconciled their water quality standards with overflows
remaining after a well-designed CSO LTCP has been developed? 47
3. How will EPA ensure that NPDES authorities and State Water Directors
participate in the review and revisions, as appropriate, of water quality
standards for CSO-receiving waters? 50
V. THE WATERSHED APPROACH 51
1. What is EPA's overall approach to watershed-based planning? 51
A. What information sources are available on watershed approaches?
51
B. How does watershed planning relate to TMDL development? 52
C. How does watershed planning affect capital planning? 53
D. Who sets the priorities for TMDLs? 53
2. How does CSO planning fit into a watershed approach? 53
3. How do states with CSO communities use watershed approaches? 55
VI. CONCLUSION 56
APPENDIX I
ANNOTATED BIBLIOGRAPHY OF CSO GUIDANCE DOCUMENTS A-l
APPENDIX II
REMOVAL OF DESIGNATED USES - 40 CFR 131.10 (g) AND (h) A-3
IV
-------
APPENDIX III
LIST OF GUIDANCE TO SUPPORT USE ATTAINABILITY ANALYSES (UAAs)
A-5
APPENDIX IV
DISCUSSION OF USE ATTAINABILITY ANALYSIS FOR RECREATIONAL USES
A-8
TABLES
Table 1 - Types of CSO Data Supporting Water Quality Standards Reviews 13
Table 2 - Categorical Uses 16
Table 3 - Qualitative Uses 16
Table 4 - Summary of EPA-Recommended Water Quality Criteria for Bacteria 20
Table 5 - Aquatic Life Use Classes 22
Table 6 - Water Body Classifications 23
Table 7 - Developing a Refined Aquatic Life Designated Use System 26
FIGURES
Figure 1 - Coordination of LTCP Development and Water Quality Standards Review and
Revision 38
-------
GLOSSARY
Best management practices ("BMPs") means schedules of activities, prohibitions of practices,
maintenance procedures, and other management practices to prevent or reduce the pollution of
"waters of the United States." BMPs also include treatment requirements, operating procedures,
and practices to control plant site runoff, spillage or leaks, sludge or waste disposal, or drainage
from raw material storage.
CWA means the Clean Water Act (formerly referred to as the Federal Water Pollution Control
Act or Federal Water Pollution Control Act Amendments of 1972). It is codified in Public
Law 92-500, as amended by Public Law 95-217, Public Law 95-576, Public Law 96-483 and
Public Law 97-117, 33 U.S.C. 1251 et seq.
Combined sewage means domestic and industrial wastewater and storm drainage carried in the
same pipe.
Combined sewer is a sewer designed to carry domestic and industrial wastewater and storm
water runoff in the same pipe.
Combined sewer overflow ("CSO") means the portion of flow from a combined sewer system
(CSS) that discharges into a water body from an outfall located upstream of the headworks of a
POTW, usually during a rainfall event or the outfall pipe which carries this discharge.
Criteria are elements of state water quality standards, expressed as constituent concentrations,
levels, or narrative statements, representing a quality of water that supports a particular use.
When criteria are met, water quality will generally protect the designated use.
Designated uses are those uses specified in water quality standards for each water body or
segment whether or not they are being attained.
Environmental Protection Agency ("EPA ") means the United States Environmental Protection
Agency.
Existing uses are those uses actually attained in the water body on or after November 28, 1975,
whether or not they are included in the water quality standards.
Infiltration means water other than wastewater that enters a wastewater system and building
sewers from the ground through such means as defective pipes, pipe joints, connections, and
manholes. (Infiltration does not include inflow.)
Infiltration and inflow ("I/I") means the total quantity of water from both infiltration and
inflow.
VI
-------
Inflow means water other than wastewater that enters a wastewater system and building sewers
from sources such as roof leaders, cellar drains, yard drains, area drains, foundation drains, drains
from springs and swampy areas, manhole covers, cross connections between storm drains and
sanitary sewers, catch basins, cooling towers, storm waters, surface runoff, street wash waters,
and drainage. (Inflow does not include infiltration.)
Interceptor sewer means a sewer without building sewer connections that is used to collect and
carry flows from main and trunk sewers to a central point for treatment and discharge.
Municipality means a city, town, borough, county, parish, district, association, or other public
body created by or under state law and having jurisdiction over disposal of sewage, industrial
wastes, or other wastes, or an Indian tribe or an authorized Indian tribal organization, or a
designated and approved management agency under section 208 of CWA.
National Pollutant Discharge Elimination System (NPDES) means the national program for
issuing, modifying, revoking and reissuing, terminating, monitoring and enforcing permits, and
imposing and enforcing pretreatment requirements, under sections 307, 402, 318, and 405 of the
CWA. The term includes an "approved program."
Peak flow means the maximum flow that occurs over a specific length of time (e.g. daily, hourly,
instantaneous).
Point source means any discernible, confined, and discrete conveyance, including but not limited
to, any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock,
concentrated animal feeding operation, landfill leachate collection system, vessel or other
floating craft from which pollutants are or may be discharged. This term does not include return
flows from irrigated agriculture or agricultural storm water runoff. (See §122.3).
Publicly Owned Treatment Works, or POTW, means a treatment works as defined by section
212 of the CWA, that is owned by a state or municipality (as defined by section 502(4) of the
CWA). This definition includes any devices and systems used in the storage, treatment, recycling
and reclamation of municipal sewage or industrial wastes of a liquid nature. It also includes
sewers, pipes and other conveyances only if they convey wastewater to a POTW treatment plant.
The term also means the municipality as defined in section 502(4) of the CWA, which has
jurisdiction over the indirect discharges to, and the discharges from, such a treatment works.
Storm water means storm water runoff, snow melt runoff, and surface runoff and drainage.
Total maximum daily load (TMDL) is a calculation of the maximum amount of a pollutant that
a waterbody can receive and still meet water quality standards, and an allocation of that amount
to the pollutant's sources, as described in 40 CFR 130.2(g)-(i)
vn
-------
Use attainability analysis (UAA) is a structured scientific assessment of the factors affecting the
attainment of a designated use, such as physical, chemical, biological, and economic factors as
described in § 131.10(g).
Variance is a discharger-specific, short-term modification to the applicable water quality
standard. A legal permit for the discharger may be based on a variance.
Water quality standards are provisions of state or federal law which consist of a designated use
or uses for the waters of the United States, water quality criteria to protect the most sensitive uses
for such waters, and an antidegradation policy and implementation procedures to protect water
quality. Water quality standards are established to protect the public health or welfare, enhance
the quality of water and serve the purposes of the CWA.
Wet weather flow means dry weather flow combined with storm water introduced into a
combined sewer, and dry weather flow combined with inflow in a separate sewer.
Vlll
-------
I. INTRODUCTION
1. Why is EPA developing this guidance?
This guidance demonstrates the U.S. Environmental Protection Agency (EPA)'s renewed
commitment to assuring that states and communities with combined sewer systems participate in
implementing the water quality-based provisions in the Combined Sewer Overflow (CSO)
Control Policy. The CSO Control Policy anticipates the "review and revision, as appropriate, of
water quality standards and their implementation procedures when developing CSO control plans
to reflect site-specific wet weather impacts of CSOs."
As part of EPA's FY 1999 Appropriation, Congress urged the Agency to facilitate water
quality and designated use reviews for CSO receiving waters by developing guidance for states
and Regional Offices. To develop this guidance, EPA held three listening sessions and a
September 1999 EPA-Water Environment Federation (WEF) experts workshop. EPA sought and
received a wide range of diverse perspectives on impediments to implementing the water quality-
based provisions in the CSO Control Policy, by talking with state and EPA staff, CSO
communities and their consultants, and environmental and watershed organizations. The
listening sessions and the experts workshop confirmed a need for guidance and clarifications in
the existing regulatory requirements and options available to the state in revising water quality
standards.1 In December 2000, Congress added Section 402(q) to the CWA to require
publication of this guidance by July 31, 2001. EPA prepared a draft guidance for public review
and comment (66 FR 364, January 3, 2001). EPA received comments from 27 interested parties.
EPA reviewed the comments and made appropriate changes to the draft guidance in response to
the submitted comments.
This guidance lays a strong foundation for integrating water quality standards reviews,
implementation of high-priority CSO controls, and development of well-designed and operated
LTCPs that support attainment of water quality standards without causing substantial and
widespread economic and social impacts. This integration occurs through increased coordination
and cooperation among CSO communities, constituency groups, states and EPA. Through
increased coordination and cooperation, CSO communities and states will be better able to
address the many scientific, technical, and economic issues involved in developing LTCPs that
1 EPA summaries of the listening sessions and of the experts workshop are: (1) Summary of the Listening
Sessions (EPA-823-R-99-017) and (2) Summary of Participant Comments at the EPA-WEF Experts
Workshop (EPA-823-R-99-016)). You can find these documents at www.epa.gov/ost/cso or request hard
copies from:
U.S. EPA/NSCEP
P.O. Box 42419
Cincinnati, OH 45242-2419
Phone: 1-800-490-9198 or (513) 489-8190
Fax: (513)489-8695
Web Site: www.epa.gov/ncepi.htm
-------
comply with permit requirements based on applicable water quality standards, and in determining
if revisions to the standards are appropriate.
This guidance applies to the development and implementation of CSO LTCPs. However,
many of the processes, procedures and ideas presented here can be used to address wet weather
issues such as storm water and other point and nonpoint sources on a watershed basis.
2. What is EPA's goal?
EPA's goal is for CSO communities to develop and implement cost-effective LTCPs that
achieve compliance with applicable water quality standards and with other CWA requirements,
and for states to review and revise water quality standards as appropriate to ensure they are
attainable. By phasing the implementation of CSO controls and evaluating their efficacy as they
are installed, communities and states can manage the complexities of: (1) improving the quality
of urban waters affected by many sources; (2) financing the high costs of structural CSO
controls; and (3) integrating LTCP development and implementation with water quality standards
reviews.
During LTCP development, EPA expects communities to identify priority controls for
sensitive areas, such as elimination or treatment of an overflow that impacts a bathing area.
These priority controls should be common to all LTCP scenarios, and therefore should be
implemented expeditiously. Following installation of these controls, communities and states will
need to collect post-construction compliance data to evaluate the effectiveness of the controls in
improving water quality and supporting the uses of the water body. If the data show that with the
installed controls CSOs will continue to contribute to the impairment of water quality standards,
the NPDES authority should work with the CSO community to evaluate other CSO control
alternatives identified in the LTCP. If, however, chemical, physical or economic factors appear
to preclude attainment of the use, the data collected during the planning process may be used to
support revisions to water quality standards. These revisions could include adoption of uses that
better reflect the water quality that can be achieved with a level of CSO control that does not
cause substantial and widespread economic and social impact.
Greater levels of coordination are needed to integrate CSO control planning and
implementation with water quality standards reviews. This guidance will clarify the roles and
responsibilities in this process for CSO communities, NPDES and water quality standards
authorities, community and environmental organizations, and EPA.
EPA plans to participate actively in the process and will encourage others to participate
actively. With increased coordination and cooperation, and the active participation of all entities
in integrating the CSO long-term control planning processes and water quality standards reviews,
states should be able to revise water quality standards as appropriate in cases where standards are
not attainable, and communities should be able to develop LTCPs that provide for the attainment
of water quality standards.
-------
3. What is included in this guidance?
This guidance focuses on improving the implementation of the water quality-based
provisions in the CSO Control Policy by: (1) outlining ways to improve the level of coordination
and cooperation among CSO communities, State Water Directors2, community and
environmental organizations, and EPA; (2) integrating development of the LTCP and
implementation of high-priority controls with the review and revision, as appropriate, of water
quality standards; and (3) reconciling water quality standards with well-designed and operated
CSO LTCPs without causing substantial and widespread economic and social impacts.
A. Existing program framework
This guidance summarizes the statutory and regulatory requirements governing the CSO
control program and the water quality standards program. The discussion also covers policy and
existing guidance documents that support the integration of LTCP development and
implementation with water quality standards reviews.
CSO Program Framework
Under the CSO Control Policy, communities with combined sewer systems are expected
to develop LTCPs that provide for attainment of water quality standards. By law, discharges that
remain after implementation of the LTCP must not interfere with the attainment of water quality
standards. More detailed information on the process for developing and implementing an LTCP
is provided in Combined Sewer Overflows - Guidance for Long-Term Control Plans. Appendix I
includes an annotated bibliography of all the CSO guidance documents.
EPA offers two approaches for CSO communities to consider when evaluating CSO
control options and ultimately selecting alternatives. These are:
! The "presumption approach," under which achievement of certain performance
criteria (i.e., 4-6 untreated overflow events or 85 percent by volume capture)
would be presumed to provide an adequate level of control to attain water quality
standards;
! The "demonstration approach," developing and implementing an LTCP that meets
applicable water quality standards.
Both approaches would entail post-construction compliance monitoring to demonstrate
attainment of water quality standards.
In selecting the demonstration approach, a community would have several options for
developing an LTCP to meet applicable water quality standards. A community could, for
2 State Water Directors could include State and Interstate Water Pollution Control Directors or other
entities responsible for NPDES permits, enforcement and water quality standards.
3
-------
example, develop an LTCP that would provide for attainment of currently-applicable water
quality standards, or it could use a total maximum daily load (TMDL) to demonstrate that water
quality standards can be attained through a combination of CSO controls and other controls.
This document describes a third alternative: Working with water quality standards and NPDES
authorities to integrate water quality standards reviews and revisions, as appropriate, with the
development of a CSO control program that supports the attainment of water quality standards
without causing substantial and widespread economic and social impacts.
Water Quality Standards Program Framework
The CWA establishes the statutory framework governing the development of water
quality standards and their use. Congress set an interim goal in section 101(a)(2) of the CWA to
provide, wherever attainable, water quality for the protection and propagation offish, shellfish,
and wildlife and for recreation in and on the water. Section 303 of the CWA directs states and
tribes, where authorized, to adopt water quality standards that protect human health and welfare,
enhance the quality of water, and serve the purposes of the CWA. Requirements for water
quality standards are further elaborated by EPA regulations for the program, found at 40 CFR
Part 131.
With the public participating, states adopt water quality standards that set the water
quality goals for the water body, serve as the legal basis for TMDLs and the applicable permit
requirements for point sources, and provide the program goals for nonpoint source management
programs. Section 402(a) of the CWA specifically require NPDES permits to provide for the
attainment of water quality standards.
The CWA requires states to review their water quality standards at least once every three
years. Any new or revised water quality standards must be approved by EPA before the
standards can be used for CWA purposes, such as the basis for a TMDL or a permit limit.
States have considerable discretion to tailor water quality standards to particular climatic,
hydrologic and seasonal conditions. This discretion, however, is not unlimited. State water
quality standards must protect public health and the environment by enhancing and maintaining
the quality of the water. To protect the uses designated in their water quality standards, states
adopt: (1) a suite of criteria to protect the most sensitive of the designated uses; and (2) an anti-
degradation policy including implementation procedures to protect water quality. In designating
uses for a water body and adopting criteria to protect those designated uses, states consider the
attainability of the uses, as well as the protection of downstream uses.
The most common state use classification systems are based on general categories of uses
(e.g. fish and aquatic life and recreation) or qualitative uses (e.g. Class AA - remarkable,
Class A - excellent). Tables 2 through 7 illustrate the various types of state use classification
systems.
-------
States protect recreational uses by adopting the appropriate criteria (E. coli or
enterococci). In urban areas, where water-based recreational opportunities may be limited, states
need to protect children who frequently splash in waters that otherwise would be considered too
shallow for adults.
This guidance also discusses applying the appropriate criteria at the point of contact
rather than at the "end-of-pipe" and use of less stringent criteria when water is unlikely to be
ingested or when the recreational use is unlikely to occur, e.g., during the winter. Some states are
building flexibility into their water quality standards while also protecting public health by
adopting sub-categories of uses. For instance, for a CSO receiving water body, a modified use
may entail precluding swimming during or immediately following a CSO event when bacterial
counts are elevated.
Examples are provided showing how some states are defining more explicitly the type of
aquatic life that exists in the water body. These state use classification systems provide the
public with a better understanding of the type offish and other aquatic life to be protected by the
water quality standards. When the aquatic life in a water body is more explicitly defined, states
and the public are better able to evaluate the potential of the water body to support healthier
aquatic communities. Also identified are the steps and data that would be necessary to develop a
tiered aquatic life system with subcategories for urban systems.
B. Reviewing and revising, as appropriate, water quality standards
Depending on the CSO impacts, possible water quality standards revisions could include:
1. Applying the Ambient Water Quality Criteria for Bacteria — 1986 (i.e., E. coli or
enterococci) at the beach or at the point of contact rather than at the end-of-pipe or
at the edge of the mixing zone where permits may require compliance with other
criteria;
2. Segmenting the water body to preserve recreation in areas where it actually
occurs;
3. Revising the use by creating subclasses to recognize intermittent exceedances of
bacteriological criteria.
Chapter HI of this guidance describes the regulatory requirements, analyses, and
documentation needed to demonstrate that there are reasons unrelated to water quality (e.g.,
physical or economic) for a water body to not fully support the designated uses. The guidance
identifies the six bases, any one of which states may use to justify revisions to designated uses
(see 40 CFR 131.10(g)(l)-(6)). Appendix II provides additional information on how and when
designated uses may be removed.
Also outlined are the circumstances under which states may not change their designated
uses. For example, states may not change a use if the use is an existing use or the use can be
-------
attained by implementing effluent limits required under sections 301(b) and 306 of the CWA and
by implementing cost-effective and reasonable best management practices for nonpoint source
controls (40 CFR 131.10(h)(2)).
States proposing revisions to designated uses that lower the level of protection afforded a
water body (e.g., reducing the number of recreational use days) must submit to the public and to
EPA a use attainability analysis (UAA; see 40 CFR 131.10(j)). A UAA is a structured scientific
assessment of the physical, chemical, biological and economic factors affecting the attainment of
the use. To support a revision, the UAA must provide sufficient information for the state, public
and EPA to determine that the use is not attainable. The UAA must also provide sufficient
information for the state to adopt an alternative use and the criteria to protect it. States may
designate an alternative use based on the demonstrated water quality improvements from an
affordable, well-designed and operated CSO control program.
Substantial guidance is available on conducting aquatic life-use UAAs and on performing
economic analyses for recreation and aquatic life uses (see Appendix HI). This guidance builds
on these documents by identifying how an LTCP can serve as the foundation for a UAA. In
particular, Appendix IV discusses recreational UAAs. This guidance explains in greater detail
the analyses needed to justify revisions based on the determination that the level of control
necessary to attain water quality standards is not affordable because the costs of the controls
would cause "substantial and widespread economic and social impact" (40 CFR 131.10(g)(6)).
This document identifies ways in which the UAA can be simplified. Common sense and
good judgment play a role. An important way to simplify UAAs is for the community, state and
EPA to reach agreement prior to initiating the UAA on the data to be collected, analyses to be
conducted, and critical factors to be used in interpreting the results.
C. Integrating CSO LTCP development and implementation with water quality
standards reviews
A key principle of the CSO Control Policy is the "review and revision, as appropriate, of
water quality standards and their implementation procedures when developing CSO control plans
to reflect the site-specific wet weather impacts of CSOs." EPA believes that communities and
states can integrate the development of affordable, well-designed and operated CSO control
programs, implementation of high-priority controls, and review (and revision, where appropriate)
of water quality standards.
The implementation of CSO controls identified in a well-designed and operated LTCP
may lead to the determination that a water body has the potential of supporting improved aquatic
life. Under this circumstance, states would upgrade their designated aquatic life use for the water
body. Alternatively, implementation of a well-designed and operated LTCP may not necessarily
ensure the attainment of water quality standards within the CSO receiving water. Where existing
standards cannot be met, CSO communities, states, and EPA will need a more intensive process
-------
than that described in the Guidance for Long-Term Control Plan. The objective of this more
intensive approach, shown in Figure 1, is for the State Water Director, EPA and the CSO
community to reach early agreement on the data and analyses that will be sufficient to support
both the development and implementation of the LTCP and the water quality standards review.
The Agency recognizes that communities are at various stages of CSO abatement efforts.
This document presents a process that starts with the initiation of LTCP development. The
process is flexible and can be tailored to programs that are currently in the process of
implementing the LTCP or that have completed implementation and find that the remaining
overflows continue to contribute to the exceedance of water quality standards.
State Water Directors and EPA may need to establish priorities and develop schedules to
participate in the more intensive process. For example, if the CSO receiving water body has been
included on the state's 303(d) (impaired waters) list for bacteria or other pollutants common to
CSO discharges, the state should coordinate the schedule for developing a TMDL with the
schedule for developing the CSO LTCP, before deciding upon the schedule for the water quality
standards review.
This guidance describes the steps for integrating the development and implementation of
the LTCP with the review and revision, where appropriate, of water quality standards. Where
available information is not sufficient to support a water quality standards review, EPA expects
that communities will install the controls common to all relevant LTCP alternatives while
collecting additional information that would support revisions to water quality standards. Where
available information demonstrates that water quality standards revisions are appropriate, EPA
expects that States will make appropriate revisions to water quality standards to enable
communities to implement LTCPs that comply with NPDES permit requirements and provide for
attainment of water quality standards.
A few states have developed the mechanisms in their water quality standards program
frameworks to integrate water quality standards reviews with long-term control plan
development. Use of continuous simulation modeling and allowances for a limited number of
overflows to define the use are examples. Another approach under consideration in some states
is adopting a high flow cutoff. Conceptually, EPA has no objection to a high flow cutoff for
bacteria and recreational uses. In the past, several states have explored high flow cut-offs, but to
date have been unable to design a standard that adequately balances the need to address the
challenges produced by high flow situations with appropriate water quality protection. EPA is
willing to continue exploring this approach with the States.
This guidance also affirms that EPA will work with the NPDES authorities to ensure that
permits, orders and decrees conform with the CSO Control Policy. In addition, EPA will track
and make available to the public information on CSO programs and water quality standards
reviews.
-------
D. The watershed approach
Chapter V discusses how CSO control planning and implementation fit into the
watershed approach. EPA recognizes that urban water quality may be affected by a combination
of CSOs, storm water discharges, other point sources and nonpoint source runoff. These sources
may be most effectively addressed on a watershed basis or through TMDL analyses. The CSO
Policy encourages permitting authorities "to evaluate water pollution control needs on a
watershed management basis and coordinate CSO control efforts with other point and nonpoint
source control activities." EPA strongly endorses and provides financial assistance to local
watershed efforts.
Some states do use a watershed approach in one or more of their water programs, such as
monitoring, designating uses, reviewing water quality standards or issuing permits. If CSO
LTCPs are integrated with an on-going TMDL or watershed analysis, EPA expects that
communities will implement high priority controls while TMDLs or watershed plans are being
completed. An iterative, phased implementation of CSO controls fits well with the watershed
approach.
-------
II. EXISTING PROGRAM FRAMEWORK
1. CSO Program Framework
A. What is the statutory authority for controlling CSOs?
CSOs are point source discharges to the waters of the United States and are therefore
subject to section 301(a) of the CWA and the implementing regulations for the NPDES Program.
The CSO Control Policy provides a national framework and guidance for controlling CSOs
consistent with CWA requirements. The Policy is a comprehensive national strategy to ensure
that municipalities, permitting authorities, water quality standards authorities, EPA and the
public engage in a comprehensive and coordinated planning effort to achieve cost effective CSO
controls that ultimately meet appropriate water quality standards. On December 21, 2000, the
CWA was amended by Section 402(q)(l), which requires that all permits, orders and decrees
issued after the date of enactment conform with the CSO Control Policy.
B. What are the technology-based requirements for controlling CSOs?
The minimum technology-based controls are the nine minimum controls (NMC)3 as
determined on a site-specific basis by the NPDES authority. The CSO Control Policy calls for
all communities to implement the NMC. The NPDES entity determines whether the NMC
satisfy the technology-based requirements of the CWA based on factors in the NPDES
regulations.4 The CSO Control Policy expected that all communities would implement the NMC
by January 1, 1997.
C. What are the water quality-based requirements for controlling CSOs?
Under the CSO Control Policy, communities with combined sewer systems are expected
to develop LTCPs to provide for the attainment of water quality standards and compliance with
other CWA requirements. By law, discharges that remain after implementation of the CSO
controls must not interfere with the attainment of water quality standards. In developing LTCPs,
communities should examine a range of CSO control alternatives and evaluate the potential CSO
reductions and water quality improvements from each alternative. The CSO Control Policy
3 The nine minimum controls are: proper operation and maintenance of collection systems; maximum use
of the collection system for storage; review and modification of pretreatment to assure CSO impacts are minimized;
maximum flow to the POTW for treatment; elimination of dry weather overflows; control of solid and floatable
materials in CSOs; pollution prevention; public notification; and monitoring.
4 The factors in 40 CFR 125.3(d)(2) and (3) cover BCT and BAT. These factors include: the
reasonableness of the relationship between the costs of attaining a reduction in the effluent and the effluent
reduction benefits; the age of the equipment and facilities involved; process employed; engineering aspects of the
various types of control techniques; process changes; and non-water quality environmental impact (including energy
requirements).
-------
recommends that communities give the highest priority to eliminating, relocating or treating
overflows to protect the designated uses in sensitive areas. Sensitive areas include areas with
primary contact recreation, drinking water supplies, shellfish beds, and waters with threatened
and endangered species and their critical habitats.
In developing their LTCPs, communities evaluate controls to address a reasonable range
of alternatives. For example, the LTCP should evaluate controls that achieve zero overflow
events per year, an average of one to three, four to seven, and eight to twelve overflow events per
year. Alternatively, communities could evaluate controls that would achieve 100 percent, 95
percent, 90 percent, 85 percent, 80 percent, and 75 percent capture for treatment. The CSO
Control Policy also recommends that communities evaluate modifying the operation of the
POTW or expanding primary and/or secondary treatment capacity to handle larger flows during
storm events. These controls can include consideration of a range of structural controls such as
sewer separation, retention structures, or high-rate treatment. The costs of the various controls
vary widely based on local conditions. This analysis of control alternatives should be sufficient
to make a reasonable assessment of costs and the expected performance of the various
alternatives.
D. What options are available in developing an LTCP that meets the intent of
the water quality-based provisions of the CSO Control Policy?
The CSO Control Policy offers two approaches for CSO communities to consider in
developing LTCPs. These are:
! The "presumption approach," with performance criteria (i.e., 4-6 untreated
overflow events or 85 percent by volume capture) used as an endpoint for LTCP
development and implementation; and
! The "demonstration approach," which entails developing and implementing an
LTCP that includes a suite of CSO controls sufficient to meet applicable water
quality standards;
Under either approach, the CSO community will need to plan controls to allow cost-
effective expansion or cost-effective retrofitting, if additional controls are subsequently
determined to be necessary based on the results of a post-construction monitoring program.
The presumption approach presumes the LTCP provides an adequate level of control to
meet the water quality-based requirements of the CWA if the LTCP meets the performance
criteria stipulated in the CSO Control Policy. Under the presumption approach, controls adopted
in the LTCP should be required to meet one of the following criteria:
! No more than an average of four overflow events per year, provided that the
permitting authority may allow up to two additional overflow events per year;
10
-------
! The elimination or the capture for treatment of no less than 85 percent by volume
of the combined sewage collected in the CSS during precipitation events on a
system-wide annual average basis; or
! The elimination or removal of no less than the mass of the pollutants identified as
causing water quality impairment through the sewer system characterization,
monitoring, and modeling effort for the volumes that would be captured for
treatment above.
An LTCP that meets the criteria listed above is presumed to provide an adequate level of
control to meet the water quality-based requirements of the CWA, provided the permitting
authority determines such a presumption is reasonable in light of the data and analysis conducted
in the characterization, monitoring and modeling of the system and consideration of sensitive
areas (H.C.4.a of the CSO Control Policy).
The Policy also offers that a "...permittee may demonstrate that a selected control
program, though not meeting the criteria of the [presumption approach] is adequate to meet the
water quality-based requirement of the CWA..." This approach is referred to as the
demonstration approach. The demonstration approach assumes that adequate data will be
developed to reasonably demonstrate that implementation of the LTCP will provide for
attainment of water quality standards.
In selecting the demonstration approach, a community would have several options for
developing an LTCP that will be sufficient to meet applicable water quality standards. A
community could, for example, develop an LTCP that would provide for attainment of currently-
applicable water quality standards, or it could use a total maximum daily load (TMDL) to
demonstrate that water quality standards can be attained through a combination of CSO controls
and other controls. This document describes a third alternative: Working with water quality
standards and NPDES authorities to integrate water quality standards reviews and revisions, as
appropriate, with the development of a CSO control program that supports the attainment of
water quality standards without causing substantial and widespread economic and social impacts.
The CSO Control Policy identifies four criteria for successful use of the demonstration
approach. An LTCP based on the "demonstration approach" should show that:
! The CSO control program will protect water quality standards unless the standard
cannot be met as a result of natural conditions or other pollution sources;
! The overflows remaining after implementation of the control program will not
prevent the attainment of water quality standards;
! The planned control program will achieve the maximum pollution reduction
benefits reasonably attainable; and
! The planned control program is designed to allow cost effective expansion or cost
effective retrofitting if additional controls are subsequently determined to be
necessary to meet water quality standards, including protection of designated uses.
11
-------
Where water quality standards cannot be met because of other pollution sources, a TMDL
or other watershed-based tool should be used to determine and apportion pollutant loads.
Regardless of whether the presumption or demonstration approach is used, the CSO
control program ultimately selected must be sufficient to meet water quality standards and other
CWA requirements. The CSO community should undertake a post-construction water quality
assessment program of monitoring and collecting sufficient data to demonstrate compliance with
water quality standards, including protection of designated uses.
E. How do CSO LTCP monitoring and modeling activities support water
quality standards reviews?
One objective of integrating CSO control planning and water quality standards reviews is
for CSO communities to help collect information and conduct analyses, whenever possible,
which will support both processes. Early involvement of state and EPA water quality standards
and monitoring personnel in developing and reviewing the monitoring plans helps CSO
communities collect the data and conduct the analyses to support the requisites of both CSO
control planning and water quality standards reviews.
Many CSO communities focus monitoring and modeling activities primarily on the
dynamics of the combined sewer system (frequency, duration, flow rate and volume of CSO
discharges). Communities interested in pursuing water quality standards reviews will need to
collect sufficient information to quantify the impacts of CSOs on the receiving water. EPA's
Combined Sewer Overflows - Guidance for Monitoring andModeling (EPA 832-B-99-002)
provides information on developing a comprehensive monitoring and modeling plan that focuses
both on the dynamics of the combined sewer system and the water quality impacts of CSOs.
CSO monitoring programs include both CSO effluent and ambient in-stream monitoring
and, where appropriate, biological assessments, toxicity testing and sediment sampling to
evaluate the effect of overflows on ambient water quality and the designated uses. These
analyses also help to identify the water quality benefits of control alternatives, and to project the
effect of remaining overflows on water quality standards attainment (See Table 1). Ideally, CSO
monitoring programs should enable the community to:
Assess attainment of water quality standards (including designated uses);
Define the baseline conditions in the receiving water (chemical, biological, and physical
parameters).
Assess the relative impact of CSOs.
Gain sufficient understanding of the receiving water to support the evaluation of proposed
CSO control alternatives, including any receiving water modeling that may be needed.
Support the review and revision, as appropriate, of water quality standards.
12
-------
EPA recognizes that in practice, many CSO communities may face resource constraints
that limit their ability to conduct comprehensive monitoring programs without collaboration
from states and other stakeholders (including other municipalities) discharging to the affected
water body. The monitoring parameters identified in the CSO Control Policy include "oxygen
demanding pollutants, nutrients, toxic pollutants, sediment contaminants, pathogens,
bacteriological indicators (e.g., enterococci, E. coif) and toxicity." This information
characterizes CSO discharges and their water quality impacts, and is used to evaluate whether
any of the CSO control plan alternatives will be sufficient to meet water quality standards. States
use these evaluations to determine if water quality standards revisions may be appropriate, or if
more extensive CSO controls are needed. It is important for the permittee, state, and EPA to
agree on the information and analyses that are necessary to support both the CSO control plan
and the review of water quality standards. The data needed to revise water quality standards are
similar to the data needed to assess the attainment of water quality standards.
Table 1 - Types of CSO Data Supporting Water Quality Standards Reviews
! Timing of CSO events and their impacts on primary contact recreational periods or fish
spawning.
! Average amount of precipitation causing a CSO event.
! Average time between CSO events.
! Season during which CSOs tend to occur more frequently.
! Estimate of the number, frequency, and duration of CSO events per year.
! Flow data for CSO-impacted waters.
! Appropriate meteorological, soils, land use and watershed modeling data.
! Identification of the designated uses.
! Use impairment data, including the severity and geographic extent of impairment (e.g.
frequency and duration of beach closures).
! Location of sensitive areas relative to CSO outfalls (e.g., swimming areas, shellfish
beds, fish spawning areas, drinking water supply intakes).
Severity, extent, duration, and frequency of water quality criteria excursions.
Pollutants in CSOs that cause or contribute to water quality criteria excursions (e.g.,
bacteria, BOD, nutrients, toxics).
Pollutant loadings from other point sources (storm water, NPDES-permitted facilities),
and from non-point sources (agricultural lands, roadways, and forestry operations).
The cost versus performance of CSO control options.
The financial impact of CSO control options.
13
-------
Collaborative monitoring through consortiums is a cost-effective way to stretch
monitoring resources, improve coordination or share expertise and the cost of data collection and
management.5 Many community organizations also support data collection with volunteer
monitoring programs. Volunteer monitoring data can have a high degree of credibility,
particularly where quality assurance and quality control procedures are documented.6
Involving community organizations in evaluating and comparing data on the operation,
maintenance and replacement costs of CSO control alternatives over different time frames can
help communities select the most cost-effective control alternative. Broad participation can also
help these organizations better understand the scientific, technical and financial issues involved
in the control of CSOs and other stressors that impair urban waters. By sharing solid information
freely, community organizations can promote consensus on CSO control options and recommend
complementary environmental enhancements that maximize improvements in the CSO-receiving
water and provide greater environmental benefits to the watershed as a whole. With this
understanding, these groups can facilitate communication with the larger community and
generate support for CSO controls and their funding.
2. Water Quality Standards Program Framework
A. Who is responsible for water quality standards?
The CWA gives the responsibility for developing, adopting and reviewing water quality
standards directly to states, territories, and authorized tribes. EPA reviews and approves or
disapproves new or revised state water quality standards. After May 30, 2000, a water quality
standard may be used for Clean Water Act purposes, such as for TMDLs and for NPDES
permits, only after EPA approves the standard.7 Under section 303(c)(4) of the CWA, EPA
promulgates federal water quality standards when:
! EPA has disapproved a new or revised standard because the state has failed to
adopt water quality standards consistent with the CWA and implementing
regulations; or
! The Administrator makes a determination that a new or revised standard is
necessary to meet the requirements of the CWA.
See U.S. EPA. 1997. Monitoring Consortiums: A Cost-Effective Means To Enhance Data Collection
And Analysis (EPA 841-R-97-006).
6 The Directory of Volunteer Monitoring Programs shows that 89 percent of those registering use
documented quality assurance and quality control procedures following state- or EPA-approved plans. EPA has
published The Volunteer Monitor's Guide to Quality Assurance Project Plans (EPA 841-B-96-003) and
organizations such as River Watch provide technical guidance (see http://www.riverwatch.org/Catalog).
7 65 FR 24641, April 27, 2000.
14
-------
B. How does a state develop and adopt water quality standards?
Under existing EPA regulations and guidance, states have considerable discretion in
adopting water quality standards for a water body.8 Water quality standards programs are
different in each state, reflecting the diversity in climate, hydrology, and ecological conditions
across the country.
Under section 303(c)(2), the CWA requires states to adopt water quality standards that
will:
! Protect the public health or welfare;
! Enhance and maintain the quality of water; and
! Serve the purposes of the CWA.
The goal of CWA section 101(a)(2), which guides the water quality standards program,
is to provide, "wherever attainable. . .water quality. . .for the protection and propagation offish,
shellfish and wildlife, and recreation in and on the water. . ." Under section 303(c)(2)(A) of the
CWA, states are directed to establish their standards, taking into consideration the use and value
of the water body for:
! Public water supplies,
! Propagation offish, shellfish, and wildlife, and
! Recreation in and on the water.
In designating uses for a water body and adopting criteria to protect those designated
uses, states consider the attainability of those uses, often weighing the environmental, social and
economic consequences of their decisions. States adopt a suite of criteria necessary to protect the
most sensitive of the designated uses and an antidegradation policy and implementation
procedures to protect water quality.
EPA's water quality standards regulations limit state discretion when adopting and
revising uses.9 For example, states may not adopt waste transport as a use for a water body.
Further, when designating uses and adopting applicable criteria, states must ensure the protection
of downstream water quality standards (see 40 CFR 131.10(b)). In revising designated uses
(discussed in more depth below), states may not remove an existing use or remove a designated
use if it can be attained with the technology-based controls under sections 301(b) and 306 of the
CWA and by implementing cost-effective and reasonable best management practices for
nonpoint source control (see 40 CFR 131.10(h)(2)).
40 CFR Part 131.
9 40 CFR 131.10.
15
-------
C. How do states classify their uses?
State-designated use classification systems fall into two general types: "categorical" and
"qualitative." The "categorical" approach uses categories that focus primarily on specific CWA
uses (see Table 2).
For example, a state may have the
classification system at the left. These uses
reflect the basic uses specified in the CWA. Any
specific water body will likely have more than
one use assigned to it (e.g., Green River - Uses 1,
3, 4, 6). For this state, there is only one aquatic
life and recreation designated use, no
subcategories are specified, and the uses do not
imply qualitative judgments.
Table 2 - Categorical Uses
1
2
3
4
5
6
7
Domestic Water Supply
Industrial Water Supply
Fish and Aquatic Life
Recreation
Irrigation
Livestock Watering and Wildlife
Navigation
Table 3 - Qualitative Uses
Class AA -
Remarkable
Class A -
Excellent
Class B -
Good
Water quality in this class
shall markedly and uniformly
exceed the requirements for
all or substantially all uses.
Water quality in this class
shall meet or exceed the
requirements for all or
substantially all uses.
Water quality in this class
shall meet the requirements
for all or substantially all
uses.
Characteristic
uses shall include
Characteristic
uses shall include
Characteristic
uses shall include
The "qualitative" approach, on
the other hand, provides uses generally
ranked in a qualitative manner, as in
Table3. The use classes clearly
provide a qualitative judgment of the
expected water quality, and a selection
of "categorical" uses are included in
the "characteristic use" section. Only
one designated use (either AA, A, or B)
is assigned to any specific water body.
States have developed a wide
range of combinations of these two
basic approaches and have refined
these basic approaches, especially for
aquatic life uses.
D. How do states protect recreational uses, particularly in urban areas?
States generally try to protect and maintain the recreational uses of their waters wherever
possible, consistent with the "swimmable" goal of the CWA. Some states adopt primary
contact recreation uses (e.g., swimming and some types of boating, such as kayaking) for all state
waters. Others evaluate site-specific factors such as actual use, existing water quality, potential
for water quality improvement, access, recreational facilities, location, safety considerations, and
physical attributes of the water body (depth, width, substrate, safety, etc.). Physical attributes of
the water body may be considered, but no single physical factor can be the only basis for
16
-------
deciding that primary contact recreation is not appropriate. Swimming may occur unless access
is precluded, for example by fences or locked gates, particularly in areas where children may not
have other swimming opportunities. In addition, children will splash and swim in shallow waters
that may otherwise be considered too shallow for full body immersion by adults.
Where primary contact recreational use of the water body does not occur during the
winter, EPA's water quality standards regulation at 40 CFR 131.10(f) allows states to adopt a
seasonal recreation use. A seasonal use defines the recreational season, such as April through
October, applies the water quality criteria associated with the primary contact recreation use
during that season, and applies less stringent water quality criteria during other months. When
people are not using the water for recreation, states may adopt a less stringent water quality
criteria to protect for incidental ingestion. These criteria are based on EPA's recommendation
for secondary contact waters (i.e. not to exceed a geometric mean five times EPA's
recommended water quality criterion for primary contact recreation). These less stringent criteria
may be applied as long as they do not impair the use during the recreational season.
For water bodies where a state has demonstrated through a UAA that primary contact
recreation is not feasible, is not feasible all the time, or poses public safety risks, the state has
several options, depending on site-specific circumstances. For example, a state could adopt a
CSO subcategory of recreational uses. Since the subcategory lowers the level of protection for
the water body, EPA regulations at 40 CFR 131.10(j) require a UAA. Such a subcategory
allows for a use less protective than swimming every day during the recreational season when a
CSO LTCP that ensures attainment of the use at all times would cause substantial and
widespread economic and social impact. How long the recreational use should be suspended and
what other water quality criteria will apply during these events should be decided on a case-by-
case basis. Such determinations should consider factors such as the proximity of outfalls to
sensitive areas, the amount of rainfall, and time of year.
To ensure public safety when the recreational use is suspended, EPA expects
municipalities to notify the public and prevent the public, wherever possible, from using the
water body for recreation. One of the NMC under the CSO Control Policy is public notification
of overflows. Recreational use should be suspended for periods when bacterial levels are
elevated, which is usually longer than the storm or runoff event causing the overflow. As with
any change in water quality standards, states must ensure that water quality standards of
downstream waters are not impaired. As noted, any change to water quality standards must be
submitted to EPA for approval or disapproval.
Some states adopt secondary contact activities, i.e., those activities where participants
have little direct contact with the water and where ingestion of water is unlikely. Examples of
secondary contact activities include canoeing, motor boating, and fishing. If the state adopts
secondary contact recreation, but with primary contact bacteriological criteria, EPA does not
require a UAA. EPA's policy is that any secondary contact criterion adopted by a state should be
appropriate for the anticipated use and not exceed a geometric mean five times EPA's
17
-------
recommended water quality criteria for primary contact recreation. Applying a less stringent
criterion to a water body where only "secondary contact" activities occur should result in no
greater risk of gastrointestinal illness than do water bodies designated with primary contact
recreation.
E. What are the appropriate criteria for protecting primary contact recreation?
EPA strongly recommends that states adopt Ambient Water Quality Criteria for Bacteria
-1986 to protect public health when waters are used for primary contact recreation. The criteria
indicators are E. coli or enterococci for fresh water, and enterococci for marine water. Table 4
lists the criteria. EPA stresses the need for states to adopt the 1986 criteria because
epidemiological studies show that E. coli and enterococci are better indicators of gastrointestinal
illness than fecal coliform. Twelve of the 34 states with CSO communities have adopted the
1986 criteria.10 For coastal and Great Lakes states, the Beaches Environmental Assessment and
Coastal Health Act of 2000 (PL 106-284, October 10, 2000) requires adoption of the 1986 water
quality criteria for bacteria within 42 months of enactment (April, 2004), or EPA will
promulgate, if necessary.
EPA recommends that for a water body to be judged fully supportive of its primary
contact recreation use, the geometric mean of the samples taken should not exceed the criterion,
and the single sample maximum should be met. Some have misinterpreted the water quality
criteria as requiring a minimum number of samples in order to determine the attainment of the
numeric water quality criteria. This may be due to the recommendation that a geometric mean be
based on five samples taken over a 30-day period. The minimum number of samples used in the
1986 water quality criteria for bacteria is for accuracy purposes only; clearly, more frequent
sampling yields more accurate results when determining the geometric mean. It is the geometric
mean of the samples collected in conjunction with a single sample maximum that determines
attainment of the numeric water quality criteria, regardless of the number collected.
To assure water quality criteria for bacteria are generally protective in all circumstances,
EPA recommends:
! Frequent monitoring of known bathing areas to determine if the water body is
attaining the water quality criteria.
! Conservative use of mixing zones for bacteria where mixing zones are authorized.
! Prohibiting mixing zones from impacting known primary contact recreation areas.
! Using the appropriate single sample maximum in the assessment of primary
contact recreation.
! Conducting a sanitary survey when higher than normal levels of bacteria are
measured.
10 States with CSO communities using enterococci for marine waters and enterococci/E.coli for fresh water
include: CA, CT, DE, IN, ME, MI, NH, NJ, OH, OR, TN, VT.
18
-------
A sanitary survey is an examination of a watershed to detect unauthorized sanitary
discharges from sources such as:
! Failed septic tank leach fields or cesspools.
! Sewage leakage from broken pipes.
! Sanitary sewer overflows from hydraulically overloaded sewers.
! Overflows from storm sewers that may contain illegal sanitary sewer connections.
In addition, EPA recommends that sanitary surveys identify other possible sources of
fecal pollution, including confined animal areas, wildlife watering points, and recreational spots,
such as dog running/walking areas. EPA is developing the data to publish additional health-
based water quality criteria to protect for other non-gastrointestinal health risks, such as skin and
respiratory infections.
In both fresh and marine waters, excess nutrients, along with the warm water temperature
of recreational waters, provide an ideal growth medium for potentially harmful pathogens. High
levels of indigenous Aeromonous hydrophila can infect cuts and scratches, and high levels of
Vibrio parahenolyticus or Vibrio vulnificus contaminate shellfish with life-threatening
consequences for vulnerable individuals. In addition to controlling nutrients for recreational
waters based on aesthetics (e.g., weeds, algal scums, and low transparency), greater levels of
nutrient control for more sensitive aquatic species should also provide a greater level of
protection for public health.
19
-------
TABLE 4
Summary of EPA-Recommended Water Quality Criteria For Bacteria11
Freshwater
enterococci
E. coli
Marine Water
enterococci
Steady State, 30-day
Geometric Mean
Indicator Density
(cfu/lOOmL)
33
126
35
Single Sample Maximum (cfu/lOOmL)
Designated Beach
Area
61
235
104
Moderate Full
Body Contact
Recreation
89
298
124
Lightly Used Full
Body Contact
Recreation
108
406
276
Infrequently Used
Full Body Contact
Recreation
151
576
500
.Ambient Water Quality Criteria for Bacteria-1986, EPA 440/5-84-002
20
-------
Thus far, EPA has published Nutrient Criteria Technical Guidance Manual: Lakes and
Reservoirs (EPA-822-BOO-001) and Nutrient Criteria Technical Guidance Manual: Rivers and
Streams (EPA-822-B-00-002). The Agency plans to publish Nutrient Criteria Technical
Guidance Manual: Estuarine and Coastal Waters during the Fall 2001. The general guidelines
in the Technical Guidance Manuals provide information states can use as they develop nutrient
criteria to protect various designated uses, such as water supply, aesthetic qualities of recreation,
and different types of aquatic species. Although health-based recreational guidelines are not
included in the document, EPA believes that if the current criteria protect sensitive aquatic
species, the criteria should also protect public health.
F. Where are the bacteria criteria applied?
Many states apply the ambient water quality criteria for bacteria directly to the discharge
("end-of-pipe") rather than at the point of contact where recreational uses actually occur. CSO
outfalls may be sufficiently removed from recreational areas so as not to pose a public health
threat. With a supporting UAA, states could also segment a water body to protect the recreation
in the area where it is most likely to occur and prohibit recreation in other areas of the water body
where CSOs and other discharges pose significant public health threats.
G. How do states protect aquatic life uses?
Some states use a single designated use (e.g., fish and aquatic life), some use simple
subcategories (e.g., warm water fishery, cold water fishery), and some use qualitative class (e.g.,
Class A). These generic aquatic life use designations, either categorical or a qualitative, do not
recognize the natural biological variations that occur among water bodies (swift flowing small
streams, large meandering rivers, lakes, wetlands, estuaries, etc.) or climatic conditions, altitude,
geology, soils, land use, or hydrologic conditions found in different ecological regions. Different
ecological regions have natural variations in biologically healthy aquatic life, as measured by
indices of species richness, diversity, composition, and condition of the aquatic habitat which can
flourish in any particular water body. More precise definitions of the type of aquatic life to be
protected give municipalities and the public a better understanding of the species to be protected
and the level of control needed. Some examples of more precise use definitions are trout and
salmon or blue gill; crappy and large mouth bass; and self-supporting fishery; stocked fishery; or
critical life stages of species.
In order to help better define and protect different aquatic communities, EPA and the
states continue to develop biological assessment tools and criteria to more accurately describe the
natural range of aquatic communities. Once additional natural aquatic communities are defined,
EPA recommends that states refine their designated uses to reflect natural differences.
21
-------
H. How have some states developed more refined aquatic life uses?
Several states have refined their aquatic life uses to reflect different biological systems
within their borders. Most states (at least, those with cold water fish) have use categories for
warm water and cold water fish. Some states have refined these classes further by focusing on
the fish populations, as in Table 5:
Table 5 - Aquatic Life Use Classes
Class 3 — Protected for use by aquatic wildlife.
Class
3A
Class
3B
Class
3C
Class
3D
Protected for cold water species of game fish and other cold water aquatic life, including the necessary aquatic
organisms in their food chain.
Protected for warm water species of game fish and other warm water aquatic life, including the necessary
aquatic organisms in their food chain.
Protected for non-game fish and other aquatic life, including the necessary aquatic organisms in their food
chain.
Protected for waterfowl, shore birds and other water-oriented wildlife not included in Classes 3A, 3B, or 3C,
including the necessary aquatic organisms in their food chain.
22
-------
Other states have developed subcategories based on physical characteristics and/or ecological
systems, as in Table 6:
Table 6 - Water Body Classifications
Classification of state waters.
(a) State waters are classified as either inland waters or marine waters.
(b) Inland waters.
(1) All inland waters are either fresh waters, brackish waters, or saline waters;
(2) All inland fresh waters are classified as follows, based on their physical
characteristics, ecological systems, and other natural criteria:
(A) Streams (perennial or intermittent);
(B) Springs and seeps, natural lakes, and reservoirs;
(C) Elevated wetlands;
(D) Low wetlands;
(3) All inland waters which are brackish waters or saline waters are classified as follows,
based on their physical characteristics, ecological systems, and other natural criteria:
(A) Coastal wetlands;
(B) Estuaries;
(C) Anchialine pools; and
(D) Saline lakes
(c) Marine waters . . .
I. Why are refined aquatic life uses important in the urban environment?
EPA believes that urban watersheds can and do support aquatic life and that improvement
and restoration of healthy urban aquatic communities is, in many cases, an attainable goal of the
CWA. States, with EPA's support, are developing biological assessment tools and biological
criteria to assess the health of their waters in relationship to the "biological integrity" goal of the
CWA. Biological integrity for a particular water body is the natural (or minimally impacted)
condition of the water body.
There are a number of water quality and non-water quality factors that affect the
attainment of natural aquatic communities in urban areas, including the amount of impervious
surface, human activity resulting in permitted and non-permitted discharges, and the type and
extent of hydrologic modifications. Some recent literature suggests the full restoration of natural
aquatic life communities may not be feasible in small watersheds with heavily urbanized areas.
Schueler found significant impairment of aquatic life where levels of impervious cover in urban
areas were in the range of 8-percent to 20-percent.12 Yoder et al. found this threshold level is
also influenced by other factors such as pollutant loadings, watershed development history,
12 Schueler, T. R. 1994. The importance of imperviousness. Watershed Protection Techniques 1:100-111.
23
-------
riparian buffers, CSOs, and types of land use.13 More sensitive aquatic life, such as brook trout,
may be unable to survive in watersheds with as little as 1- to 2-percent impervious land cover.14
However, states that base their aquatic life use classification systems on biological criteria and on
a range of use subcategories which lead to the appropriate aquatic life goal for a water body, have
a framework for evaluating attainability of improvements in urban aquatic life ecosystems.
EPA recognizes the need for additional guidance to better define the factors to consider in
designating and protecting appropriate aquatic life uses in urban areas. Such guidance would
address a variety of urban stressors that might prevent attainment of an otherwise expected
aquatic community, cover a broad range of geographic areas, and consider the full range of
imperviousness in urban areas. This guidance would help states adopt subcategories of aquatic
life uses and water quality criteria that more accurately and precisely define actual and attainable
aquatic communities. Once this information is developed, states, watershed organizations, and
local communities will be able to identify the recovery potential of the aquatic communities,
adopt appropriate water quality standards, and design affordable restoration and protection
strategies.
J. What steps are necessary to develop a system of tiered aquatic life uses and
subcategories for urban systems?
A two-step process is outlined below in Table 7. First, the state defines the biological
communities for various water body types in areas with minimal human impacts (Column A)
based on EPA bioassessment/biocriteria methodologies.15 Second, the state defines reasonably
attainable biological communities for the urban-impacted areas (Column B). Once a refined
designated use system is developed, individual water bodies may be assigned refined designated
uses, as appropriate.
13 Yoder, C. O., et.al. 1999. Assessing the status of aquatic life designated uses in urban and suburban
watersheds, pp. 16-28. In Everson, A., et al. National Conference on Retrofit Opportunities for Water Resource
Protection in Urban Environments, Chicago, II. EPA-625-R-99-002.
14 Maryland Biological Stream Survey, http://www.dnr.state.md.us/streams.mbss/brook.html
Biological Criteria: National Program Guidance for Surface Waters. 1990. EPA-440/5-90-004.
- Biological Criteria: Technical Guidance for Streams and Small Rivers, Revised Edition. 1996.
EPA822-B-96-001.
- Draft Estuarine And Coastal Marine Waters Bioassessment and Biocriteria Technical Guidance. 1997.
EPA822-B-97-001.
- Lake and Reservoir Bioassessment and Biocriteria: Technical Guidance Document. 1998. EPA 841-B-
98-007.
- Rapid Bioassessment Protocols For Use in Streams and Wadeable Rivers: Periphyton, Benthic
Macroinvertebrates, and Fish. Second Edition. 1999. EPA 841-B-99-002.
24
-------
K. What is the process for assigning subcategories of uses to individual water
bodies?
Revision of use classification systems requires a revision to state water quality standards
subject to EPA review and approval or disapproval, as outlined in EPA's water quality standards
regulations. EPA's water quality standards regulations require states to use a UAA to develop an
appropriate scientific, technical or economic justification for the change when reclassifying
waters with a less protective use than the current designated use.
The new designated use must be equal to or better than the "existing" use.16 No UAA is
required if the state adopts a new designated use that is either equivalent to the reference
condition for that particular water body type or meets the "fishable/swimmable" goal of the
CWA and the state adopts criteria equal to, or more stringent than the current designated use.
Under the EPA's water quality standards regulations, a combination of a new use subcategory
with less stringent criteria would trigger a UAA.17
16 Existing uses are those uses actually attained in the water body on or after November 28, 1975, whether
or not they are included in the water quality standards (40 CFR 131.3). See also 40 CFR 131.10(g).
17 40 CFR 131.6(b) and 131.10(j)(2).
25
-------
Table 7 - Developing A Refined Aquatic Life Designated Use System
Step
1
2
3
4
5
6
Column A
For refined use designations reflecting the
range of natural biological communities in the
area . . .
Develop bioassessments able to differentiate
between the natural biological communities in
the different water body types.
Conduct bioassessments of the different water
body types to collect data reflecting non-
impacted waters (reference condition).
Refine the aquatic life designated use
categories to reflect the natural biological
communities within each water body type (e.g.,
lakes/impoundments, small streams, rivers,
estuaries, wetlands).
Develop biological criteria that protect the
natural community (reference condition) for
each designated use category.
In establishing each designated use applied to a
water body type, determine the range of
allowable difference from the reference
condition that meets the "fishable" goal of the
CWA.
Adopt refined designated use categories,
biological criteria defining those uses, and
protective chemical and physical water quality
criteria into water quality standards.
Column B
In addition, qualitative subcategories reflecting
achievable biological communities in urban-impacted
areas . . .
Refine bioassessment protocols to differentiate
between the range of urban impacts (e.g.,
imperviousness, land use type (industrial, residential,
etc), development history, hydrologic modification) in
the different water body types of concern.
Conduct bioassessments to capture the biological
impacts from a range of urban conditions.
Determine the achievable biological condition for the
range of urban impacts.
Develop qualitative subcategories for each designated
use based on achievable biological conditions (e.g.,
based on percent imperviousness, land use).
Develop biological criteria that reflect the attainable
biological community for each qualitative
subcategory.
For each urban impacted subcategory, determine if its
biological criteria fall within the range of allowable
difference from reference condition and meet the
"fishable" goal of the CWA
Adopt subcategories, biological criteria defining
those subcategories, and protective chemical and
physical water quality criteria into water quality
standards.
The supporting information for aquatic life use refinements in a use classification system
(whether or not a formal UAA has been performed) should address:
! Does the refined designated use and its description of the aquatic community
(biocriteria) reflect the reference condition (i.e., natural state) for the kinds of
waters to which the new classification is to be applied?
! If newly proposed water quality criteria are necessary to protect the use, are they
scientifically defensible?
Even if a UAA is not required, these are important questions for the state to address.
EPA regulations at 40 CFR 131.10(c) allow states to adopt categories of a use and set appropriate
criteria to protect varying needs of the use. When refining the aquatic life use categories, the
26
-------
state needs to explain how the proposed biological description correctly reflects the aquatic life
use potential for that water body.
For example, one state adopted a "Limited Resource Water" subcategory of aquatic life
use. This subcategory is described as "waters that have been the subject of a use attainability
analysis and have been found to lack the potential for any resemblence of any other aquatic life
habitat as determined by the biological criteria . . . The use attainability analysis must
demonstrate that the extant fauna is substantially degraded and that the potential for recovery of
the fauna to the level characteristic of any other aquatic life habitat is realistically precluded due
to natural background conditions or irretrievable human-induced conditions." The state assigns
less stringent water quality criteria to Limited Resource Waters. One of the causative factors
associated with Limited Resource Waters is:
"small drainageway maintenance - these are highly modified surface water drainageways
(usually less than three square miles in drainage area) that do not posses the stream
morphology and habitat characteristics necessary to support any other aquatic life habitat
use. The potential for habitat improvements must be precluded due to regular stream
channel maintenance required for drainage purposes."
Another state adopted a subcategory of aquatic life use called "Limited Warmwater
Fishery." This use class has less stringent dissolved criteria oxygen that apply from May through
November. In addition, chronic aquatic life criteria for Limited Warmwater Fishery are
implemented using a stream design flow statistic with a more frequent return interval (7Q2
instead of a 7Q10). This is another example of a refined aquatic life use subcategory that a state
adopted and EPA approved. As with the first example, any stream assigned a Limited
Warmwater Fishery use has a supporting UAA.
27
-------
III. REVIEWING AND REVISING WATER QUALITY STANDARDS
1. How often are water quality standards reviewed?
The CWA requires states to review their water quality standards at least once every three
years. EPA expects that the recent revisions to EPA's water quality standards regulations
("Alaska Rule," 65 FR 24641, April 27, 2000) will result in states submitting more frequent
revisions to their standards, because any new or revised standards cannot be used for CWA
purposes until EPA approves them. The extent to which this occurs depends in part on state
authorizing statutes, regulatory requirements, and administrative procedures. Some states have
more lengthy processes, particularly where the legislature enacts water quality standards into
state law before the new or revised standards are submitted to EPA, or where an independent
board adopts the standards revised by the state agency responsible for the water quality standards
program. Limited resources may be another constraint.
Where CSO communities collect the information outlined in this document and follow
the process for developing their draft LTCPs (as shown in Figure 1) and coordinate with State
Water Directors throughout the planning and implementation processes, states will have a
stronger basis on which to conduct timely water quality standards reviews. State water quality
standards reviews could result in identification of information needed to support water quality
standards actions, such as:
! Time-limited variances.
! Water quality standards revisions.
! No revisions to the water quality standards.
2. What type of water quality standards revisions are possible?
State water quality standards reviews may include any element of the standard including
uses, criteria, the anti-degradation policy and other policies affecting the implementation of the
water quality standards program, such as variances or compliance schedules. For example, a
review of the suite of criteria to a particular water body may result in adding new criteria,
revising criteria based on national guidance (e.g., adopting E. coli or enterococci) or setting a
site-specific criterion, if appropriate. In addition, states may review implementation policies on
where criteria are applied, e.g., applying the bacteria criteria at the point of contact rather than at
the end-of-pipe. Another option may be segmenting the water body to preserve recreation in
areas where it actually occurs.
To protect recreational uses as much as possible, some states are looking at creating
subclasses of recreational uses that recognize intermittent exceedances of bacteriological criteria
due to CSOs. This approach retains the recreational use, but lowers the level of protection for
the use by specifying the maximum number of days when recreation can not safely take place.
For example, the subcategory may state that during the recreation season, recreation can be
28
-------
suspended up to a certain number of days. The number of allowable days that the use could be
suspended would be based on a site-specific use attainability analysis (see 3. below). The
analysis would project the number of days that bacteriological levels are likely to be elevated
after implementing a well-designed and operated CSO control program that does not cause
substantial and widespread economic and social impact. Before lowering the level of protection
for a use, states must provide an opportunity for the public to review the proposal and analyses
justifying the revision (see 40 CFR 131 .20(b)). States must also ensure that any revision
provides for the attainment and maintenance of downstream water quality standards (see 40 CFR
States may not remove:
! An "existing" use, i.e., a use actually attained in the water body on or after
November 28, 1975 (see 40 CFR 131.3(e) and 131.10(h)(l)); or
! A use that can be attained by the imposition of effluent limits required under
sections 301(b) or 306 of the CWA and cost-effective and reasonable best
management practices for non-point source control (see 40 CFR 131.10(d) and
3. What type of analysis is required to remove or lower the level of protection for a use?
EPA's water quality standards regulation at 40 CFR 131.10(j) requires a use attainability
analysis (UAA) whenever a state fails to adopt a use designation, or changes the use designation
with the effect of removing or lowering the level of protection for the protection and propagation
offish, shellfish and wildlife, or for the protection of recreation in and on the water. Once a use
is designated, it cannot be modified unless the state demonstrates through a UAA that attaining it
is not feasible.
A UAA is a structured scientific assessment of the physical, chemical, biological and
economic factors affecting the attainment of the use. Included in the regulation are six bases that
address circumstances which may preclude the attainment of the use. A description of how and
when designated uses may be removed is presented in Appendix n. Any one of the following
factors can be used to justify changes in the designated use:
1 . Naturally occurring pollutant concentrations prevent the attainment of the use.
2. Natural, ephemeral, intermittent, or low flow conditions or water levels prevent
the attainment of the uses, unless these conditions may be compensated with
sufficient effluent discharges.
3 . Human-caused conditions or sources of pollution prevent the attainment of the use
and cannot be remedied or would cause more damage than to leave in place.
4. Dams, diversions or other types of hydrological modifications preclude the use,
and it is not possible to restore the water body or operate the modification in such
a way that would result in attainment.
29
-------
5. Physical conditions related to the natural features of the water body unrelated to
water quality preclude attainment of aquatic life uses.
6. Controls necessary to attain the use would cause substantial and widespread
economic and social impact.
The UAA must provide sufficient information for the state to determine that the
designated use is not attainable and also provide the basis for adopting an alternative use and the
criteria to protect that use. To support the 101(a) "fishable/swimmable" goal uses, the state
should adopt an attainable alternative use as close as possible to the goal uses. As noted, the
public must also have an opportunity to review the UAA and the alternative use before the state
submits the revisions and the UAA to EPA for approval or disapproval.
Guidance is available on conducting UAAs (Appendix ID). Although most of this
guidance addresses aquatic life uses and the economic analyses, several EPA Regional Offices
have developed guidelines for recreational use UAAs. Appendix IV contains a recreational UAA
discussion.
4. What bases may be appropriate for determining that a use is not attainable in CSO
receiving waters?
EPA recognizes that even in the absence of CSO discharges, attainable restoration goals
for some urban systems may not be the same as those attainable for non-urban systems. Urban
waters may have permanently altered uses due to modified flow regimes, contaminated
sediments, changes to in-stream or riparian habitat, or other types of "human-caused conditions
or sources of pollution that cannot be remedied" or "would cause more environmental damage to
correct than to leave in place" (40 CFR 131.10(g)(3)). Although controlling CSOs generally
does have a beneficial effect on aquatic life and recreation, some of these alterations may persist
independent of CSO controls. In determining the attainable use, the state will need to evaluate
the extent to which the factors contributing to the impairment can be restored.
Physical alterations in the urban environment often preclude full attainment of uses due to
limited access, channelization, and hydraulic impairments that pose logistical as well as safety
constraints for swimmers, waders, fisherman, and boaters. Examples of such alterations include
modifications for shipping channels and certain types of flood control projects. Physical
alterations may justify the need for a review and possible revision of applicable water quality
standards when developing LTCPs.
Revisions to water quality standards based on CSO discharges however, are most likely
when the controls necessary to attain the standard would cause "substantial and widespread
30
-------
economic and social impact."18 The Interim Economic Guidance For Water Quality Standards19
identifies the analyses states may use to support this determination for water pollution control
projects, including CSO LTCPs. States may also use alternative analyses and criteria to support
this determination, provided they explain the basis for these alternative analyses and/or criteria.
For the public sector, the Guidance includes the tools for water pollution control projects,
including CSO LTCPs for states to evaluate:
! Who within the community would bear the costs of the CSO LTCP.
! Whether these costs are substantial.
! Whether changes in socioeconomic conditions indicate widespread impacts.
In determining whether the costs of the draft LTCP are substantial, the annualized per-
household cost of sewer services, including existing and new costs, is divided by the median
household income. If the result (termed a municipal affordability screener) is less than 1 percent,
the state could decide that the annualized costs are minimal and that financial and economic
impacts do not warrant revising the water quality standard on that basis. If the municipal
affordability screener is between 1 and 2 percent (a mid-range impact) or greater than 2 percent
(a large impact), additional analyses may be appropriate. These secondary analyses include
evaluation of the following indicators:
! Bond rating.
! Overall net debt as a percent of the full market value of taxable property.
! Unemployment rate.
! Median household income.
! Property tax revenue as a percent of full market value of taxable property.
! Property tax collection rate.
The results of these secondary assessment scores are summarized as a cumulative
secondary indicator (<1.5 minimal impact; 1.5 - 2.5 mid-range; and >2.5 strong). The state
combines the municipal affordability screener and the secondary indicator in a matrix to help
determine whether the impacts are "substantial."
The derivation of the 2 percent yardstick is based on EPA studies across environmental
programs that collected financial information from communities around the country. The studies
found that two cutoffs were appropriate for determining the difficulty the community would have
in affording additional project costs. Based on the data across many federal and state programs,
EPA found that affording an annual sewer bill of:
18. 40CFR131.10(g)(6).
. Interim Economic Guidance For Water Quality Standards: Workbook (EPA-823-B-95-002, March,
1995).
31
-------
! Less than 1 percent of median household income per year may not be difficult for
the consumer,
! Between 1 percent and 2 percent may be difficult for some consumers, but more
information is needed.
! Greater than 2 percent may be difficult for the consumer.
If the impacts are found to be substantial, the state would also have to demonstrate that
they are widespread before proposing a water quality standards revision. There are no explicit
criteria on which to evaluate "widespread" impacts, although EPA recommends evaluating the
change in the following indicators:
! Median household income
! Community unemployment rate
! Overall net debt as a percent of full market value of taxable property
! Percent of households below the property line
! Impact on community development potential
! Impact on property value.
The significance of the changes will help the state determine whether impacts are widespread.
Therefore, EPA cannot identify an acceptable or unacceptable estimated change for each
indicator.
If the state determines that the community cannot afford a level of CSO control to no
longer interfere with the attainment of water quality standards, EPA policy allows states to revise
their water quality standards based on the water quality improvements to be achieved by the
maximum level of CSO control that would not cause substantial and widespread social and
economic impacts on the community. This revision must be approved by EPA before it becomes
effective for purposes of the CWA.
5. Are there ways to simplify the UAA process?
Simplifying the UAA process begins with an inclusive process. With an inclusive
process a broad range of state, local and federal entities can actively participate in the scientific,
technical and funding discussions related to the CSO LTCP. An inclusive CSO LTCP process
simplifies the UAA process by broadening the cadre of knowledgeable individuals familiar with
the CSO issues and the likelihood of identifying other opportunities for further water quality and
use improvements with different types of CSO controls. These individuals increase the
likelihood of identifying other watershed opportunities for further water quality and use
improvements. They can also facilitate communication with the community-at-large by
explaining why additional controls or water quality standards revisions are needed.
32
-------
Common sense and good judgment play an important role in determining the amount of
data and level of analyses needed to justify changes in the designated use. The UAA process is
simplified when the CSO community, the state and EPA agree in advance on the scope of the
UAA, the data to be collected, and the analyses to be conducted.
The amount of data to be collected and analyses to be conducted will depend on the
particular water body. Some are inexpensive. Others are more difficult, such as examining the
effect of continued CSOs on a productive estuary. For the process to work smoothly, everyone
needs to agree on:
! Study design and objectives
! Data to be used and the methods and procedures to collect it
! Analyses to be conducted
! Critical factors to be used in interpreting the results.
Another way to simplify the UAA process is for the state to tailor the UAA to the factor
most likely precluding the attainment of the use. A less rigorous UAA would be needed for a
particular aquatic life use when the physical features of the water body prevent attainment.
Where physical features are the limiting factor for a particular aquatic life use, there may be no
need to conduct extensive water quality analyses. In CSO-impacted waters, where pathogens are
often the limiting factor in attaining recreational uses, there may be no need to conduct extensive
biological monitoring.
The UAA is also simplified where existing data are available. For example, a state that
has a biologically-based, refined classification system for aquatic life protection might have
generated extensive biological monitoring data to support the classification system. The data
would include numerical values or procedures for calculating numerical values applicable to a
particular type of aquatic life. Because they have data and an agreed-to basis for interpreting
those data, UAAs will be easier for states with such scientifically-based aquatic life use
classification systems. EPA continues to encourage states to adopt a biologically-based refined
aquatic life use protection classification system.
Another way to simplify the UAA process is to follow examples of UAAs that have been
used to support water quality standards revisions or that have shown a use to be attainable. Some
states have an outline of the data and analyses needed. They also provide examples of UAAs that
have been used to support water quality standards revisions. Following state outlines and
examples and other general models in the guidance documents should provide a good starting
point.
Additionally, "generic" assumptions could be developed if groups of water bodies share
similar characteristics. However, every water body and combined sewer system is different, and
additional data will be needed to demonstrate that the generic assumptions are applicable to the
circumstances of a particular water body. Such generic assumptions might relate to:
33
-------
! Physical, chemical and biological characteristics of the water body,
! Existing and designated uses,
! Hydraulic characteristics of the combined sewer system,
! Number and volume of the overflows,
! Response of the system to different types of storm events,
! Type of controls to be implemented.
6. What is a variance and when is it appropriate?
A variance is a time-limited change in the water quality standards, typically of three- to
five-year duration, with renewals possible. Variances that extend longer than three years need to
be reviewed triennially to confirm their continuing appropriateness. Variances provide a
"bridge" if additional data or analyses are needed before the state can make a determination that
the designated use is not attainable and adopts an alternative use. When a state (or EPA) adopts
the variance, it must have sufficient data to determine that the designated use is not attainable
within the duration of the variance. Because a variance is a change in the water quality standard,
the same requirements apply for a variance as for a new or revised standard, e.g., public review
and comment, and EPA approval or disapproval.
When adopting a variance for an individual discharger for specific pollutants, such as
bacteria, states have to demonstrate that the designated use is not an existing use (40 CFR
131.10(h)(l)) and that the designated use is not attainable with the technology-based controls in
sections 301(b) and 306 of the CWA and with cost effective and reasonable best management
practices for nonpoint sources (40 CFR 131.10(h)(2)).
To preserve existing uses, and ensure progress toward the ultimate attainment of the
designated use, conditions in a variance are set as close as possible to those for the designated
use, and always retained at the level needed to preserve the existing use. Other pollutant limits or
discharger effluent limits are not affected by a variance. For example, a state may adopt a
bacteria variance for specific CSO outfalls, but other point source dischargers would have to
continue to comply with the bacteria limits in their permits.
Because the underlying designated use remains (and because the variance will ultimately
lapse), the rigor of the analyses and the level of demonstration used for a variance are generally
less than that required for a permanent change in the use. States still need to demonstrate,
however, that at least one of the six bases for a change in a use apply at least during the variance
period. EPA expects that sufficient information will be available in a draft LTCP to justify a
variance.
In approving a variance, EPA looks at the conditions the state has included in the
variance (e.g., implementation of portions of the CSO LTCP and water quality monitoring).
Further environmental progress can be attained when variances include provisions such as:
34
-------
Prohibition on further degradation of water quality or further impairment of the
designated use.
Permit requirement for implementing high priority CSO controls (e.g.,
eliminating, treating or directing overflows from sensitive areas).
Collection of additional monitoring data.
Analyses that address complex questions related to determining an attainable goal
for the water body.
! Evaluation of whether further environmental benefits could be attained in the
water body or watershed by supplementing CSO controls with other
environmentally beneficial projects linked to the CSO receiving water body.
Once the agreed-to portion of the LTCP is implemented and the effect on water quality is
evaluated, the state will be better able to judge whether the use can be attained with additional
controls, or it needs to revise the water quality standards. Given the extended duration that EPA
anticipates for implementation of many LTCPs, longer term variances for specific pollutants
associated with particular CSO outfalls similarly may be warranted, based on the demonstrations
described above, subject to triennial review to determine continuing appropriateness.
35
-------
IV. INTEGRATING CSO LTCP DEVELOPMENT AND IMPLEMENTATION WITH
WATER QUALITY STANDARDS REVIEWS
1. How do you integrate the development of CSO LTCPs by communities and the review
of water quality standards by states?
EPA believes that communities and states can integrate the development of affordable,
well-designed and operated CSO control programs, implementation of high-priority controls, and
water quality standards reviews. One purpose of the CSO Control Policy is "to coordinate the
planning, selection, design and implementation of CSO management practices and controls to
meet the requirements of the CWA and to involve the public fully during the decision making
process." The Policy also includes four key principles, one of which is the "review and revision,
as appropriate, of water quality standards and their implementation procedures when developing
CSO control plans to reflect the site-specific wet weather impacts of CSOs."
Given the above principle and the importance of early and frequent coordination among
municipalities, State Water Directors, NPDES authorities, if different,20 and the public, this
guidance lays out a process (Figure 1) that is intended to ensure that all key groups engage in a
comprehensive and coordinated planning effort to achieve cost-effective CSO controls that
ultimately meet appropriate water quality standards. The process can be used by municipalities
that are developing or are implementing their LTCPs, or by municipalities that have implemented
their LTCPs but find that remaining CSOs continue to impair the attainment of water quality
standards. It is an iterative process as shown in Figure 1 and the accompanying narrative. The
purpose and major objectives of the process and flow chart are to:
! Delineate clear roles and responsibilities for CSO communities, NPDES
authorities, State Water Directors, EPA and others.
! Secure early agreement on the process and scope of the data and information
needed to support an LTCP and a water quality standards review.
! Ensure early input of the public in the LTCP and water quality standards review
processes.
! Ensure the acceptance of a draft LTCP is closely coordinated with decisions on
water quality standards revisions, if appropriate.
! Ensure the final LTCP and the water quality standards are reconciled.
Further, efficient use of resources can be realized through incorporating certain guidelines
into the process early. Some of these suggested guidelines include the following, and should be
considered before starting the process outlined in Figure 1:
20 NPDES authorities may be authorized States, or EPA Regional Offices, or federally recognized tribes.
36
-------
! Close coordination between state permitting and water quality standards programs
to identify priority water bodies for CSO control and evaluate the existing uses
and the applicability of current standards.
! Identification of ongoing or planned TMDL activities for CSO-impacted waters,
to promote synergy in data collection and water body assessment.
! Formation of the coordination team, which should include a review of Figure 1 to
ensure that the appropriate entities plan to be fully involved when needed, because
not everyone is needed at every point in the process.
The flow chart in Figure 1 lays out a series of steps that provide greater assurance that
affordable, well-designed and operated LTCPs support the attainment of appropriate water
quality standards. Figure 1 is intended to expand upon and explain, but not replace, the process
described in the Combined Sewer Overflows - Guidance for Long-Term Control Plan (EPA 832-
B-95-002).
EPA recognizes that the integration of the LTCP and water quality standards processes
requires a substantial commitment from CSO communities, states, and EPA. However, by
agreeing on priorities and a schedule for water quality standards reviews, state water quality
standards and NPDES authorities and EPA can make efficient use of their resources and assure
their full participation at key points in the process.
37
-------
FIGURE 1 - Coordination of LTCP Development and Water Quality Standards Review and Revision
STEP 5 STEP 4 STEP 3 STEP 2 STEP 1
Collect data
' and develop draft
LTCP, with the ,
public involved
Agree on the data
and analyses to
support LTCP
development and
alternative
evaluation, and
WQS reviews
Establish a
coordination team
to oversee LTCP
development and
WQS review
Implement the
NMCs and
evaluate their
efficacy
Issue permit requiring
implementation of Nine
Minimum Controls (NMCs)
and LTCP development
STEP 6
Review and accept
draft LTCP and
evaluate attainability
of WQS
Implement
and, through WQ
monitoring, evaluate
effectiveness of priority
controls (e.g. for sensitive
areas) and controls
common to all
alternatives
Responsible Entity
/N Water Quality Agency(s)
^ /NPDES and WQS Authorities)
NPDES Authority with
Coordination Team
CSO Community
WQS Authority
STEP 11
WQS revisons
may be needed
WQS attainable,
no revision
necessary
Propose revisions
and revise WQS,
if needed
STEP 7
STEPS
Review and
approve LTCP,
and modify permit
STEP 9
Implement
post-construction
compliance
monitoring to
evaluate attainment
of WQS
STEP 10
38
-------
Step 1 - Issue permit requiring implementation of the NMC and LTCP
development. The NPDES authority issues a permit or other enforceable mechanism that
requires the CSO community to implement the NMC and develop an LTCP. The permit or
enforceable order will require that the CSO community immediately proceed with the
implementation of the NMC.
Step 2 - Implement the NMC and evaluate their efficacy. The CSO community
should evaluate the efficacy of the NMC in controlling the number and quality of the overflows.
One of the goals of the CSO Policy is to achieve an early level of CSO control, even as the
municipality is involved in developing the LTCP. Following an assessment of NMC
effectiveness, municipalities should ultimately integrate the NMC into their LTCPs.
Step 3 - Establish a coordination team to oversee LTCP development and WQS
review. The NPDES authority organizes a team to coordinate the development of a draft LTCP.
The coordination team will promote timely discussion of issues, identify sources of information,
and provide technical assistance. The coordination team should include decision-making
representatives from the CSO community, NPDES authority, and State Water Director . It may
also be helpful to include a representative from EPA at this point because if a water quality
revision becomes necessary, the revision will need to be reviewed and approved by EPA. The
coordination team may also include representatives from local community stakeholders,
including those involved in watershed planning efforts, other point sources, nonpoint source
representatives, and persons involved in TMDL development, if applicable.
This process requires significant coordination and cooperation and full participation by
the communityand state (and if needed EPA). State Water Directors and their NPDES and water
quality standards entities will need to set priorities among CSO communities and the affected
water bodies. The state should coordinate the schedule for developing a TMDL with the
schedule (in the permit, administrative order or judicial order) for developing the CSO LTCP
before deciding on the schedule for the water quality standards review. Priorities might include:
! A court ordered TMDL analysis is underway on a receiving water where the
NPDES authority has approved the CSO LTCP, or the municipality (or separately
permitted municipal dischargers located along the same river reach) has
developed sufficient information to determine that:
- The use is not attainable based on a water body survey and assessment
including the factors in 40 CFR 131. 10(g)(l)-(5), or
- The level of CSO control required to attain or no longer interfere with the
attainment of water quality standards would cause substantial and widespread
economic and social impact.
! A municipality (or separately permitted municipal dischargers located along the
same river reach) has implemented the approved CSO LTCP and has collected
post-construction monitoring data showing that the remaining overflows
contribute to exceedances of water quality standards.
39
-------
! A municipality (or separately permitted municipal dischargers located along the
same river reach) has received approval of its CSO LTCP that contains sufficient
information to justify state adoption of a variance that would allow time to gather
further information, either on the efficacy of the controls in meeting water quality
standards, or on the attainability of the recreational use.
State authorities in the NPDES and water quality standards programs need to actively
participate in the coordination team where particular controversy exists, and EPA participation
may be necessary where there are interstate issues on a common body of water. Once the review
is scheduled, states and EPA can phase their active participation among communities and water
bodies, depending on the community's progress.
Some states and EPA Regional Offices have successfully used "kick off or periodic
meetings with CSO communities to respond to common issues or questions. Communities have
also expanded their own coordination efforts beyond their local constituency groups by involving
downstream communities affected by overflows, and other state and EPA personnel.
A community that is currently implementing an approved LTCP may request that the state
review the water quality standards for CSO receiving waters. A community could also request
that the NPDES authority form a coordination team to assist the water quality standards authority
in evaluating the attainability of the standards.
Step 4 - Agree on the data and analyses to support LTCP development and
alternative evaluation, and water quality standards review. The objective of this step is to
ensure that there is early agreement on the planned process (i.e., key milestones and dates) and
scope of the LTCP (e.g., presumption or demonstration approach), including the data and
analyses needed to support selection of control alternatives and review of water quality standards.
The members of the coordination team should agree on:
! The amount and type of data needed (i.e., characterization, monitoring and
modeling of the sewer system and its impacts on the receiving water body; data
needed for post construction compliance monitoring to be included in the
community's monitoring and modeling plan21).
! The range of alternative control levels to be evaluated, including cost and
performance information for each alternative examined.
Relevant sensitive areas.
A timetable for completion of key events.
Combined Sewer Overflows - Guidance For Monitoring and Modeling. (EPA 832-B-002, January,
1999).
40
-------
Together, the CSO community and the coordination team review historical data and
information on the combined sewer system and receiving water quality to develop a profile of
conditions, identify additional information to collect, and agree on the components of the
monitoring and modeling plan. The monitoring and modeling plan needs to:
! Support a thorough evaluation of the combined sewer system.
! Characterize the response of the system to various precipitation events.
! Determine the efficacy of the NMC.
! Determine the characteristics of the CSO effluent, and the effect of overflows on
ambient water quality.
! Describe post-construction compliance monitoring.
The monitoring and modeling plan identifies the parameters of concern in the receiving
water and water quality standards. In many cases, the principal concern will be pathogens.
Biological assessment, toxicity testing and sediment sampling may also be included in the plan,
where appropriate. All appropriate entities should reach agreement with the community on the
monitoring and modeling plan needed to support both the draft LTCP and the water quality
standards review. At a minimum, the NPDES authority, State Water Director and the community
are critical to securing this agreement. Coordination during this step provides greater certainty
that ultimately, the NPDES authority will approve the LTCP. Data collection efforts should also
be coordinated with any planned or on-going TMDL.
The coordination team should seek to optimize the development and analysis of the
information on CSO impacts in a manner that will support the water quality standards review and
the evaluation of the improvements in water quality during the implementation of the controls.
The amount and type of data will depend on the nature and extent of the site-specific CSO
impacts and the availability of data. The LTCP can serve as the foundation for a water quality
standards review.
The common components of an LTCP and a water quality standards review include:
! Water quality monitoring and modeling.
! Hydraulic monitoring and modeling.
! Detailed descriptions of existing and designated uses.
! Analyses of the potential for use attainment.
! Analyses of control costs.
The objective of this step is for the coordination team to agree on the additional data and
analyses and the critical factors to be used in interpreting the information; the schedule for the
studies; and the list of participating parties - before the community, state, EPA, or other federal
agency (e.g., U.S. Geological Survey) initiates any of the studies. Integrating water quality
standards reviews with the development and implementation of an affordable level of CSO
control necessitates that all parties agree in advance on the information and analyses that are
41
-------
appropriate to support a water quality standards revision that can be adopted, consistent with the
CWA and EPA's implementing regulation at 40 CFR 131.10. Agreement on the data needed for
the LTCP will support the collection of information needed for a UAA to the greatest extent
possible.
EPA regulations at 40 CFR 131.10(j) require a UAA whenever the state proposes to
reduce the level of protection for the water body. If the State Water Director agrees that a UAA
is appropriate, UAA guidance is available (Appendix HI). Appendix IV discusses recreational
UAAs.
EPA regulations at 40 CFR 131.10(i) also require that if the water body supports a use
with more stringent water quality requirements than the designated use, the state must revise the
use on that water body to reflect the use that is being attained. States are not required to conduct
UAAs when adopting more stringent criteria for a water body.
The state is responsible for making the determination, based on a UAA, that a use is
attainable, or that another appropriate attainable use needs to be adopted. EPA expects that the
UAA will be based in large part on data collected as part of the LTCP process, recognizing that
the data collection for the LTCP should be designed to support a UAA if ultimately needed. The
State Water Director should agree on the amount and type of data needed, taking into
consideration the nature and extent of the site-specific CSO impacts when making this judgment.
As discussed previously, before states can adopt a use that lowers the level of protection
for a water body, they must:
! Document that the current water quality standards are not attainable based on any
one of the factors in 40 CFR 131.10(g)(l)-(6).
! Provide an opportunity for the public to review the proposal and analyses
justifying the revision (40 CFR 131.20(b)).
! Ensure that any revision provides for the attainment and maintenance of
downstream water quality standards (40 CFR 131.10(b)).
In addition, states may not lower the level of protection for or remove:
! An "existing" use, i.e., a use actually attained in the water body on or after
November 28, 1975 (40 CFR 131.3(e) and 131.10(h)(l)): or
! A use that can be attained by the imposition of effluent limits required under
section 301(b) or 306 of the CWA and cost-effective and reasonable best
management practices for non-point source control (40 CFR 131.10(d) and
42
-------
Step 5 - Collect data and develop draft LTCP, with the public involved. With
agreement on the scope of the LTCP and the data collection and analyses, the CSO community
implements the monitoring and modeling plan and develops a draft LTCP.
In order to design a CSO control plan adequate to meet the requirements of the CWA, the
CSO community should have a thorough understanding of its sewer system, the overflows, and
the water quality impacts that result from CSOs. Monitoring and modeling should be used to
adequately characterize the system for a range of storm events. The characterization should show
the response of the sewer system to wet weather events, including the number, location and
frequency of CSOs, volume, concentration and mass of pollutants discharged and the impacts of
the CSOs on the receiving waters and their designated uses. The monitoring and modeling data
will be used to evaluate the expected effectiveness of the NMC and LTCP in meeting water
quality standards.
For each CSO control level examined, the CSO community evaluates the constructability,
costs, performance, water quality benefits, and protection of sensitive areas. The CSO
community also identifies other sources of pollution impacting the CSO receiving water which
may preclude the attainment of water quality standards, regardless of the level of CSO control.
At a minimum, the CSO community considers the following levels of control:
! Levels of control that would be necessary to achieve the following average
number of overflow events:
! — Zero overflow events (e.g., 100 percent capture for treatment ), eliminating
the contribution of CSOs to water quality standards violations.
One to three overflow events per year
- Four to seven overflow events per year,
- Eight to twelve overflow events per year
! Treating or directing CSOs away from sensitive areas.
Alternatively, the CSO community could evaluate controls to achieve varying levels of
capture rather than limiting the number of overflow events in its LTCP. In this case, the
alternative control levels should include various percentages of the wet weather flow volume
entering the combined sewer system during wet weather under average annual conditions (e.g.,
100 percent, 95 percent, 90 percent, 85 percent, 80 percent, 75 percent of the combined sewage
collected in the combined sewer system during wet weather events).
Communities often hold workshops during the development of the draft LTCP to identify
priorities for controls and control alternatives to examine. Workshops on the LTCP, combined
with discussion of the analyses needed to support a water quality standards review, can promote
coordination and inform the public about the effect of various levels of CSO control on the use of
the water body and the attainment of water quality standards. Such workshops can also promote
a timely dialogue among the CSO community, the public, the state, and EPA about additional
control alternatives and appropriate water quality standards revisions. Information on the water
43
-------
quality standards program should be available to support workshop discussions.22 Prior to
accepting the LTCP, states may require communities to hold a public hearing, take comment on
the LTCP, and show how the comments were addressed.
The LTCP should include a financing plan that identifies sources of capital funds. The
CSO Control Policy recognizes that financial capability is a significant factor in establishing
implementation schedules for CSO controls and therefore, if necessary, allows a phased
implementation schedule that is prioritized based on the relative importance of adverse impacts
upon water quality standards, including designated uses. Where implementation of CSO controls
causes financial burden, construction may be phased in over an extended period of time.
Typically, schedules are negotiated by the CSO community and its NPDES authority.
The CSO community submits the draft LTCP, including the data and analyses assessing
the attainability of current water quality standards, to both the NPDES authority and to the State
Water Director. In moving from Step 5 to Step 6, coordination between the NPDES authority
and water quality standards authority becomes paramount. Up-front planning is likely to be
necessary to ensure that the analysis and decisions made by the two entities are synchronized.
Step 6 - Review and accept draft LTCP and evaluate the attainability of water
quality standards; implement and, through water quality monitoring, evaluate
effectiveness of priority controls (e.g., for sensitive areas) and controls common to all
alternatives. The State Water Director and the NPDES authority (if different) need to review the
draft LTCP. The CSO community needs to work with the regulatory agency to confirm that the
basis of the LTCP is acceptable, e.g., the data, the alternatives examined, and the schedule for
implementing controls common to all alternatives examined. If the draft LTCP is insufficient,
the NPDES authority returns the draft to the community for revision.
Concurrently, if sufficient data are available, the State Water Director evaluates the
attainability of the applicable water quality standards. Coordination between the NPDES
authority and the water quality standards authority is essential in this step. At a minimum, this
assessment will include the factors discussed in Section in.3 and Appendix IV.
The data collected and analyses conducted by the CSO community may be sufficient to
justify a water quality standards revision, or may show that a water quality standards revision is
not justified. If the state agrees that the data and analyses support a water quality standard
revision (recognizing the revision may produce more or less stringent standards), this would
represent a commitment from the state to proceed with proposing water quality standards
revisions.
22. Elder, D., G. Killam and P. Koberstein, Chapter 4, Water Quality Standards and the Public's Role, in
The Clean Water Act: An Owner's Manual. River Network, Portland, OR, 1998; U.S. EPA, Introduction to Water
Quality Standards (EPA-823-F-99-020, October, 1999; U.S. EPA, Developing Criteria To Protect Our Nation's
Waters (EPA-823-F-98-002, April, 1998).
44
-------
If the data and analyses show that currently applicable water quality standards can be
attained, and that revisions to the water quality standards are not justified, the state notifies the
community and the coordination team. The NPDES authority then works with the community to
revise the LTCP, as described in Step 8.
If sufficient data are not available to evaluate the attainability of the use, the State Water
Director, in consultation with the coordination team, identifies the parameters for which
additional information is needed. If the community wishes to pursue a water quality standards
review, these additional data should be collected while implementation of the LTCP is initiated.
In accordance with the CSO Control Policy, municipalities should identify all sensitive
water bodies and the CSO outfalls that discharge to them as part of developing the LTCP.
According to the CSO Control Policy, sensitive areas include:
! Outstanding National Resource Waters
! National Marine Sanctuaries
! Water with threatened or endangered species or their designated critical habitat
! Primary contact recreation waters, such as bathing beaches
! Public drinking water intakes or their designated protection areas
! Shellfish beds
Municipalities may also identify other areas for special protection.
As soon as the state review of the LTCP has been completed and priority controls
accepted, EPA expects that municipalities will begin to implement these priority controls, such
as treating or re-directing CSOs which impact sensitive areas. The NPDES authority may need
to revise or reissue the NPDES permit or other enforceable mechanism (e.g., administrative or
judicial order) requiring the implementation of these "priority controls." In addition, the permit
or other enforceable mechanism would include the requirements contained in a variance, if
adopted by the state, and monitoring to be conducted to evaluate the efficacy of the controls in
reducing overflows and improving water quality. This information could cause the community to
re-think planned controls, based on the water quality improvements already achieved.
Step 7 - Propose revisions and revise WQS, if needed. To reach this step, the CSO
community, NPDES authority, and State Water Director should have agreed that the LTCP
contains adequate data and information to support the selection of CSO controls and identify
needed revisions to the water quality standards. The state should proceed as expeditiously as
possible to propose and adopt these revisions, taking into consideration public comment,
including those of EPA before adopting final revisions.
Once the community has implemented priority CSO controls, the state may determine
that a water body has the potential to support improved aquatic life. Under this circumstance, the
state would upgrade the aquatic life use for the water body. In other cases, the state may
45
-------
determine that the recreational uses are not fully attained all the time, and may refine the
recreational uses to reflect the maximum level of control from a well-designed and operated
control program that does not cause substantial and widespread economic and social impact. As
discussed in Step 4, other revisions applicable to recreation may include:
Applying the standard at the point of contact rather than at the end-of-pipe.
Creating subclasses of the current designated use to recognize intermittent
exceedances of bacteriological criteria.
! Segmenting the water body to preserve the designated use in areas where it
actually occurs.
Prior to submitting a proposed water quality standard revision to EPA for review, EPA's
water quality standards regulations require the state to hold a public hearing and request
comment on the proposed revisions. This public hearing is an opportunity for the CSO
community to be actively involved and to help explain the proposed CSO control alternatives and
their relationship to the proposed water quality standards revision. This hearing also affords the
public an opportunity to have input on the selection of the final CSO program at a key decision
point, given the LTCP's relationship to the attainment of water quality standards.
EPA's water quality standards regulations at 40 CFR 131.21(b) require that any analyses,
including the UAA, used in support of the water quality standard revision be made available for
public review and comment at the time the revisions are proposed. Subsequent to public review
and comment and appropriate revision, the state submits the revision, supporting analyses and
public comments to EPA for review.
Before the revisions in the water quality standards may be used for CWA programs,
including TMDLs and NPDES permits, EPA must approve the state-adopted water quality
standards revision (see 65 FR 24641, April 27, 2000). Again, where there has been close
coordination and cooperation, the approval process is more likely to proceed expeditiously. EPA
is expected to approve a state's new or revised standard within 60 days, or disapprove within 90
days.
Step 8 - Revise LTCP, as appropriate. If the water quality standards decisions differ
from those that the CSO community anticipated, or if the previously implemented controls have
not performed as predicted, the community would have to revise the draft LTCP.
The CSO community should work closely with the regulatory authorities to confirm the
project implementation schedule for the CSO control program. Key milestones include, for
example, design completion, attainment of funding, construction milestones, completion dates,
and implementation of post-construction monitoring. Guidance on these issues is available in
Combined Sewer Overflows - Guidance for Long-Term Control Plan.
46
-------
Step 9 - Review and approve LTCP, and modify permit. The NPDES authority
coordinates the review of the revisions and, if appropriate, approves the final LTCP, which
provides that CSO discharges do not contribute to excursions of water quality standards or non-
compliance with other CWA requirements. The NPDES authority issues a permit or
administrative order, or proceeds with revisions to an enforceable order requiring implementation
of the approved LTCP.
Step 10 - Implement the LTCP. The CSO community implements the control
measures described in the approved LTCP and required in its NPDES permit or other enforceable
mechanism. The LTCP includes an operational plan and a post-construction compliance
monitoring program to ensure continued compliance with the requirements of the CWA.
Step 11 - Implement post-construction compliance monitoring to evaluate
attainment of water quality standards. In addition to proposing a CSO control strategy, the
LTCP outlines the post-construction operational plan and compliance monitoring activities that
the community will undertake to assure that the controls function as planned. Post-construction
compliance monitoring is necessary to verify that any remaining CSOs do not contribute to
excursions of water quality standards or non-compliance with other requirements of the CWA.
Both during and after construction of the CSO controls described in either Step 6 or Step
10, the community collects and analyzes collection system and receiving water data, as
appropriate, to assess whether the controls function as planned. If, after implementing the
controls outlined in the LTCP, the CSO community finds that it is still contributing to the non-
attainment of the applicable water quality standards, it will use the monitoring data and return to
Step 6 to consider revising the LTCP. Revisions may include changes to operating plans or the
operation and maintenance schedules, or development of expanded or additional controls, which
may be retrofitted to existing controls. The municipality may also request that the water quality
standards authority review and revise the standard based on the results of a use attainability
analysis, including a finding that additional controls would cause substantial and widespread
economic and social impact.
2. How have states reconciled their water quality standards with overflows remaining
after a well-designed CSO LTCP has been developed?
By using the flexibility in their water quality standards program framework, a few states
have the mechanisms in place for integrating water quality standards reviews with the
development and implementation of a well-designed and operated CSO control program.
One approach EPA recommends is to use continuous simulation modeling and volumetric
stream flow to develop TMDLs, waste load allocations, and water quality-based permit limits,
and to support UAAs as appropriate. This approach takes into account episodic events,
integrating wet weather variables such as storms (frequency, duration and intensity), surface
runoff, and land-use patterns. Daily flow data are available on about 6,200 stream reaches with
U.S. Geological Survey gaging stations, and estimated flows can be calculated where measured
47
-------
values are unavailable. Guidance is available through BASINS (Better Assessment Science
Integrating Point and Nonpoint Sources), which integrates a geographic information system
(GIS), national watershed data, and environmental assessment and modeling tools into a single
assessment tool (see www.epa.gov/ost/basins).
The State of Oregon allows the discharge of untreated domestic waste, with exceptions,
based on a storm event greater than the one-in-five-year 24-hour duration storm in the winter,
and greater than the one-in-ten-year 24-hour duration storm in summer. This only applies where
the state has approved a basin- or geographic-specific bacteria control management plan that:
! Identifies the specific hydrologic conditions under which the numeric criteria
would be waived.
! Identifies the public notification and education processes to inform the public
about an event and the plan.
! Describes the water quality assessment conducted to determine the bacteria
sources and loads associated with the specified hydrologic conditions.
! Describes the bacteria control program that is being implemented in the basin or
specified geographic area.
The State of Washington addresses remaining overflows by allowing, on average, a once-
per-year exemption to several parts of its mixing zone policy. The exemption waives provisions
related to the maximum size of the mixing zone, the applicable acute criteria, and to the
overlapping mixing zone criteria. However, the state does not waive the mixing zone policy
provision that prohibits the mixing zone from contributing to a loss of sensitive or important
habitat, substantially interfering with the existing uses of the water body, damaging the
ecosystem, or adversely affecting public health.
Another approach used by Massachusetts and Maine is to subdivide their uses into CSO
subclasses. Based on a UAA, and under specified circumstances, Massachusetts temporarily
suspends the primary contact recreational use and the bacteria criteria during CSO events. Maine
uses the same type of temporary suspension, but also suspends shell fishing. Although these
states developed and will implement their approaches differently, the approaches have a great
deal in common. For example, both states:
Maximize the protection of sensitive use areas.
Require state-approved well-designed control programs (in Massachusetts,
controls must meet the recreational goal use 95 percent of the time; Maine
suspends uses for the shortest duration practicable, in the smallest area possible,
and where the public impacts are minimal).
Call for UAAs consistent with the requirements in 40 CFR 131.10.
Use variances when they don't know whether the designated uses can be fully
attained, and require additional water quality data collection before deciding that
the use is not attainable.
48
-------
! Make implementation of CSO controls a condition for the community eligibility
to use the criteria and temporary use suspension.
! Review progress periodically.
Some states are also considering adopting a high-flow cutoff into their water quality
standards that suspends bacteria criteria and thus, the recreational uses, under certain defined
conditions of high wet weather flows in the receiving water. The concept of a flow cutoff for
extremely high flows or dangerous velocities may have merit. However, cutoff proposals need to
be based on rigorous scientific assessment and must reflect public input. Additionally, such a
cutoff should be applied on a case-by-case basis (rather than state-wide, for example), tailored to
the water body (rivers, as distinct from lakes), and set high enough to only be applicable under
certain limited conditions. Water body flow and velocity vary greatly, depending on a
combination of many factors, such as the amount of impervious surface, slope, soil texture,
vegetative cover, soil compaction, soil moisture, etc. The conditions affecting velocity also vary
with the depth and width of the water body's channel. If a state adopts a flow cutoff, several
questions need to be answered:
! Will the cutoff protect the other uses?
! What is the resulting velocity?
! Would the velocity preclude all recreational uses (including kayaking) that
typically occur during high velocity flows?
! Do the high flows have a minimal effect on the velocity of the flow, posing little
or no danger to persons using the waters for recreation?
For how many days would the cutoff apply?
Will the state adopt the cutoff statewide, create a discharger-specific variance, or
develop recreational subcategories that correlate to the cutoff?
! Has a UAA shown that an affordable well-designed and operated control program
could not achieve a higher level of CSO control than that afforded by the cutoff?
! What effect would the high flow cutoff have on implementing controls for other
sources of bacterial contamination to the water body (e.g., storm water, leaking
septic systems, feed lots, row crops, etc)?
EPA has not developed a national policy on a high flow/velocity cutoff for bacteria and
recreational uses, similar to the low flow cutoff for aquatic life criteria. Guidance implementing
such a policy should include scientifically valid methodologies for maintaining and protecting the
section 101(a)(2) recreational uses when normal flow returns, and for protecting downstream
uses. EPA envisions a methodology that states could apply on a site-specific basis using the
water body channel and landscape characteristics. States could also create a subcategory of the
recreational uses to which the cutoff would apply. Since use of a high flow/velocity cutoff
reduces the level of protection for the water body, a UAA would be required for its application to
a specific water body. It would be particularly important to demonstrate that a community could
not afford a higher level of control (or, for example, additional storm water or agricultural
BMPs). As with other changes in designated uses, the public must have an opportunity to
49
-------
comment on the proposed revision to the water quality standard before a state adopts and submits
it to EPA for approval or disapproval.
3. How will EPA ensure that NPDES authorities and State Water Directors participate in
the review and revisions, as appropriate, of water quality standards for CSO-receiving
waters?
EPA will work with states and NPDES authorities to require that all permits, orders, and
decrees conform with the CSO Control Policy as provided for in Section 402(q)(l) of the CWA.
To ensure the availability of accurate and timely data concerning permitting actions and other
CSO program actions described in the Policy, EPA will establish a database tracking system for
CSO permit requirements and water quality standards reviews.
50
-------
V. THE WATERSHED APPROACH
EPA recognizes that urban water quality may be affected by a combination of CSOs,
storm water, other point source discharges, and nonpoint source runoff. These sources may be
addressed most effectively through TMDL analyses or other watershed-based management plans.
Congress also recognized the importance of the watershed approach in section 402(q) of the
CWA by authorizing "wet weather watershed pilot projects."
1. What is EPA's overall approach to watershed-based planning?
EPA encourages the use of a watershed approach to prioritize actions to achieve
environmental improvements, promote pollution prevention, and meet other important
community goals. Watersheds provide a natural framework around which to manage water
quality improvement and protection programs. CSO planning on a watershed basis allows a
community to assess the full range of sources (including other wet weather sources such as storm
water) and ensure that investments yield the greatest environmental benefit. Sound scientific
analyses, including TMDLs that address both the point and the non-point sources of the
pollutants impairing the water body, support the watershed approach. The watershed approach is
an inclusive, collaborative process that involves many diverse interests who use the data and
information to define the goals, set priorities, and develop a suite of integrated controls that
achieve the water quality goals for the water body.
Under a watershed approach, local stakeholders coordinate the development of a
comprehensive watershed plan that provides for collection of environmentally relevant data and
serves as the basis for identifying appropriate regulatory and non-regulatory actions to be
implemented to improve water quality. A watershed approach does not provide any additional
liability protection or change the legal status of discharges to waters of the United States.
Watershed plans can be considered, however, when developing enforcement schedules for
bringing unauthorized discharges into compliance with the CWA.
A watershed approach to controlling CSOs and other wet weather discharges has the
potential to: improve the basis for water quality management decisions; provide an equitable and
cost-effective allocation of responsibility among dischargers; and, in so doing, deliver the same
or greater levels of environmental improvement sooner and at a cost savings. A watershed
approach emphasizes the role of CSO communities and other local stakeholders in identifying
water quality priorities, and increases the opportunity for using risk-based approaches to
environmental protection.
A. What information sources are available on watershed approaches?
Several EPA documents explain the principles of watershed-based water quality planning.
EPA's NPDES Watershed Strategy (March, 1994) outlines national objectives and
implementation activities for integrating NPDES program functions into a broad watershed
51
-------
approach and provides support for development of state-wide basin management approaches.
The Watershed Framework (May, 1996) describes EPA's expectations for state and tribal
implementation of watershed approaches. The 1998 Clean Water Action Plan has, at its core, an
emphasis on local watershed planning. It calls upon state, federal, and local agencies, watershed-
based organizations, and the public to identify watersheds most in need of restoration and to
cooperate in the development of watershed restoration action strategies and implementation of
these strategies.
In addition, EPA lists many excellent publications and web-based resources for watershed
groups on the Agency's web site at www.epa.gov/owow.
B. How does watershed planning relate to TMDL development?
A TMDL is a watershed plan, developed to attain a particular water quality standard. The
watershed planning process and TMDL analyses generate valuable information on total pollutant
loadings and the relative contribution of the pollutant sources. Since TMDLs must be developed
to meet existing water quality standards, the permit (or other enforceable mechanism) for
implementation of the LTCP also must provide for the attainment of water quality standards,
including any revisions to the water quality standards made as a result of the TMDL or LTCP.
Consequently, it is important that LTCPs be developed and implemented in explicit coordination
with TMDL evaluations and other watershed management planning.
The TMDL considers seasonal variations and reasonably foreseeable increases in
pollutant loads in allocating the reductions in pollutant loadings needed to attain and maintain
water quality standards. Participation in watershed planning and support of state- or EPA-
developed TMDLs may yield efficiencies for CSO communities. For example, using an existing
watershed organization as the public advisory group for CSO control planning and
implementation, the community gains knowledgeable individuals committed to finding solutions.
By participating in watershed/TMDL analyses, a CSO community can help provide the
information to support an equitable allocation of pollutant loading reductions among all point
and nonpoint sources. This is particularly important where CSO receiving waters are affected by
numerous sources, and a watershed-level effort is needed to allocate pollutant loadings. Where
pollutant sources from different states contribute to the impairment of a shared water body or a
downstream water body, states may need to involve EPA in the development of the TMDL in
order to bring all jurisdictions into the planning process.
In urban areas, water quality may be impacted by many sources. These can include
wastewater, storm water, and upstream point and non-point pollution sources. TMDL analyses
may evaluate a number of different options to attain water quality standards, including:
! Eliminating or treating all CSOs.
! Imposing more stringent controls for leaking septic tanks, storm water discharges,
or animal feeding operations.
52
-------
Developing stronger non-point source control programs.
Revising the water quality standard for a particular pollutant and the applicable
permit requirements.
Watershed planning and TMDL analyses can promote flexibility and innovation for
addressing CSOs and other pollutant sources. The planning and analyses may identify more cost-
effective allocation of pollutant reductions using a combination of BMPs and CSO controls
which together yield greater environmental benefits than would CSO controls alone. Participants
can identify complementary environmental projects, such as upstream storm water controls,
along with nonstructural CSO controls, that may enhance the aquatic habitat and foster
improvements in both recreation and aquatic life uses. Development of a TMDL may also
support a UAA to review and revise water quality standards, as appropriate.
C. How does watershed planning affect capital planning?
EPA is exploring ways to support capital investments in combined and separate sanitary
sewer collection systems that are consistent with and complementary to broader watershed
planning objectives. Many municipalities are well positioned to coordinate with other watershed
stakeholders in the development of LTCPs addressing needs and deficiencies in storm water and
wastewater infrastructure. CSO communities may find it advantageous to take a leadership role
in local watershed planning, particularly where CSOs and other urban wet weather discharges
contribute heavily to water quality impacts or where a municipality has substantial data,
resources, or incentive to take a leadership role.
D. Who sets the priorities for TMDLs?
States set the priorities for conducting a TMDL although in some cases litigation has
resulted in a court setting the schedule. Therefore, the state should coordinate the schedule for
the development of a TMDL with the schedule for deciding on any appropriate revisions to the
water quality standards. This is particularly important where a court-ordered schedule directs
that a TMDL be established prior to the state's water quality standards review. In this
circumstance, a state-adopted variance may be especially appropriate.
2. How does CSO planning fit into a watershed approach?
The approach identified in Figure 1 for coordinating LTCP development and water
quality standards review lends itself well to coordination with watershed stakeholders to address
wet weather sources of pollution. The data collection, planning, and coordination activities
identified in Figure 1 can be an integral part of a comprehensive watershed planning and
implementation process, in which stakeholders identify water quality and environmental
problems through a comprehensive watershed assessment. The process would involve
coordination of the LTCP development process, the process for reviewing and (as appropriate)
53
-------
revising water quality standards, and other programs to improve water quality in a more efficient
and effective fashion.
The watershed planning process typically begins with identification of stakeholders who
can contribute significantly to the implementation of coordinated periodic management activities,
who are significantly impacted by water quality problems, who will need to undertake control
measures because of legal or regulatory requirements, or who oversee their implementation. This
process would include satellite municipalities whose collection systems significantly contribute
to wet weather problems; owners of agricultural, industrial, or other pollutant sources outside the
urban area that contribute to impairment; and members of the public. Where possible, the
stakeholder identification process should be integrated with identification of the coordination
team formed to oversee the LTCP and water quality standards processes (Step 3 of Figure 1).
Under this process, each regulated stakeholder would be required to implement
appropriate minimum measures without delay. For example, the CSO community would be
responsible for implementing the nine minimum controls required in Step 1 of Figure 1.
The parties to the watershed planning process would coordinate efforts to assess the
sources of impairment in the watershed and the degree to which sources contribute to
impairment. If the assessment indicates the need for pollution controls beyond minimum
measures, the parties should agree on recommendations for allocation of water quality
management responsibilities based on sources' relative contributions to impairment. This
approach is reflected in Step 4 of Figure 1, where the CSO community, the coordination team,
and other involved entities agree on the amount and types of data needed, development of a
monitoring and modeling plan, and gathering of the essential data needed to support the draft
LTCP and a draft UAA, where appropriate.
The watershed plan should identify recommendations for interim and final LTCP goals,
including recommendations to NPDES authorities for establishing or adjusting enforceable
requirements. Responsibilities for funding planning and remediation projects should be defined.
When allowed under state law, and consistent with any applicable TMDL, the NPDES authority
could agree to phase additional water quality regulatory requirements to accommodate the
planning process and to synchronize requirements such as monitoring among participants.
Special consideration would be warranted for sensitive and high-exposure areas such as beaches
and drinking water supplies.
EPA expects that communities will implement high priority controls, such as eliminating
or fully treating overflows to sensitive areas, while TMDLs or watershed plans are being
developed. CSO control planning and phased implementation of the controls allows
communities to implement their initial controls and evaluate the water quality improvements.
They may be able to re-evaluate planned controls based on the water quality improvements
already achieved. Watershed plans can be taken into account when developing enforcement
54
-------
schedules for bringing unauthorized or unpermitted discharges into compliance with the CWA,
but watershed plans (including the planning process) are not a bar to enforcement actions.
3. How do states with CSO communities use watershed approaches?
States with CSO communities can apply the watershed approach in different ways. Using
the watershed as the basis for managing all state water quality programs (e.g., Delaware and
Ohio) promotes logical scheduling. When data are collected on a rotating basis, they support
several activities:
! Water quality standards reviews
! "303(d) list" development of non-attained waters
! TMDL analyses
! Permit issuance
Others use the watershed approach selectively for monitoring, designating uses,
reviewing water quality standards, or issuing permits:
! Monitoring (Indiana)
! Use designations (Delaware River Basin Commission, Washington),
! Water quality standards reviews (Ohio), and
! Permit issuance (Georgia, Kentucky, Nebraska, West Virginia).
Watershed plans and TMDLs afford the opportunity to identify complementary projects
that could save resources or gain additional environmental benefits for the community. Targeting
CSO controls to eliminate overflows to parks or swimming areas may stimulate public
improvement projects that yield greater environmental benefits and offset the costs of eliminating
the overflows. Or, stream bank stabilization might improve aquatic life more than large storage
facilities for combined sewers would have.
55
-------
VI. CONCLUSION
EPA believes that communities and states can integrate water quality standards reviews
with the development of an affordable, well-designed and operated CSO control program and
implementation of priority controls. EPA expects that CSO communities will collect information
on the efficacy of the controls in improving water quality. This information should be adequate
to allow the community and the state to determine that the LTCP, when completed, prevents
CSOs from causing or contributing to the non-attainment of applicable water quality standards
and/or to assist the state in determining if the use is not attainable and in identifying another
attainable use. Once reconciliation occurs, CSO communities and states will have carried out the
water quality-based provisions in the CSO Control Policy.
56
-------
APPENDIX I
ANNOTATED BIBLIOGRAPHY OF CSO GUIDANCE DOCUMENTS
Combined Sewer Overflows - Guidance for Long-Term Control Plan (EPA 832-B-95-002)
This guidance describes how municipalities can develop comprehensive long-term
control plans that recognize the site-specific nature of CSOs and their impacts on
receiving water bodies. The document describes how to develop a long-term control plan
that includes technology-based and water quality-based control measures that are
technically feasible, affordable, and consistent with the CSO Control Policy.
Combined Sewer Overflows - Guidance for Nine Minimum Controls (EPA 832-B-95-003)
This guidance provides information on nine minimum technology-based controls that
communities are expected to use to address CSO problems, without extensive
engineering studies or significant construction costs, before long-term measures are taken.
Communities were expected to implement the nine minimum controls and submit
documentation no later than January 1, 1997.
Combined Sewer Overflows - Guidance for Screening and Ranking (EPA 832-B-95-004)
This guidance presents a process for screening and ranking combined sewer systems to
help permitting authorities establish CSO permitting priorities. May also help permittees
rank their CSOs in order to best allocate their limited resources.
Combined Sewer Overflows - Guidance for Funding Options (EPA 832-B-95-007)
This guidance will help permittees as they develop CSO control funding plans. The
guidance presents plain-English descriptions of a broad spectrum of options that may be
available to fund the capital, debt service, and operational costs of CSO controls. It
describes the benefits and limitations of various funding options.
Combined Sewer Overflows - Guidance for Permit Writers (EPA 832-B-95-008)
This guidance is intended primarily for NPDES permitting authorities and permit writers
and describes how to develop and issue NPDES permits with CSO conditions that reflect
the CSO Policy. It provides example permit language and stresses the need for
coordination between permittees, permit writers, water quality standards authorities,
enforcement authorities, and the public.
Combined Sewer Overflows - Guidance for Financial Capability Assessment and Schedule
Development (EPA 832-B-97-004)
This guidance discusses how a community's financial capability and other factors
identified in the CSO Policy may be used to negotiate reasonable compliance schedules
for implementation of CSO controls. It presents a two-phase process for assessing
financial capability, based on EPA's experience in the Construction Grants, State
Revolving Fund, enforcement, and water quality standards programs. It stresses the need
A-l
-------
for flexibility and evaluation of site-specific factors in the development of
implementation schedules for CSO controls.
Combined Sewer Overflows - Guidance for Monitoring andModeling (EP'A 832-B-99-002)
This manual explains the role of monitoring and modeling in the development and
implementation of a CSO control program. It expands discussions of monitoring and
modeling introduced in the CSO Control Policy and presents examples of data collection
and simulation of sanitary and storm water flows in the combined sewer system. To use
this manual, a municipality should already be familiar with the basic functioning of its
CSS, basic monitoring procedures, and the general purpose of modeling.
The guidance documents are available on the EPA website at http://www.epa.gov/npdes by
clicking on the "CSO" program area. In addition, EPA has printed a limited number of copies of
each guidance document and has made them available through several sources:
EPA's Water Resource Center ((202) 260-7786)
National Small Flows Clearinghouse ((800) 624-8301 or
http://www.estd.wvu.edu/nsfc)
National Technical Information Service (NTIS) ((800) 553-6847 or
http: //www/nti s. gov)
Educational Resources Information Center (ERIC) ((800) 276-0462 or
http://www.aspensys.com/eric/catalog/)
State environmental offices
EPA Regional Offices
A-2
-------
APPENDIX II
REMOVAL OF DESIGNATED USES - 40 CFR 131.10 (g) AND (h)
[excerpted from: EPA's Water Quality Standards Handbook:
Second Edition, Chapter 2.7 (1994)]
The basic steps for determining how and when a designated use may be removed are as
follows:
Step 1 - Is the Use Existing? Once a use has been designated for a particular water
body or segment, the water body segment cannot be reclassified for a different use except under
specific conditions. If a designated use is an existing use (as defined in 40 CFR 131.3) for a
particular water body, the existing use cannot be removed unless a use requiring more stringent
criteria is added. However, uses requiring more stringent criteria may always be added because
doing so reflects the goal of further improvement of water quality. Thus, a recreational use for
wading may be deleted if a recreational use for swimming is added, or the state may add the
swimming use and keep the wading use as well.
Step 2 - Is the Use Specified in Section 101(a)(2)? If the state wishes to remove a
designated use specified in section 101(a)(2) of the Clean Water Act, the state must perform a
use attainability analysis.
Step 3 - Is the Use Attainable? A state may change activities within a specified use
category but may not change to a use that requires less stringent criteria, unless the state can
demonstrate that the designated use cannot be attained using the factors in 40 CFR 131.10(g).
For example, if a state has a broad aquatic life use, EPA generally assumes that the use will
support all aquatic life. The state may demonstrate that for a specific water body, such
parameters as dissolved oxygen or temperature will not support trout but will support perch when
technology-based effluent limitations are applied to point source dischargers and when cost-
effective and reasonable best management practices are applied to non-point sources.
Step 4 - Is a Factor from 131.10(g) Met? Even after the previous steps have been
considered, the designated use may be removed, or subcategories of a use established, only under
the conditions given in section 131.10(g). The state must be able to demonstrate that attaining
the designated use is not feasible because:
1. Naturally occurring pollutant concentrations prevent the attainment of the use; or
2. Natural, ephemeral, intermittent, or low flow conditions or water levels prevent
the attainment of the uses, unless these conditions may be compensated with
sufficient effluent discharges; or
3. Human-caused conditions or sources of pollution prevent the attainment of the use
and cannot be remedied or would cause more damage than to leave in place; or
A-3
-------
4. Dams, diversions or other types of hydrological modifications preclude the use,
and it is not possible to restore the water body or operate the modification in such
a way that would result in attainment; or
5. Physical conditions related to the natural features of the water body unrelated to
water quality preclude attainment of aquatic life uses; or
6. Controls necessary to attain the use would cause substantial and widespread
economic and social impact.
Step 5 - Provide Public Notice. As provided for in section 131.10(e), states must
provide notice and opportunity for public hearing in accordance with section 131.20(b). Of
course, EPA intends for states to make appropriate use of all public comments received through
such notice.
A-4
-------
APPENDIX III
LIST OF GUIDANCE TO SUPPORT USE ATTAINABILITY ANALYSES (UAAs)
EPA has published:
! Technical Support Manuals for Conducting Use Attainability Analyses (Volumes
I-in, Rivers and Streams, Estuaries, Lakes, 1983 and 1984)
http://www.epa.gov/ost/library/wqstandards/123.pdf. These three volumes each
contain sections on assessing physical, chemical and biological characteristics of
the specific water body type.
EPA has developed more recent guidance on assessing biological characteristics in the
following documents:
! Macroinvertebrate Field and Laboratory Methods for Evaluating Biological
Integrity of Surface Waters (1990) -EPA/600/4-90/030 (PB91-171363).
This manual describes guidelines and standardized procedures for the use of
macroinvertebrate studies in evaluating the biological integrity of surface waters.
It was developed to provide biomonitoring programs with benthic invertebrate
methods for measuring the status and trends of environmental pollution on
freshwater, estuarine, and marine macroinvertebrates in fields and laboratory
studies. These studies are carried out to assess biological criteria for the
recognized beneficial uses of water, to monitor surface water quality, and to
evaluate the health of the aquatic environment.
! Fish Field and Laboratory Methods for Evaluating the Biological Integrity of
Surface Waters (1992) - EPA/600/R-92/111.
This manual describes guidelines and standardized procedures for the use offish
in evaluating the biological integrity of surface waters. It was developed to
provide biomonitoring programs with fisheries methods for measuring the status
and trends of environmental pollution on freshwater, estuarine, and marine
habitats in field and laboratory studies. These studies are carried out to assess
biological criteria for the recognized beneficial uses of water, to monitor surface
water quality, and to evaluate the health of the aquatic environment.
! Surface Waters: Field Operations and Methods for Measuring the Ecological
Condition ofWadeable Streams (1998) - EPA/620/R-64/004F.
This manual describes guidelines and standardized procedures for evaluating the
biological integrity of surface waters. It was developed to provide the
Environmental Monitoring and Assessment Program (EMAP) with bioassessment
methods for determining the status and monitoring trends of the environmental
conditions of freshwater streams.
A-5
-------
! Biological Criteria: Technical Guidance for Streams and Small Rivers, Revised
Edition (1996) - EPA/822/B-96/001.
This document helps states and tribes develop and use biocriteria for streams and
small rivers. The document includes a general strategy for biocriteria
development, identifies steps in the process, and provides technical guidance on
how to complete each step, using the experience and knowledge of existing state,
regional and national surface water programs. The document is designed
primarily for water resource managers and biologists familiar with standard
biological survey techniques. It should be used in conjunction with Rapid
Bioassessment Protocols for Use in Wadeable Streams and Rivers.
\ Lake and River Bioassessment and Biocriteria, Technical Guidance Document
(1998) - EPA/841/B-98/007.
This document is intended to provide managers and field biologists with
functional methods and approaches that will facilitate the implementation of lake
bioassessment and biocriteria programs. Procedures are provided for program
design, reference condition determination, field biosurveys, biocriteria
development and data analysis. The document also provides information on the
application and effectiveness of lake bioassessment to existing EPA and
state/tribal programs. This guidance was developed through the experience of
existing state, regional and national lake monitoring programs and several lake
programs are used as case studies and examples to illustrate specific concepts and
methods.
! Rapid Bioassessment Protocols for Use in Wadeable Streams and Rivers, Second
Edition (1999) - EPA/841/B-99/002.
This document provides state and local water quality monitoring agencies with a
practical technical reference for conducting cost-effective biological assessments
of lotic systems. Rapid Bioassessment Protocols (RBPs) are essentially a
synthesis of existing methods that have been employed by various state water
resource agencies. Protocols for three aquatic assemblages (periphyton, benthic
macroinvertebrates, fish) and habitat assessment are presented. All of these
protocols have been tested in streams in various parts of the country.
! Estuarine and Coastal Marine Water Bioassessment and Biocriteria Technical
Guidance (December, 2000).
This technical guidance document is based on the concept that bioassessment and
biocriteria programs for estuaries and near coastal waters are interrelated and
critical components of comprehensive water resource protection and management.
This guidance provides detailed descriptions of the appropriate habitat
measurements that can be used to determine the homogeneous biological areas
within an estuary (classification) and then describes four levels of investigative
intensity or sampling tiers that can be used to collect the necessary bioassessment
A-6
-------
data that is used in biocriteria derivation. Numerous different sampling methods
and techniques that an investigator could choose are explained. The document
also provides guidance on the process for deriving biocriteria from the
bioassessment data and provides real-world examples from different estuaries
around the country where bioassessments have been conducted and biocriteria
developed.
In addition, EPA has published:
! Interim Economic Guidance for Water Quality Standards: Workbook, 1995.
http://www.epa.gov/ost/econ
The Water Environment Research Foundation published:
! A Suggested Framework for Conducting UAAs;
\ Interpreting Results and a Comprehensive UAA Technical Reference.
A-7
-------
APPENDIX IV
DISCUSSION OF USE ATTAINABILITY ANALYSIS FOR RECREATIONAL USES
EPA is providing this discussion to help states and municipalities apply the Guidance on
Implementing the Water Quality-Based Provisions in The CSO Control Policy. It is intended to
respond to requests for information on evaluating whether recreational uses are attainable in
waters affected by "wet weather" discharges, particularly in those urban areas affected by
combined sewer overflow (CSO) discharges. Our objective is to enhance application of existing
guidance for conducting use attainability analyses (UAAs), such as that contained in EPA's
Water Quality Standards Handbook. EPA expects to supplement its UAA guidance based on
recommendations received from a planned practitioners' workshop of state and EPA personnel
involved in developing and reviewing UAAs.
Because this document focuses on water bodies affected by CSOs, the discussion refers to
"states" rather than "states and authorized tribes"as the applicable decision-makers on attainment
of designated uses. The Agency is not aware of any authorized tribes with combined sewer
systems.
Several factors may influence UAA priority setting where waters are affected by CSOs,
including 1) a court-ordered total maximum daily load (TMDL) analysis is underway on a
receiving water where the NPDES Authority has approved the CSO long term control plan
(LTCP); 2) the municipality (or separately permitted municipal dischargers located along the
same river reach) has developed sufficient information to determine that the use is not attainable
based on a water body survey and assessment of the factors in 40 CFR 131.10(g)(l)-(5); or 3) the
level of CSO control to attain or no longer interfere with the attainment of water quality
standards would cause substantial and widespread economic and social impact.
A UAA may be initiated at any time during the development of the LTCP. The
municipality and appropriate state and EPA personnel should meet to agree on the data and
information that would support a scientifically defensible UAA during the CSO LTCP process.
Groups of municipalities on the same body of water may share in the data collection and analysis
for a UAA. However, until some or all of the controls are implemented, uncertainties may
remain as to whether the recreational use is attainable. If it is not, there may be further
uncertainty in identifying the most protective attainable use. Prior to proceeding with a proposal
to revise the use or to adopt a variance, the state must have sufficient information to fully support
the action. As noted above, however, less complete information is generally required to support
a variance than to support a permanent revision to the water quality standards.
I. WHAT ARE THE CURRENT LAWS, REGULATIONS, AND PRACTICES?
What are the applicable Clean Water Act (CWA) requirements for recreation?
\ Section 101(a)(2) of the CWA establishes a goal that wherever attainable water quality
provides for recreation in and on the water.
A-8
-------
! Section 303(c)(2)(A) of the CWA states that standards shall protect public health or
welfare, enhance the quality of water, serve the purposes of the Act and take into
consideration their use and value for recreational purposes.
What are the applicable implementing regulations?
\ Exhibit 1 paraphrases the regulatory requirements for designating recreational uses and
evaluating their attainment.
How have states differentiated recreational uses and assigned protective criteria?
\ Primary contact recreation - activities with a high potential for ingestion of water,
associated with bacterial criteria sufficient to protect against the risk of excessive
gastrointestinal illnesses and other criteria to support the recreational experience.
Primary contact recreational uses are consistent with the 101(a)(2) recreational goals of
the CWA; therefore, states do not need to support the adoption of this use with a UAA.
! Secondary contact recreation - activities with a low potential for ingestion of or
immersion in water. These activities are associated with less stringent bacterial criteria,
but with the lower risk of exposure, the less stringent criterion should result in no greater
risk of gastrointestinal illness than water bodies designated for primary contact
recreational uses. States must support adoption of secondary contact recreation with a
UAA.
! Seasonal primary contact recreation - for areas where recreation only occurs during
certain seasons; ensures that users of the water body are protected by sufficient bacterial
criteria during the period of time when the activities are likely to occur.
! Sub-categories of primary contact recreation - state-specified periods of allowable
intermittent exceedance of primary contact bacterial criteria.
! Recreational fish or shellfish harvesting - illness from consumption offish is protected
by criteria, fish advisories or shellfish bed closures.
What is a use attainability analysis (UAA) and how is it used?
\ A UAA is a structured scientific assessment of the factors affecting the attainment of the
use which may include physical, chemical, biological, and economic factors as described
in40CFR131.10(g).
! UAAs provide the state, public and EPA with analyses supporting adoption of:
S More protective uses where pollution controls have improved water quality.
S Uses that do not include the CWA 101(a)(2) primary contact recreation.
S Subcategories of primary contact recreation with allowable intermittent
exceedance of primary contact bacterial criteria.
! UAAs can also support adoption of a variance (a temporary standard; short-term
suspension of a use).
A-9
-------
What are the objectives of a UAA?
\ Identify existing uses.
! Provide sufficient information to determine whether the particular use is attainable.
! If the use is not attainable, identify the "highest" (i.e., most protective) attainable use,
given the physical, chemical, and biological characteristics of the water body and the
socioeconomic condition of the affected community.
What are the likely components of a UAA for recreation?
\ A water body survey and assessment that examines the physical, chemical and if
appropriate, the biological characteristics of the water body.
! An analysis of pollutant sources and loads to identify the pollutant loading reductions
necessary to attain the use, if impairment is due to exceedances of criteria.
! Economic analyses to evaluate whether the cost of controls beyond those required by
sections 301(b) and 306 of the CWA would result in substantial and widespread
economic and social impact and, if so, identification of the most protective attainable use
with the maximum affordable level of CSO control.
Who conducts a UAA ?
\ States, municipalities or consultants may collect the data and conduct the analyses.
! The state is responsible for evaluating the data and information.
! Only the state may determine whether the use is attainable. If the determination results in
a proposed revision to water quality standards, the state must provide the UAA and the
proposed revision to the public for review and comment and to EPA for approval or
disapproval.
A-10
-------
II. HOW ARE UAAs CONDUCTED?
EXHIBIT 1 - APPLICABLE REGULATORY PROVISIONS
40 CFR 131.10 provisions include:
(a) - specifying appropriate uses to be achieved and protected taking into consideration use and
value for recreation in and on the water;
(b) - taking into consideration downstream waters and ensuring that WQS provide for the
attainment and maintenance of downstream standards;
(c) - permitting adoption of sub-categories of a use and set the appropriate criteria to reflect the
varying needs of such sub-categories;
(d) - making the determination that uses are attainable if they can be achieved by the imposition
of effluent limits required under sections 301(b) and 306 of the Act and cost effective and
reasonable best management practices for nonpoint source control;
(e) - providing notice and an opportunity for a public hearing prior to adding or removing any
use or establishing sub-categories of a use;
(f) - allowing adoption of seasonal uses requiring less stringent criteria provided that such
criteria do not preclude the attainment maintenance of a more protective use in another season;
(g) - authorizing removal of a designated use which is not an existing use or establishing sub-
categories of a use if the state/tribe can demonstrate that attaining the designated use is not
feasible because
1. naturally occurring pollutant concentrations prevent the attainment of the use; or
2. natural, ephemeral, intermittent or low flow conditions or water levels prevent
attainment of the use, unless these conditions may be compensated for with sufficient
volume of effluent discharges without violating water conservation requirements; or
3. human caused conditions or sources of pollution prevent the attainment of the use and
cannot be remedied or would cause more environmental damage to correct than to
leave in place; or
4. dams, diversions or other types of hydrologic modifications preclude the attainment of
the use, and it is not feasible to restore the water body to its original condition or to
operate such modification in a way that would result in the attainment of the use; or
5. physical conditions related to the natural features of the water body unrelated to water
quality preclude the attainment of aquatic life uses; or
6. controls more stringent than those required by sections 301(b) and 306 of the Act would
result in substantial and widespread economic and social impact.
(h) - prohibiting removal of designated uses if:
1. they are existing uses, unless a use requiring more stringent criteria is added; or
2. such uses will be attained by implementing effluent limits under sections 301(b) and 306
of the Act and by implementing cost-effective and reasonable best management
practices for nonpoint source control;
(i) - requiring revision of standards to reflect the uses actually being attained.
(j) - requiring a use attainability analysis whenever:
1. State/tribe designates or has designated uses that do not include the uses specified in
section 101(a)(2) of the Act; or
2. State/tribe wishes to remove a designated use that is specified in section 101(a)(2) or to
adopt subcategories of the uses specified in section 101(a)(2) which require less
stringent criteria.
(k) - allowing adoption of the section 101(a) goal uses without a use attainability analysis.
40 CFR 131.12(a)(l) requires that existing in-stream water uses and the level of water quality necessary
to protect the existing uses shall be maintained and protected.
40 CFR 131.20(b) requires the state to provide the proposed water quality standards revision and
supporting analyses for public review and comment.
A-ll
-------
What are the steps in conducting a UAA?
\ If the state has a process or UAA protocol, that process or protocol should be followed
with appropriate adjustments to account for site-specific factors.
! EPA allows a significant degree of latitude as long as:
S The process is inclusive.
S
S The data collected and analyzed are scientifically and technically defensible.
! Depending on the particular circumstances associated with the site and the combined
sewer system, the state or EPA may
request data to be added, or agree that
Exhibit 2 Steps in Conducting a UAA
existing data are sufficient.
What are some general guiding principles?
\ Building public trust and support for
water quality standards actions will
be facilitated by the involvement of a
broad array of local constituencies
throughout the UAA process,
including citizen advisory committees
and downstream constituencies.
! At a minimum, states must provide an
opportunity for the public to review
and comment on the analyses if the
state proposes revisions to the water
quality standards, including adoption
of a variance.
! Early involvement of state and EPA
personnel enables decision-makers to
mutually agree on acceptable data and
analyses.
! Problem and objective statements
provide the basis for rebutting the
presumption that the use is attainable,
e.g.: "Identify which of the six factors
in 131.10(g) will be used as the
hypothesis for determining that the
designated use is not attainable," and help the states identify the most protective use that
is attainable.
! Throughout the process, there should be communication among state, EPA, and citizen
advisory committees; updates on the data and analyses; and presentation of the
preliminary findings, as appropriate.
! Any recommendation for revisions in the water quality standard should include an
evaluation of the effect of the action on downstream uses, more sensitive uses in another
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Involve state, federal and local
constituencies early in the process.
Reach agreement on the problem
statement/objective of the UAA.
Analyze existing data/identify data
gaps and agree on the additional data
to be collected.
Identify and use an appropriate
sampling and analysis plan, quality
assurance/quality control procedures
and statistical procedures
Agree on the bases that will be used to
evaluate the information.
Collect and analyze the data and
information
Integrate and summarize the data and
information
Identify the uncertainties/evaluate the
adequacy of information
Develop recommendations and identify
the highest potential uses
Communicate the results and if
appropriate, initiate revisions to water
quality standards
A-12
-------
season, threatened and endangered species and their critical habitat, and designated
essential fish habitat.
! Clear, concise presentation of data is essential if state decision-makers, the public, and
EPA are to understand the basis of the recommendations.
What specific questions should be addressed for a recreational UAA?
\ How does the state define primary contact recreation, and what activities are included (i.e.
ensure that all parties fully understand the definition from the beginning of the process.)?
! What are the existing in-stream water uses, and levels of water quality necessary to
protect the existing uses?
! At accessible locations along the water body or segment, is there sufficient flow, pool
depth, etc., to attract adults to swim or children to play and splash?
! Does the public have access to the segment (e.g., roads, trails, bike paths, parks), or
access either upstream or downstream of the location in question?
! Does the municipality or state have public policies or facilities that encourage public
access, e.g., water front parks, boat ramps, bike paths, playgrounds, or festivals?
! Are people physically restricted from getting to the entire water body or segment in
question by tall fences, locked gates, etc.?
! Is there potential for overcoming any impediments to the recreation use that are not
related to water quality, e.g., removing shallow dams, or low flow augmentation?
! If primary contact recreational use is not attainable for reasons other than water quality,
what level of water quality must be provided to protect existing uses, downstream uses
(e.g., swimming, shellfish beds), any threatened and endangered species and their critical
habitat, or designated essential fish habitat?
! What parameters in the CSO discharge cause or contribute to the impairment of the
water quality standard? Depending on the parameter, what is the magnitude and extent of
the impairment?
! What level of CSO control is needed to ensure CSOs no longer interfere with the
attainment of the recreational use?
! What level of recreation (e.g., the maximum swimmable days during an average rainfall
year) is supported by the maximum affordable level of control (e.g., the most protective
attainable use)?
! Do any of the CSO control alternatives examined fully protect "waters with primary
contact recreation" or "shellfish beds," two of the sensitive areas identified in
Section n.C.3 of the CSO Control Policy which are to be given the highest priority for
controls?
! Would the installation of controls necessary to assure that CSOs no longer interfere with
the attainment of water quality standards cause substantial and widespread economic and
social impact?23
See Interim Economic Guidance For Water Quality Standards Workbook, EPA-823-B-95-002, March
1995 at http://www.epa.gov/ost/econ.
A-13
------- |