vvEPA
                United States
                Environmental Protection
                Agency
                 Office of Water
                 (4305)
EPA-S23-B-94-005a
August 1994
Water Quality  Standards
Handbook:
                Second Edition
       Contains Update #1
       August 1994
                           "... to restore and maintain the chemical,
                           physical, and biological integrity of the Nation's
                           waters."

                                   Section 101 (a) of the Clean Water Act
                                                Recycled/Recyclable
                                                Printed on oaperthatcontains
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vvEPA
               United States
               Environmental Protection
               Agency
                Office of Water
                (4305)
EPA-823-B-94-005a
August 1994
Water Quality Standards
Handbook:
               Second Edition
                          "... to restore and maintain the chemical,
                          physical, and biological integrity of the Nation's
                          waters."
       Contains Update #1
       August 1994
                                Section 101 (a) of the Clean Water Act

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WATER QUALITY STANDARDS

            HANDBOOK

        SECOND EDITION
        Water Quality Standards Branch
        Office of Science and Technology
      U.S. Environmental Protection Agency
           Washington, DC 20460
              September 1993
                                          Contains update #1
                                               August 1994

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                                                            Washington, DC 20460
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                                                                                       Table of Contents
                                           FOREWORD
        Dear Colleague:

        The following document entitled Water Quality Standards Handbook - Second Edition provides guidance
issued in support of the Water Quality Standards Regulation (40 CFR 131, as amended). This Handbook includes
the operative provisions of the first volume of the Handbook issued in 1983 and incorporates subsequent guidance
issued since 1983. The 1993 Handbook contains only final guidance previously issued by EPA—it contains no
new guidance.

        Since the 1983 Handbook has not been updated in ten years, we hope that this edition will prove valuable
by pulling together current program guidance and providing a coherent document as a foundation for State and
Tribal water quality standards programs.  The Handbook also presents  some of the evolving program concepts
designed to reduce human and ecological risks, such as endangered species protection; criteria to protect wildlife,
wetlands, and sediment quality; biological  criteria to better define desired  biological communities  in aquatic
ecosystems; and nutrient criteria.

        This Handbook is intended to serve as a "living document," subject to future revisions as the water quality
standards program moves forward, and to reflect the needs and experiences of EPA and the States.  To this end,
the Handbook is published  in a loose leaf format designed to be placed  in three ring binders.  This copy of the
Handbook includes updated material for 1994 (see Appendix X),  and EPA anticipates publishing  additional
changes periodically and providing them to Handbook recipients.  To ensure that you will receive these updates,
please copy the reader response card in Appendix W and mail it to the address on the reverse.

        The Handbook also contains a listing, by title and date, of the guidance issued since the Handbook was
first published in 1983 that  is incorporated in the Second Edition. Copies of these documents are available upon
request.

        The Water Quality Standards Handbook - Second Edition provides guidance on the national water quality
standards program. EPA regional offices and States may have additional guidance that provides more detail on
selected topics of regional interest.  For information on regional or State  guidance, contact the appropriate
regional water quality standards coordinator listed in Appendix U.

        EPA invites participation from interested parties in the water quality standards program, and appreciates
questions on this guidance as well as suggestions and comments for improvement. Questions or comments may
be directed to the EPA regional water quality standards coordinators or to:

        David Sabock, Chief
        U.S. Environmental Protection Agency
        Water Quality Standards Branch (4305)
        401  M Street, S.W.
        Washington, D.C. 20460
        Telephone (202)475-7315
                                                   Betsy Southerland, Acting Director
                                                   Standards and Applied Science Division
(8/15/94)                                                                     .                      iii

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 Water Quality Standards Handbook - Second Edition
                                    Note to the Reader

       The Water Quality Standards Handbook, first issued in 1983, is a compilation of EPA's
 guidance on the water quality standards program and provides direction for States in reviewing,
 revising and implementing water quality standards.  The Water Quality Standards Handbook -
 Second Edition retains all the guidance in the 1983 Handbook unless such guidance was specifically
 revised in subsequent years. An annotated list of the major guidance and policy documents on the
 water quality standards program issued since 1983 is included in the Introduction and material added
 to the Second Edition by periodic updates since 1993 is summarized in Appendix X. Material in the
 Handbook contains only guidance previously issued by EPA;  it contains no new guidance.

       The guidance contained in each of the documents listed in the Introduction is either:
 1) incorporated in its entirety, or summarized, in the text of the appropriate section of this
 Handbook, or 2) attached as an appendix (see Table of Contents).  If there is uncertainty or
 perceived inconsistency on any of the guidance incorporated into this Handbook, the reader is
 directed to review the original guidance documents or call the Water Quality Standards Branch at
 (202) 260-1315.  Copies  of all original guidance documents not attached as appendices  may be
 obtained from the source listed for each document in the Reference section of this Handbook.

       Limited  free copies of this Handbook may be obtained from:

 Office of Water Resource Center, RC-4100
 U. S. Environmental Protection Agency
 401 M Street, S.W.
 Washington, DC 20460
 Telephone: (202)  260-7786 (voice mail publication request line)

       Copies may also be obtained from:

 Education Resource Information Center/Clearinghouse for Science, Mathematics and Environmental
 Education (ERIC)
 1929 Kenny Road
 Columbus, OH  43210-1080  (Telephone: 614-292-6717)
 (VISA, Mastercard and purchase order numbers from schools  and businesses accepted)


 U.S. Department of Commerce
National Technical Information Service (NTIS)
5285 Port Royal Road
Springfield, VA 22161  (Telephone: 1-800-553-6847)
 (American Express,  VISA and Mastercard accepted)
                                              Robert S. Shippen
                                              Editor
                                                                                     (8/15/94)

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                                                                         Table of Contents
                              TABLE OF CONTENTS
Foreword	iii

Note to the Reader	iv

Table of Contents	v

Glossary	GLOSS-1

Introduction	INT-1

      History of the Water Quality Standards Program .	INT-1
      Handbook Changes Since 1983	INT-5
      Overview of the Water Quality Standards Program	INT-8
      The Role of WQS in the Water Quality Management Program	INT-13
      Future Program Directions	INT-14

Chapter 1 - General Provisions  (40 CFR 131 - Subpart A)

      1.1   Scope - 40 CFR 131.1		1-1
      1.2   Purpose - 40 CFR 131.2	1-1
      1.3   Definitions - 40 CFR 131.3		1-1
      1.4   State Authority - 40 CFR 131.4	1-2
      1.5   EPA Authority - 40 CFR 131.5	1-3
      1.6   Requirements for Water Quality Standards Submission - 40 CFR 131.6	1-4
      1.7   Dispute Resolution Mechanism - 40 CFR 131.7	1-4
      1.8   Requirements for Indian Tribes To Qualify for the WQS Program - 40 CFR
            131.8	 . .	1-9
      1.9   Adoption of Standards for Indian Reservation Waters  . . . .  . .	  1-18
      Endnotes	1-21

Chapter 2 - Designation of Uses (40 CFR 131.10)

      2.1   Use Classification - 40 CFR 131.10(a)		2-1
      2.2   Consider Downstream Uses - 40 CFR 131.10(b)	2-4
      2.3   Use Subcategories - 40 CFR 131.10(c)		2-5
      2.4   Attainability ^f Uses - 40 CFR 131.10(d)	2-5
      2.5   Public Hearing  for Changing Uses - 40 CFR 131.10(e)	2-6
      2.6   Seasonal Uses - 40 CFR 131.10(f)	,		2-6
      2.7   Removal of Designated Uses -  40 CFR 131.10(g) and (h) .  .	2-6
      2.8   Revising Uses to Reflect Actual Attainment - 40 CFR 131.10(1)	2-8
      2.9   Use Attainability Analyses - 40 CFR 131.10Q) and (k)	2-9
(8/15/94)

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Water Quality Standards Handbook - Second Edition
Chapter 3 - Water Quality Criteria (40CFR131.il)

       3.1   EPA Section 304(a) Guidance	3-1
       3.2   Relationship of Section 304(a) Criteria to State Designated Uses	  3-10
       3.3   State Criteria Requirements	3-12
       3.4   Criteria for Toxicants	 3-13
       3.5   Forms of Criteria  	3-23
       3.6   Policy on Aquatic Life Metals Criteria  	3-34
       3.7   Site-Specific Aquatic Life Criteria	3-38
       Endnotes	3-45

Chapter 4 - Antidegradation  (40 CFR 131.12)

       4.1   History of  Antidegradation	4-1
       4.2   Summary of the Antidegradation Policy	4-1
       4.3   State Antidegradation Requirements	4-2
       4.4   Protection of Existing Uses - 40 CFR 131.12(a)(l)	4-3
       4.5   Protection of Water Quality in High-Quality Waters - 40 CFR 131.12(a)(2) ....  4-6
       4.6   Applicability of Water Quality Standards to Nonpoint Sources Versus Enforceability
             of Controls	                       4-9
       4.7   Outstanding National Resource Waters (ONRW) - 40 CFR 131.12(a)(3)	  4-10
       4.8   Antidegradation Application and Implementation  	4-10

Chapter 5 - General Policies  (40 CFR 131.13)

       5.1   Mixing Zones  	5-1
       5,2   Critical Low-Flows	5-9
       5.3   Variances From Water Quality Standards	5-11

Chapter 6 - Procedures for Review and Revision of Water Quality Standards
             (40 CFR 131 - Subpart C)

       6.1   State Review and Revision	6-1
       6.2   EPA Review and Approval  	6-8
       6.3   EPA Promulgation	6-13

Chapter 7 - The Water Quality-based Approach to Pollution Control

       7.1   Determine  Protection Level	7-2
       7.2   Conduct Water Quality Assessment  	7-3
       7.3   Establish Priorities	7-5
       7.4   Evaluate Water Quality Standards for Targeted Waters  	7-6
       7.5   Define and Allocate Control Responsibilities	7-7
       7.6   Establish Source Controls  	7-8
       7.7   Monitor and Enforce Compliance   	7-12
       7.8   Measure Progress	7-13

References	REF-1


VI                                                                                   (8/15/94)

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                                                                               Table of Contents
Appendices:

       A-   Water Quality Standards Regulation - 40 CFR 131.

       B -   Chronological Summary of Federal Water Quality Standards Promulgation Actions.

       C -   Biological Criteria: National Program Guidance for Surface Waters, April 1990.

       D -   National Guidance: Water Quality Standards for Wetlands, July 1990.

       E -   An Approach for Evaluating Numeric  Water Quality Criteria for Wetlands Protection,
             July 1991.

       F -   Coordination Between the Environmental Protection Agency, Fish and Wildlife Service
             and National Marine Fisheries Service Regarding Development of Water Quality
             Criteria and Water Quality Standards Under the Clean Water Act, July  1992.

       G -   Questions and Answers on: Antidegradation, August 1985.

       H -   Derivation of the 1985 Aquatic Life Criteria.

       I -    List of EPA Water Quality Criteria Documents.

       J -    Attachments to Office of Water Policy and Technical Guidance on Interpretation and
             Implementation of Aquatic Life Metals Criteria, October  1993.

       K -   Procedures for the Initiation of Narrative Biological Criteria, October 1992.

       L -   Interim Guidance on Determination and Use of Water-Effect Ratios for Metals,
             February 1994.

       M -   Reserved.

       N -   IRIS [Integrated Risk Information System] Background Paper.

       O-    Reserved.

       P -   List of 126 Section 307(a) Priority Toxic Pollutants.

       Q -   Wetlands and 401 Certification:  Opportunities and Guidelines for States and Eligible
             Indian Tribes - April 1989.

       R -   Policy on the Use of Biological Assessments and Criteria in the Water Quality
             Program, May 1991.

       S  -    Reserved.

       T -   Use Attainability Analysis  Case Studies.

(8/15/94)                                                                                  Vli

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Water Quality Standards Handbook - Second Edition
       U -   List of EPA Regional Water Quality Standards Coordinators.



       V -   Water Quality Standards Program Document Request Forms.




       W -   Update Request Form for Water Quality Standards Handbook - Second Edition.



       X -   Summary of Updates
                                                                                   (8/15/94)

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         GLOSSARY
                                 O
                                 GO
WATER QUALITY STANDARDS HANDBOOK



         SECOND EDITION

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                                                                                     Glossary
                                       GLOSSARY
The "Act" refers to the Clean Water Act (Public Law 92-500, as amended (33 USC 1251, et seq.1 (40
       CFR 131.3.)

"Acute" refers to a stimulus severe enough to rapidly induce an effect; in aquatic toxicity tests, an
       effect observed in 96- hours or less is typically considered acute.  When referring to aquatic
       toxicology or human health, an acute affect  is not always measured in  terms of lethality
       (USEPA, 1991a.)

"Acute-chronic ratio" (ACR) is the ratio of the acute toxicity of an effluent or a toxicant to its chronic
       toxicity. It is used as a factor for estimating chronic toxicity on the basis of acute toxicity data,
       or for estimating acute toxicity on the basis of chronic toxicity data (USEPA, 1991a.)

"Acutely toxic conditions" are those acutely toxic to aquatic organisms following their short-term
       exposure within an affected area (USEPA, 1991a.)

"Additivity" is the characteristic property of a mixture of toxicants that  exhibits a total toxic effect
       equal to the arithmetic sum of the effects of the individual toxicants (USEPA, 199 la.)

"Ambient toxicity" is measured by a toxicity test on a sample collected from a water body (USEPA,
       1991a.)

11 Antagonism" is the characteristic property of a mixture of toxicants that exhibits a less-than-additive
       total  toxic effect (USEPA, 1991a.)

"Aquatic community" is an association of interacting populations of aquatic organisms in a given water
       body or habitat (USEPA, 1990; USEPA, 1991a.)

"Averaging period" is the period of time over which the receiving water concentration is averaged for
       comparison with criteria concentrations. This specification limits the duration of concentrations
       above the criteria (USEPA,  1991a.)

"Bioaccumulation" is the process by which a compound is taken up by an aquatic organism, both from
       water and through food (USEPA, 1991a.)

"Bioaccumulation factor"  (BAF)  is the ratio of a  substance's concentration in tissue versus its
       concentration in ambient water, in situations where the organism and the food chain are exposed
       (USEPA, 1991a.)

"Bioassay" is a test used to evaluate the relative potency of a chemical or a mixture of chemicals by
       comparing its effect on a living organism with the effect of a standard preparation on the same
       type of organism. Bioassays are frequently used in the pharmaceutical industry to evaluate the
       potency of vitamins and drugs (USEPA, 1991a.)
(9/15/93)                                                                            GLOSS-1

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Water Quality Standards Handbook - Second Edition
''Unavailability" is a measure of the physicochemical access that a toxicant has to the biological
       processes of an organism. The less the bioavaUability of a toxicant, the less its toxic effect on
       an organism (USEPA, 1991a.)

"Bioconcentration" is the process by which a compound is absorbed from water through gills or
       epithelial tissues and is concentrated in the body (USEPA, 1991a.)

"Bioconcentration factor" (BCF) is the ratio of a substance's  concentration in tissue versus its
       concentration in water, in situations where the food chain is not exposed or contaminated. For
       non-metabolized substances, it represents equilibrium partitioning between water and organisms
       (USEPA, 1991a.)

"Biological criteria" are narrative expressions or numeric values  of the biological characteristics of
       aquatic communities based on appropriate reference conditions. As such, biological criteria serve
       as an index of aquatic community health.  It is also known as biocriteria (USEPA, 1991a.)

"Biological integrity11 is the condition of the aquatic community inhabiting unimpaired water bodies of
       a specified habitat as measured by community structure and function (USEPA,  1991a.)

"Biological monitoring" describes the use of living organisms in water quality surveillance to indicate
       compliance with water quality standards or effluent limits and to document water quality trends.
       Methods of biological monitoring may include, but are not limited to, toxicity testing (such as
       ambient toxicity testing or whole-effluent toxicity testing) and  biological surveys. It is also
       known as biomonitoring (USEPA, 1991a.)

"Biological survey or biosurvey" is collecting, processing, and analyzing a representative portion of
       the resident aquatic community to determine its structural and/or functional characteristics
       (USEPA. 1991a.)

"Biomagnification" is the process by which the concentration of a compound increases in species
       occupying successive  trophic levels (USEPA, 1991a.)

"Cancer potency slope factor" (qx*) is an indication of a chemical's human cancer-causing potential
       derived using animal studies or epidemiological data on human exposure; based on extrapolation
       of high-dose levels over short periods of time to low-dose levels and a lifetime exposure period
       through the use of a linear model (USEPA, 1991a.)

"Chronic" defines a stimulus that lingers or continues for a relatively long period of time, often one-
       tenth of the life span or more. Chronic should be considered a relative term depending on the
       life span of an organism. The measurement of a chronic effect can be reduced growth, reduced
       reproduction, etc., in  addition to lethality (USEPA, 1991a.)

"Community component" is a general term that may pertain to the biotic guild (fish, invertebrates,
       algae), the taxonomic  category (order, family, genus, species), the feeding strategy (herbivore,
       omnivore, predator),  or the organizational  level (individual, population,  assemblage)  of a
       biological entity within the aquatic community (USEPA, 1991a.)
GLOSS-2                                                                            (9/15/93)

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"Completely mixed condition" is defined  as  no measurable difference in the concentration of a
       pollutant exists across a transect of  the water body (e.g., does not vary by 5%) (USEPA,
       1991a.)

"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 (40 CFR 131.3.)

"Criteria continuous concentration" (CCC) is the EPA national water quality criteria recommendation
       for the highest instream concentration of a toxicant or an effluent to which organisms can be
       exposed indefinitely without causing unacceptable effect (USEPA, 1991a.)

"Criteria maximum concentration" (CMC) is the EPA national water quality criteria recommendation
       for the highest instream concentration of a toxicant or an effluent to which organisms can be
       exposed for a brief period of tune without causing an acute effect (USEPA, 1991a.)

"Critical life stage" is the period of tune in an organism's lifespan in which it is the most susceptible
       to adverse effects caused by exposure  to toxicants, usually during early development (egg,
       embryo, larvae).  Chronic toxicity tests are often  run on critical life stages  to replace long
       duration, life cycle tests since the most toxic effect usually occurs during the critical life stage
       (USEPA, 1991a.)

"Critical species" is a species that is commercially or recreationally important at  the site, a species that
       exists at the site and is listed as threatened or endangered under section 4 of the Endangered
       Species Act, or a species for which there is evidence that the loss of the species from the site
       is likely to cause an unacceptable impact on a commercially or recreationally important species,
       a threatened or endangered species, the abundances of a variety of other species, or the structure
       or function of the community (USEPA, 1994a.)

"Design flow" is the flow used for steady-state waste load allocation modeling (USEPA, 1991a.)

"Designated uses" are those uses  specified in water quality standards for each water body or segment
       whether or not they are being attained (40 CFR 131.3.)

"Discharge length scale" is the square root of the cross-sectional area of any discharge outlet (USEPA,
        1991a.)

 "Diversity" is the number and abundance of biological taxa in a specified location (USEPA, 1991a.)

 "Effective concentration" (EC) is a point estimate of the toxicant concentration that would cause an
        observable adverse effect (such as death, immobilization, or serious incapacitation) hi a given
        percentage of the test organisms (USEPA, 1991a.)

 "Existing uses" are those uses actually attained hi the water body on or after November  28, 1975,
        whether or not they are included hi the water quality standards  (40 CFR 131.3.)
 (8/15/94)                                                                              GLOSS-3

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 Water Quality Standards Handbook - Second Edition
 "Federal Indian Reservation," "Indian Reservation," or "Reservation" is defined as all land within
        the limits of any Indian reservation under the jurisdiction of the United States Government,
        notwithstanding the issuance of any patent, and including rights-of-way running through the
        reservation (40 CFR 131.3.)

 "Final acute value" (FAV) is an  estimate of the concentration of the toxicant corresponding to a
        cumulative probability of 0.05 in the acute toxicity values for all genera for which acceptable
        acute tests have been conducted on die toxicant (USEPA, 1991a.)

 "Frequency" is how often criteria can be exceeded without unacceptably affecting the  community
        (USEPA, 1991a.)  '

 "Harmonic  mean  flow" is the number  of daily flow measurements divided by the sum of the
        reciprocals of the flows. That is, it is the reciprocal of the mean of reciprocals (USEPA, 1991a.)

 "Indian Tribe" or "Tribe" describes any Indian Tribe, band, group, or community recognized by the
        Secretary of the Interior and exercising governmental authority over a Federal Indian reservation
        (40 CFR 131.3.)

 "Inhibition concentration" (1C) is a point estimate of the toxicant concentration that would cause a
        given percent reduction (e.g., IC25)  hi  a non-lethal biological measurement of the test
        organisms, such as reproduction or growth (USEPA, 1991a.)

 "Lethal concentration" is the point estimate of the toxicant concentration that would be lethal to a
       given percentage of the test organisms during a specified period (USEPA, 1991a.)

 "Lipophilic" is a high affinity for lipids (fats) (USEPA, 1991a.)

 "Load allocations" (LA) the portion of a receiving water TMDL that is attributed either to one  of its
       existing or future nonpoint sources of pollution or to natural background sources (USEPA
       1991a.)

 "Lowest-observed-adverse-effect-level" (LOAEL) is the lowest concentration of an effluent or toxicant
       that results in statistically significant adverse health effects as observed hi chronic or subchronic
       human epidemiology studies  or animal exposure (USEPA, 1991a.)

 "Magnitude" is how much of a pollutant (or pollutant parameter such as toxicity),  expressed as a
       concentration or toxic unit is allowable (USEPA, 1991a.)

 "Minimum level" (ML) refers to the level at which the entire analytical system gives recognizable  mass
       spectra and acceptable calibration points when analyzing for pollutants of concern. This  level
       corresponds to the lowest point at which the calibration curve is determined (USEPA, 1991a.)

 "Mixing zone" is an area where an effluent discharge undergoes initial dilution and is extended to cover
       the secondary mixing in the  ambient water body. A mixing zone is an allocated impact  zone
       where water quality criteria can be exceeded as long as acutely toxic conditions are prevented
       (USEPA, 1991a.)
GLOSS-4                                                                            (8/15/94)

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                                                          	Glossary

"Navigable waters" refer to the waters of the United States,  including the territorial seas (33 USC
       1362.)
                                                                             j
"No-observed-adverse-effect-lever1 (NOAEL) is a tested dose of an effluent or a toxicant below which
       no adverse biological effects are observed, as identified from chronic or subchronic human
       epidemiology studies or animal exposure studies (USEPA,  1991a.)

"No-observed-effect-concentration" (NOEC) is the highest tested concentration of an effluent or a
       toxicant at which no adverse effects are observed on the aquatic test organisms at a specific tune
       of observation. Determined using hypothesis testing (USEPA, 1991a.)

"Nonthreshold effects" are associated with exposure to chemicals that have no safe exposure levels.
       (i.e., cancer) (USEPA, 1991a.)

"Persistent pollutant" is not subject to decay, degradation, transformation, volatilization, hydrolysis,
       or photolysis (USEPA, 1991a.)

"Pollution" is defined as the man-made or man-induced alteration of the chemical, physical, biological
       and radiological integrity of water (33 USC 1362.)

"Priority pollutants" are those pollutants listed by the Administrator under section 307(a) of the Act
       (USEPA,  1991a.)

"Reference ambient concentration" (RAC) is the concentration of a chemical in water which will not
       cause adverse impacts to human health; RAC is expressed in units of mg/1 (USEPA, 1991a.)

"Reference conditions" describe the characteristics of water body segments least impaired by human
       activities.  As such, reference conditions can be used to describe attainable biological or habitat
       conditions for water body segments with common watershed/catchment characteristics within
       defined geographical regions.

"Reference tissue concentration" (RTC) is the concentration of a chemical in edible fish or shellfish
       tissue which will not cause adverse impacts to human health when ingested. RTC is expressed
       in units of mg/kg (USEPA, 1991a.)

"Reference dose" (RfD) is an estimate of the daily exposure to human population that is likely to be
       without appreciable risk of deleterious effect during a lifetime; derived from NOAEL or LOAEL
       (USEPA,  1991a.)

"Section 304(a) criteria" are developed by EPA under authority of section 304(a) of the Act based on
       the latest scientific information on the relationship that the effect of a constituent concentration
       has on particular aquatic species and/or human health.  This information is issued periodically
       to the States as guidance for use hi developing criteria (40 CFR 131.3.)

 "Site-specific aquatic life criterion" is a water quality criterion for aquatic life that has been derived
       to be specifically appropriate to the water quality characteristics and/or species composition at
       a particular location (USEPA,  1994a.)
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 Water Quality Standards Handbook - Second Edition
 "States" include: the 50 States, the District of Columbia, Guam, the Commonwealth of Puerto Rico,
       Virgin  Islands,  American  Samoa,  the Trust Territory  of  the  Pacific Islands,  and  the
       Commonwealth of the Northern Mariana Islands, and Indian Tribes that EPA determines qualify
       for treatment as States for the purposes of water quality standards (40 CFR 131.3.)

 "Steady-state model" is a fate and transport model that uses constant values of input variables to
       predict constant values of receiving water quality concentrations (USEPA, 1991a.)

 "STORET"  is EPA's computerized water quality database that includes physical, chemical, and
       biological data measured in water bodies throughout the United States (USEPA, 1991a.)

 "Sublethal" refers to a stimulus below the level that causes death  (USEPA, 1991a.)

 "Synergism" is the characteristic property of a mixture of toxicants that exhibits a greater-than-additive
       total toxic effect (USEPA, 1991a.)

 "Threshold effects"  result from chemicals that have a safe level (i.e., acute, subacute, or chronic
       human health effects) (USEPA, 1991a.)

 "Total maximum daily load"  (TMDL) is the  sum of the individual waste load allocations (WLAs) and
       load allocations (LAs); a margin of safety is included with  the two types of allocations so that
       any additional loading, regardless of source, would not produce a violation  of water quality
       standards (USEPA,  1991a.)

 "Toxicity test" is a procedure to determine the toxicity of a chemical or an effluent using living
       organisms. A toxicity test measures the degree of effect on exposed test organisms of a specific
       chemical or effluent (USEPA, 1991a.)

 "Toxic pollutant" refers to those pollutants,  or combination of pollutants, including disease-causing
       agents,, which after discharge and upon exposure, ingestion, inhalation, or assimilation into any
       organism,  either directly from the environment or indirectly by ingestion through food chains,
       will, or on  the basis  of information available to the administrator, cause death, disease,
       behavioral abnormalities, cancer,  genetic  mutations, physiological malfunctions (including
       malfunctions hi reproduction) or physical deformations, hi such organisms or then- offspring (33
       USC section 1362.)

 "Toxic units" (TUs) are a measure of toxicity in an effluent as determined by the acute toxicity units
       (TUa) or chronic toxicity units (TUc) measured (USEPA, 1991a.)

 "Toxic unit acute"  (TUa) is the reciprocal of the effluent concentration that causes 50 percent of the
       organisms  to die by the end of the acute exposure period (i.e., 100/LC50)  (USEPA, 1991a.)

 "Toxic unit chronic" (TUc) is the reciprocal of the effluent concentration that causes no observable
       effect on the test organisms  by the end of the  chronic exposure period (i.e., 100/NOEC)
       (USEPA, 1991a.)
GLOSS-6                                     .                                        (8/15/94)

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                                                      	Glossary

"Use attainability analysis" (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 in section 131.10(g) (40 CFR 131.3.)

"Waste load allocation" (WLA) is the portion of a receiving water's TMDL that is allocated to one
       of its existing or future point sources of pollution (USEPA, 1991a.)

"Waters of the United States" refer to:

       (1)     all waters which are currently used, were used in the past, or may be susceptible to use
              in interstate or foreign commerce, including all waters which are subject to the ebb and
              flow of the tide;

       (2)     all interstate waters, including interstate wetlands;

       (3)     all other waters such as intrastate lakes, rivers, streams (including intermittent streams),
              mudflats, sandflats, wetlands, sloughs, prairie potholes, wet meadows, playa lakes, or
              natural ponds the use or degradation of which would affect or could affect interstate or
              foreign  commerce,  including any such waters:

              (i)     which are or could be used by interstate or foreign travelers for recreational or
                     other purposes;

              (ii)    from which fish or shellfish are or could be taken and sold hi interstate or foreign
                     commerce; or

              (iii)    which are or could be  used for  industrial purposes by  industries hi interstate
                     commerce.

       (4)     all impoundments of waters otherwise defined as waters of the United States under this
              definition;

       (5)     tributaries of waters hi paragraphs (1) through (4) of this definition;

       (6)     the territorial sea; and

       (7)     wetlands  adjacent to waters (other than waters that are themselves wetlands) identified
              hi paragraphs (1) through (6) of this definition. "Wetlands"  are  defined as those  areas
              that are inundated or saturated by surface or groundwater at a frequency arid duration
              sufficient to support, and that under normal circumstances do support, a prevalence of
              vegetation typically adapted for life  in saturated soil conditions.  Wetlands generally
              include swamps, marshes, bogs, and similar areas.

       Waste  treatment systems, including  treatment ponds or  lagoons  designed to  meet the
       requirements of the  Act (other than cooling ponds as defined in 40 CFR 423.11(m) which also
       meet the criteria for this definition) are not waters  of the United States. (40 CFR 232.2.)
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 Water Quality Standards Handbook - Second Edition
 11 Water-effect ratio" (WER) is an appropriate measure of the toxicity of a material obtained in
       a site water divided by the same measure of the toxicity of the same material obtained
       simultaneously in a laboratory dilution water (USEPA, 1994a.)

 "Water qualify assessment" is an evaluation of the condition of a water body using biological surveys,
       chemical-specific analyses of pollutants in water bodies, and toxicity tests (USEPA, 1991a.)

 "Water quality limited segment" refers to any segment where it is known that water quality does not
       meet applicable water quality standards and/or is not expected to meet applicable water quality
       standards  even after application of technology-based effluent limitations required by sections
       301(b)(l)(A) and (B) and 306 of the Act (40 CFR 131.3.)

 "Water quality standards" (WQS) 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 for such waters based upon
       such uses.  Water quality standards are to protect public health or welfare, enhance the quality
       of the water and serve the purposes of the Act (40 CFR 131.3.)

 "Whole-effluent toxicity"  is the total toxic effect of an effluent measured directly with a toxicity test
       (USEPA,  1991a.)
GLOSS-8                                                                             (8/15/94)

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      INTRODUCTION
WATER QUALITY STANDARDS HANDBOOK




         SECOND EDITION

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                                                                                   Introduction
       HISTORY OF THE WATER QUALITY STANDARDS PROGRAM
Statutory History

The first comprehensive legislation  for  water
pollution control was the Water Pollution Control
Act of 1948 (Public Law 845, 80th Congress).
This law, passed after a half century of debate on
the responsibility of the Federal Government for
resolving water  pollution  problems,  adopted
principles of State-Federal cooperative program
development,   limited  Federal   enforcement
authority,   and  provided   limited   financial
assistance.  These concepts were continued in the
Federal Water Pollution Control Act (FWPCA) of
1956 (Public Law 660, 84th Congress) and in the
Water Quality Act of 1965. Under the 1965 Act,
States  were  directed to develop  water  quality
standards for  interstate waters.  As a result of
enforcement  complexities and other  problems,
however, this approach  was not  sufficiently
effective. In the FWPCA Amendments of 1972
(Public Law  92-500), Congress  established  a
discharge permit  system and provided a broader
Federal  role  through  more extensive  Federal
grants to finance  local sewage treatment systems
-and   through    Federal   (EPA)   setting   of
technology-based effluent limitations.  The 1972
Amendments extended the water quality standards
program to intrastate  waters  and provided for
implementation of water quality standards through
discharge permits.

Section 303(c) of the 1972 FWPCA Amendments
(33 USC 1313(c)) established the statutory basis
for the current water quality standards program.
It completed the transition from  the  previously
established program of water quality standards for
interstate waters to one requiring standards for all
surface waters of the United States.
Although  the major  innovation  of  the  1972
FWPCA was technology-based controls, Congress
maintained the concept of water quality standards
both as a mechanism to establish goals for the
Nation's waters and as a regulatory requirement
when standardized technology  controls for point
source discharges and/or nonpoint source controls
were inadequate.  In recent years, Congress and
EPA have given these water quality-based controls
new emphasis in the continuing quest to enhance
and maintain water quality  to protect the public
health and welfare.

Briefly stated, the key elements of section 303(c)
are as follows:

 (1)  A water quality  standard is defined as the
     designated  beneficial   uses   of a   water
     segment  and  the water quality  criteria
     necessary to  support those uses;

 (2)  The  minimum  beneficial  uses  to  be
     considered by States in establishing  water
     quality  standards are  specified  as  public
     water supplies,  propagation  of fish and
     wildlife,   recreation,   agricultural   uses,
     industrial uses, and navigation;

 (3)  A requirement specifies that State standards
     must protect  public  health   or welfare,
     enhance the quality of water, and serve the
     purposes of the Clean Water Act;

 (4)  A  requirement  specifies  that  States must
     review their  standards  at least once each 3-
     year  period  using  a process  that includes
     public participation;
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 Water Quality Standards Handbook - Second Edition
  (5) The process is described for EPA review of
     State standards that might ultimately result in
     the promulgation of a superseding Federal
     rule in cases where a State's standards are
     not   consistent  with   the  applicable
     requirements of the CWA,  or in situations"
     where the Agency determines that Federal
     standards  are  necessary  to  meet  the
     requirements of the Act.

 The  Federal  Water  Pollution   Control  Act,
 including  the major  1977,  1981,  and  1987
 Amendments  are  commonly  referred  to  as the
 "Clean Water Act" (the Act or CWA).

 On February 4,1987, Congress enacted the Water
 Quality Act of 1987 (Public Law  100-4), making
 substantial additions to  the Clean Water Act and
 directly   affecting   the   standards   program.
 Congress concluded that toxic pollutants in water
 constitute one of the most pressing water pollution
 problems.  The Water Quality Act provided a new
 approach   to  controlling  toxic   pollutants  by
 requiring  "... States to identify waters that do
 not  meet  water quality  standards due  to  the
 discharge of toxic substances,  to adopt numerical
 criteria for the pollutants in such waters,  and to
 establish  effluent  limitations  for  individual
 discharges to  such water bodies"  (from Senator
 Mitchell,  133 Congressional  Record S733).  As
 now amended, the Clean Water Act requires that
 States adopt numeric criteria for toxic pollutants
 listed under section 307(a) of the Clean Water Act
 for  which  section  304(a) criteria have been
published,  if the presence of these pollutants is
likely to adversely  affect the water body's use.
Guidance on these changes is discussed in detail
in section 3.4 of this Handbook.  Additionally,
for the first time, the Act explicitly recognizes
antidegradation (see section 303(d)(4) of the Act).
Regulatory History

EPA  first  published a water quality  standards
regulation in 1975 (40 CFR 130.17, promulgated
in 40 F.R. 55334, November 28, 1975) as part of
EPA's water  quality  management regulations,
mandated under section 303(e) of the Act.   The
first Water Quality  Standards Regulation did not
specifically address  toxic pollutants or  any other
criteria.  It simply  required "appropriate" water
quality criteria necessary  to  support designated
uses.

In the late 1970s and early 1980s, the public and
Congress raised concerns about toxic pollutant
control. EPA realized that promulgating effluent
guidelines or effluent standards under section 307
of the Act would not  comprehensively address
toxic pollutants.  So,  EPA decided to use the
statutory  connection  between  water  quality
standards and NPDES permits provided by section
301(b)(l)(C) to effectively control a range of toxic
pollutants from point sources.  To best accomplish
this process,  the  Agency  decided to amend the
Water Quality Standards Regulation to  explicitly
address  toxic  criteria  requirements  in  State
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                                                                                    Introduction
standards.  Other legal and programmatic issues
also necessitated a revision  of the Standards
Regulation.   The culmination of this effort was
the promulgation of the present Water  Quality
Standards Regulation on November 8, 1983 (54
F.R. 51400).

The present Water  Quality Standards Regulation
(40 CFR Part 131) is a much more comprehensive
regulation than its predecessor.  In subpart B, the
Regulation addresses  both the designated use
component and the  criteria component of a water
quality   standard.     Section  131.11   of the
Regulation requires States to  review available
information and ".  . .to identify specific water
bodies where toxic pollutants may be adversely
affecting water  quality  .  .  .  and  must adopt
criteria for such toxic pollutants applicable to the
water body sufficient  to protect the designated
use."  The Regulation provides that either or both
numeric   and  narrative   criteria   may   be
appropriately used in water quality standards.

Since the middle of the  1980's, EPA's annual
program guidance  to  the States reflected the
increasing emphasis on controlling toxics.  States
were strongly encouraged to adopt criteria in their
standards for the pollutants listed pursuant to
section 307(a) of the Act, especially  where EPA
has published  criteria  guidance under  section
304(a) of the Act.

State  reaction to EPA's  initiative  was  mixed.
Several States proceeded to adopt large numbers
of  numeric  toxic  pollutant criteria, although
primarily for the protection of aquatic life. Other
States relied on  a narrative "free from" toxicity
criterion, using so-called "action levels" for toxic
pollutants or for calculating site-specific criteria.
Few States specifically addressed human health
protection outside the National Primary Drinking
Water  Standards promulgated under  the Safe
Drinking Water Act.

In  support  of  its   1983   regulation,   EPA
simultaneously issued program  guidance  entitled
Water Quality Standards  Handbook (December
1983). The foreword to the guidance noted that
EPA's approach  to  controlling toxics included
both  chemical-specific  numeric  criteria  and
biological testing in whole-effluents or ambient
waters.  More detailed programmatic guidance on
the application of biological testing was provided
in the Technical Support Document for  Water
Quality-based Toxics Control (EPA 44/4-85-032,
September 1985).   This document  provides the
information needed to  convert  chemical-specific
and biologically based  criteria into permit limits
for point source dischargers.

State  water quality standards reviews submitted
began to show the effects of EPA's efforts.  More
and more numeric criteria for toxics were being
included in  State standards as  well  as more
aggressive use of the "free from toxics" narratives
in  setting  protective   NPDES permit  limits.
However,  because of perceived problems in
adopting numeric toxic pollutant criteria in State
rulemaking   proceedings,  many  States  were
reluctant to adopt numeric toxics criteria.  Thus,
in  1987,  Congress  responded to  the  lack of
numeric criteria for toxic pollutants within State
standards  by mandating State adoption of such
criteria.

In response to  this new congressional  mandate,
EPA redoubled its efforts to promote and assist
State  adoption  of water  quality standards  for
priority toxic pollutants.  EPA's efforts included
the development and issuance of guidance to the
States on  December 12, 1988, which contained
acceptable implementation procedures for several
new  sections of  the  Act,  including  sections
303(c)(2)(B).
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 Water Quality Standards Handbook - Second Edition
 EPA,   in   devising   guidance   for   section
 303(c)(2)(B), attempted to provide States with the
 maximum  flexibility  that  complied  with the
 express  statutory language but  also  with the
 overriding   congressional  objective:   prompt
 adoption and implementation  of  numeric toxics
 criteria.    EPA  believed that  flexibility  was
 important so that each State could comply with
 section 303(c)(2)(B) and to the extent possible,
 accommodate its  existing water quality standards
 regulatory approach. The options EPA identified
 are described in section 3.4.1  of  this Handbook.

 EPA's December 1988 guidance also addressed
 the timing issue for State compliance with section
 303(c)(2)(B).  The  statutory directive was clear:
 all State standards triennial reviews initiated after
 passage of the Act must include a consideration of
 numeric toxic criteria.

 States   significantly  responded  to  the  1987
 requirement  for  numeric  criteria  for  toxic
 poEutants.   For  example, in  1986 on average,
 each State had 10 numeric criteria for freshwater
 aquatic life.   By February  1990, the average
 number of freshwater aquatic life criteria  was
 increased to  30.   Also, States averaged 36
 numeric criteria  for human health in  February
 1990. However, by September 1990, many States
 had  failed to fully satisfy the requirements of
 section 303(c)(2)(B).

 The addition  of section 303(c)(2)(B) to the Clean
 Water Act was an unequivocal signal to the States
 that Congress wanted toxics criteria in the State's
 water quality standards.   EPA, consistent with
 this mandate, initiated Federal promulgation of
 toxic  criteria for  those States  that  had  not
 complied with the Act.  EPA proposed Federal
 criteria  for  toxic pollutants for  22 States  and
 Territories, based on a preliminary assessment of
 compliance, on November 19, 1991 (56 F.R.
 58420), and promulgated toxic criteria for 14 of
 those States  on December 22, 1992 (57 F.R.
 60848).
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                        HANDBOOK CHANGES SINCE 1983
In December, 1983, EPA published its first Water
Quality  Standards  Handbook.     The   1983
Handbook was designed to help States implement
the Water Quality Standards Regulation as revised
in November 1983 (48 F.R. 51400).  Since then,
Congress enacted the Water Quality Act of 1987
(Public Law 100-4), making substantial additions
to the Clean Water Act (CWA) directly affecting
the standards program.  In response to the Water
Quality Act of 1987, and  as a result of Federal
promulgation actions, EPA amended the  Water
Quality Standards Regulation several times (see
Appendices A  and B).   Since 1983 EPA also
issued  additional  guidance  to  assist in the
implementation of the WQS Regulation.   Water
Quality Standards Handbook - Second Edition
incorporates all the WQS  guidance issued since
the 1983 Handbook was published.  A summary
of these guidance documents are as follows.

EPA Guidance on the Water Quality Act of
1987

On February 4, 1987, Congress enacted the Water
Quality Act of 1987 (Public Law 100-4), making
substantial  additions to the  Clean  Water Act
directly affecting the standards program. Section
303(c)(2)(B) of the  Clean Water Act requires
States  to  adopt  numeric  criteria  for   toxic
pollutants listed under section 307(a) of the Clean
Water  Act  for which section 304(a) criteria have
been published, if the presence of these pollutants
is likely to affect a water  body's  use.   EPA
published Guidance for State Implementation of
WQS for CWA section 303(c)(2)(B) on December
12, 1988 (USEPA,  1988b).   This  guidance is
incorporated into this Handbook at section 3.4.1.

The 1987  Act also added a new section 518,
which  requires EPA to promulgate a regulation
specifying   how  the  Agency  will  authorize
qualified  Indian  Tribes  to  administer  CWA
programs including section  303 (water quality
standards)   and   section   401   (certification)
programs.   Section 518  also requires EPA, in
promulgating  this regulation,  to  establish  a
mechanism to resolve unreasonable consequences
that may result from an Indian Tribe and a State
adopting differing water quality standards  on
common bodies of water.   EPA promulgated a
final regulation on December  12, 1991 (56 F.R.
64875).  Guidance on water quality standards for
Indian Tribes is contained in chapter 1.

Other EPA Guidance

Since  1983,  EPA  also developed additional
policies and guidance on virtually all areas of the
WQS Regulation.  Following is a complete list of
these guidance documents.

State Water Quality  Standards Approvals: Use
     Attainability  Analysis Submittals  (USEPA,
     1984d), clarifies EPA  policy on  several
     issues regarding approval of water body use
     designations   less   than   the
     fishable/swimmable goal  of the CWA.  See
     section 6.2 for a discussion of this topic.

Interpretation  of the  Term  "Existing   Use"
     (USEPA,  1985e),  expands  on  EPA's
     interpretation of when a use becomes an
     "existing use"   as  defined  by the  WQS
     Regulation. Discussion of "existing uses" is
     contained in  section 4.4.

Selection of Water Quality Criteria in State Water
     Quality  Standards     (USEPA,   1985f),
     established   EPA  policy   regarding   the
     selection of appropriate water quality criteria
     for toxic pollutants in State water quality
     standards. This guidance preceded both the
     Guidelines for Deriving Numerical National
     Water  Quality  Criteria for the  for  the
     Protection of Aquatic Organisms and Their
     Uses  (USEPA,  1985b),  and  the  1988
     guidance on section  303(c)(2)(B)  of  the
     CWA, discussed above.  Both of these later
     documents expand upon  the February 1985
     guidance, but the policy  established therein
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 Water Quality Standards Handbook - Second Edition
      has  not   been   substantively   changed.
      Adoption of criteria for toxic pollutants is
      discussed in section 3.4.

 Variances in Water Quality Standards (USEPA,
      1985g), reinterprets the factors that could be
      considered  when  granting  water  quality
      standards variances. Variances are discussed
      in section 5.3.

 Antidegradation,   Waste loads,  and  Permits
      (USEPA,   1985h),   clarifies   that   the
      antidegradation   policy   is   an   integral
      component  of water quality  standards and
      must be considered when developing waste
      load  allocations  and   NPDES  permits.
      Antidegradation is discussed in chapter 4.

 Questions and  Answers   on  Antidegradation
      (Appendix G), provides guidance on various
      aspects  of the antidegradation policy where
      questions  had   arisen  since  the  1983
      Regulation and Handbook were published.

 Antidegradation    Policy   (USEPA,    1985i),
      reiterates the need for all States to have: (1)
      an antidegradation policy that fully complies
      with  the Federal  requirements,  and (2) a
     procedure for consistently implementing that
     policy.

Answers to Questions on Nonpoint Sources  and
      WQS (USEPA,  1986e),  responded to  two
     questions on nonpoint source pollution and
     water quality  standards.   The relationship
     between nonpoint source pollution and water
     quality standards is discussed in section 7.

Determination of "Existing Uses" for Purposes of
     Water Quality  Standards  Implementation
     (USEPA,  1986f),  responds   to  concerns
     expressed to EPA on the interpretation of
     when a  recreational  use  becomes   an
     "existing use"  as defined by the Regulation.
     Discussion of "existing uses" is contained in
     section 4.4.
 Nonpoint Source  Controls and  Water  Quality
      Standards (USEPA, 1987d), provides further
      guidance on nonpoint sources pollution and
      water   quality  standards   reflecting   the
      requirements of section 319  of the CWA as
      added by the 1987 CWA amendments.

 EPA  Designation  of  Outstanding  National
      Resource Waters  (USEPA, 1989f),  restates
      the  basis  for  EPA's  practice   of   not
      designating  State waters as  Outstanding
      National Resource Waters (ONRW) where a
      State does not do so.  ONRWs are discussed
      in section 4.6.

 Guidance for the  Use  of Conditional Approvals
     for State WQS (USEPA, 1989g), provides
      guidelines for  regional offices  to  use in
      granting State  water  quality   standards
      approvals conditioned on the performance of
      specified actions by the State.  Conditional
      approvals are discussed in section 6.2.3.

Application  of Antidegradation  Policy  to  the
     Niagara River  (USEPA, 1989c), provides
     guidance on acceptable interpretations of the
     antidegradation policy to help  attain  the
     CWA objective to "restore and maintain" the
     integrity of the Nation's waters.

Designation of Recreation Uses (USEPA, 1989h),
     summarizes previously issued guidance, and
     outlines a number of acceptable State options
     for designating recreational uses.  The  use
     designation process is discussed in chapter 2.
Biological Criteria: National Program Guidance
    for Surface Waters (Appendix C), provides
     guidance on the effective development and
     application of biological criteria in the water
     quality  standards  program.     Biological
     criteria are discussed in section 3.5.3.

National Guidance: Water Quality Standards for
     Wetlands (Appendix D), provides guidance
     for meeting the  EPA priority to develop
     water quality standards for wetlands.
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                                                                                   Introduction
     Section 401 certification and FERC licenses
     (USEPA,  1991h), clarifies  the range  of
     water quality standards elements that States
     need to apply when  making CWA  section
     401 certification decisions.  Section 401 of
     the CWA is discussed in section 7.6.3.

Technical Support Document for Water Quality-
     based  Toxics  Control,  (USEPA,  199la),
     provides technical guidance for assessing and
     regulating the discharge of toxic substances
     to the waters of the United States.

Policy on the Use of Biological Assessments and
     Criteria  in the  Water  Quality  Program
     (USEPA,  199li), provides  the basis for
     EPA's policy that biological surveys shall be
     fully integrated with  toxicity and chemical-
     specific assessment methods in State water
     quality programs. Further discussion of this
     policy is contained in section 3.3.

Numeric  Water Quality  Criteria for  Wetlands
     (Appendix E),  evaluates EPA's  numeric
     aquatic life criteria to determine how they
     can be applied to wetlands. Wetland aquatic
     life criteria are discussed  in section 3.5.6.

Endangered   Species  Act  Joint  Guidance
     (Appendix F),  establishes a procedure  by
     which  EPA, the U.S. Fish and  Wildlife
     Service, and the National Marine Fisheries
     Service will consult  on the development of
     water quality criteria and standards.

Office of Water Policy and Technical Guidance on
     Interpretation and Implementation of Aquatic
     Life Metals  Criteria  (USEPA,   1993f),
     transmits Office of Water (OW) policy and
     guidance   on    the   interpretation   and
     implementation of aquatic life criteria for the
     management  of  metals.     Section  3.6
     discusses EPA's policy on aquatic life metals
     criteria.

Interpretation   of   Federal   Antidegradation
     Regulatory Requirement  (USEPA,  1994a),
     provides guidance on the interpretation of
     the  antidegradation  policy  in  40  CFR
     131.12(a)(2)  as  it  relates  to  nonpoint
     sources.    Antidegradation  and  nonpoint
     sources are discussed in Section 4.6.

Interim Guidance on Determination and Use of
     Water-Effect Ratios for Metals (Appendix
     L), provides interim guidance concerning the
     experimental determination of water-effect
     ratios  (WERs) for metals and supersedes all
     guidance concerning water-effect ratios and
     the Indicator Species Procedure in USEPA,
     1983a  and in  USEPA,   1984f.    It  also
     supersedes  the  guidance "in these earlier
     documents for the Recalculation Procedure
     for  performing  site-specific  aquatic  life
     criteria modifications.  Site-specific aquatic
     life criteria are discussed in Section 3.7.

The guidance contained in each  of the above
documents  is either incorporated into the text of
the  appropriate section of this  Handbook or
attached as appendices  (see Table of Contents).
The reader is directed  to the original guidance
documents  for the explicit guidance on the topics
discussed.    Copies  of all original  guidance
documents  not attached as appendices  may be
obtained from the source listed for each document
in the Reference section of this  Handbook.

The Water  Quality Standards Handbook - Second
Edition is reorganized from the 1983 Handbook.
An  overview to Water Quality Standards and
Water Quality  Management programs has been
added, and chapters 1 through 6 are organized to
parallel the  provisions  of the  Water  Quality
Standards  Regulation.     Chapter   7  briefly
introduces  the role of water quality standards in
the  water  quality-based approach to pollution
control.

The Water Quality Standards Handbook - Second
Edition retains  all  the guidance in the  1983
Handbook  unless such guidance was specifically
revised in subsequent years.
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 Water Quality Standards Handbook - Second Edition
      OVERVIEW OF THE WATER QUALITY STANDARDS PROGRAM
 A water quality standard defines the water quality
 goals  of a water body,  or portion thereof,  by
 designating the use or uses to be made of the
 water, by setting criteria necessary to protect the
 uses,  and by  preventing degradation  of water
 quality through antidegradation provisions.  States
 adopt water quality standards to protect public
 health or welfare, enhance the quality of water,
 and serve the purposes of the Clean Water Act.

 "Serve the purposes of the Act" (as defined in
 sections 101(a), 101(a)(2), and 303(c) of the Act)
 means that water quality standards:

 •   include   provisions   for   restoring  and
     maintaining   chemical,   physical,   and
     biological integrity of State waters;

 •   wherever  attainable, achieve a level of water
     quality that provides for the protection and
     propagation of fish, shellfish, and wildlife,
     and  recreation   in  and  on  the   water
     ("fishable/swimmable"); and

 *   consider the use  and value  of State  waters
     for public water supplies, propagation of fish
     and wildlife,  recreation,  agriculture and
     industrial  purposes, and navigation.

 Section 303(c)  of the Clean Water Act provides
 the statutory basis for the water quality standards
 program. The regulatory requirements governing
 the  program,   the  Water  Quality  Standards
 Regulation, are published at 40 CFR 131.  The
 Regulation is  divided into  four  subparts  (A
 through D), which are summarized below.

 General Provisions (40 CFR 131 - Subpart A)

 Subpart A includes the scope (section 131.1) and
 purpose   (section  131.2)  of  the  Regulation,
 definitions of  terms  used  in  the  Regulation
 (section  131.3), State  (section 131.4) and EPA
 (section   131.5)  authority  for  water  quality
 standards, and  the minimum requirements for a
 State water quality standards submission (section
 131.6).

 On December 12, 1991, the EPA promulgated
 amendments to Subpart A of the Water Quality
 Standards  Regulation in response to the CWA
 section 518 requirements (see 56 F.R.  64875).
 The Amendments:

 •    establish   a   mechanism   to    resolve
     unreasonable consequences that may result
     from  an Indian Tribe and a State  adopting
     differing water quality standards on common
     bodies of water (section 131.7); and

 •    add procedures by which an Indian Tribe can
     qualify  for  the section 303  water quality
     standards and section  401  certification
     programs of the Clean Water Act  (section
     131.8).

 The sections of Subpart A are discussed in chapter
 1.

 Establishment of Water Quality Standards -
 (Subpart B)

 Subpart B  contains regulatory requirements  that
 must be included in State water quality standards:
 designated  uses  (section  131.10),  criteria  that
 protect the designated uses (section 131.11), and
 an antidegradation  policy that protects  existing
 uses and  high water quality (section  131.12).
 Subpart B  also provides for State discretionary
policies, such as mixing zones and water quality
 standards variances (section 131.13).

Each of these sections is summarized below and
discussed  in  detail in chapters 2  through  5
respectively.

    Designation of Uses

The Water  Quality Standards Regulation  requires
that States  specify appropriate water uses to be
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                                                                                     Introduction
achieved   and   protected  by   taking   into
consideration the use and value of the water body
for public water supply, for propagation of fish,
shellfish,  and  wildlife,  and  for  recreational,
agricultural, industrial, and navigational purposes.
In  designating uses  for  a water  body, States
examine the suitability of a  water  body for the
uses  based  on  die  physical,  chemical,  and
biological characteristics  of the water body,  its
geographical setting and scenic qualities, and the
social-economic and cultural characteristics of the
surrounding area.  Each water body  does not
necessarily require a unique set of uses.  Instead,
the characteristics necessary to support a use can
be identified so that  water bodies  having those
characteristics  might be grouped  together  as
supporting particular  uses.

Any water body with standards not consistent with
the section 101(a)(2) goals of the Act must  be
reexamined every 3  years to determine if new
information  has become available that would
warrant a revision of the standard.  In addition,
the Regulation requires that where existing water
quality standards specify designated uses less than
those which are presently being attained, the State
shall revise its  standards to  reflect  the  uses
actually being attained.

When reviewing uses,  States must perform and
submit to EPA a use  attainability analysis if:

•    either the State designates or has designated
     uses that do not  include the uses specified in
     section 101(a)(2) of the Act;

•    the State wishes to remove a designated use
     that is specified in section  101(a)(2); or

•    the State wishes to adopt subcategories of
     uses  specified  in  section 101(a)(2) that
     require  less  stringent  criteria  than are
     currently adopted.

States may adopt seasonal uses as an alternative to
reclassifying a water body or segment thereof to
uses requiring less stringent criteria. In no case
may a State  remove an existing use.   No use
attainability analysis is required when designating
uses  that  include  those  specified  in  section
101(a)(2) of the Act.

     Criteria Development and Review

States adopt water quality criteria with sufficient
coverage of parameters and of adequate stringency
to protect designated uses.  In adopting criteria to
protect the designated uses,  States may:

•    adopt the criteria that EPA publishes  under
     section 304(a) of the Act;

•    modify the section 304(a) guidance to reflect
     site-specific conditions; or

•    use other scientifically defensible methods.

Section 131.11 encourages  States to adopt both
numeric and narrative criteria. Numeric criteria
are  important  where  the cause of toxicity  is
known or  for protection  against pollutants with
potential human health impacts or potential for
bioaccumulation.  Narrative toxic criteria, based
on whole-effluent toxicity (WET) testing, can be
the basis for limiting toxicity in waste discharges
where a specific pollutant  can be identified as
causing or contributing to the toxicity but there
are no numeric criteria in the  State standards or
where toxicity cannot be traced to a particular
pollutant.  Whole-effluent toxicity testing is also
appropriate for discharges containing multiple
pollutants because WET testing provides a method
for evaluating synergistic  and antagonistic effects
on aquatic life.

Section  303(c)(2)(B) requires  States  to  adopt
criteria for all  section 307(a) toxic  pollutants for
which the Agency has published criteria under
section 304(a) of the Act, if the discharge or
presence  of the pollutant  could reasonably  be
expected to interfere with the designated uses of
the water body.  The section 307(a) list contains
65 compounds and families of compounds, which
the   Agency  has  interpreted to  include  126
 "priority" toxic pollutants for regulatory purposes.
If data indicate that it is reasonable to expect that
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 Water Quality Standards Handbook- Second Edition
 one or more of the section 307(a) toxic pollutants
 will interfere with the attainment of the designated
 use, or is actually interfering with the designated
 use, then the State must adopt a numeric limit for
 the specific pollutant.  Section 303(c)(2)(B) also
 provides that where EPA-recommended numeric
 criteria are not available,  States  shall adopt
 criteria  based  on  biological  monitoring  or
 assessment methods.
      Antidegradation  Policy
      mentation Methods
and   Imple-
 Water quality standards include an antidegradation
 policy  and  methods  through which the  State
 implements the antidegradation policy.  Section
 131.12 sets  out a three-tiered approach for the
 protection of water quality.

 "Tier 1" (40CFR131.12(a)(l)) of antidegradation
 maintains   and protects existing  uses  and the
 water quality necessary to protect these uses. An
 existing use can be established by demonstrating
 that  fishing, swimming,  or  other uses  have
 actually occurred  since November 28, 1975, or
 that the water quality is suitable to allow such
 uses  to occur,  whether or not such  uses are
 designated uses for the water body in question.

 "Tier 2" (section 131.12(a) (2)) protects the water
 quality in waters whose quality is better than that
 necessary to protect "fishable/ swimmable" uses
 of the water body. 40CFR131.12(a)(2) requires
 that certain procedures  be followed and certain
 showings be made (an "antidegradation review")
 before  lowering water  quality  in  high-quality
 waters. In no case may water quality on a Tier II
 water body  be lowered to  the  level at which
 existing uses are impaired.

 "Tier  3"   (section   131.12  (a)(3))  protects
 outstanding national resource waters (ONRWs),
 which are provided the highest level of protection
 under the  antidegradation  policy.    ONRWs
 generally include the highest quality waters of the
 United   States.      However,   the  ONRW
 antidegradation  classification also offers special
protection for waters of "exceptional ecological
 significance," i.e.,  those water bodies which are
 important, unique,  or sensitive ecologically, but
 whose  water  quality,  as  measured  by  the
 traditional parameters such as  dissolved oxygen
 or pH,  may not be particularly high.  Waters of
 exceptional ecological significance also include
 waters whose characteristics cannot adequately be
 described  by traditional   parameters  (such  as
 wetlands and estuaries).

 Antidegradation   implementation    procedures
 address how States will  ensure that the permits
 and control programs meet water quality standards
 and antidegradation policy requirements.

     General Policies

 The Water Quality Standards Regulation allows
 States to include in their standards State policies
 and provisions regarding water quality standards
 implementation, such as mixing zones, variances,
 and low-flow exemptions subject to EPA review
 and approval.   These  policies and provisions
 should be  specified in the State's water quality
 standards  document.  The State's rationale and
 supporting documentation should be submitted to
 EPA for review during the water quality standards
 review and approval process.

         Mixing Zones

 States may,  at  their discretion,  allow  mixing
zones for dischargers.  The States' water quality
standards  should  describe the  methodology for
determining the  location,  size,  shape, outfall
design,  and in-zone quality of mixing zones.
Careful  consideration  must be  given  to  the
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appropriateness  of  a  mixing  zone  where  a
substance   discharged   is   bioaccumulative,
persistent,   carcinogenic,    mutagenic,   or
teratogenic.

         Low-Flow Provisions

State water quality standards should protect water
quality  for the designated and existing  uses in
critical low-flow situations. States may, however,
designate  a  critical  low-flow  below  which
numerical  water  quality  criteria do  not apply.
When reviewing standards, States should review
their low-flow provisions for conformance with
EPA guidance.

          Water Quality Standards Variances

As an alternative to removing a designated use, a
State may wish to include a variance as part of a
water quality standard,  rather  than change  the
standard across  the board, because  the State
believes that the  standard  ultimately  can  be
attained. By maintaining the standard rather than
changing it, the State will  assure  that further
progress is made in improving water quality and
attaining the standard. EPA has approved State-
adopted variances in the past and will continue to
do so if:

•    the variance is included as part of the water
     quality standard;

•    the variance is subjected to the same public
     review  as  other changes  in water quality
     standards;

•    the  variance  is  granted  based  on  a
     demonstration that meeting the standard is
     not feasible due to the presence of any of the
     same  conditions  as  if  the  State  were
     removing a designated use (these conditions
     are  listed  in  section  131.10(g)  of  the
     Regulation); and

•    existing uses will be fully protected.
Water Quality Standards Review and Revision
Process - (Subpart C)

The Clean Water Act requires States to hold a
public hearing(s) to review  their water quality
standards at least once every 3 years and revise
them if appropriate.   After  State water quality
standards are  officially adopted,  a Governor or
designee submits the standards to the appropriate
EPA Regional Administrator for review.  EPA
reviews the State standards to determine whether
the  analyses  performed  are  adequate.    The
Agency also evaluates whether the designated uses
and criteria are compatible throughout the water
body and whether the downstream water quality
standards are protected.   After reviewing  the
standards,  EPA makes a determination whether
the standards  meet the requirements of the law
and EPA's water quality standards regulations. If
EPA disapproves a standard, the Agency indicates
what changes must be made for the standard to be
approved.  If a State fails  to make the required
changes, EPA promulgates a Federal standard,
setting  forth  a new  or revised water quality
standard applicable to the State.

     State Review and Revision

States identify additions or  revisions necessary to
existing  standards based on their 305(b) reports,
other available water quality  monitoring data,
previous  water quality standards reviews, or
requests from industry, environmental groups, or
the public.  Water quality standards reviews and
revisions  may take  many  forms,  including
additions to and modifications in uses, in criteria,
in   the   antidegradation  policy,   in   the
antidegradation implementation procedures, or in
other general policies.

Some States  review parts of their water  quality
standards every year.  Other  States perform  a
comprehensive  review every  3  years.   Such
reviews  are necessary because new scientific and
technical   data   may   become   available.
Environmental  changes over  time  may  also
necessitate the need for the review.
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 Water Quality Standards Handbook - Second Edition
      EPA Review

 When States adopt new or revised WQS, the State
 is required under CWA section 303(c) to submit
 such   standards  to   EPA  for  review   and
 approval/disapproval.     EPA  reviews   and
 approves/disapproves  the  standards  based  on
 whether the standards  meet the requirements of
 the CWA.   As  a result  of the EPA review
 process, three actions are possible:

 •    EPA approval (in whole or in part) of the
      submitted State water quality standards; or

 •    EPA disapproval (in whole or in part) of the
      submitted State water quality standards; or

 •    EPA conditional approval (in whole or in
      part) of the submitted State water quality
      standards.

 Revisions to  State water quality standards  that
 meet the requirements  of the Act and the WQS
 Regulation are approved by the  appropriate EPA
 Regional Administrator. If only a partial approval
 is  made, the Region,  in  notifying  the  State,
 identifies the portions  which should be revised
 (e.g., segment-specific requirements).

 If the Regional Administrator determines that the
 revisions submitted are not consistent with or do
 not meet the requirements of the Act or the WQS
 Regulation,   the   Regional   Administrator
 disapproves the standards within 90 days with  a
 written notification to  the  State.    The  letter
 notifies  the  State  that  the  Administrator will
 initiate promulgation proceedings if the State fails
 to adopt and submit the necessary revisions within
 90 days after notification. The State water quality
 standard  remains   in    effect,  even  though
 disapproved by EPA, until the State revises it or
 EPA promulgates a rule that supersedes the State
 water quality standard.
Federally   Promulgated    Water   Quality
Standards -  (Subpart D)

As discussed above, EPA may promulgate Federal
Water Quality Standards.   Section 303 of  the
Clean Water  Act permits the Administrator to
promulgate Federal standards:

•    if a revised or new water quality standards
     submitted by the State is determined by  the
     Administrator not to be consistent with  the
     applicable requirements of the Act; or

•    in  any   case  where   the  Administrator
     determines that a new or revised standard is
     necessary to  meet  the requirements of  the
     Act.

Federal promulgations are codified under Subpart
D  of the Regulation.
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                                                                                   Introduction
      THE ROLE OF WQS IN THE WATER QUALITY MANAGEMENT
                                       PROGRAM
    State water quality standards play a central
role in  a State's  water  quality management
program, which identifies the overall mechanism
States use to integrate the  various Clean Water
Act quality control requirements into a coherent
management   framework.     This  framework
includes, for example:

•    setting  and  revising  standards for  water
     bodies;

•    Water  Quality  Assessments  to  determine
     attainment of designated uses;

•    CWA   section   305(b)   water   quality
     monitoring  to  provide information  upon
     which water quality-based decisions will be
     made,  progress  evaluated,  and  success
     measured;

•    calculating   total  maximum daily  loads
     (TMDLs), waste  load allocations (WLAs)
     for point sources  of pollution, and  load
     allocations (LAs) for nonpoint sources of
     pollution;

•    developing a water quality management plan,
     certified by the Governor and approved by
     EPA,  which   lists   the  standards  and
     prescribes the regulatory  and construction
     activities necessary to  meet the standards;

•    preparing section 305(b)  reports and lists
     that document the condition of the State's
     water quality;

•    developing, revising,  and implementing an
     effective CWA section 319  program and
     CZARA  section 6217 program to control
     NFS pollution;
 •    making decisions involving CWA  section
     401  certification of Federal  permits  or
     licenses; and

 •    issuing NPDES permits for all point source
     discharges.   Permits are written  to  meet
     applicable water quality standards.

 The Act provides the basis for two different kinds
 of pollution control programs.   Water quality
 standards are the basis of the water quality-based
 control program.   The  Act  also provides for
 technology-based limits known as best available
 treatment technology economically achievable for
 industry and secondary  treatment  for  publicly
 owned  treatment  works.    In  some cases,
 application of these technologically based controls
 will result in attaining  water  quality standards.
 Where  such is not the case, the Act requires the
 development of more stringent limitations to meet
 the water quality standards.

 Regulations, policy,  and  guidance have  been
•issued  on all the  activities  mentioned  in  this
 section. Chapter 7 contains a  brief discussion of
 how water  quality standards relate to many of
 these   activities  in  the  water  quality-based
 approach to pollution  control, but additional
 details  on these  other programs is  beyond the
 scope of this Handbook. For further information,
 see  the EPA guidance documents  referenced in
 chapter 7.                3
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 Water Quality Standards Handbook - Second Edition
                          FUTURE PROGRAM DIRECTIONS
 Since the 1960's, the water science program has
 moved from solving a limited set of problems in
 a limited set of waters to one that  is solving a
 broad range of complex problems in categories of
 U.S. waters and addressing cross-media aspects of
 water quality decisions. Initial efforts focused on
 the more  visible sources of pollution such  as
 organic loadings, solids, oil, and grease, and then
 shifted to toxics and more complex mixtures of
 pollutants.

 Developments in two  areas  have  significantly
 affected the scientific underpinnings of the water
 program.  First is the science of risk assessment
 used to estimate risk to  human health and the
 environment  from  exposure to  contaminants.
 Second is our ability to measure pollutants in the
 environment at an increasing level of precision.
 The evolution of methods and capabilities within
 these  two  scientific disciplines has significantly
 advanced the sophistication of scientific analyses
 used to manage the water program.

 As the water science program moves toward the
 21st   Century,   we  must  provide  technical
 information  and tools that allow  States,   the
 regulated   community,   and  the  public   to
 understand  and apply the methods, criteria,  and
 standards  to  environmental  systems.    This
 includes   updating  science   and   adapting
 technologies as appropriate to keep the foundation
 of our program solid as  well as  employing or
 modifying these approaches when appropriate for
 new problems.

 The CWA  provides broad authority through its
 goals and policy, such as:

     ...  to restore  and  maintain the
     chemical,   physical,   and  biological
     integrity of the Nation's waters (section
     101(a)); and

     .  .  . wherever attainable .  . . water
     quality   which  provides   for  the
     protection  and  propagation  of  fish,
     shellfish, and wildlife  ... to protect
     the water of the United States (section
 The breadth of this authority is also reflected in
 specific EPA  mandates such as those in section
 304(a):

     [EPA] shall develop and publish . .  .
     criteria for water accurately reflecting
     the latest scientific knowledge (A) on
     the kind  and extent of all identifiable
     effects on health and welfare . . .  (B)
     on the concentration and dispersion of
     pollutants .  .  .   through  biological,
     physical, and chemical processes; and
     (C)  the  effects  of  pollutants  on
     biological   community   diversity,
     productivity,  stability . . .  including
     eutrophication  and rates of ...
     sedimentation  .  .  .   (CWA  section
     304(a)(l)); and

     [EPA]  shall develop and publish .  .  .
     information   (A)   on   the   factors
     necessary to restore and maintain  the
     chemical,  physical,  and  biological
     integrity  ... (B)  on the  factors
     necessary  for  the  protection   and
     propagation  of shellfish,  fish,  and
     wildlife . .  . and to allow recreational
     activities  in and on the  water . .  .".)
     (304(a)(2))(CWA section 304(a)(2))

EPA  has  traditionally  focused on criteria  for
chemical  pollutants, but  has also developed
criteria for a  limited number of physical  (e.g.,
color, turbidity,  dissolves solids) and biological
(bacteria,  "free  from"  nuisance  aquatic life)
parameters (NAS/NAE,  1973; USEPA,  1976).
However,  as  EPA's water  quality protection
program has evolved, it has become apparent that
chemical criteria alone, without the criteria for the
biological  and physical/habitat components of
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                                                                                     Introduction
water bodies, are insufficient to fully achieve the
goals of the CWA.

Future  directions  in  the criteria  and standards
program will  focus on providing scientific and
technical tools to  aid regional, State, and local
environmental managers in (1) implementating the
standards program,  and  (2)  developing  new
science and technology  that will  reduce human
and  ecological risks  resulting  from exposure to
unaddressed contaminants and prevent pollution
from point and nonpoint sources.

Setting future national program priorities will be
based on the consideration of risk assessment;
statutory  and  court-mandated  obligations;  the
expressed  needs of  regional,  State,  and local
environmental   managers   and   the  regulated
community; and the  potential  effectiveness of a
program   to    influence   real   environmental
improvement.

EPA  will  be  developing  methodologies and
criteria in areas beyond  the traditional chemical-
specific type criteria of  the  past.   Areas  of
scientific examination and potential  regulatory
controls include  criteria   to  protect  wildlife,
wetlands, and sediment quality; biological criteria
to better define desired biological communities in
aquatic ecosystems; and nutrient  criteria. EPA
has  also moved in the direction of the  physical
and habitat components of water quality protection
in other water quality programs.  For example,
the CWA section  404(b)(l) Guidelines (40 CFR
230) evaluate  physical  characteristics  (such  as
suspended  particulates, flow, and hydroperiod),
and   habitat components  (such  as food  web
organisms,  breeding/nesting areas,  and  cover).
Implementation of these various types of criteria
will be influenced by the environmental concerns
in specific watersheds.

To protect human health, program emphasis will
shift to focus on the human  health impacts of
pathogenic microorganisms in ambient waters that
cause illness in humans, and will address concerns
about the risk that contaminated fish may pose to
sensitive populations  whose daily  diet includes
large quantities of fish.

In an expanded effort to protect ecology, there
will be increasing  emphasis oh the  watershed
approach   by assessing  all potential and actual
threats  to  a   watershed's  integrity.     Risk
assessment of the watershed and setting priorities
based on  those risks will  become increasingly
important in future program efforts in criteria and
standards as supporting elements to the watershed
approach.

Over the  next few years,  there  will be more
emphasis on developing effective  risk reduction
strategies  that include both traditional and  non-
traditional controls and approaches.

Future program directions in criteria development
and then adoption and  implementation of water
quality standards will be based on the principle of
ecological  and human  health  risk  reduction
through sound and implementable science.

Endangered Species Act

An important consideration  in future criteria and
standards development will be the conduct of the
consultation provisions of the Endangered Species
Act (ESA)  and  the  implementation  of  any
revisions   to  standards  resulting  from  those
consultations.   Section  7  of  the Endangered
Species Act requires  all  Federal agencies, in
consultation with the Fish  and  Wildlife Service
and the National Marine Fisheries Service  (the
Services)  to assure that any action authorized,
funded, or implemented by a Federal agency does
not jeopardize the existence of endangered or
threatened species or result in the destruction or
adverse modification of their critical habitat.  The
definition of a Federal  action is very  broad and
encompasses  virtually  every  water  program
administered by EPA.

The responsibility for ensuring  that consultation
occurs with the Services lies with EPA, although
in  fulfilling  the  requirements  a  non-Federal
representative  may be designated for informal
 (9/15/93)
                                       INT-15

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 Water Quality Standards Handbook - Second Edition
 consultation. (Note:  Consultation may be formal
 or informal; the latter form is the most prevalent.)
 Protection of threatened and endangered species
 and their habitat is a critical national priority, and
 the criteria and  standards  programs  can  be
 effective tools to meet this national priority.  All
 aspects   of  standards,  including  aquatic  life
 criteria, uses, antidegradation, and implementation
 actions  related to the standards  are subject to
 consultation.    All  future revised  aquatic  life
 criteria, sediment, wildlife, and biological criteria
 will be subject to the consultation requirements as
 will their adoption into enforceable standards.

 To  form an  effective partnership  between the
 Services and EPA in creating a framework for
 meeting the responsibilities under section 7 of the
 Endangered  Species Act  and  applicable EPA
 regulations, the Services and EPA entered into a
 joint guidance agreement in  July 1992 (see
 Appendix F).   This  agreement  sets forth the
 procedures to  be  followed by the Services  and
 EPA to  assure compliance with section 7 of the
 ESA in the development of water quality criteria
 published pursuant to section 304(a)  of the CWA
 and the adoption of water quality standards under
 section 303(c).  This agreement also indicated that
 the regional and field  offices of EPA  and the
 Services could establish sub-agreements specifying
 how  they would  implement the  joint  national
 guidance.

 During the preparation of this second edition
 Handbook, the  Services and EPA initiated a work
group   to  develop   a  more  extensive  joint
agreement.   This  group was  charged with the
responsibility  of  reviewing   the   July   1992
agreement, making appropriate revisions  to the
water quality criteria and standards sections, and
adding a new section discussing the consultation
procedures to be followed for the NPDES permit
program.    When the  revised  agreement is
approved by the Agencies, it  will  replace the
agreement included in this Handbook as Appendix
F.

Both the current  agreement and the proposed
revision seek to ensure  a  nationally consistent
consultation process that allows flexibility to deal
with site-specific issues  and to streamline the
process to minimize the regulatory burden. The
overriding goal is  to  provide for the protection
and support of the recovery of threatened and
endangered species and the  ecosystems on  which
they depend.
INT-16
                                                                                      (9/15/93)

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                                                              Chapter 1 - General Provisions
                                 CHAPTER 1

                          GENERAL PROVISIONS

                        |  (40 CFR 131 - Subpart A)

                              Table of Contents

1.1 Scope - 40 CFR 131.1	1-1

1.2 Purpose - 40 CFR 131.2	 1-1

1.3 Definitions - 40 CFR 131.3	1-1
    1.3.1     States	1-1
    1.3.2     Waters of the United States  	1-2

1.4 State Authority - 40 CFR 131.4	1-2

1.5 EPA Authority - 40 CFR 131.5	1-3

1.6 Requirements for Water Quality Standards Submission - 40 CFR 131.6	1-4

1.7 Dispute Resolution Miechanism - 40 CFR 131.7  	1-4
    1.7.1     Responsibility Is With Lead FJPA Regional Administrator	1-5
    1.7.2     When Dispute Resolution May Be Initiated	1-5
    1.7.3     Who May Request Dispute Resolution and How	1-6
    1.7.4     EPA Procedures in Response to Request   	1-6
    1.7.5     When Tribe and State Agree to a Resolution   	1-6
    1.7.6     EPA Options for Resolving the Dispute	1-7
    1.7.7     Time Frame for Dispute Resolution  	1-8

1.8 Requirements for Indian Tribes To Qualify for the WQS Program - 40 CFR 131.8 . . 1-9
    1.8.1     Criteria Tribes Must Meet	1-9
    1.8.2     Application, for Authority To Administer the Water Quality Standards
              Program	1-13
    1.8.3     Procedure  Regional Administrator Will Apply	  1-14
    1.8.4     Time Frame for Review of Tribal Application   	  1-16
    1.8.5     Effect of Regional Administrator's Decision 	  1-16
    1.8.6     Establishing Water Quality Standards on Indian Lands	  1-16
    1.8.7    EPA Promulgation of Standards for Reservations  	  1-18

1.9 Adoption of Standards for Indian Reservation Waters	  1-18
    1.9.1     EPA's Expectations for Tribal Water Quality Standards 	  1-18
    1.9.2    Optional Policies	1-19
    1.9.3     Tribal Submission and EPA Review  	1-19
    1.9.4    Regional Reviews   	1-19

Endnotes	1-21

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-------
                                                                     Chapter 1 - General Provisions
                                        CHAPTER!
                                GENERAL PROVISIONS
         Scope - 40 CFR 131.1
The Water Quality Standards Regulation (40 CFR
131) describes State requirements and procedures
for developing, reviewing, revising, and adopting
water  quality  standards  (WQS),  and  EPA
requirements  and procedures for   reviewing,
approving, disapproving, and promulgating water
quality standards as authorized by section 303(c)
of the Clean Water Act.  This Handbook serves
as guidance for implementing the Water  Quality
Standards Regulation and its provisions.
        Purpose - 40 CFR 131.2
A water quality standard defines the water quality
goals for  a water body, or portion thereof,  by
designating the use or uses to be made of the
water, by  setting criteria necessary to protect the
uses, and by protecting water  quality through
antidegradation provisions.  States adopt water
quality  standards  to  protect  public  health  or
welfare, enhance the quality of water, and serve
the purposes of the Clean Water Act (the Act).
"Serve the purposes of the A.ct" means that water
quality standards should:

•  wherever attainable, achieve a level of water
   quality that provides for1 the protection and
   propagation of fish, shellfish, and wildlife, and
   for recreation in and on the water, and take
   into consideration the use and value of public
   water supplies, and agricultural, industrial, and
   other purposes, including navigation (sections
   101(a)(2) and 303(c) of the Act); and

•  restore and maintain the chemical,  physical,
   and biological integrity  of the Nation's waters
   (section 101(a)).
       CLEAN WATER ACT GOALS

     Achieve a level of water quality that
     provides for the protection and propaga-
     tion of fish, shellfish, and wildlife, and
     for  recreation in  and  on the water,
     where attainable.

     Restore  MCniaintain  the ctiemical,
     physical* and biological integrity of the
     Nations waters.
These standards  serve  dual  purposes:  They
establish the water quality goals for a specific
water body, and they serve as the regulatory basis
for establishing  water quality-based  treatment
controls   and   strategies   beyond   the
technology-based levels of treatment required by
sections 301 (b) and 306 of the Act.
         Definitions - 40 CFR 131.3
Terms used in the  Water  Quality Standards
Regulation are defined in  section 131.3 of the
regulation.  These definitions, as well as others
appropriate  to  the  water  quality  standards
program,  are  contained in the glossary of this
Handbook.  No additional guidance is necessary
to  explain  the  definitions;   however,  some
background  information on  the definitions of
"States" and "waters of the United States" may be
helpful.

1.3.1 States

Indian Tribes  may now qualify for the  water
quality standards and 401 certification programs.
The February  4, 1987, Amendments to the Act
(9/15/93)
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 Water Quality Standards Handbook - Second Edition
 added  a new  section 518 requiring EPA  to
 promulgate regulations specifying how the Agency
 will treat qualified Indian Tribes as States for the
 purposes of,  the section  303  (water  quality
 standards)    programs,    the   section   401
 (certification) programs, and other programs. On
 December  12,  1991, the EPA  promulgated
 amendments to Subpart A of the Water Quality
 Standards Regulation  in  response  to  the  CWA
 section 518 requirements (see 56 F.R.  64893).
 These  amendments modified the  definition  of
 States by adding the  phrase  "...  and Indian
 Tribes that EPA determines qualify for treatment
 as States for purposes of water quality standards."

 1.3.2  Waters of the United States

 Section 303(c)  of the  CWA  requires States  to
 adopt  water  quality  standards for  "navigable
 waters," which are defined at section 502(7)  of
 the Act as "waters of the United States."  The
 Water Quality Standards Regulation contains no
 definition of  "waters  of  the  United States,"
 although  this  term is  used in the  definition  of
 "water quality standards." The phrase "waters of
 the United States" has  been defined elsewhere in
 Federal regulations (e.g., in regulations governing
 the  National  Pollutant Discharge  Elimination
 System (NPDES) and  section 404 programs (40
 CFR  sections   122.2,  230.3,   and   232.3,
 respectively).    This  definition appears  in the
 glossary  of  this Handbook and  is  used  in
 interpreting the phrase "water quality standards."

 The definition of "waters of the United States"
 emphasizes protection of a broad range of waters,
 including interstate and intrastate lakes, streams,
 wetlands, other surface waters, impoundments,
 tributaries of waters, and the territorial seas.

BPA believes that some  States  may  not be
providing the same protection to  wetlands that
they provide to other surface waters. Therefore,
EPA wishes to emphasize that wetlands deserve
the same protection under water quality standards.
For more information on the application of water
quality standards to wetlands, see Appendix D of
this Handbook.
    WATERS OF THE UNITED STATES
         Streams
         Wetlands
         Other surface waters
         Impoundments
         Tributaries of waters
         Territorial seas
 Concerns have been raised regarding applicability
 of water quality standards to riparian areas other
 than riparian wetlands. "Riparian areas" are areas
 in a stream's floodplain with life characteristic of
 a floodplain.   Wetlands are  often found  in
 portions of riparian areas.  The Clean Water Act
 requires States to adopt water quality standards
 only for "waters of the  United States," such as
 wetland portions of riparian areas that meet the
 regulatory definition.  Of course, States may, at
 their discretion,  choose to adopt water quality
 standards or other mechanisms  to protect other
 riparian areas.
         State Authority - 40 CFR 131.4
States (including Indian Tribes qualified for the
purposes   of  water  quality  standards)   are
responsible  for  reviewing,  establishing,  and
revising water quality standards.   Under section
510 of the Act, States may develop water quality
standards  more  stringent than required by  the
Water Quality Standards Regulation.

Under section 401  of the Act, States also have
authority to issue water quality certifications for
federally permitted or licensed activities.   This
authority   is  granted  because   States   have
jurisdiction over their waters  and can influence
the design and  operation  of projects  affecting
those waters.  Section 401 is intended to ensure
that Federal  permits  and licenses  comply with
applicable water quality requirements, including
State water quality standards, and applies to all
1-2
                                                                                       (9/15/93)

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                                                                       Chapter 1 - General Provisions
 Federal agencies that grant a license or permit.
 (For example,  EPA-issued permits for  point
 source   discharges   under  section  402  and
 discharges of dredged  and fill material under
 section 404 of the Clean Water Act; permits for
 activities  in  navigable  waters  that  may affect
 navigation under sections 9 and 10 of the Rivers
 and Harbors Act (RHA); and licenses required for
 hydroelectric  projects issued under  the  Federal
 Power  Act).    Section  401  certifications  are
 normally   issued  by  the State  in  which  the
 discharge originates.

 States   may   deny    certification,   approve
 certification,   or  approve  certification  with
 conditions. If the State denies certification,  the
 Federal  permitting   or  licensing  agency   is
 prohibited from issuing  the permit or  license.
 Certifications  are  subject  to  objection  by
 downstream States where the downstream State
 determines that the  proposed  activity  would
 violate its water quality standards.  [For more
 information on the 401 certification process, refer
 to Wetlands and 401  Certification: Opportunities
for States  and Eligible  Indian  Tribes (USEPA,
 1989a).]
         EPA Authority - 40 CFR 131.5
Under section 303(c) of the Act, EPA is to review
and to approve or disapprove State-adopted water
quality  standards.     This  review  involves  a
determination of whether:

•  the State has adopted water uses consistent
   with the requirements of the Clean Water Act;

•  the State has  adopted criteria that protect the
   designated water uses;

•  the State has followed its legal procedures for
   revising or adopting standards;

•  the State standards that do not include the uses
   specified in section 101(a)(2) of the Act are
   based upon appropriate technical and scientific
   data and analyses; and
•  the State  submission meets the requirements
   included in section 131.6 of the Water Quality
   Standards Regulation.

EPA reviews State water  quality standards to
ensure that the standards meet the requirements of
the Clean Water Act.  If EPA  determines  that
State water quality standards are consistent with
the five factors  listed above, EPA approves the
standards.    EPA disapproves the  State  water
quality standards  and may promulgate Federal
standards  under section 303(c)(4) of the Act if
State-adopted standards are not consistent with the
factors listed above.   Section 510 of the  Act
provides that the States are  not  precluded from
adopting  requirements  regarding  control  or
abatement   of  pollution   as  long   as   such
requirements  are  not  less  stringent  than  the
requirements of the Clean Water Act.    The
Agency is not authorized to disapprove a State
water  quality standard on  the  basis  that EPA
considers the standard to be too stringent.  EPA
may also promulgate a new  or revised standard
where necessary to meet the requirements of the
Act.  In certain cases, EPA may conditionally
approve  a  State's  standards.   A conditional
approval is appropriate only:

•  to correct minor deficiencies  in  a State's
   standards; and

•  when a State agrees to a specific time schedule
   to make the corrections in as  short a time as
   possible.  Section 6.2 provides guidance on
   conditional approvals.
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Water Quality Standards Handbook - Second Edition
EPA also has the authority to issue section 401
certification where a State or interstate agency has
no authority to do so.
        Requirements  for  Water  Quality
        Standards Submission - 40 CFR 131.6
The following elements must be included in each
State's water quality standards submittal to EPA
for review:

•  use designations consistent with the provisions
   of sections 101(a)(2) and 303(c)(2) of the Act;

*  methods  used  and analyses  conducted to
   support water quality standards revisions;

*  water quality criteria sufficient to protect the
   designated uses, including criteria for priority
   toxic pollutants and biological criteria;

•  an antidegradation policy and implementation
   methods consistent with section 131.12 of the
   Water Quality Standards Regulation;

*  certification by the State Attorney General or
   other  appropriate  legal authority within the
   State that the water quality standards were duly
   adopted pursuant to State law; and

*  general information to  aid  the Agency in
   detennining the adequacy  of the  scientific
   bases  of the standards that do not include the
   uses specified in section 101(a)(2) of the Act
   as well as  information on general  policies
   applicable to State standards that may affect
   their application and implementation.

EPA may also request additional information from
the State to aid in determining the adequacy of the
standards.
        Dispute Resolution  Mechanism - 40
        CER 131.7
Section 518 of the Act requires EPA to establish
a  "mechanism   for  the   resolution  of  any
unreasonable consequences that may arise as a
result of differing water  quality standards  that
may be set by States and Indian Tribes located on
common bodies  of water."   EPA's  primary
responsibility in response to this requirement is to
establish a practical procedure to address and,
where possible,  resolve such disputes as they
arise.   However,  the Agency's  authority is
limited.

For example, EPA does not believe that section
518 grants EPA authority to override section 510
of the Act.  EPA believes that the provisions of
section 510 would apply  to  Indian Tribes  that
qualify for treatment as States.   Section 518(e)
and its accompanying legislative history suggest
that Congress intended for section 510 to apply to
Tribes as well as States. Were Tribes prohibited
from  establishing standards more stringent than
minimally approvable by  EPA,  there would be
little need for the dispute resolution mechanism
required by section 518(e)(2).  Therefore, EPA
does not believe that section 518 authorizes  the
Agency to disapprove  a  State  or  Tribe  water
quality standard and promulgate a less stringent
standard as  a means of resolving a State/Tribe
dispute.

EPA also believes there are strong policy reasons
to allow Tribes to set any water quality standards
consistent  with  the Water  Quality Standards
Regulation.   First, it puts Tribes and States on
equal footing with respect to standards setting.
There is no indication that Congress intended to
treat Tribes as "second class" States under  the
Act.   Second,  treating  Tribes as  essentially
equivalent to States is consistent with EPA's 1984
Indian Policy.  Third,  EPA believes it would be
unfeasible to require Tribes to adopt "minimum"
standards allowed under Federal law.  EPA has
no procedures in place for defining a "minimum"
level  of standards  for Indian  Tribes.    EPA
evaluates only whether the standards are stringent
enough, not how  much more  stringent than any
Federal minimum.
1-4
                                      (9/15/93)

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                                                                      Chapter 1 - General Provisions
1.7.1 Responsibility  Is  With   Lead  EPA
      Regional Administrator

EPA's role in dispute resolution is to work with
all parties to the dispute hi an effort to reach an
agreement that resolves the dispute.  The Agency
does not automatically support the Indian position
in all disputes  over water quality  standards.
Rather, EPA employees  serving as  mediators or
arbitrators will serve outside the normal Agency
chain of command and  are expected to act hi  a
neutral fashion.

The  lead EPA Regional Administrator will be
determined using OMB Circular A-95.  The lead
Region is  expected to  enlist the  aid  of other
affected  Regions in routine dispute  resolution.
EPA Headquarters will also oversee the process to
ensure that  the interests of all affected Regions
are represented. Designation as the lead Region
for resolving a dispute or programmatic issues
within EPA does not mean that the lead Region
has  a  license  to  act  unilaterally.    Rather,
designation    as   lead    Region   assigns   the
responsibility to ensure that the process leading to
a decision is fair to all parties.

The Regional Administrator may include other
parties besides Tribes and States in the dispute
resolution process.   In some cases,  the inclusion
of permittees or landowners subject to nonpoint
source restrictions may be needed to arrive at  a
meaningful  resolution of the dispute.   However,
only the  Tribe and State are hi a position to
implement a change in water quality  standards and
are,  thus,  the only "necessary" parties in the
dispute resolution.

1.7.2  When  Dispute  Resolution   May  Be
       Initiated

The regulation establishes conditions under which
the Regional Administrator would be responsible
for  initiating a dispute  resolution action.  Such
actions would be initiated where,  in the judgment
of the Regional Administrator:

•  there are unreasonable consequences;
•  the  dispute is between a State  and a Tribe
   (i.e., not between a Tribe and another Tribe or
   a State and another State);

•  a reasonable effort has been made to resolve
   the   dispute   before   requesting   EPA
   involvement;

•  the  requested relief is within the authority of
   the  Act (i.e., not a request to replace State or
   Tribe standards that comply  with the Act with
   less stringent Federal standards);

•  the  differing  standards  have been adopted
   pursuant to State or Tribe law and approved by
   EPA;

•  a valid written request for EPA involvement
   has   been   submitted   to   the  Regional
   Administrator by the State or Tribe.

Although the Regional Administrator may decline
to initiate a dispute resolution action based on any
of the above factors, EPA  is willing to discuss
specific  situations.   EPA  is  also  willing to
informally  mediate  disputes  between Tribes
consistent  with  the procedures for  mediating
disputes between States (see 48 F.R. 51412).

The regulation  does not  define  "unreasonable
consequences" because:

•  it would be  a presumptuous  and unjustified
   Federal intrusion into local and State concerns
   for  EPA to  define what  an  unreasonable
   consequence might be as a basis  for a national
   rule;

•  EPA does not want to unnecessarily narrow
   the scope of problems to be addressed by the
   dispute resolution mechanism; and

•  the possibilities of what might  constitute an
   unreasonable consequence are so numerous as
   to defy a logical regulatory  requirement.

Also,  the occurrence  of  such  "unreasonable"
consequences  is  dependent  on   the  unique
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                                           1-5

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 Water Quality Standards Handbook - Second Edition
 circumstances associated with the dispute.   For
 example,   what   might  be  viewed   as  an
 unreasonable consequence on a stream segment in
 a large, relatively unpopulated, water-poor area
 with a single discharge would likely be viewed
 quite differently in or near an area characterized
 by  numerous  discharges  and/or  large  water
 resources.    The  Regional  Administrator has
 discretion  to  determine  when  consequences
 warrant initiating a dispute resolution action.

 1.7.3  Who May Request  Dispute Resolution
       and How

 Ether the State or the Tribe may request EPA
 involvement in the dispute.  The requesting party
 must include the  following  items in its written
 request:

 * a   statement describing  the  unreasonable
   consequences;

 • description of the actions taken to resolve the
   dispute before requesting  EPA involvement;

 * a  statement describing  the water  quality
   standards provision (such  as  the particular
   criterion) that has resulted in the unreasonable
   consequences;

 * factual  data substantiating  the  claim  of
   unreasonable consequences; and

 • a statement of relief sought (that is, the desired
   outcome of the dispute resolution action).
 1.7.4 EPA Procedures in Response to Request

 When the  Regional Administrator decides that
 EPA involvement is  appropriate (based on the
 factors discussed in section  1.7.2,  above), the
 Regional Administrator will notify the parties in
 writing that EPA dispute resolution action is being
 initiated and  will solicit their written response.
 The  Regional  Administrator  will  also  make
 reasonable  efforts to ensure that other interested
 individuals or groups have notice of this action.
 These "reasonable efforts" will include, and are
 not limited to, the following:

 •  written notice to responsible Indian and State
    Agencies and other affected Federal Agencies;

 •  notice to the specific individual or entity that
    is claiming that an unreasonable consequence
    is resulting from differing standards having
    been adopted for a common water body;

 •  public notice in local newspapers,  radio, and
    television,  as appropriate;

 •  publication in trade journal newsletters; and

 •  other appropriate means.

 1.7.5 When  Tribe and  State Agree  to  a
      Resolution

 EPA encourages Tribes and States to resolve the
 differences  without EPA involvement  and  to
 consider jointly establishing a mechanism  to
 resolve disputes before such disputes  arise.  The
 Regional  Administrator  has  responsibility  to
 review  and either approve or  disapprove the
 Tribe-State  agreement.  Section 518(d) provides
 that Tribe-State  agreements in general for water
 quality management are to be  approved by EPA.
As a  general  rule,  EPA will  defer  to the
procedure   for   resolving   disputed  jointly
established by the  Tribe and State so long as the
procedure and the end result are consistent with
the provisions of  the CWA and Water  Quality
Standards Regulation.
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                                                                       Chapter 1 - General Provisions
1.7.6 EPA Options for Resolving the Dispute

The dispute resolution mechanism included in the
final  "Indian  Rule"  provides EPA  Regional
Administrators with several alternative courses of
action.      The   alternatives   are   mediation,
non-binding arbitration, and a default procedure.

The first technique,  mediation, would allow the
Regional  Administrator to appoint a mediator
whose primary function  would be  to facilitate
discussions between the parties with the objective
of arriving  at a State/Tribe agreement or other
resolution acceptable to the parties. The mediated
negotiations could be informal or formal, public
or private.  The mediator could also establish an
advisory group, consisting of representatives from
the affected parties,  to study the problem  and
recommend an appropriate resolution.

The second  technique, non-binding  arbitration,
would require  the  Regional  Administrator to
appoint an arbitrator (or arbitration panel) whose
responsibilities  would  include  gathering   all
information pertinent to the dispute, considering
the factors listed in  the Act, and recommending
an appropriate solution. The parties would not be
obligated, however, to abide by the arbitrator's or
arbitration panel's decision,,   The arbitrator or
arbitration panel would be responsible for issuing
a written  recommendation to all parties and the
Regional Administrator. Arbitrators or arbitration
panel members who are EPA employees would be
allowed to operate independently from the normal
chain  of  commend  within the Agency  while
conducting the arbitration process.  Arbitrators or
arbitration panel members would not be allowed
to have ex pane communication pertaining to the
dispute, except that  they v/ould be allowed to
contact EPA's  Office of the General Counsel for
legal advise.

EPA  has  also  provided for a  dispute resolution
default procedure  to be used where one or more
parties  refuse to participate  in  mediation  or
arbitration.   The default procedure will be used
only as a last  resort, after all other avenues of
resolving the dispute have been exhausted.  This
dispute resolution technique would be similar to
arbitration, but has been included as a separate
Regional Administrator option because arbitration
generally refers to a process whereby all parties
participate voluntarily.         \

The default procedure simply provides for the
Agency to review available information  and to
issue a recommendation for resolving the dispute.
EPA's recommendation in this situation would
have no enforceable impact.  The Agency hopes
that public presentation of its position will result
in either public pressure  or reconsideration by
either  affected  party  to  continue  resolution
negotiations.    Any    written  recommendation
resulting from this procedure would be provided
to all parties involved in the dispute.

EPA envisions a number of possible outcomes
that, individually or in combination, would likely
resolve most of  the  disputes that would arise.
These  actions might include, but are not  limited
to, the following:

•  a State or Tribe agrees to revise the limits of
   a permit  to ensure  that downstream water
   quality standards are met;

•  a State or Tribe agrees to permanently remove
   a use (consistent with 40 CFR 131.10(g));

•  a State or Tribe issues a variance from water
   quality standards for a particular discharge;

•  a permittee  or landowner agrees to provide
   additional water pollution control;

•  EPA assumes permit-issuing authority for  a
   State or Tribe and re-issues a permit to ensure
   that downstream  water quality  standards are
   met; or

•  EPA  promulgates  Federal  water   quality
   standards where a State or Tribe standard does
   not meet the requirements of the Act.

In  some cases  (last  example,  above),  EPA
recognizes that the Agency  will have to act to
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 resolve the dispute.  An example would be where
 a National Pollutant Discharge Elimination System
 (NPDES) permit for an upstream discharger does
 not provide for the attainment of the water quality
 standards for a downstream jurisdiction.  The
 existing NPDES  permitting  and  certification
 processes under the Act  may  be used by the
 downstream   jurisdiction   to   prevent   such
 situations.    Today's rule  does  not  alter  or
 minimize  the  role  of  these  processes  in
 establishing appropriate  permit limits to ensure
 attainment of water quality standards. States and
 Tribes  are encouraged  to participate  hi these
 permitting and certification processes rather than
 wait for unreasonable consequences to occur.

 In these cases, EPA believes that the Agency has
 authority to object to the upstream NPDES permit
 and, if necessary, to assume permitting authority.
 This authority was upheld in a case in which EPA
 assumed authority to issue a permit for a North
 Carolina discharge that, among other factors, did
 not meet Tennessee's downstream water quality
 standards.1

 Mediators and arbitrators may be EPA employees,
 employees of other Federal agencies,  or other
 individuals   with  appropriate   qualifications.
 Because of resource constraints, EPA anticipates
 that mediators and arbitrators will generally be
 EPA   employees   rather   than   consultants.
 Employees from other Federal agencies would be
 selected  where appropriate,  subject  to   their
 availability.    EPA  intends for mediators and
 arbitrators  to  conduct  the dispute resolution
 mechanism in a fair  and impartial manner, and
 will select individuals who have not been involved
 with  the  particular  dispute.    Members  of
 arbitration panels will be  selected by the Regional
 Administrator in consultation with the parties. In
 some cases,  such panels may consist  of one
 representative from each  party to the dispute plus
 one neutral  panel member.    Implicit hi the
 regulation  is  the sense  that  mediators  and
 arbitrators  will   act  fairly  and  impartially.
 Although   not  specifically  covered  in  the
 regulation, EPA believes it is  well  within the
Regional Administrator's power to remove any
 mediator or arbitrator for any reason (including
 showing bias or unfairness or taking illegal or
 unethical actions).

 Arbitrators and arbitration panel members shall be
 selected to include  only individuals  who  are
 agreeable   to   all   affected   parties,   are
 knowledgeable  concerning  the   water  quality
 standards program requirements, have a basic
 understanding  of the  political  and  economic
 interests of Tribes, and will fulfill the duties fairly
 and impartially.  These  requirements  are  not
 applicable to mediators.  EPA did not provide for
 State or Tribe approval of mediators because EPA
 believes that  such an approval  process would
 provide too  great an opportunity to  delay  the
 initiation of the mediation process and because the
 role of the mediator is limited  to  acting as  a
 neutral facilitator.  There is no prohibition against
 the Regional Administrator consulting with  the
 parties  regarding  a  mediator; there is just no
 requirement to do so.

 Where  one of the parties to the dispute believes
 that an arbitrator has recommended an action to
 resolve the dispute which is not authorized by the
 Act, the regulation allows the party to appeal the
 arbitrator's    decision    to   the   Regional
 Administrator.  Such requests must be in writing
 and must include a statement of the statutory basis
 for altering the arbitrator's recommendation.

 1.7.7  Time Frame for Dispute Resolution

 The regulation  does  not  include a fixed time
 frame for resolving disputes.  While EPA intends
 to proceed as quickly as possible and to encourage
parties to the dispute to resolve it quickly and to
 establish informal time  frames,  the variety of
potential disputes to be resolved would appear to
preclude EPA from specifying a single regulatory
time limit.  EPA believes it is better to obtain a
reasonable   agreement   or  decision   than  to
arbitrarily establish a tune frame within which an
agreement or decision must be made.
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                                                                       Chapter 1 - General Provisions
         Requirements  for Indian  Tribes To
         Qualify for the WQS Program  - 40
         CFR 131.8
Consistent with  the  statutory  requirement  of
section 518  of  the  Act,  the  Water  Quality
Standards Regulation  establishes procedures  by
which an Indian Tribe may qualify for the water
quality standards  and section 401  certification
programs. . Section  131.8 of the Water Quality
Standards Regulation is  intended to ensure that
Tribes  treated  as  States   for  standards  are
qualified,   consistent  with   Clean  Water Act
requirements, to conduct a  standards  program
protective of public  health and the environment.
The procedures are not intended to act as a
barrier to tribal program assumption.   For the
section 401   certification  program,   131.4(c)
establishes that where EPA  determines that a
Tribe is qualified for the water quality standards
program, that Tribe would, without further effort
or submission of information, also qualify for the
section 401 certification program.

Section 518 authorizes EPA to qualify a Tribe for
programs involving water resources that are:

   . .  . held  by an Indian Tribe, held by the
   U.S. in trust for Indians, held by a member
   of an Indian Tribe if such, property interest
   is subject to a trust restriction on alienation,
   or otherwise within the borders of an Indian
   reservation ....
  7////////////J//////,
Tribes   are   limited   to  obtaining  program
authorization only for water resources within the
borders of the reservation over which they possess
authority to regulate water quality.  The meaning
of the term  "reservation" must,  of course,  be
determined in  light of  statutory  law and with
reference to relevant case law.  EPA considers
trust  lands  formally set apart for the use  of
Indians to be "within a reservation" for purposes
of section 518 (e)(2), even if they have not been
formally designated  as   "reservations."2   This
means it is the status and use of the land that
determines if it  is to be considered "within a
reservation" rather than  the label attached to it.
EPA believes that it was the intent of Congress to
limit  Tribes  authority   to   lands  within  the
reservation.  EPA bases this conclusion, in part,
on the definition of "Indian Tribe" found in CWA
section 518(h)(2). EPA also does not believe that
section 518(e)(2) prevents EPA from recognizing
tribal authority over non-Indian water resources
located  within  the reservation if  the  Tribe can
demonstrate (1) the requisite authority over such
water resources, and (2) the authority to  regulate
as necessary to protect the public health, safety,
and welfare of its tribal members.

1.8.1 Criteria Tribes Must Meet

New section 131.8 of the Water Quality Standards
Regulation  includes  the criteria  Tribes  are
required to meet to be authorized to administer
the water quality standards and 401 certification
programs.  These criteria are provided in section
518 of the Act.  The Tribe must:
                             BMBjitBtoMUBa^taa^iiimB^^
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Water Quality Standards Handbook - Second Edition
•  be federally recognized;

*  carry out substantial governmental duties and
   powers over a Federal Indian reservation;

•  have  appropriate authority  to regulate the
   quality of reservation waters; and

*  be  reasonably  expected to be  capable  of
   administering the standards program.

The first criterion requires the  Tribe to  be
recognized by the  Department of the Interior.
The Tribe may address this requirement by stating
that it is  included on the  list of  federally
recognized Tribes published periodically by the
Department of the Interior, or by submitting other
appropriate  documentation (e.g.,  the  Tribe  is
federally recognized but not yet included on the
Department of the Interior list).

The second criterion requires the Tribe to have a
governing body  that is carrying out substantial
governmental duties and powers.   EPA defines
"substantial governmental duties and  powers"  to
mean  that the  Tribe  is  currently  performing
governmental functions to promote  the  health,
safety, and welfare of the affected population
within a defined  geographical area. Examples of
such functions include,  but are not limited to, the
power to tax, the power of eminent domain, and
police power.    Federal  recognition  by  the
Department of the Interior does not, in  and  of
itself, satisfy this criterion.  Tribes must submit a
narrative statement describing the form of tribal
government,  describing the types of  essential
governmental functions currently performed, and
identifying the sources  of authorities  to perform
these functions (e.g., tribal constitutions, codes).

The third criterion, concerning tribal authority,
means that EPA may authorize an Indian Tribe to
administer the water quality standards  program
only where the Tribe already possesses and can
adequately demonstrate authority to manage and
protect water  resources  within the  reservation
borders.  The Clean Water Act authorizes use of
existing tribal regulatory authority for managing
EPA  programs,  but  the Act  does  not  grant
additional authority to Tribes.  EPA recognizes
that, in general, Tribes  possess the authority to
regulate activities affecting water quality on the
reservation.    The  Agency  does not believe,
however, that it is appropriate to recognize tribal
authority and approve tribal administration of the
water quality standards program in the absence of
verifying documentation.  EPA will not delegate
water quality standards  program  authority  to a
Tribe unless the Tribe adequately shows that it
possesses the requisite authority.

EPA does not read the Supreme Court's decision
in Brendale3 as preventing EPA from recognizing
Tribes' authority to regulate water quality oh fee
lands within the reservation, even if section 518
is not an  express delegation  of authority.  The
primary significance of Brendale is  its  result,
fully consistent with Montana v. United States,4
which previously had held:

   To be  sure, Indian tribes retain inherent
   sovereign power to exercise some forms of
   civil jurisdiction over non-Indians on their
   reservations, even on non-Indian fee lands.
   A tribe may regulate ...  the activities of
   non-members   who    enter   consensual
   relationships with the tribe or its members,
   through  commercial  dealing,  contracts,
   leases,  or other arrangements. ... A tribe
   may also retain inherent power to exercise
   civil authority over  the conduct of non-
   Indians on fee lands  within its reservation
   when that conduct threatens or has some
   direct effect on the political integrity, the
   economic security, or the health or welfare
   of the tribe.

The ultimate decision regarding tribal authority
must be made on a Tribe-by-Tribe basis, and EPA
has finalized the  proposed process for making
those determinations. EPA sees no reason in light
of Brendale to assume that Tribes would be per se
unable to demonstrate authority over water quality
management on  fee  lands  within reservation
borders.  EPA believes  that as  a general matter
there are substantial legal and factual reasons to
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                                                                       Chapter 1 - General Provisions
assume that Tribes  ordinarily have the  legal
authority to regulate surface water quality within
a reservation.

In evaluating  whether a Tribe has authority to
regulate a particular activity on land owned in fee
by nonmembers but located within a reservation,
EPA will examine the Tribe's authority hi light of
the evolving case law as reflected hi Montana and
Brendale.    The  extent of such tribal  authority
depends on the effect of that activity on the Tribe.
As discussed above, hi the absence of a contrary
statutory  policy,  a  Tribe  may  regulate the
activities of non-Indians on fee lands within its
reservation when those activities threaten or have
a  direct  effect  on the poMcal  integrity, the
economic security,  or the heiilth or welfare of the
Tribe.

The Supreme Court, in recent cases, has explored
several options to  ensure that the  impacts upon
Tribes of the activities of non-Indians on fee land,
under the  Montana  test,  are  more  than  de
minims,  although  to date the Court  has not
agreed,  in  a  case  on  point,   on  any  one
reformulation of the test.  In response to this
uncertainty, the Agency will apply, as an interim
operating rule, a formulation of the standard that
will require a showing that the potential impacts
of regulated activities on the Tribe are serious and
substantial.

The  choice  of  an   Agency operating   rule
containing this standard is taken solely as a matter
of prudence in light of judicial uncertainty and
does  not  reflect  an Agency endorsement of this
standard per se.  Moreover, as discussed below,
the Agency believes that the activities  regulated
under the various environmental statutes generally
have  serious and substantial impacts on human
health and welfare.   As  a  result, the Agency
believes that Tribes usually will be able to meet
the Agency's operating rule, and that use of such
a rule by the  Agency  should not create an
improper burden of proof on Tribes or create the
administratively  undesirable result of checker-
boarding reservations.
Whether a Tribe has jurisdiction over activities by
nonmembers will be determined  case by case,
based on factual findings.  The determination as
to whether the required effect is present in a
particular case depends on the circumstances.

Nonetheless,  the  Agency may  also take into
account the provisions of environmental statutes,
and any legislative findings that the effects of the
activity  are serious,  hi making  a  generalized
finding that Tribes are likely to possess sufficient
inherent   authority   to  control   reservation
environmental quality.*   As a result, in making
the required factual findings as to the impact of a
water-related activity on a particular Tribe, it may
not be necessary to develop  an extensive and
detailed  record in each case.  The Agency may
also rely on  its  special expertise and  practical
experience  regarding the importance of water
management,   recognizing  that  clean  water,
including critical habitat (e.g., wetlands, bottom
sediments, spawning beds), is absolutely crucial to
the survival of many Indian reservations.

The Agency believes that congressional enactment
of the Clean Water Act  establishes a  strong
Federal interest in effective management of water
quality.   Indeed, the primary objective  of the
CWA "is to restore  and maintain the chemical,
physical, and biological integrity of the Nation's
waters"  (section  101 (a)), and to  achieve that
objective,   the Act  establishes  the  goal  of
eliminating all discharges of pollutants into the
navigable waters of the United States and attaining
a level  of water quality that is  fishable and
swimmable (sections  101(a)(l) and (2)).  Thus the
statute itself constitutes, in  effect,  a legislative
determination  that  activities  affecting  surface
water and critical habitat quality may have serious
and substantial impacts.

EPA also notes that, because of the mobile nature
of pollutants in surface waters and the relatively
small length or size of stream segments or other
water bodies  on reservations, it would be very
difficult to separate  the effects of water quality
impairment on  non-Indian  fee  land within a
reservation as compared with those on tribal
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 portions.  In other words, any impairment that
 occurs on, or as a result of, activities on non-
 Indian fee lands is very likely to impair the water
 and critical habitat quality  of the tribal lands.
 This also suggests that the serious and substantial
 effects of water  quality impairment within  the
 non-Indian portions  of a reservation are very
 likely to affect the tribal interest in water quality.
 EPA believes  that a  "checkerboard" system  of
 regulation, whereby the Tribe and State split up
 regulation  of surface  water  quality   on  the
 reservation,  would  ignore   the  difficulties  of
 assuring compliance with water quality standards
 when   two  different  sovereign   entities  are
 establishing standards for the same small stream
 segments.

 EPA also believes that Congress has expressed a
 preference for tribal regulation of surface water
 quality to ensure compliance with  CWA goals.
 This is confirmed  by the  text and legislative
 history  of  section  518  itself.     The  CWA
 establishes  a   policy  of   "recogniz[ing],
 preservpng],   and  protect[ing]   the  primary
 responsibilities and rights of States to  prevent,
 reduce, and eliminate pollution, [and] to plan the
 development  and use  (including  restoration,
 preservation, and enhancement) of land and water
 resources"  (section 101(b)). By extension, the
 treatment of Indian Tribes as States means that
 Tribes  are to  be primarily  responsible  for the
 protection of reservation water resources.   As
 Senator Burdick, floor manager of the 1987 CWA
 Amendments, explained, the purpose of section
 518 was to "provide clean water for the people of
 this Nation" (133 Congressional Record S1018,
 daily ed., Jan. 21, 1987).  This goal was to be
 accomplished, he asserted, by giving "tribes . . .
 the  primary  authority  to  set  water  quality
 standards to assure fishable and swimmable water
 and to satisfy all beneficial uses."6

In light of the Agency's statutory responsibility
for implementing  the  environmental statutes,  its
interpretations  of the intent of  Congress  in
allowing for tribal management of water quality
within the reservation are  entitled to substantial
deference.7
The Agency also believes that the effects on tribal
health and welfare necessary to support tribal
regulation  of  non-Indian  activities  on  the
reservation may be easier  to  establish in the
context of water quality management man with
regard to zoning, which was at issue in Brendale.
There is a significant distinction between land use
planning  and water quality  management.  The
Supreme Court has explicitly recognized such a
distinction: "Land use planning in essence chooses
particular  uses for  the land;    environmental
regulation .  .  . does not mandate particular uses
of the land but requires only that,  however the
land is used, damage to the environment is kept
within prescribed limits."8  The Court has relied
on this distinction to support a finding that States
retain authority to  carry  out  environmental
regulation even in cases where their ability to
carry out general land use regulation is preempted
by Federal law.9

Further,  water quality management serves  the
purpose  of protecting public health and safety,
which is a core governmental function whose
exercise  is critical to  self-government.   The
special status of governmental actions to  protect
public health and safety is well established.  By
contrast, the power to zone can be exercised to
achieve purposes that have little  or no  direct
nexus to public health and safety.10  Moreover,
water pollution is by nature highly mobile, freely
migrating from one local jurisdiction to another,
sometimes over large distances.   By contrast,
zoning regulates the uses of particular properties
with impacts that are much more  likely to be
contained within a given local jurisdiction.

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                                                                     Chapter 1 - General Provisions
Operationally,    EPA's  generalized  findings
regarding the relationship of water quality to
tribal health and welfare will affect the legal
analysis  of a tribal submission  by, in  effect,
supplementing the factual showing a Tribe makes
in applying for authority to administer the water
quality  standards program.    Thus,  a tribal
submission meeting the requirements of section
131.8 of this regulation  will need to make a
relatively simple  showing  of  facts that there are
waters within the reservation used by the Tribe or
tribal members (and thus that the Tribe or tribal
members   could  be  subject to exposure  to
pollutants present in, or introduced into, those
waters),  and that the waters  and critical  habitat
are subject to protection under the Clean Water
Act.  The Tribe  must also explicitly assert that
impairment of such waters by the  activities of
non-Indians would have a  serious and substantial
effect on the health and  welfare of the Tribe.
Once the Tribe meets this initial burden, EPA
will, in light of the facts presented by the Tribe
and the generalized statutory and factual findings
regarding the importance of reservation water
quality discussed above, presume that there has
been an adequate  showing of tribal jurisdiction on
fee lands, unless an appropriate governmental
entity   (e.g.,  an  adjacent:   Tribe  or  State)
demonstrates a lack of jurisdiction on the part of
the Tribe.

The Agency recognizes that jurisdictional disputes
between Tribes and States can be complex and
difficult and that it will, in some circumstances,
be forced  to address such (disputes.  However,
EPA's ultimate responsibility is protection of the
environment.    In view  of the  mobility of
environmental problems, and the interdependence
of various jurisdictions, it is imperative that all
affected  sovereigns  work  cooperatively  for
environmental protection  rather than engage in
confrontations over jurisdiction.

To verify authority,  the Tribe  is  required to
include a  statement signed  by  the tribal legal
counsel, or an equivalent official, explaining the
legal basis for the  Tribe's regulatory authority.
Tribe  also is  required to provide appropriate
additional  documentation  (e.g.,  maps,  tribal
codes, and ordinances).

The fourth criterion requires that the Tribe, in the
Regional  Administrator's judgment,  should be
reasonably capable  of administering an effective
standards program.  The Agency recognizes that
certain Tribes have not had substantial experience
in administering surface water quality programs.
For this reason, the Agency requires that Tribes
either show  that  they   have the  necessary
management and technical skills or submit a plan
detailing  steps  for  acquiring the  necessary
management and technical skills.  The plan must
also address how the Tribe will obtain the funds
to  acquire  the administrative  and  technical
expertise. When considering tribal capability, the
Agency will also consider whether the Tribe can
demonstrate  the existence of  institutions  that
exercise   executive,  legislative,  and   judicial
functions, and whether the Tribe has a history of
successful  managerial  performance  of public
health or environmental programs.

1.8.2 Application for Authority To Administer
      the Water Quality Standards Program

The  specific information  required  for tribal
applications to EPA is described in 40 CFR.  The
application is required, in general, to include a
statement on tribal recognition by the Department
of  the  Interior, documentation that the  tribal
governing body has substantial duties and powers,
documentation of tribal authority to regulate water
quality on the federally recognized reservation, a
narrative   statement  of  tribal  capability  to
administer water quality standards programs, and
any other information requested by the Regional
Administrator.

When evaluating tribal experience in public health
and environmental programs (under paragraph
131.8(b)(4)(ii), EPA will look for indications that
the Tribe has  participated  in  such  programs,
whether the programs are administered by EPA,
other Federal agencies, or Tribes.  For example,
several Tribes  are  known to have participated in
developing areawide water management plans or
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 tribal water quality standards.  EPA will also look
 for evidence  of historical budget  allocations
 dealing  with  public  health  or  environmental
 programs along with any experience in monitoring
 related programs.

 The regulation allows a Tribe to describe either
 how it presently  has the capability to manage an
 effective water quality standards program or how
 it proposes to acquire the additional administrative
 and technical expertise to manage such a program.
 EPA will carefully review for reasonableness any
 plans that propose to acquire expertise. EPA will
 not approve tribal capability demonstrations where
 such  plans do not include reasonable provisions
 for acquisition of needed personnel  as well as
 reliable funding  sources.    This requirement is
 consistent with other Clean Water Act programs.
 Tribes may wish to apply for section 106 funds to
 support their water quality standards programs
 and may include  this source in any discussion of
 obtaining necessary funds.

 If  the Tribe has qualified  to administer  other
 Clean Water Act or Safe Drinking Water Act
 programs,  then the Tribe need only provide the
 information  that  has   not   been   submitted
 previously.

 Qualifying for administration of the water quality
 standards program is optional for Indian Tribes
 and there is no time frame limiting when such
 application may be made.  As a general policy,
 EPA  will not deny a tribal  application.  Rather
 than formally deny the Tribe's request, EPA will
 continue to work  cooperatively with the Tribe in
 a continuing effort to resolve deficiencies  in the
 application or the tribal program so that tribal
 authorization may occur. EPA also concurs with
 the view that the intent of  Congress and the EPA
 Indian Policy is to support tribal governments in
 assuming  authority  to manage  various  water
 programs.  Authority exists for EPA to re-assert
 control over certain water programs due to the
 failure of  the  State  or Tribe  to execute the
programs  properly.  Specifically, in the  water
 quality standards program, the Administrator has
authority to promulgate Federal standards.
 1.8.3  Procedure Regional Administrator Will
       Apply

 The review procedure established in section 131.8
 is the  same procedure applicable to all water
 programs.  Although experience  with the initial
 application in other programs  indicated some
 delay in the process, EPA believes that as EPA
 and  the  Tribes  gain  experience  with  the
 procedures, delays will be minimal.

 The EPA review procedure in paragraph 131.8(c)
 specifies   that   following  receipt   of  tribal
 applications,  the Regional Administrator will
 process  such applications in  a timely  manner.
 The procedure calls for prompt notification to the
 Tribe  that  the application has been received,
 notification  within   30  days  to  appropriate
 governmental entities  (e.g.,  States  and other
 governmental entities located  contiguous  to the
 reservation and that possess authority  to regulate
 water quality under section 303 of the  Act) of the
 application and the substance and basis  for the
 Tribe's assertion of  authority over reservation
 waters, and allowance of 30 days for review of
 the Tribe's assertion of authority.

 EPA recognizes that city and county governments
 which may be subject  to  or  affected by tribal
 standards may also want to  comment  on  the
 Tribe's assertion  of authority.  Although EPA
 believes that the responsibility  to coordinate with
 local governments faUs primarily on the State, the
 Agency will make an effort to provide notice to
 local governments by placing an announcement in
 appropriate newspapers.  Because the  rule limits
 EPA to considering comments from governmental
 entities with Clean  Water  Act section 303
 authority, such newspaper  announcements will
 advise interested  parties to  direct  comments on
 tribal authority to  appropriate State governments.

Where  a  Tribe's  assertion  of  authority  is
challenged,   the  Regional  Administrator,   in
consultation  with the Tribe,  the  governmental
entity  challenging  the  Tribe's   assertion   of
authority, and the Secretary of the Interior, will
determine  whether the  Tribe has  adequately
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                                                                     Chapter 1 - General Provisions
demonstrated authority to regulate water quality
on  the  reservation.    Where  the  Regional
Administrator concludes  that the Tribe has not
adequately demonstrated its authority with respect
to an area hi dispute, then tribal assumption of the
standards   program  would   be   restricted
accordingly.   If the authority in dispute  were
focused  on  a  limited  area,  this  would not
necessarily  delay  the  Agency's  decision  to
authorize the Tribe to administer the program for
the nondisputed areas.

The procedure allowing participation by  other
governmental entities in  EPA's  review  of  tribal
authority does not  imply that States or Federal
agencies (other than EPA) have veto power over
tribal  applications   for  treatment  as  a State.
Rather,  the procedure  is  simply intended to
identify  any competing jurisdictional claim and
thereby ensure that  the Tribe has the necessary
authority to administer the standards program.
EPA will not rely  solely on the assertions of a
commenter who challenges the Tribe's authority;
EPA will make an independent evaluation of the
tribal showing and all available information.

When evaluating tribal  assertions of authority,
EPA will apply the test from Montana v. United
States, 450 U.S. 544 (1981), and will consider the
following:

•  all information   submitted with  the Tribe's
    assertion of authority;

•  all information submitted during the required
    30-day comment period by the governmental
    entities identified in 40 CFR  131.8(c)(2); and

 •  all information  obtained  by the Agency via
    consultation   with  the  Department of  the
    Interior  (such consultation is required where
    the  Tribe's  assertion   of  authority  is
    challenged).

 EPA  and the Department of the Interior have
 agreed to procedures for conducting consultations
 between the agencies. The procedure established
 as the Secretary of the Interior's designees the
Associate Solicitor, Division of Indian Affairs,
and  the  Deputy Assistant  Secretary  - Indian
Affairs (Trust and Economic Development).  EPA
will  forward a copy of the  application and any
documents asserting a competing or conflicting
claim of authority to such designees as soon as
possible.  For most applications,  an EPA-DOI
conference will be scheduled from 1 to 3 weeks
after the date the Associate Solicitor receives the
application.     Comments  from  the  Interior
Department  will  discuss  primarily  the  law
applicable to the issue to assist EPA in its own
deliberations.  Responsibility for legal advice to
the  EPA Administrator or  other EPA decision
makers  will  remain  with   the  EPA General
Counsel.    EPA  does  not  believe  that the
consultation process with the Department of the
Interior should involve notice and opportunity for
States and  Tribes  because  such  parties are
elsewhere provided  appropriate  opportunities to
participate in EPA's review  of tribal authority.

EPA will take  all reasonable  means  to  advise
interested  parties   of  the  decision  reached
regarding  challenges  of  tribal  assertions of
authority.    At least,  written  notice will be
provided to  State(s)  and  other  governmental
entities sent notice of the tribal application. In
addition, the Water Quality  Standards Regulation
requires  EPA  to  publish   an  annual list of
standards  approval  actions' taken  within the
preceding year. EPA will expand that listing to
include Indian Tribes qualifying for  treatment as
States in the preceding year.

Comments  on  tribal compliance with criteria
necessary for assuming the program  is limited to
the  criterion  for  tribal authority.  The  Clean
Water Act does not require EPA to provide public
comment on the entire tribal application, nor does
EPA believe that public comment will assist with
EPA's  decision-  making  regarding  the  other
criteria.  (The other criteria  are the recognition of
the  Tribe by the  Department of the Interior,  a
description of the tribal governing body, and the
capability of the Tribe to administer an effective
 standards program.) EPA believes that providing
public  comment on these  three  criteria  would
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 Water Quality Standards Handbook - Second Edition
 unnecessarily complicate and potentially delay the   1.8.6 Establishing Water Quality Standards on
 process.     .                                          Indian Lands
 1.8.4 Time  Frame
       Application
for  Review  of Tribal
 EPA has not specified a time frame for review of
 tribal application.   The Agency believes it is
 impossible  to  approve   or  disapprove  all
 applications within a designated  time  frame.
 Because  EPA  has  no  reasonable  way   to
 predetermine  how complete  initial applications
 might be, what challenges  might arise,  or how
 numerous or  complex the issues might  be,  the
 Agency deems it  inappropriate to  attempt  to
 establish  time  frames  that  might  not  allow
 sufficient time for resolution.  Similarly, EPA's
 experience with States applying for various EPA
 programs indicates that, at  times, meetings and
 discussions between EPA  and  the  States  are
 necessary before all requirements are met. The
 Agency believes that  the same  communication
 with  Tribes   will  be  important   to   ensure
 expeditious processing of tribal applications.

 1.8.5  Effect   of  Regional  Administrator's
       Decision

 A decision by the Regional  Administrator that a
 Tribe  does  not  meet  the  requirements   for
 administering the water quality standards program
 does not preclude the Tribe from resubmitting the
 application at a future date. Rather than formally
 deny the Tribe's request, EPA will continue to
 work cooperatively with the Tribe in a continuing
 effort to resolve deficiencies in the application or
 the tribal program so that tribal authorization may
 occur.  EPA believes that the intent of Congress
 and of EPA's Indian Policy is to support tribal
 governments in assuming authority to  manage
 various water programs.

Where the Regional Administrator determines that
the  tribal  application  satisfies  all  of  the
requirements of  section  131.8,  the  Regional
Administrator will promptly notify the Tribe that
the Tribe has  qualified to administer the water
quality standards program.
 Where Tribes qualify to be treated as States for
 the purposes of water quality standards, EPA has
 the responsibility to assist the Tribe in establishing
 standards that are appropriate for the reservation
 and consistent with the Clean Water  Act.  EPA
 recognizes that Tribes have limited resources for
 development of water quality standards.

 EPA  considers  the  following three  options
 acceptable to complete the task of establishing
 water quality  standards on Indian lands:

 •  the Tribe  may   negotiate  a  cooperative
    agreement  with an adjoining State to apply the
    State's standards to the Indian lands;

 •  the Tribe may incorporate the standards from
    an adjacent State as the Tribe's own; or

 •  the Tribe may independently develop and adopt
    standards that account for unique site-specific
    conditions  and water body uses.

 The first two  options would be the quickest and
 least  costly ways for establishing  tribal water
 quality standards. Under option 1, the negotiated
 agreement could also cover requirements such as
 monitoring,   permitting,   certifications,   and
 enforcement of water quality standards on the
 reservation.   Option 2 would make full use of
 information and data developed by the State which
 may  apply to  the   reservation.   Tribes,  as
 sovereign governments, have the legal authority to
 negotiate cooperative agreements with a State to
 apply  that State's standards  to waters  on the
 reservation or to use State standards as the basis
 for tribal standards.  These options do not suggest
 that the Tribe relinquishes its sovereign powers or
 enforcement  authority or  that  the  State  can
 unilaterally apply  its  standards to reservation
 waters.

 Option 3 would require more time and resources
to implement because  it would require the Tribe
to  create  an  entire  set  of  standards  "from
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                                                                     Chapter 1 - General Provisions
scratch." EPA does not intend to discourage this
approach, but notes that Indian Tribes may want
to make full use, where appropriate, of programs
of  adjacent States.    Tribes should  use  this
Handbook  as   guidance   when   developing
standards.

EPA emphasizes  that the development of tribal
water quality standards is an iterative process, and
that the  standards development option initially
selected by  the Tribe can change in subsequent
years.   For example, a Trite may want to use
option 1 or 2 to get the standards program started.
This does not preclude the Tribe from developing
its  own  water quality  standards hi subsequent
years.

Tribes establishing standards for the first  time
should carefully consider which water body uses
are appropriate.     Once designated uses are
adopted,  removing  the  use or  adopting  a
subcategory of  use  would  be subject  to the
requirements of  section  131.10 of  the Water
Quality Standards Regulation.

EPA  expects  that, where Tribes  qualify to be
treated as States for the purposes of water quality
standards,  standards   will   be   adopted   and
submitted to EPA for review within 3 years  (a
triennium) from the date that the Tribe is notified
that it is qualified to administer the standards
program.  This time frame  corresponds to that
provided to States under the provisions of the
 1965 Federal Water Pollution Control Act,  when
the water quality standards program was created.
EPA  believes   that  this   is   an  equitable
arrangement,  and  that  the  Tribes  should  be
allowed sufficient tune to develop their programs
and adopt appropriate  standards for reservation
waters.

Once EPA determines  that a Tribe qualifies to
administer   the   standards   program,   tribal
development,  review,  and  adoption of  water
quality  standards  are subject  to  the  same
requirements that States are subject to under the
Clean  Water   Act  and  EPA's  implementing
regulations.

Until Tribes qualify for the standards program and
adopt standards under the Clean Water Act, EPA
will, when possible, assume that existing water
quality  standards  remain  applicable.    EPA's
position  on this issue  was  expressed  in  a
September  9,  1988,  letter  from  EPA's then
General  Counsel,  Lawrence  Jensen,  to  Dave
Frohnmayer, Attorney General for the State of
Oregon.    This  letter states:  "if States  have
established  standards  that purport to  apply to
Indian reservations, EPA will  assume without
deciding that those  standards remain applicable
until a Tribe is authorized to establish its own
standards or until EPA otherwise determines in
consultation with a State and Tribe that the State
lacks jurisdiction . . . ."  This policy is not an
assertion   that  State   standards  apply   on
reservations as a matter of law, but the  policy
merely recognizes that fully implementing a role
for Tribes under  the Act will require a transition
period.   EPA may apply  State standards in this
case because (1)  there are no Federal standards
that apply generally, and (2) to ignore previously
developed State standards would be a regulatory
void that EPA believes would not be beneficial to
the reservation water quality.  However, EPA will
give serious consideration to Federal promulgation
of water quality standards on Indian lands where
EPA finds a particular need.

Where a State asserts authority to establish future
water quality standards for a reservation, EPA
policy is to ensure that the affected Tribe is made
aware of the assertion so that any issues the Tribe
may wish to raise can be  reviewed as part of the
normal  standards  setting process.   EPA  also
encourages   State-Tribe   communication   on
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 Water Quality Standards Handbook - Second Edition
 standards issues, with one possible outcome being
 the  establishment  of   short-term  cooperative
 working agreements pertaining to standards and
 NPDES permits on reservations.

 1.8.7 EPA Promulgation of  Standards  for
       Reservations

 If EPA determines  that  a  Tribe possesses
 authority  to  regulate   water  quality   on  a
 reservation  but  the  Tribe  declines  to  seek
 authority to administer the water quality standards
 program, EPA has the authority under section 303
 of the Act to  promulgate Federal water quality
 standards.  EPA's responsibility stems from the
 Act's directive to establish water quality standards
 for all "navigable waters."   Depending on the
 circumstances, EPA may use the standards of an
 adjacent  State as  a starting point for such  a
 promulgation.      EPA   will  prioritize   the
 promulgations  based on various factors, not the
 least  of which is availability of Agency resources
 to undertake the Federal  rulemaking process.
 Because the Federal promulgation process is slow
 and complex, EPA may promulgate water quality
 standards in conjunction with re-issuing permits
 on the reservations.

 The intent of the Clean  Water Act is for States
 and Tribes qualifying for treatment as States to
 have  the first opportunity to set standards. Thus,
 EPA  prefers to work cooperatively with States
 and Tribes on water quality standards issues and
 to  initiate Federal  promulgation actions only
 where absolutely necessary.

 BPA's entire policy with respect to  Federal
 promulgation is  straightforward.    EPA much
 prefers to work with the States and have them
 adopt standards   that   comply   with   CWA
 requirements.  Where Federal promulgation is
 necessary to achieve CWA compliance, however,
 EPA will act. This same philosophy will apply to
Indian Tribes   authorized  to  administer  the
program.
          Adoption of  Standards  for  Indian
          Reservation Waters
 This guidance recognizes that Tribes have varying
 abilities to develop water quality standards. Some
 Tribes  have  more  technical  capability  and
 experience in drafting implementable regulations
 than other Tribes and may be capable of adopting
 more complex standards. However, most Tribes
 may not have access to sufficient resources, either
 in personnel or in contractor funds, to pursue this
 course.   Moreover,  EPA  does not  have the
 resources   to  provide   substantial   technical
 assistance to individual Tribes to develop other
 than basic water quality standards.

 1.9.1 EPA's  Expectations for Tribal  Water
       Quality Standards

 Tribal water quality standards, initially at least,
 should focus on basic contents and reflect existing
 uses and existing  water quality.   The  standards
 must be established for an inventory of "waters of
 the  United States,"  including wetlands.   The
 Tribes should  focus on the basic structure of a
 water quality standards system:   designated uses
 for   identified  water   segments,  appropriate
 narrative and numeric criteria, an antidegradation
 policy, and other general implementation policies.
 How complex or sophisticated these elements need
 to be depends upon the abilities of the Tribe and
 the  environmental concerns affected  by  tribal
 standards.

 EPA has consistently recommended to Tribes that
 they use directly, or with slight modification, the
 standards of the adjacent States as a beginning for
 tribal standards.  Tribal water quality standards
 should be developed considering  the quality and
 designated uses of waters entering and leaving
 reservations.   It  is  important that the Tribes
 recognize what the surrounding State (or another
Indian reservation) water quality standards are
even though there is no requirement  to  match
those  standards,   although   the  water  quality
 standards regulation does require consideration of
downstream water  quality standards (see section
2.2,  this Handbook).
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                                                                      Chapter 1 - General "Provisions
At  a minimum,  tribal  water quality  standards
should be established upstream and downstream
from point sources where NPDES permits are
applicable. It is also desirable that water quality
standards  be applied to  waters where significant
nonpoint sources enter so thait the effectiveness of
best management practices on  the reservation's
waters can be evaluated.

Water quality criteria should be carefully selected
recognizing that making criteria more stringent in
subsequent water quality  standards reviews  is
more  feasible than  attempting relaxation of
stringent criteria.  While there is no mandatory
list of criteria, the following should be considered
the minimum:

•  narrative "free froms";

•  dissolved oxygen;

•  pH;

•  temperature;

•  bacteriological criteria  (for recreational and
   ceremonial uses); and

•  toxics   (including   nonconventionals,  e.g.,
   ammonia  and chlorine).  [Use  of option 1,
    section 2.1.3, is recommended.]

1.9.2 Optional Policies

The  Tribes  must  also  specify  which optional
policies they  wish to use pursuant to 40  CFR
 131.13 (see chapter 6, this Handbook).  These
include the following:

 •   mixing zones  for point sources;

 •   variances for point sources;

 •   design  low-flow   specification   for   the
    application of numeric criteria; and

 •   schedules   of  compliance  for   criteria  in
    NPDES, and permits.
Guidance for applying these policies are generally
available  in  either  this  Handbook  or in the
Technical Support Document for Water Quality-
based Toxics Control (USEPA, 1991a).

1.9.3 Tribal Submission and EPA Review

The initial submission of the tribal water quality
standards must contain the items listed in 40 CFR
131.6 plus use attainability analyses for all waters
not classified "fishable/swimmable" (see section
2.9, this Handbook).   In addition,  it should
contain identification of endangered or threatened
aquatic species or wildlife subject to protection by
water quality standards.   There should also be
included a record containing information on the
regulatory and public participation aspects of the
water quality standards, public comments made,
and the Tribe's responses to those comments and
other  relevant  material required by  40  CFR
131.20.

1.9.4  Regional Reviews

The Regions  should  carefully coordinate the
reviews within the Water Management Divisions
to ensure:

•  that the required items in   section 131.6 are
   included;

•  that all waters with NPDES permits have water
   quality standards; and

•  that  the  tribal  rulemaking   meets   the
   requirements of 40 CFR 131.20.

In commenting on tribal water quality standards,
the Regions should identify situations where the
dispute resolution mechanism in 40  CFR  131.7
may ultimately  be  called into  play  and should
attempt  to  de-fuse such situations  as early  as
possible in the standards adoption process.  One
possibility is to encourage Tribes and States to
establish review  procedures before any specific
problem develops as suggested in section 131.7(e)
of the regulation.
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 Water Quality Standards Handbook - Second Edition
 Where NPDES permits exist, the downstream
 jurisdiction and the Region should determine if
 total  maximum daily  loads  or  waste  load
 allocations will be  needed.  Where this burden
 falls on the Tribe,  EPA may  need to assist the
 Tribe  in  these assessments  or  perform  the
 necessary modeling for the Tribe.  The Region
 also should assess the scope of any section 401
 procedures  needed  in future NPDES  permit
 renewals.  The interstate nature of tribal water
 quality standards may become important to EPA
 because of the recent Arkansas v. Oklahoma U.S.
 Supreme Court case (112 section 1046, February
 26,  1992), especially when EPA is the permit
 writing authority.
        NOTE:      Additional   discussion
        supporting  the Agency's lulemaking
        with respect to Indian Tribes and
        EPA's views on related questions may
        be found in the preamble discussion to
        the  final  rule  (56  F,R.  64893,
        December 12, 1991).
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                                                                   Chapter 1 - General Provisions
                                       Endnotes
   1. Champion International Corp. v. EPA, 850 F.2d 182 (4th Cir. 1988)
   2. Oklahoma Tax Commission v. Citizen Band Potawatomi Indian Tribe of Oklahoma, 111 S.Ct.
     905, 910 (1991).
   3. Brendale v. Confederated Tribes and Bands of the YaUma Nation, 492 U.S. 408, (1989)
   4. Montana v. United States, 450 U.S. at 565-66 (citations omitted).
   5. See, e.g., Keystone Bituminous CoalAssoc. v. DeBenedictis, 480 U.S. 470, 476-77 and notes
     6,7  (1987).
   6. Id.
   7. Washington Dept. of Ecology v. EPA, 752 F.2d 1465,  1469 (9th Cir. 1985); see generally
     Chevron,  USA v.  NRDC, 467 U.S. 837, 843-45 (1984).
   8. California Coastal Commission v.  Granite Rock Co., 480 U.S. 572, 587 (1987).
   9. Id. at 587-89.
   10. See e.g. Brendale, 492 U.S. at 420 n.5 (White, J.) (listing broad range of consequences of
     state zoning decision).
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                               CHAPTER 2

                        JDESIGNATION OF USES

                             (40 CFR 131.10)

                             Table of Contents

2.1 Use Classification - 40 CFR 131.10(a) . . ..	2-1
    2.1.1     Public Water Supplies	2-1
    2.1.2     Protection and. Propagation of Fish, Shellfish, and Wildlife	2-1
    2.1.3     Recreation	2-2
    2.1.4     Agriculture and Industry	2-3
    2.1.5     Navigation	2-4
    2.1.6     Other Uses  	2-4

2.2 Consider Downstream Uses - 40 CFR 131.10(b)	2-4

2.3 Use Subcategories -  40 CFR 131.10(c)	2-5

2.4 Attainability of Uses - 40 CFR 131.10(d)	2-5

2.5 Public Hearing for Changing Uses - 40 CFR 131.10(e)	2-6

2.6 Seasonal Uses - 40 CFR 131.10(f)  	2-6

2.7 Removal of Designated Uses -  40 CFR 131.10(g) and (h)	2-6
    2.7.1     Step 1 - Is the Use Existing?	2-6
    2.7.2     Step 2 - Is the Use Specified in Section 101(a)(2)?    	2-8
    2.7.3     Step 3 - Is the Use Attainable?	  . 2-8
    2.7.4     Step 4 - Is a Factor from 131.10(g) Met?		2-8
    2.7.5     Step 5 - Provide Public Notice  .	2-8

2.8 Revising Uses to Reflect Actual Attainment - 40 CFR 131.10(i)	2-8

2.9 Use Attainability Analyses - 40 CFR 131.100) and (k)	2-9
    2.9.1     Water Body Survey and Assessment - Purpose and Application	2-9
    2.9.2     Physical Factors	  2-10
    2.9.3     Chemical  Evaluations	 .  2-12
    2.9.4     Biological Evaluations	2-12
    2.9.5     Approaches to Conducting the Physical, Chemical, and Biological
             Evaluations	  2-15
    2.9.6     Estuarine  Systems	  2-18
    2.9.7    Lake Systems	  2-23

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                                                                                                                                        i    n mil i      i ii   i n    J   11 
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                                                                     Chapter 2 - Designation of Uses
                                        CHAPTERS
                                DESIGNATION OF
         Use Classification - 40 CFR 131.10(a)
A water quality standard defines the water quality
goals of a water body or portion thereof, in part,
by designating the use or uses to be made of the
water.  States adopt water quality standards to
protect public health or welfare,  enhance  the
quality of water, and serve the purposes of the
Clean Water  Act.   "Serve the purposes of the
Act" (as defined in sections 101(a)(2), and 303(c)
of the Act) means that water  quality standards
should:

•  provide, wherever attainable, water quality for
   the  protection  and  propagation  of  fish,
   shellfish, and  wildlife, and  recreation in and
   on the water ("fishable/swimmable"),  and

•  consider the use and value of State waters for
   public water supplies, propagation  of fish and
   wildlife, recreation,  agriculture and industrial
   purposes, and navigation.

These sections of the Act describe various uses of
waters that are considered desirable and should be
protected.  The States must take these uses into
consideration  when classifying  State waters and
are free to add use  classifications.   Consistent
with  the  requirements  of the Act and Water
Quality Standards Regulation, States are free to
develop and adopt any  use classification system
they  see  as  appropriate,  except  that waste
transport and assimilation is not an acceptable use
in any case (see 40 CFR 131.10(a)).  Among  the
uses listed in  the Clean Water Act, there  is no
hierarchy.    EPA's  Water  Quality Standards
Regulation emphasizes  the  uses  specified   in
section  101(a)(2) of the Act (first bullet,  above).
To be consistent with the 101(a)(2) interim goal
of the Act, States must provide water quality for
the protection  and propagation  offish, shellfish,
and wildlife, and provide for recreation in and on
the water ("fishable/swimmable") where attainable
(see 40 CFR 131.10(j)).
           B1SIGNA
              40 CFR
       Uses specked is Water Quality
       Standards for each water body or
       segment whether or not they are;
       being attained,
2.1.1 Public Water Supplies

This use includes waters that are the source for
drinking water supplies and often includes waters
for food processing.  Waters for drinking water
may require treatment prior to  distribution in
public water systems.

2.1.2 Protection and  Propagation  of Fish,
      Shellfish, and Wildlife

This classification is  often divided into several
more specific subcategories, including coldwater
fish, warmwater fish, and shellfish. For example,
some coastal States have a use specifically  for
oyster propagation.  The use may also include
protection  of  aquatic   flora.     Many  States
differentiate  between   self-supporting   fish
populations  and stocked  fisheries.    Wildlife
protection should include waterfowl, shore birds,
and other water-oriented wildlife.

To more fully protect aquatic habitats and provide
more comprehensive assessments of aquatic life
use attainment/non-attainment, it is EPA's policy
that States should designate aquatic life uses that
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Water Quality Standards Handbook - Second Edition
appropriately  address biological integrity and
adopt biological criteria necessary to protect those
uses (see Appendix R).
             TYPES OF USES
        CWA SECTION 303(c)(2)(A)

          Public water supplies
          Protection and propagation of
          fish, shellfish, and wildlife
          Recreation
          Agriculture
          Industry
          Navigation
          Coral reef preservation
          Marinas
          Groundwater recharge
          Aquifer protection
          Hydroelectric power
2.1.3 Recreation

Recreational uses have traditionally been divided
into  primary  contact  and  secondary  contact
recreation.    The  primary  contact  recreation
classification protects people from illness due to
activities involving the potential for ingestion of,
or  immersion  in,  water.    Primary  contact
recreation   usually   includes   swimming,
water-skiing,  skin-diving,  surfing,  and  other
activities  likely to result in immersion.   The
secondary  contact recreation   classification  is
protective when immersion is unlikely.  Examples
are boating, wading, and rowing.  These two
broad uses can be logically  subdivided into an
almost infinite number of subcategories  (e.g.,
wading, fishing, sailing, powerboating, rafting.).
Often fishing is considered in the recreational use
categories.

Recreation in and on the water, on the other hand,
may not be attainable in certain  waters, such as
wetlands,  that  do  not have  sufficient water,  at
least seasonally.  However, States are encouraged
to recognize and protect recreational uses that do
not directly involve contact with water, including
hiking, camping, and bird watching.

A number of acceptable  State  options may be
considered for designation of recreational uses.

   Option 1

Designate primary contact recreational uses for all
waters of the State, and set bacteriological criteria
sufficient to support primary contact  recreation.
This option fully conforms with the requirement
in section 131.6 of the "Water Quality Standards
Regulation to designate uses consistent with the
provisions of sections 101(a)(2)  and 303(c)(2) of
the CWA. States are not required to conduct use
attainability  analyses   (for  recreation)   when
primary contact recreational uses are designated
for all waters of the State.

   Option 2

Designate either primary contact recreational uses
or  secondary  contact recreational  uses for all
waters of the State and,  where secondary contact
recreation  is  designated,  set  bacteriological
criteria  sufficient  to support  primary  contact
recreation. EPA believes that a secondary contact
recreational use (with criteria sufficient to support
primary contact recreation) is consistent with the
CWA section 101(a)(2)  goal.  The rationale for
this option is  discussed in the  preamble to the
Water Quality Standards Regulation, which states:
"... even though it may not make  sense to
encourage use of a stream  for swimming because
of the flow, depth or the velocity of the water, the
States and EPA must recognize that swimming
and/or wading may occur anyway.  In order to
protect public health, States must set criteria to
reflect  recreational  uses  if  it  appears  that
recreation  will in  fact occur   in  the  stream."
Under  this  option,  future revisions  to the
bacteriological  criterion  for   specific  stream
segments  would be subject to  the  downgrading
provisions of the Federal Water Quality Standards
Regulation (40 CFR 131.10).
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                                                                     Chapter 2 - Designation of Uses
   Option 3

Designate  either  primary  contact  recreation,
secondary contact recreation (with bacteriological
criteria sufficient to  support primary  contact
recreation), or conduct use attainability analyses
demonstrating  that recreational  uses  consistent
with the  CWA section 101(a)(2)  goal  are not
attainable for all waters of the State.  Such use
attainability  analyses  are required by  section
131.10  of   the   Water  Quality   Standards
Regulation, which also specifies  six factors that
may be used  by States in  demonstrating that
attaining a use is not feasible.  Physical factors,
which are important in determining attainability of
aquatic life uses, may not be used as the basis for
not designating a recreational use consistent with
the CWA section 101(a)(2) goal.  This precludes
States  from  using  40  CFR  131.10(g) factor  2
(pertaining to low-flows) and factor 5 (pertaining
to physical factors in general).  The basis for this
policy  is  that  the  States  and  EPA  have  an
obligation to  do as much as possible to protect the
health  of the public.  In certain instances, people
will use whatever water bodies are available for
recreation, regardless of the physical conditions.
In conducting  use attainability analyses  (UAAs)
where available data are scajrce  or nonexistent,
sanitary surveys are useful  in  determining the
sources  of  bacterial  water  quality  indicators.
Information  on land  use  is   also  useful  in
predicting bacteria levels and sources.

   Other Options

•  States  may  apply  bacteriological  criteria
   sufficient  to support primary contact recreation
   with  a   rebuttable  presumption  that  the
   indicators show the presence  of human fecal
   pollution.    Rebuttal of  this  presumption,
   however,  must be based on a sanitary survey
   that demonstrates a lack of contamination from
   human sources.  The basis for this option  is
   the   absence  of  data  demonstrating   a
   relationship   between   high   densities  of
   bacteriological water quality indicators and
   increased  risk of swimming-associated  illness
   in animal-contaminated waters.  Maine is an
   example  of  a State  that  has  successfully
   implemented this option.

•  Where States adopt a standards package that
   does not support the swimmable goal and does
   not contain a UAA to justify the omission,
   EPA may conditionally approve  the package
   provided that  (1) the State commits, in writing,
   to  a schedule  for  rapid  completion  of  the
   UAAs,   generally   within   90   days  (see
   conditional approval guidance in section 6.2 of
   this Handbook); and (2) the omission may be
   considered a  minor deficiency  (i.e., after
   consultation with the State, EPA determines
   that there is no basis for  concluding that the
   UAAs would support upgrading the use of the
   water body).  Otherwise, failure to support the
   swimmable goal  is  a major  deficiency  and
   must be disapproved to allow prompt Federal
   promulgation action.

•  States may conduct basinwide use attainability
   analyses  if the circumstances relating to the
   segments in question are sufficiently similar to
   make the results of the  basinwide analyses
   reasonably applicable to each segment.

States may add other recreation classifications as
they  see fit.  For example, one State protects
"consumptive   recreation"   (i.e.,    "human
consumption of aquatic life, semi-aquatic life, or
terrestrial wildlife that depend  on surface waters
for survival  and well-being").   States also may
adopt seasonal recreational uses (see section 2.6,
this Handbook).

2.1.4 Agriculture and Industry

The agricultural use classification defines waters
that  are  suitable  for  irrigation  of  crops,
consumption by  livestock, support of vegetation
for range grazing, and other uses in  support of
farming and  ranching and protects livestock and
crops  from  injury due to irrigation  and other
exposures.

The industrial use classification  includes industrial
cooling  and  process   water  supplies.    This
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 Water Quality Standards Handbook - Second Edition
 classification protects industrial equipment from
 damage from cooling  and/or process waters.
 Specific criteria would depend on  the industry
 involved.

 The Report  of the Committee on Water Quality
 Criteria, the "Green Book" (FWPCA, 1968) and
 Water  Quality Criteria 1972, the "Blue Book"
 (NAS/NAE, 1973) provide information for certain
 parameters  on   protecting   agricultural   and
 industrial uses, although section 304(a)(l) criteria
 for protecting  these  uses  have   not   been
 specifically  developed  for  numerous  other
 parameters, including toxics.

 Where  criteria   have  not  been   specifically
 developed for agricultural and industrial uses, the
 criteria developed for human health and aquatic
 life are usually sufficiently  stringent to protect
 these uses.   States also may establish criteria
 specifically designed to protect these uses.

 2.1.5 Navigation

 This use classification is designed to protect ships
 and their crews and to maintain water quality so
 as not to restrict or prevent navigation.

 2.1.6 Other Uses

 States  may adopt other uses  they consider  to be
 necessary.    Some  examples  include coral reef
 preservation,  marinas,  groundwater  recharge,
 aquifer protection,  and hydroelectric  power.
 States  also  may  establish  criteria  specifically
 designed to protect these uses.
         Consider Downstream Uses - 40 CFR
When  designating uses, States  should  consider
extraterritorial  effects  of their  standards.   For
example, once  States revise or adopt standards,
upstream jurisdictions will be  required, when
revising their standards and issuing permits, to
provide for attainment and maintenance of the
downstream standards.
 Despite  the  regulatory requirement  that States
 ensure  downstream  standards  are  met  when
 designating  and  setting   criteria  for  waters,
 occasionally  downstream  standards are not met
 owing to  an upstream pollutant  source.   The
 Clean Water Act offers three solutions  to such
 problems.

 First, the opportunity for public participation for
 new or revised water quality standards provides
 potentially  affected  parties  an  approach   to
 avoiding  conflicts  of water quality standards.
 States and Tribes are encouraged  to  keep other
 States informed of their water quality standards
 efforts and to invite comment  on standards  for
 common water bodies.

 Second, permit limits under the National Pollutant
 Discharge Elimination System (NPDES) program
 (see section 402  of the Act) are required to be
 developed  such  that applicable water  quality
 standards are achieved.   The  permit issuance
 process  also  includes  opportunity  for   public
 participation  and,  thus,   provides  a  second
 opportunity to consider and  resolve potential
 problems  regarding  extraterritorial  effects  of
 water quality standards.  In a decision in Arkansas
 v. Oklahoma (112 section  1046,  February 26,
 1992), the U.S.  Supreme Court  held that the
 Clean  Water Act  clearly  authorized EPA  to
 require that point sources in upstream States not
 violate water quality standards  in downstream
 States, and that  EPA's interpretation of those
 standards should govern.

Third, NPDES permits issued by EPA are subject
to certification under the requirements of section
401 of the Act.  Section 401 requires  that States
grant,  deny,  or  condition "certification"  for
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                                                                      Chapter 2 - Designation of Uses
federally permitted or licensed activities that may
result  in  a discharge to waters  of the United
States.    The  decision  to  grant  or to  deny
certification, or to grant a conditional certification
is based  on a State's detemu'nation regarding
whether the proposed activity will  comply with
applicable  water  quality standards  and  other
provisions.  Thus, States may deny certification
and prohibit EPA  from issuing an NPDES permit
that   would violate  water  quality  standards.
Section 401 also allows a Slate to participate in
extraterritorial  actions that will affect that State's
waters if a federally issued permit is involved.

In addition to  the above sources for solutions,
when the problem arises  between a State and an
Indian Tribe qualified for treatment  as a State for
water  quality  standards, the dispute resolution
mechanism could  be invoked (see section 1.7, of
this Handbook).
         Use Subcategories - 40 CFR 131.10(c)
States are required to designate uses considering,
at a minimum, those uses listed in section 303(c)
of the Clean Water  Act  (i.e., public water
supplies,  propagation    of  fish  and  wildlife,
recreation^  agriculture  and industrial  purposes,
and navigation).  However, flexibility inherent in
the State process for designating  uses allows the
development of subcategories of  uses within the
Act's  general categories  to refine  and  clarify
specific use classes. Clarification of the use class
is particularly helpful when a variety of surface
waters  with distinct characteristics fit within the
same  use class,  or do not  fit  well  into  any
category.   Determination  of non-attainment in
waters  with broad use categories may be difficult
and open to  alternative  interpretations.    If  a
determination  of non-attainment is in dispute,
regulatory actions will be difficult to accomplish
(USEPA, 1990a).

The State selects the level of specificity it desires
for identifying designated uses and subcategories
of uses (such as whether to treat recreation as a
single  use  or  to define   a  subcategory  for
secondary recreation).  However, the State must
be at least as specific as the uses listed in sections
101(a) and 303(c) of the  Clean Water Act.

Subcategories of aquatic life uses may be on the
basis of attainable habitat (e.g., coldwater versus
warmwater   habitat);  innate   differences  in
community  structure  and function  (e.g.,  high
versus low  species richness  or productivity); or
fundamental differences in important community
components  (e.g., warmwater fish  communities
dominated by bass versus catfish).  Special uses
may also be designated  to  protect particularly
unique,  sensitive, or valuable aquatic  species,
communities, or habitats.

Data  collected  from  biosurveys as  part  of a
developing biocriteria program may assist States
in refining  aquatic life use classes  by revealing
consistent differences among aquatic communities
inhabiting different waters of the same designated
use.  Measurable biological attributes could then
be  used to divide  one class into two or  more
subcategories (USEPA, 1990a).

If States adopt subcategories that do not require
criteria sufficient to  fully protect the goal uses in
section 101(a)(2) of the  Act (see section 2.1,
above), a use attainability analysis pursuant to 40
CFR  131.10(j) must be conducted for waters to
which these subcategories are assigned.  Before
adopting  subcategories  of   uses,  States  must
provide  notice  and  opportunity  for  a  public
hearing because these actions are changes to the
standards.
         Attainability  of  Uses   -   40  CFR
 When  designating  uses,  States may  wish  to
 designate  only  the uses  that are  attainable.
 However, if the State does not designate the uses
 specified in section 101(a)(2) of the Act, the State
 must perform  a  use attainability analysis  under
 section  131.10(j) of the regulation.  States are
 encouraged  to  designate  uses that  the  State
 believes can be attained in the future.
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 Water Quality Standards Handbook - Second Edition
 "Attainable uses"  are, at a minimum,  the uses
 (based  on  the State's  system  of  water  use
 classification)  that can  be  achieved 1) when
 effluent limits under sections 301(b)(l)(A) and (B)
 and section 306 of the Act are imposed on point
 source dischargers and 2) when cost-effective and
 reasonable best management practices are imposed
 on nonpoint source dischargers.
         Public Hearing for Changing Uses - 40
         CFR 131.10(e)
The Water Quality Standards Regulation requires
States to provide opportunity for public hearing
before adding or removing a use or establishing
subcategories of a use.  As mentioned in section
2.2   above,   the   State   should  consider
extraterritorial effects of such changes.
         Seasonal Uses - 40 CFR 131.10(£)
In some areas of the country, uses are practical
only  for  limited seasons.   EPA recognizes
seasonal uses in the Water Quality Standards
Regulation.  States may specify the seasonal uses
and criteria protective of that use as well as the
time frame for the "... season, so long as the
criteria do not prevent the attainment of any more
restrictive uses attainable in other seasons."

For  example,  in  many northern  areas,  body
contact recreation is  possible only a few months
out of the year.   Several States have  adopted
 primary  contact  recreational  uses,  and  the
 associated microbiological criteria, for only those
 months when primary contact recreation actually
 occurs,  and  have  relied  on  less  ,stringent
 secondary contact recreation criteria to protect for
 incidental  exposure  in  the   "non-swimming"
 season.

 Seasonal  uses that may require  more stringent
 criteria are uses that protect sensitive organisms
 or life stages during a specific season such as the
 early life stages of fish  and/or  fish  migration
 (e.g., EPA's Ambient Water Quality  Criteria for
 Dissolved Oxygen  (see Appendix  I) recommends
 more stringent dissolved oxygen  criteria  for the
 early life stages of both coldwater and warmwater
 fish).
         Removal of Designated Uses - 40 CFR
         131.10(g) and (h)
Figure 2-1 shows how and when designated uses
may be removed.

2.7.1 Step 1 - Is the Use Existing?

Once a use has been designated  for a particular
water body or segment, the water body or 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 (see
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                                                   Chapter 2 - Designation of Uses
     Stept
      Step 2 Xls Use
              Specified in
      Step 3
      Step 4
      StepS
                                                  May Not
                                                 Remove Use
                Is Use
               Attainable
                           May Not
                         Remove Use
                                       May Not
                                     Remove Use
131.10(g) factor
     m€>t?
                                     May Remove
 Public Notice
 Figure 2-1.   Process for Removing a Designated Use
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 Water Quality Standards Handbook - Second Edition
  section 4.4, this Handbook, for further discussion
  of existing uses).  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.

  2.7.2 Step 2 - Is the Use Specified in Section
 If the State wishes to remove a designated  use
 specified in section 101(a)(2) of the Act, the State
 must perform a use attainability analysis (see
 section 131.100)). Section 2.9 of this Handbook
 discusses use attainability analyses for aquatic life
 uses.

 2.7.3 Step 3 - Is the Use Attainable?

 A State may change activities within a specific 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.    (See  section  2.4,   above,  for  the
 definition of "attainable uses.")  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 nonpoint sources.
 (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   use,   unless   these
       conditions may be compensated for by the
       discharge of sufficient volume of effluent
       discharges  without  violating State water
       conservation requirements to enable uses to
       be met;

 (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;

 (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;

 (5)   physical conditions related  to the  natural
       features of the water body, such as the lack
      of a proper substrate, cover, flow, depth,
      pools, riffles,  and  the like, unrelated to
       [chemical]   water   quality,    preclude
      attainment of aquatic life protection uses; or

 (6)   controls more stringent than those required
      by sections 301(b)(l)(A) and (B) and 306 of
      the Act would result in substantial and
      widespread economic and  social impact.
2.7.4 Step 4 - Is a Factor from 131.10(g) Met?   2.7.5 Step 5 - Provide Public Notice
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:
As provided for in section 131.10(e), States must
provide notice and opportunity for public hearing
in accordance with section 131.20(b) (discussed in
section 6.1 of this Handbook).  Of course, EPA
intends for States to make appropriate use of all
public comments received through such notice.
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                                                                      Chapter 2 - Designation of Uses
         Revising  Uses  to  Reflect   Actual
         Attainment <• 40 Cl^R 131.10(i)
When performing its trienniid review, the State
must evaluate what uses are being attained.  If a
water body is designated for a use  that requires
less  stringent criteria than  a use that  is being
attained, the State must revise the use on that
water body to  reflect the  use  that  is being
attained.
         Use Attainability Analyses - 40 CFR
         131.10(j) and (k)
Under  section  131.10(j) of  the  Water  Quality
Standards  Regulation,  States  are required  to
conduct a  use  attainability  analysis  (UAA)
whenever:

(1)   the State designates or  has designated uses
      that do  not include  the  uses specified in
      section 101(a)(2) of this Act; or

(2)   the State wishes to remove a designated use
      that is specified in section 101(a)(2) of the
      Act or adopt subcategories of uses specified
      in   section  101(a)(2)  that  require  less
      stringent criteria.

States are not required to  conduct UAAs when
designating uses  that include those specified in
section 101(a)(2) of the Act, although they may
conduct   these  or   similar   analyses   when
determining  the  appropriate  subcategories  of
section 101(a)(2) goal uses.
States may also conduct generic use attainability
analyses for groups of water body  segments
provided that the circumstances relating to the
segments in  question are sufficiently similar to
make  the  results  of  the   generic   analyses
reasonably applicable to each segment.

As defined  in  the Water  Quality  Standards
Regulation (40 CFR 131.3), a use  attainability
analysis is:

   ... a  structured scientific assessment  of
   the factors affecting  the attainment of a use
   which  may include  physical, chemical,
   biological,  and  economic   factors   as
   described in section  131.10(g).

The  evaluations  conducted   in  a  UAA  will
determine  the  attainable uses  for  a  water body
(see sections 2.4 and 2.8, above).

The physical,  chemical, and  biological factors
affecting the attainment of a  use are  evaluated
through a -water body survey and assessment. The
guidance on water  body survey and assessment
techniques that appears in  this Handbook  is for
the evaluation  of fish,  aquatic life,  and wildlife
uses only  (EPA  has not developed guidance for
assessing recreational uses). Water body surveys
and assessments conducted by the States should be
sufficiently  detailed to answer   the  following
questions:

• What are the aquatic use(s) currently  being
   achieved  in the water body?

• What are the  causes of any impairment  of the
   aquatic uses?

• What are the aquatic use(s)  that can be attained
   based on the physical, chemical, and biological
   characteristics of the water body?

The  analysis  of economic  factors  determines
 whether substantial  and widespread economic and
 social  impact would   be  caused  by pollution
 control requirements more stringent than (1) those
 required under sections 301(b)(l)(A) and (B) and
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 Water Quality Standards Handbook - Second Edition
 section  306  of  the  Act  for  point  source
 dischargers, and (2) cost-effective and reasonable
 best management  practices for nonpoint source
 dischargers.

 2.9.1 Water Body  Survey  and Assessment -
       Purpose and Application

 The purpose of this section is  to  identify the
 physical,  chemical,  and  biological  factors that
 may be examined to determine whether an aquatic
 life protection use is attainable  for a given water
 body.   The  specific analyses  included in this
 guidance are optional.  However, they represent
 the type of analyses EPA believes are sufficient
 for States to justify changes in uses designated in
 a water quality standard and to  determine  uses
 that  are attainable.   States may  use alternative
 analyses  as long as  they  are  scientifically and
 technically   supportable.      This   guidance
 specifically addresses  streams and river systems.
 More detailed guidance is given in the Technical
 Support   Manual:   Waterbody  Surveys   and
 Assessments for  Conducting Use  Attainability
 Analyses,  Volume I (USEPA, 1983c).  EPA has
 also developed guidance for estuarine and marine
 systems and  lakes,   which  is  summarized in
 following  sections.  More  detailed guidance for
 these aquatic systems is available in the Technical
 Support Manual, Volume 11,  Estuarine Systems,
 and Volume III, Lake Systems (USEPA, 1984a,b).

 Several approaches for analyzing the aquatic life
 protection  uses to determine if  such  uses  are
 appropriate for a given water body are discussed.
 States are encouraged to  use  existing data to
 perform the physical, chemical,  and biological
 evaluations presented in this guidance document.
 Not  all of these  evaluations  are  necessarily
 applicable.  For example, if an assessment reveals
 that the physical habitat is the limiting  factor
 precluding a use, a chemical evaluation would not
 be  required.   In addition,  wherever possible,
 States also should consider  grouping together
 water bodies having similar physical, chemical,
 and   biological  characteristics  either  to treat
 several  water bodies  or stream segments as  a
 single unit or to establish representative conditions
 applicable to other similar water bodies or stream
 segments within a river basin.   Using existing
 data and  establishing  representative conditions
 applicable  to  a  number  of water  bodies or
 segments should conserve the limited resources
 available to the States.

 Table  2-1  summarizes the  types  of physical,
 chemical,  and  biological  factors that  may be
 evaluated  when conducting  a  UAA.   Several
 approaches  can be  used for  conducting the
 physical, chemical, and biological evaluations,
 depending  on  the complexity  of the situation.
 Details on the various evaluations can be found in
 the  Technical  Support  Manual:    Waterbody
 Surveys and Assessments for  Conducting  Use
 Attainability Analyses, Volume I (USEPA, 1983c).
 A survey need not consider all of the parameters
 listed; rather, the survey should be designed on
 the basis of the water body  characteristics and
 other considerations relevant  to  a  particular
 survey.

 These approaches may be adapted to the water
 body  being examined.    Therefore,   a  close
 working relationship between EPA and the States
 is  essential  so  that EPA  can  assist States in
 determining the appropriate analyses to be used in
 support of any water quality standards revisions.
 These analyses should  be  made available to all
 interested parties before any public forums on the
 water quality standards to allow for full discussion
 of the data and analyses.

 2.9.2    Physical Factors

 Section 101(a) of the Clean Water Act recognizes
 the importance of preserving the physical integrity
 of  the Nation's water  bodies.  Physical habitat
 plays an important role in the overall aquatic
 ecosystem and impacts the types and number of
 species  present in a particular  body  of water.
Physical parameters of a water body are examined
to identify factors that impair the propagation and
protection of aquatic life and  to determine what
uses could be obtained in the  water body given
such limitations.  In general, physical parameters
such as flow, temperature, water depth, velocity,
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                                                                        Chapter 2 - Designation of Uses
       PHYSICAL
         characteristics
       » size
         width/depth}
       - Sow/velocity  .
       - antwal hydrology
       - total volume
        - temperature
        <• sedimeatatJon
        -channel
          modifications
        * channel stability

        * substrate
         composition and
         characteristics

        4 channel debris

        4 sludge deposits

        4 riparian
         characteristics

        * downstream
         characteristics
CHEMICAL gACTOttS

4 dissolved oxygen

4 toxicants

4 suspended solids

4 nutrients
 - nitrogen
 - phosphorus
        ','
4 sediment oxygen
  demand

4 salinity

4 hardness

• alkalinity

4 pH

 4 dissolved solids
BTOLflftlCAL FACTORS

4 biological
  inventory
  (existing use
  analysis)
 -fish
 - mactolaverteferates
 - microiavertebrates
 - phytoplankton
 - peripfeytoa
 - maerap&ytes

 4 biological
  potential
  analysis
 * diversity indices
 - H$I models
 - tissue Analyses
 * recovery index
 - intolerant species analysis
 - omnivore-earnivore
, analysis

 4 biological
   potential
   analysis
 - reference  react
    comparison
  Table 2-1.  Summary of Typical Factors Used in Conducting a Water  Body Survey  and
              Assessment
substrate, reaeration rates, and other factors are
used to identify any physical limitations that may
preclude  attainment  of  the  designated  use.
Depending on the water body in question, any of
the physical parameters listed in Table 2-1 may be
appropriately examined. A State may use any of
these parameters to  identify physical limitations
and characteristics of a water body. Once a State
has identified any physical limitations based on
evaluating   the   parameters  listed,    careful
consideration of "reversibility" or the ability to
restore the physical integrity of the water body
should be made.
            Such considerations may include whether it would
            cause more environmental damage to correct the
            problem than to leave the water  body as is, or
            whether physical impediments such as dams can
            be  operated or modified in a  way that would
            allow attainment of the use.

            Several   assessment   techniques  have   been
            developed   that   correlate  physical   habitat
            characteristics  to  fishery  resources.     The
            identification of physical factors limiting a fishery
            is a critical assessment that provides important
            data for  management of  the water body.   The
            U.S.  Fish  and Wildlife Service  has developed
            habitat evaluation  procedures (HEP) and habitat
 (9/15/93)
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  Water Quality Standards Handbook - Second Edition
  suitability indices (HSI).   Several  States have
  begun  developing  their  own  models  and
  procedures for habitat assessments.  Parameters
  generally   included   in   habitat  assessment
  procedures are temperature, turbidity, velocity,
  depth, cover,  pool and riffle  sizes,  riparian
  vegetation, bank  stability, and siltation.   These
  parameters are  correlated  to fish  species  by
  evaluating the habitat variables important to the
  life cycle of the species.  The value of habitat for
  other groups  of aquatic   organisms  such  as
  macroinvertebrates and periphyton also may be
  considered. Continued research and refinement of
  habitat  evaluation   procedures  reflect  the
  importance of physical  habitat.

  If physical limitations of a stream restrict the use,
  a variety of habitat modification techniques might
  restore a habitat so that a species could  thrive
  where  it  could  not   before.    Some of the
  techniques  that   have  been  used  are   bank
  stabilization,  flow control,  current  deflectors,
  check dams, artificial meanders, isolated oxbows,
  snag   clearing   when   determined not  to be
  detrimental to the life cycle or reproduction of a
  species, and  installation of  spawning beds and
 artificial spawning channels.  If the habitat is a
 limiting factor to the propagation and/or survival
 of aquatic  life, the  feasibility of  modifications
 might be examined before additional controls are
 imposed on dischargers.

 2.9.3  Chemical Evaluations

 The chemical characteristics of a water body are
 examined to determine why a designated  use is
 not being met and to determine the potential of a
 particular species to survive in the water body if
 the concentration of particular chemicals  were
 modified.   The  State   has  the  discretion to
 determine the parameters required to perform an
 adequate water  chemistry evaluation.  A partial
 list of the parameters that may be evaluated is
 provided in Table 2-1.

 As part of the evaluation of the water chemistry
 composition, a natural background evaluation is
 useful  in determining the relative contribution of
  natural background contaminants  to  the water
  body;  this  may  be  a  legitimate factor  that
  effectively prevents a designated use from being
  met.    To  determine  whether   the   natural
  background  concentration  of  a  pollutant  is
  adversely impacting the survival of species, the
  concentration may be compared to one of the
  following:

  • 304(a) criteria guidance documents; or

  • site-specific criteria;  or

  • State-derived criteria.

  Another way  to  obtain  an  indication  of  the
  potential for the species to survive is to determine
  if the species are found in other waterways with
  similar chemical concentrations.

 In determining whether human-caused pollution is
 irreversible, consideration needs to be given to the
 permanence of the damage,  the  feasibility of
 abating   the   pollution,   or   the   additional
 environmental  damage  that  may  result  from
 removing the pollutants.  Once a State  identifies
 the chemical or water quality characteristics that
 are limiting attainment of the use, differing levels
 of remedial control measures may be explored.
 In addition,  if instream  toxicants  cannot  be
 removed  by  natural processes  and cannot  be
 removed   by  human   effort   without  severe
 long-term  environmental impacts, the  pollution
 may be considered irreversible.

 In some areas, the water's chemical characteristics
 may have to be  calculated using predictive water
 quality models.  This will be true if the receiving
 water is to  be impacted  by new dischargers,
 changes  in land  use,  or  improved treatment
 facilities.  Guidance is available on the selection
 and use of receiving water models for biochemical
 oxygen demand, dissolved oxygen, and ammonia
 for instream  systems  (USEPA,  1983d,e)  and
dissolved oxygen, nitrogen, and phosphorus for
lake   systems,  reservoirs,   and  impoundments
(USEPA, 1983f).
2-12
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                                                                     Chapter 2 - Designation of Uses
2.9.4 Biological Evaluations

In evaluating what aquatic life protection uses are
attainable,  the biology of the water body should
be evaluated.  The interrelationships between the
physical, chemical, and biological characteristics
are  complex,  and  alterations  in  the physical
and/or chemical  parameters result in biological
changes.  The biological evaluation described in
this section encourages States to:

•  provide a more  precise  statement of which
   species  exist in the water body and should be
   protected;

•  determine the  biological health of the water
   body; and

•  determine the species  that  could potentially
   exist in the water body if  the physical and
   chemical  factors  impairing  a  use   were
   corrected.

This section of  the guidance  will  present the
conceptual  framework    for   making    these
evaluations.   States have the  discretion to use
other  scientifically  and technically  supportable
assessment methodologies d
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  Wafer Quality Standards Handbook - Second Edition
  Before any field work is conducted, existing data
  should be collected.  EPA can provide data from
  intensive monitoring surveys and special studies.
  Data,  especially for fish, may be available from
  State  fish  and  game departments,  recreation
  agencies,  and  local  governments,  or  through
  environmental impact statements, permit reviews,
  surveys, and university or other studies.

    Biological   Condition/Biological  Health
    Assessment

 The biological  inventory  can be  used  to gain
 insight into the biological health of the water body
 by evaluating:
    species richness or the number of species;
    presence of intolerant species;
    proportion of omnivores and carnivores;
    biomass or production; and
    number of individuals per species.
 The role  of the biologist  becomes critical  in
 evaluating  the  health of the  biota  because the
 knowledge of  expected  richness  or  expected
 species  comes  only from  understanding  the
 general biological traits  and regimes of the area.
 Best professional judgments by local biologists are
 important.  These judgments are based  on many
 years  of experience  and on observations of the
 physical and chemical changes  that have occurred
 over time.

 Many methods for evaluating biotic communities
 have been and  continue to be developed.   The
 Technical Support Manual for Conducting  Use
Attainability Analyses (USEPA, 1983c) and Rapid
Bioassessment Protocols for Use in Streams and
Rivers (USEPA, 1989e) describe methods  that
States  may want  to consider  using   in  their
biological evaluations.

A number of other methods have been and are
being  developed  to  evaluate  the  health  of
biological components of the aquatic ecosystem
including  short-term  in situ  or  laboratory
bioassays and partial or fuU life-cycle toxicity
tests.  These methods are discussed in several
  EPA  publications,  including  the  Biological
  Methods Manual (USEPA, 1972).  Again, it is
  not the intent of this document to specify tests to
  be conducted by the States. This will depend on
  the information available, the predictive accuracy
  required, site-specific  conditions of the water
  body being examined,  and the cooperation and
  assistance the State receives  from  the  affected
  municipalities and industries.

     Biological Potential Analysis

  A significant step in the use attainability analysis
  is  the  evaluation of  what communities  could
  potentially exist in  a particular water  body  if
  pollution were abated or if the physical habitat
  were  modified.  The approach presented is to
  compare the water body in question  to reference
  reaches within a region.  This approach includes
  the development of baseline conditions to facilitate
  the comparison of  several water  bodies at less
 cost.   As with the  other analyses mentioned
 previously, available data  should  be  used  to
 minimize resource impacts.

 The biological potential analysis involves:

 •  defining boundaries of fish faunal  regions;

 •  selecting  control sampling  sites in  the
    reference reaches of each area;

 •  sampling fish and recording observations at
    each reference sampling site;

 •  establishing the community characteristics
    for the reference reaches of each area; and

 •  comparing the water body in question to the
    reference reaches.

In  establishing  faunal regions  and  sites,  it is
important to select reference areas for sampling
sites that have conditions typical of the region.

The establishment of reference areas may be
based on physical and hydrological characteristics.
The number of reference reaches needed will be
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                                                                     Chapter 2 - Designation of Uses
determined  by  the  State  depending  on  the
variability of the waterways within the State and
the number of classes that the State may wish to
establish.  For example,  the State may  want to
use  size, flow, and substrate  as the defining
characteristics and may consequently desire to
establish  classes  such  as  small,  fast  running
streams with sandy substrate or large, slow rivers
with cobble bottom.   It is at  the  option of the
State to:

•  choose the parameters to be used in classifying
   and establishing reference reaches; and

•  determine the number of classes (and thus the
   refinement) within the fauna! region.

This approach can also be applied to other aquatic
organisms such as  macroinvertebrates (particularly
freshwater mussels) and algae.

Selection of the reference reaches is of critical
importance  because the  characteristics of  the
aquatic  community  will  be  used to  establish
baseline conditions against which similar reaches
 (based   on   physical   and   hydrological
 characteristics) are companjd. Once the reference
 reaches  are  established,  the water  body  in
 question can be compared to the reference reach.
 The results of this analysis will reveal whether the
 water body in question has the typical  biota for
 that class or a less desirable community and will
 provide  an  indication  of what species  may
 potentially exist if pollution were abated or the
 physical habitat limitations were remedied.

 2.9.5 Approaches to Conducting the Physical,
       Chemical,  and Biological Evaluations

 In some cases, States that assess the status of their
 aquatic resources, will have relatively simple
 situations not requiring extensive data collection
 and evaluation.  In other situations, however, the
 complexity resulting from variable environmental
 conditions and the stress from multiple uses of the
 resource will require both intensive and extensive
 studies to produce a  sound  evaluation of the
 system.    Thus,   procedures  that a State may
develop for conducting a water body assessment
should be flexible enough to be adaptable to  a
variety of site-specific conditions.

A  common   experimental   approach  used  in
biological assessments has  been  a hierarchical
approach to the analyses.  This can be a rigidly
tiered approach.  An alternative is presented in
Figure 2-2.

The flow  chart  is  a general illustration  of  a
thought process used to conduct a use attainability
analysis.     The  process  illustrates   several
alternative  approaches  that can  be  pursued
separately or, to varying degrees, simultaneously
depending on:

•  the amount of data available on the site;

•  the  degree  of  accuracy  and  precision
    required;

•  the importance of the resource;

 •  the  site-specific conditions  of the  study
    area; and

 •  the controversy associated with the site.

 The degree of sophistication is variable for each
 approach. Emphasis is placed  on  evaluating
 available data first.  If information is found to  be
 lacking or incomplete, then field testing or field
 surveys should be conducted.

 The  major elements of  the process  are briefly
 described below.

    Steps 1 and 2

 Steps 1 and 2 are the basic organizing steps in the
 evaluation process.   By carefully defining the
 objectives and scope of the  evaluation, there will
 be some indication of the level of sophistication
 required in subsequent surveys and testing. States
 and the regulated community can then adequately
 plan and allocate resources  to the analyses. The
 designated use  of the  water body in  question
  (9/15/93)
                                                                                            2-1-5

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 Water Quality Standards Handbook - Second Edition
                   Stepf
                   Step 2
                   Step 3
                  Step 4

                  Steps
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        D-
                 Step 6
                 Step?
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Mgure 2-2. Steps in a Use Attainability Analysis
                                                                                                 (9/15/93)

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                                                                      Chapter 2 - Designation of Uses
should be identified as well  as the minimum
chemical, physical,  and biological requirements
for maintaining the use.  Minimum requirements
may  include,  for  example,  dissolved  oxygen
levels, flow rates, temperature, and other factors.
All relevant information on the water body should
be  collected  to  determine   if  the available
information  is adequate  for  conducting  an
appropriate level of analysis.   It is assumed that
all.water body evaluations, based on existing data,
will either formally or informally be conducted
through Steps 1 and 2.

   Steps 3 and 4

If the available information proves  inadequate,
then   decisions   regarding   the   degree  of
sophistication required in the evaluation process
will need to be made.  These decisions will, most
likely, be based on the five criteria listed in Step
3  of Figure 2-2.   Based on these decisions,
reference areas should be chosen  (Step 4), and
one or more of the  testing approaches should be
followed.

   Steps 5A, B, C, D

These approaches  are  presented  to  illustrate
several possible ways of  analyzing the water
body. For example, in some cases chemical data
may  be  readily available for  a water body but
little or no biological information is known.  In
this case, extensive chemical sampling may not be
required, but enough samples should be taken to
confirm  the accuracy of the available data set.
Thus, to accurately define the biological condition
of the resource, 5C may be chosen, but 5A may
be pursued in a less intensive way to supplement
the chemical data already available.

Step 5A is a general survey to establish relatively
coarse ranges for physical and chemical variables,
and the  numbers and relative  abundances of the
biological  components  (fishes,  invertebrates,
primary producers) in the v/ater body. Reference
areas may or may not need! to be evaluated here,
depending on the types of questions being asked
and the degree of accuracy required.
Step 5B focuses more narrowly on site-specific
problem areas with the intent of separating, where
possible,  biological  impacts  due  to physical
habitat  alteration versus those  due to chemical
impacts.   These  categories  are  not mutually
exclusive but some attempt should be made to
define the causal factors in a stressed area so that
appropriate control  measures can be implemented
if necessary.

Step 5C would be conducted to evaluate possibly
important trends  in the  spatial and/or temporal
changes associated  with the physical, chemical,
and biological variables of interest.  In general,
more rigorous quantification of these variables
would be needed to allow for more sophisticated
statistical analyses  between reference and study
areas which would,  in turn, increase the degree of
accuracy and confidence in the predictions based
on this  evaluation.   Additional laboratory testing
may  be  included,  such  as  tissue  analyses,
behavioral tests,  algal assays, or tests for flesh
tainting.  Also, high-level chemical analyses  may
be needed, particularly if the presence of toxic
compounds is suspected.

Step  5D is,  in some respects, the most  detailed
level of study. Emphasis  is  placed  on  refining
cause-effect   relationships   between   physical-
chemical alterations and the biological responses
previously established from available data  or steps
5A through 5C.  In many  cases, state-of-the-art
techniques will be used.  This pathway would be
conducted by the States  only where it  may be
necessary  to establish,  with a high degree of
confidence, the cause-effect relationships  that are
producing   the   biological   community
characteristics   of  those   areas.      Habitat
requirements or tolerance limits for representative
or important species may have to  be  determined
for  those factors limiting the potential of the
ecosystem.  For these evaluations, partial or full
life-cycle toxicity tests, algal assays, and sediment
bioassays may be needed along with  the shorter
term bioassays designed  to  elucidate sublethal
effects  not readily apparent  in  toxicity tests
(e.g.,   preference-avoidance   responses,
 (9/15/93)
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  Water Quality Standards Handbook - Second Edition
  production-respiration
  bioconcentration estimates).

     Steps 6 and 7
estimates,   and      Physical Processes
  After field sampling is completed, all data must
  be integrated and summarized. If this information
  is still not adequate, then further testing may be
  required and a more  detailed pathway chosen.
  With adequate data, States should be able to make
  reasonably specific recommendations concerning
  the natural potential of the water body, levels of
  attainability consistent  with this  potential, and
  appropriate use designations.

  The evaluation procedure outlined  here allows
  States  a  significant  degree  of  latitude  for
  designing assessments to meet their specific goals
  in water quality and water use.

 2.9.6 Estuarine Systems

 This section provides an overview of the factors
 that  should  be considered  in  developing use
 attainability  analyses   for   estuaries.   Anyone
 planning to conduct a use attainability analysis for
 an estuary should consult the Technical Support
 Manual:  Waterbody Surveys and Assessments for
 Conducting Use Attainability Analyses, Volume II:
 Estuarine Systems  (USEPA,  1984a) for more
 detailed guidance. Also, much of the information
 for streams and rivers that is presented above and
 in Volume I  of the Technical Support  Manual,
 particularly with respect to chemical evaluations,
 will apply to estuaries and is not repeated here.

 The term "estuaries" is generally used to denote
 the lower reaches of a river where tide and river
 flows  interact.   Estuaries  are very  complex
 receiving waters  that  are  highly  variable  in
 description and are not absolutes in definition,
 size,  shape,  aquatic life,  or other  attributes.
 Physical,  chemical, and biological attributes may
 require consideration unique to estuaries and are
 discussed below.
                     Estuarine  flows  are the result  of a complex
                     interaction of the following physical factors:
                       tides;
                       wind shear;
                       freshwater inflow (momentum and buoyancy);
                       topographic factional resistance;
                       Coriolis effect;
                       vertical mixing; and
                       horizontal mixing.
                    In performing a use attainability study, one may
                    simplify  the  complex  prototype  system  by
                    determining which of these effects or combination
                    of effects is most important at the time scale of
                    the evaluation (days, months, seasons, etc.).

                    Other ways to simplify the approach to analyzing
                    an estuary is to place it in a broad classification
                    system to permit comparison  of similar types of
                    estuaries.  The most common groupings are based
                    on  geomorphology,  stratification,  circulation
                    patterns,  and  time  scales.    Each of  these
                    groupings is discussed below.

                    Geomorphological classifications can include types
                    such as  drowned  river valleys  (coastal plain
                    estuaries), fjords, bar-built estuaries,  and other
                    estuaries  that   do   not  fit  the  first  three
                    classifications  (those  produced   by  tectonic
                    activity,   faulting,   landslides,   or   volcanic
                    eruptions).

                    Stratification is most often used for classifying
                    estuaries  influenced  by  tides  and  freshwater
                    inflows.   Generally, highly stratified estuaries
                    have large river discharges flowing  into them,
                    partially  mixed  estuaries  have  medium  river
                    discharges;  and  vertically  homogeneous  have
                    small river discharges.

                    Circulation  in an  estuary  (i.e.,   the  velocity
                   patterns  as they change  over  time) is primarily
                   affected  by  the  freshwater  outflow,  the tidal
                   inflow,  and  the  effect of  wind.   In  turn,  the
                   difference in  density  between outflow and inflow
2-18
                                                                                      (9/15/93)

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                                                                     Chapter 2 - Designation of Uses
sets up  secondary currents that ultimately affect
the salinity distribution across the estuary.  The
salinity distribution is important because it affects
the distribution of fauna and flora  within  the
estuary.   It  is  also  important because  it  is
indicative of the mixing properties of the estuary
as they may affect the dispersion of pollutants
(flushing properties).  Additional  factors  such as
friction forces  and the size  and geometry of the
estuary  also contribute to the circulation patterns.
The  complex  geometry   of   estuaries,   in
combination with the presence of wind, the effect
of the Earth's rotation  (Coriolis effect), and other
effects, often results in residual currents  (i.e., of
longer period than the tidal cycle) that  strongly
influence the mixing processes in estuaries.

Consideration  of time  scales  of the  physical
processes being evaluated is very important for
any water quality study.

Short-term conditions  are much more influenced
by a variety  of short-termi events that  perhaps
have to be  analyzed  to evsiluate a "worst case"
scenario. Longer term (seasonal) conditions are
influenced  predominantly  by  events  that  are
averaged over the duration of that time scale.

    Estuary  Substrate Composition

Characterization of sediment/substrate properties
is important in a use attainability analysis because
such properties:

•  determine the extent to which toxic compounds
    in sediments are available to the biota; and
         t*
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  Water Quality Standards Handbook - Second Edition
  from external phenomena.  This function may be
  particularly important during wet weather periods
  when relatively high stream flows discharge high
  loads of sediment and pollutants to the estuary.
  The wetlands slow the peak  velocity,  to  some
  extent  alleviate the  sudden  shock of  salinity
  changes, and filter some of the sediments and
  nutrients that would  otherwise be discharged
  directly into the estuary.

     Hydrology and Hydraulics

  The two most important sources of freshwater to
  the estuary are  stream flow  and precipitation.
  Stream  flow  generally represents  the  greatest
  contribution to the estuary.  The location of the
  salinity gradient in a river-controlled estuary is to
  a large extent a function of stream flow.  Location
  of  the  iso-concentration  lines may  change
  considerably,  depending  upon whether  stream
  flow is high or low.  This in turn may affect the
  biology of  the estuary, resulting in population
  shifts as biological species  adjust to changes in
  salinity.  Most estuarine  species are adapted to
  survive temporary changes  in  salinity either by
  migration  or  some  other  mechanism  (e.g.,
  mussels can close their shells).   However, many
 cannot  withstand  these  changes  indefinitely.
 Response of an estuary to rainfall events depends
 upon the intensity of rainfall, the drainage area
 affected  by the  rainfall,  and  the size of  the
 estuary.  Movement of the salt front is dependent
 upon tidal influences and freshwater flow to the
 estuary.  Variations in  salinity  generally follow
 seasonal  patterns such  that the  salt front will
 occur farther down-estuary during a rainy season
 than during  a dry season.   The salinity profile
 also may vary from day to day, reflecting the
 effect of individual rainfall events, and  may
 undergo  major  changes  due  to  extreme
 meteorological events.

 Anthropogenic activity also may have a significant
 effect on salinity  in  an estuary.  When feeder
 streams are used as sources of public water supply
and the withdrawals are not returned, freshwater
flow to the estuary is reduced, and the salt wedge
is found  farther up the estuary.   If the water is
  returned,  usually  in the  form  of wastewater
  effluent, the salinity gradient of the estuary may
  not  be  affected,   although  other   problems
  attributable to nutrients and other pollutants in the
  wastewater may occur.

  Salinity also may  be affected by the way that
  dams along the river are operated.  Flood control
  dams result in controlled discharges to the estuary
  rather than relatively short but massive discharge
  during high-flow periods.    Dams operated to
  impound water for water supplies during low-flow
  periods  may drastically  alter the  pattern  of
  freshwater flow to  the estuary, and although the
  annual discharge may remain the same, seasonal
  changes may have  significant impact on the
  estuary and its biota.

    Influence of Physical Characteristics on Use
    Attainability

  "Segmentation" of an estuary can provide a useful
 framework  for  evaluating   the  influence of
 estuarine  physical   characteristics   such   as
 circulation, mixing, salinity, and geomorphology
 on  use  attainability.     Segmentation  is   the
 compartmentalization of an estuary into subunits
 with homogeneous physical characteristics. In the
 absence   of   water   pollution,   physical
 characteristics of different regions of the estuary
 tend to. govern the  suitability for  major  water
 uses.  Once the segment  network is established,
 each  segment  can  be   subjected  to a  use
 attainability   analysis.      In  addition,   the
 segmentation process offers a useful management
 structure for monitoring conformance with  water
 quality goals in future years.

 The segmentation process is an  evaluation tool
 that recognizes that an estuary is an interrelated
 ecosystem composed of chemically, physically,
 and biologically diverse areas.  It assumes that an
 ecosystem as diverse as  an estuary cannot  be
 effectively managed  as only one  unit because
 different uses and associated water  quality  goals
 will  be  appropriate   and  feasible  for  different
regions of the estuary. However, after developing
a network based  upon physical  characteristics,
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                                                                     Chapter 2 - Designation of Uses
sediment boundaries can be refined with available
chemical and biological data to  maximize the
homogeneity of each segment.

A  potential  source  of  concern  about  the
construction  and  utility  of  the segmentation
scheme for use attainability evaluations is that the
estuary is a fluid system with only a few obvious
boundaries,  such  as the  sea  surface and the
sediment-water interface.  Fixed boundaries may
seem unnatural to scientists, managers, and users,
who are more likely to view  the estuary as a
continuum   than   as  a  system  composed  of
separable parts.   The best approach  to  dealing
with such concerns is a segmentation scheme that
stresses the dynamic nature of the estuary.  The
scheme  should   emphasize  that the  segment
boundaries are operationally defined constructs to
assist   in   understanding   a  changeable,
intercommunicating   system    of    channels,
embayments, and tributaries.

To account for the dynamic nature of the estuary,
it is  recommended  that  estuarine  circulation
patterns be a prominent factor in delineating the
segment network.  Circulation patterns control the
transport of and residence times for heat, salinity,
phytoplankton, nutrients,  sediment,  and other
pollutants throughout the estuary. Salinity should
be another important  factor in  delineating the
segment  network.   The variations  in  salinity
concentrations from head  of tide to  the mouth
typically produce  a  separation  of   biological
communities  based on  salinity  tolerances  or
preferences.

   Chemical Parameters

The most critical chemical water quality indicators
for aquatic  use  attainment  in  an estuary are
dissolved oxygen, nutrients and chlorophyll-a, and
toxicants. Dissolved oxygen (DO) is an important
water quality indicator for all fisheries uses.  In
evaluating  use attainability, assessments of DO
impacts should consider the relative contributions
of three different sources of oxygen demand:
•  photosynthesis/respiration   demand  from
   phytoplankton;

•  water column demand; and

•  benthic oxygen demand.

If use impairment is occurring, assessments of the
significance of each oxygen sink can be used to
evaluate the feasibility  of  achieving  sufficient
pollution control to  attain the designated use.

Chlorophyll-a is the most popular indicator of
algal concentrations and nutrient overenrichment,
which  in turn can be  related to diurnal  DO
depressions due to algal respiration. Typically, the
control  of  phosphorus  levels can  limit  algal
growth  near the head of the estuary,  while the
control  of nitrogen  levels can  limit algal growth
near the mouth  of  the  estuary; however, these
relationships are dependent upon factors such as
nitrogen phosphorus  ("N/P")  ratios  and  light
penetration potential, which can vary  from one
estuary  to  the next.   Excessive  phytoplankton
concentrations,  as  indicated  by  chlorophyll-a
levels,  can cause adverse DO impacts such as:

•  wide diurnal variations in surface DO due to
   daytime photosynthetic oxygen production and
   nighttime oxygen depletion by respiration; and

•  depletion   of   bottom   DO   through  the
   decomposition of dead algae.

Excessive  chlorophyll-a levels also  result in
shading, which  reduces light penetration for
submerged   aquatic   vegetation   (SAV).
Consequently, the  prevention »of  nutrient over-
enrichment is probably the most important water
quality   requirement   for   a  healthy   SAV
community.

The nutrients of greatest concern  in the estuary
are nitrogen  and  phosphorus.   Their sources
typically are discharges  from sewage  treatment
plants and industries and runoff from urban and
agricultural areas.   Increased nutrient levels lead
to  phytoplankton   blooms  and   a  subsequent
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 reduction in DO levels and light penetration, as
 discussed above.

 Sewage treatment plants are typically the major
 source of nutrients, particularly phosphorus, to
 estuaries  in urban areas. Agricultural land uses
 and urban land uses represent significant nonpoint
 sources of nutrients, particularly nitrogen.  It is
 important  to base  control  strategies   on  an
 understanding of the  sources of each  type of
 nutrient, both in  the  estuary and in its feeder
 streams.

 Point sources of nutrients are typically much more
 amenable to  control  than  nonpoint  sources.
 Because   phosphorus  removal  for  municipal
 wastewater discharges  is typically less expensive
 than nitrogen removal operations, the control of
 phosphorus  discharges is  often  the method of
 choice for  the  prevention or reversal   of  use
 impairment in the upper estuary (i.e., tidal fresh
 zone).   However, nutrient control in the upper
 reaches of the estuary may cause algal blooms in
 the lower reaches, e.g., control of phosphorus in
 the upper reaches may reduce the algal blooms
 there, but in doing so also increase the amount of
 nitrogen transported  to the lower reaches where
 nitrogen is the limiting nutrient causing a bloom
 there. Tradeoffs between nutrient controls  for the
 upper and lower estuary should be considered in
 evaluating measures  for prevention of reversing
 use impairment.

 Potential interferences from toxic substances, such
 as  pesticides, herbicides,   heavy  metals,  and
 chlorinated effluents, also need to be considered
 in  a  use attainability study.  The presence of
 certain  toxicants, in   excessive  concentrations
 within bottom sediments of the water column may
 prevent the attainment of water uses (particularly
 fisheries  propagation/harvesting  and sea grass
 habitat uses) in estuary segments that satisfy water
 quality  criteria for DO,  chlorophyll-a/nutrient
 enrichment, and fecal coliform.
    Biological Community Characteristics

 The  Technical  Support  Manual,  Volume  II
 (USEPA,  1984a) provides a discussion  of the
 organisms typically found  in estuarie$ in more
 detail than  is appropriate for  this Handbook.
 Therefore,  this discussion will focus on more
 general characteristics of estuarine biota and their
 adaptations  to   accommodate  a   fluctuating
 environment.

 Salinity,   light   penetration,   and   substrate
 composition are  the most critical factors to the
 distribution  and  survival  of  plant and  animal
 communities  in  an   estuary.    The  estuarine
 environment is characterized by variations  in
 circulation, salinity, temperature, and dissolved
 oxygen supply.  Colonizing plants and animals
 must  be  able  to  withstand  the   fluctuating
 conditions in estuaries.

 The depth to which attached plants may become
 established is limited by turbidity because plants
 require light for  photosynthesis. Estuaries are
 typically turbid because  of large quantities of
 detritus  and  silt contributed  by  surrounding
 marshes and rivers. Algal growth also may hinder
 light  penetration. If too much light is withheld
 from the  lower depths,  animals  cannot  rely
 heavily on visual  cues  for  habitat  selection,
 feeding, or finding a mate.

 Estuarine  organisms are recruited from the  sea,
 freshwater environments,  and  the  land.    The
 major environmental factors to which  organisms
 must   adjust   are  periodic   submersion   and
 desiccation  as  well  as  fluctuating  salinity,
 temperature, and dissolved oxygen.

Several generalizations concerning the responses
of estuarine organisms to salinity have been noted
(Vernberg, 1983) and reflect a correlation of an
organism's habitat to its tolerance:

• organisms living in estuaries subjected to wide
  salinity  fluctuations  can withstand  a  wider
  range of salinities than  species that occur in
  high-salinity estuaries;
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                                                                      Chapter 2 - Designation of Uses
•  intertidal zone animals tend to tolerate wider
   ranges  of  salinities  than  do  subtidal  and
   open-ocean organisms;

•  low intertidal species are less tolerant of low
   salinities than are high intertidal species; and

•  more sessile  animals  are  likely to be more
   tolerant of fluctuating salinities man organisms
   that  are  highly  mobile  and  capable  of
   migrating during times of salinity stress.

Estuaries are  generally  characterized  by  low
diversity of species but high productivity because
they serve as the nursery or breeding grounds for
some species.  Methods to measure the biological
health and diversity of estuaries are discussed in
USEPA (1984a).

   Techniques for Use Attainability Evaluations

In assessing use levels for aiquatic life protection,
determination of the present use and whether this
corresponds to the designated use is evaluated in
terms  of biological measurements and indices.
However, if the present use? does not correspond
to the designated, use, physical and chemical
factors are used to explain the lack of attainment
and the highest level the system can achieve.

The  physical  and  chemical  evaluations  may
proceed on  several levels depending on the level
of detail required, amount of knowledge available
about  the system (and  similar systems),  and
budget for the use attainability study.  As a first
step, the estuary is classified in terms of physical
processes  so  that  it  can be compared  with
reference estuaries  in terms  of differences in
water quality and biological communities, which
can  be  related  to  man-made alteration  (i.e.,
pollution discharges).

The second step is to perform  desktop or simple
computer model  calculations to  improve  the
understanding  of spatial  and temporal  water
quality conditions in the present system.  These
calculations include  continuous point source  and
simple  box  model-type calculations.   A more
detailed discussion of the desktop  and computer
calculations is given in USEPA (1984a).

The third  step  is to  perform detailed  analyses
through the use of more sophisticated computer
models.  These tools can be used to evaluate the
system's response to  removing individual point
and nonpoint source discharges, so as  to assist
with  assessments of  the cause(s) of  any  use
impairment.

2.9.7 Lake Systems

This section will focus on the factors that  should
be  considered in  performing  use attainability
analyses for lake systems.  Lake systems  are in
most cases linked physically to rivers and streams
and exhibit a transition from riverine habitat and
conditions  to lacustrine habitat  and  conditions.
Therefore, the information presented  in section
2.9.1 through 2.9.5 and the Technical Support
Manual, Volume I (USEPA, 1983c) will to some
extent apply to lake systems.  EPA has provided
guidance specific to lake systems in the Technical
Support Manual for Conducting Use Attainability
Analyses,   Volume HI: Lake Systems (USEPA,
1984b).   This manual should be  consulted by
anyone performing a use attainability analysis for
lake systems.

Aquatic  life  uses of a  lake are  defined in
reference to the plant  and animal life in a lake.
However,  the types and abundance of the biota
are  largely  determined  by  the  physical  and
chemical  characteristics  of the  lake.    Other
contributing   factors   include  the   location,
climatological conditions,  and historical  events
affecting the lake.

   Physical Parameters

The physical parameters  that describe the size,
shape, and flow regime of a lake  represent the
basic characteristics that affect physical, chemical,
and  biological processes.   As  part  of  a use
attainability analysis, the physical parameters must
be  examined  to understand  non-water quality
factors that affect the lake's aquatic life.
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The origins of a lake determine its morphologic
characteristics and strongly influence the physical,
chemical,  and  biological conditions  that  will
prevail.  Therefore, grouping lakes formed by the
same process  often will allow  comparison of
similar  lake  systems.    Measurement  of  the
following morphological characteristics may be of
importance to a water body survey:
   surface area;
   volume;
   inflow and outflow;
   mean depth;
   maximum depth;
   length;
   length of shoreline;
   depth-area relationships;
   depth-volume relationships; and
   bathymetry (submerged contours).
These physical parameters can in some cases be
used  to predict biological  parameters.    For
example,  mean  depth has  been  used  as  an
indicator of productivity.   Shallow lakes tend to
be more productive, and deep, steep-sided lakes
tend to be less productive.  These parameters may
also be used to calculate other characteristics of
the lake such as mass flow rate of a chemical,
surface loading rate, and detention time.

Total lake volume and inflow and outflow rates
are physical  characteristics that  indirectly affect
the lake's aquatic community.  Large inflows and
outflows for lakes with small volumes produce
low detention times  or high flow-through rates.
Aquatic life  under  these conditions  may  be
different than when relatively  small inflows and
outflows occur for a  large-volume lake  where
long detention times occur.

The  shape factor (lake length divided by lake
width) also  may be  correlated to chemical and
biological characteristics.   This  factor has been
used to predict parameters such as chlorophyll-a
levels in lakes. For  more detailed lake analysis,
information   describing   the   depth-area  and
depth-volume  relationships   and   information
describing the bathymetry  may be required.
In  addition to  the  physical  parameters listed
above, it is also important to obtain and analyze
information concerning the lake's contributing
watershed. Two major parameters of concern are
the drainage area of the contributing watershed
and the land uses  of that watershed.   Drainage
area will aid in the analysis of inflow volumes to
the lake due to surface  runoff.   The land use
classification of the area  around the lake can be
used to predict flows and also nonpoint source
pollutant loadings to the lake.

The physical parameters discussed above may be
used  to understand and analyze  the various
physical processes that  occur in lakes.  They can
also be used directly in  simplistic relationships
that predict productivity to aid in aquatic use
attainability analyses.

   Physical Processes

Many complex and interrelated physical processes
occur  in  lakes.   These  processes  are  highly
dependent  on the lake's physical parameters,
location, and characteristics of the contributing
watershed.  Several of the major  processes are
discussed below.

   Lake Currents

Water movement in a lake affects productivity and
the biota because it influences the distribution of
nutrients,  microorganisms, and plankton.  Lake
currents are propagated by wind, inflow/outflow,
and the Coriolis force.  For small shallow lakes,
particularly long and narrow lakes, inflow/outflow
characteristics   are  most important,  and  the
predominant current is a steady-state flow through
the lake.   For  very  large  lakes, wind  is the
primary generator  of currents,  and except for
local effects, inflow/outflow  have a relatively
minor effect on lake circulation. Coriolis effect,
a deflecting force that is  the function  of the
Earth's rotation, also plays a role in circulation in
large lakes such as the Great Lakes.
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   Heat Budget

Temperature and its distribution within lakes and
reservoirs affects not only the water quality within
the lake but also the thermal regime and quality of
a river system  downstream  of the lake.   The
thermal regime of a lake is a function of the heat
balance around the body of water.  Heat transfer
modes into and out of the lake include  heat
transfer   through   the   air-water   interface,
conduction through the mud-water interface, and
inflow and outflow  heat advection.

Heat  transfer  through the  air-water interface is
primarily    responsible   for  typical  annual
temperature cycles.  Heat is transferred across the
air-water  interface by three  different processes:
radiation exchange, evaporation, and conduction.
The  heat flux of  the  air-water interface is a
function  of  location   (latitude/longitude  and
elevation),    season,    time  of  day,   and
meteorological   conditions   (cloud   cover,
dew-point, temperature, barometric pressure, and
wind).

   Light Penetration

Transmission  of light through the water column
influences  primary productivity  (phytoplankton
and macrophytes), distribution of organisms, and
behavior of fish. The reduction of light through
the water  column  of a lake  is  a function of
scattering and absorption.  Light transmission is
affected by the water surface film, floatable and
suspended   particulates,    turbidity,   dense
populations of algae and bacteria, and color.

An important parameter based on the transmission
of light is  the depth to  which photosynthetic
activity is possible.  The minimum light intensity
required for photosynthesis has been  established
to be about 1.0 percent of the incident surface
light (Cole,  1979). The portion of the lake from
the surface to  the depth at which  the 1.0 percent
intensity occurs is  referred to as the "euphotic
zone."
   Lake Stratification

Lakes in temperate and northern latitudes typically
exhibit vertical density stratification during certain
seasons of  the  year.  Stratification  in lakes  is
primarily due to temperature differences, although
salinity and suspended solids concentrations may
also affect density.   Typically,  three zones  of
thermal stratification are formed.

The upper layer of warmer, lower density  water
is  termed the  "epilimnion,"  and  the lower,
stagnant layer of colder, higher density water is
termed the "hypolimnion."  The transition zone
between  the epilimnion and the hypolimnion,
referred to as the "metalimnion," is characterized
by the maximum rate of temperature decline with
depth (the thermocline). During stratification, the
presence of the  thermocline suppresses many  of
the mass transport phenomena that are otherwise
responsible  for  the  vertical  transport of  water
quality constituents within a lake.  The aquatic
community present in a lake is highly dependent
on the thermal structure.

With respect  to internal flow  structure,  three
distinct classes of lakes are defined:

•  strongly stratified, deep lakes characterized by
   horizontal isotherms;

•  weakly   stratified  lakes   characterized  by
   isotherms that are tilted along the longitudinal
   axis of the reservoir; and

•  non-stratified,   completely   mixed    lakes
   characterized by isotherms that are essentially
   vertical.

Retardation  of   mass  transport  between the
hypolimnion and the  epilimnion results in sharply
differentiated water quality and biology between
the lake strata.   One of the  most  important
differences between the layers is often dissolved '
oxygen. As this is depleted from the hypolimnion
without being replenished, life functions of  many
organisms  are impaired,  and  the  biology and
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 biologically  mediated reactions  fundamental to
 water quality are altered.

 Vertical stratification of a lake  with respect to
 nutrients can also occur. Dissolved nutrients are
 converted to paniculate organic material through
 photosynthetic processes  in  the epilimnion in
 ecologically  advanced lakes.   This assimilation
 lowers the ambient nutrient concentrations in the
 epilimnion.  When the algae die and sink to the
 bottom, nutrients are carried to the hypolimnion
 where they are released by decomposition.

 Temperature also has a direct effect on biology of
 a lake because most biological processes (e.g.,
 growth,  respiration,  reproduction,  migration,
 mortality, and decay) are strongly influenced by
 ambient temperature.

   Annual   Circulation   Pattern   and  Lake
   Classification

 Lakes can be classified on  the basis of their
 pattern  of  annual mixing.   These classifications
 are described below.

 (1)   Amictic - Lakes that never circulate and are
      permanently covered with ice, primarily in
      the Antarctic and very high mountains.

 (2)   Holomictic - Lakes  that mix from top to
      bottom   as  a result  of  wind-driven
      circulation.    Several  subcategories   are
      defined:

      •   Oligomictic  -  Lakes characterized by
         circulation that is unusual, irregular, and
         short  in  duration;  generally small  to
         medium tropical  lakes  or  very deep
         lakes.

      •   Monomictic -  Lakes that undergo one
         regular circulation per year.

      •   Dimictic - Lakes  that circulate  twice a
         year, in spring and fall, one of the most
         common types of  annual mixing in cool
         temperate  regions such  as  central and
         eastern North America.

      •  Polymictic   -   Lakes   that  circulate
         frequently or continuously,  cold  lakes
         that  are  continually near  or  slightly
         above 4°C,  or  warm equatorial  lakes
         where  air  temperature  changes  very
         little.

(3)   Meromictic - Lakes  that do not circulate
      throughout the entire water column.   The
      lower water stratum is perennially stagnant.

   Lake Sedimentation

Deposition  of  sediment  received   from  the
surrounding watershed is an  important physical
process in lakes.   Because  of  the low water
velocities through the lake or reservoir, sediments
transported by inflowing waters tend to settle out.

Sediment  accumulation  rates   are  strongly
dependent   both   on   the    physiographic
characteristics of a  specific  watershed and on
various characteristics of the lake. Prediction of
sedimentation rates can be estimated in two  basic
ways:

•  periodic sediment surveys on a lake; and
•  estimation of watershed erosion and bed  load.

Accumulation  of sediment in lakes  can,  over
many years, reduce the life of the water body by
reducing  the water storage capacity. Sediment
flow into the lake also reduces light penetration,
eliminates bottom  habitat for many plants and
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                                                                     Chapter 2 - Designation of Uses
animals, and carries with it adsorbed chemicals
and organic matter that settle  to the bottom and
can be harmful to the ecology of the lake. Where
sediment accumulation is a major problem, proper
watershed  management  including  erosion  and
sediment control must be put into effect.

   Chemical Characteristics

Freshwater chemistry is discussed in section 2.9.3
and in the Technical Support Manual, Volume I
(USEPA, 1983c). Therefore, the discussion here
will focus on chemical phenomena that are of
particular importance to lakes. Nutrient cycling
and   eutrophication are the primary factors of
concern in this discussion, but the effects of pH,
dissolved oxygen,  and redox  potential on lake
processes are also involved.

Water chemistry in a lake is closely  related to the
stages in the annual lake turnover.    Once a
thermocline has  formed,  the  dissolved oxygen
levels in the hypolimnion tend to decline.  This
occurs because the hypolimmion is isolated from
surface waters by the  thermocline and there is no
mechanism for aeration.

The decay of organic matter and the respiration of
fish and other organisms in the hypolimnion serve
to deplete DO.   Extreme depletion of  DO may
occur in ice- and snow-covered lakes in which
light   is  insufficient   for  photosynthesis.    If
depletion of DO  is great enough, fish kills may
result.   With  the depletion  of  DO,  reducing
conditions prevail and many compounds that have
accumulated in the sediment by precipitation are
released to  the surrounding water.   Chemicals
solubilized   under   such   conditions   include
compounds   of  nitrogen,  phosphorus,  iron,
manganese,  and  calcium.    Phosphorus  and
nitrogen are of particular concern because of their
role in the eutrophication process  in lakes.

Nutrients released  from  the  bottom sediments
during stratified  conditions are not available to
phytoplankton in the epilimaion. However, during
overturn periods, mixing of the layers distributes
the nutrients throughout the water column.  The
high nutrient availability is short-lived because the
soluble  reduced forms are  rapidly oxidized to
insoluble forms that precipitate out and settle to
the bottom.  Phosphorus and nitrogen are also
deposited through sorption to particles that settle
to the bottom and as  dead plant material  that is
added to the sediments.

Of the many raw materials required  by aquatic
plants   (phytoplankton  and  macrophytes) for
growth, carbon, nitrogen, and phosphorus are the
most important.  Carbon is available from carbon
dioxide,  which is in almost unlimited supply.
Since growth is generally limited by the essential
nutrient that is in lowest supply, either  nitrogen or
phosphorus is usually the limiting nutrient for
growth of primary producers.  If these nutrients
are available in adequate supply,  massive algal
and macrophyte blooms  may occur with  severe
consequences  for the lake.  Most  commonly in
lakes,  phosphorus  is the limiting nutrient for
aquatic  plant  growth.    In  these  situations,
adequate control of phosphorus, particularly from
anthropogenic sources,  can  control  growth of
aquatic  vegetation.   Phosphorus  can in  some
cases,  be removed from the water  column by
precipitation,  as  described  in  the   Technical
Support Manual,  Volume III (USEPA, 1984b).

   Eutrophication and Nutrient Cycling

The term "eutrophication" is used in two general
ways:  (1) eutrophication  is defined as  the process
of nutrient enrichment in a water  body; and (2)
eutrophication is  used to  describe  the effects of
nutrient enrichment,  that is, the uncontrolled
growth of plants,  particularly phytoplankton, in a
lake or  reservoir.    The  second   use  also
encompasses changes in the composition of animal
communities  in the water body.   Both uses are
commonly found  in  the  literature, and the
distinction, if important,  must be discerned from
the context of use.

Eutrophication  is  often  greatly accelerated by
anthropogenic nutrient  enrichment,  which has
been termed "cultural eutrophication." Nutrients
are transported to lakes  from external sources.
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 and once in the lake, may be recycled internally.
 A consideration of attainable uses in a lake must
 include an  understanding  of the  sources  of
 nitrogen  and  phosphorus,  the  significance  of
 internal cycling, especially of phosphorus, and the
 changes that might be anticipated if eutrophication
 could be controlled.

   Significance of Chemical Phenomena to Use
   Attainability

 The  most critical water  quality indicators for
 aquatic use attainment in a lake are DO, nutrients,
 chlorophyll-a,  and toxicants.  In evaluating use
 attainability, the  relative importance of  three
 forms of oxygen  demand should be considered:
 respiratory  demand   of   phytoplankton  and
 macrophytes during non-photosynthetic  periods,
 water column demand, and benthic demand. If use
 impairment is  occurring,  assessments   of the
 significance of each oxygen sink can be useful in
 evaluating the  feasibility of achieving sufficient
 pollution  control, or  in implementing  the best
 internal nutrient management practices to attain a
 designated use.

 Chlorophyll-a  is  a  good  indicator of  algal
 concentrations  and of nutrient overenrichment.
 Excessive   phytoplankton   concentrations,   as
 indicated by high  chlorophyll-a levels, can cause
 adverse DO impacts such as:

 •  wide diurnal variation in surface DO due to
   daytime  photosynthesis   and   nighttime
   respiration, and

 •  depletion  of  bottom   DO  through  the
   decomposition of dead algae.

 As discussed previously, nitrogen and phosphorus
 are the nutrients of concern in most lake systems,
 particularly where anthropogenic sources result in
 increased nutrient loading.  It is important to base
 control  strategies  on  an understanding  of the
 sources of each type of nutrient, both in  the lake
 and in its feeder streams.
 Also, the presence of toxics such as pesticides,
 herbicides, and heavy metals in sediments or the
 water column should by considered in evaluating
 uses. These pollutants may prevent the attainment
 of uses  (particularly  those  related  'to  fish
 propagation and maintenance in water bodies) that
 would otherwise be supported by the water quality
 criteria for DO and other parameters.

   Biological Characteristics

 A  major  concern  for  lake biology  is  the
 eutrophication due to  anthropogenic sources of
 nutrients.  The increased presence of  nutrients
 may result in phytoplankton blooms that can, in
 turn, have adverse impacts on other components
 of the biological community. A general trend that
 results  from  eutrophication is  an increase in
 numbers of organisms but a decrease in  diversity
 of species, particularly among nonmotile species.
 The  biological  characteristics   of lakes  are
 discussed in more detail in the Technical Support
 Manual, Volume HI.

   Techniques for Use Attainability Evaluations

 Techniques for use attainability  evaluations of
 lakes  are discussed  in detail in the Technical
 Support Manual,  Volume III.  Several empirical
 (desktop)   and   simulation   (computer-based
 mathematical)  models  that can  be  used  to
characterize   and  evaluate  lakes  for   use
attainability are presented in that document and
will not be included here owing to the complexity
of the subject.
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                                                           Chapter 3 - Water Quality Criteria
                                 CHAPTERS

                       WATER QUALITY CRITERIA

                               (40 CFR 131.11)

                              Table of Contents

3.1 EPA Section 304(a) Guidance   	3-1
    3.1.1     State Use of EPA Criteria Documents	3-1
    3.1.2     Criteria for Aquatic Life Protection	3-2
    3.1.3     Criteria for Human Health Protection  	3-3

3.2 Relationship of Section 304(a)  Criteria to State Designated Uses  	 3-10
    3.2.1     Recreation	3-10
    3.2.2     Aquatic Life	3-11
    3.2.3     Agricultural and Industrial Uses	3-11
    3.2.4     Public Water Supply	3-11

3.3 State Criteria Requirements	3-12

3.4 Criteria for Toxicants	3-13
    3.4.1     Priority Toxic Pollutant Criteria	3-13
    3.4.2     Criteria for Nonconventional Pollutants	3-23

3.5 Forms of Criteria	3-23
    3.5.1     Numeric Criteria	3-24
    3.5.2     Narrative Criteria  	3-24
    3.5.3     Biological Criteria	3-26
    3.5.4     Sediment Criteria	3-28
    3.5.5     Wildlife Criteria	3-31
    3.5.6     Numeric Criteria for Wetlands	3-33

3.6 Policy on Aquatic Life Criteria for Metals	3-34
    3.6.1     Background	3-34
    3.6.2     Expression of Aquatic Life Criteria	,	3-34
    3.6.3     Total Maximum Daily Loads (TMDLs) and National Pollutant Discharge
              Elimination System (NPDES) Permits	3-36
    3.6.4     Guidance on Monitoring  	3-37

3.7 Site-Specific Aquatic Life Criteria	3-38
    3.7.1     History of Site-Specific Criteria Guidance	3-38
    3.7.2     Preparing to Calculate Site-Specific Criteria  	3-40
    3.7.3     Definition of a Site	3-41
    3.7.4     The Recalculation Procedure	 . 3-41
    3.7.5     The Water-Effect Ratio (WER) Procedure	 3-43
    3.7.6     The Resident Species Procedure	3-44

Endnotes 	3-45

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                                                                  Chapter 3 - Water Quality Criteria
                                       CHAPTERS
                            WATER QUALITY CRITERIA
The term "water quality criteria" has two different
definitions under the  Clean Water Act (CWA).
Under  section 304(a),  EPA  publishes  water
quality   criteria   that   consist  of  scientific
information regarding concentrations of specific
chemicals or levels of parameters in water that
protect aquatic life and human health (see section
3.1 of this Handbook). The States may use these
contents as the basis for developing enforceable
water quality standards. Water quality criteria are
also elements of State  water quality standards
adopted under section 303(c) of the CWA (see
sections  3.2 through 3.6  of  this Handbook).
States are required to adopt water quality criteria
that will protect the designated  use(s) of a water
body.   These criteria must be based on  sound
scientific  rationale and  muist contain sufficient
parameters  or   constituents   to  protect  the
designated use.
         EPA Section 304(a) Guidance
EPA and a predecessor agency have produced a
series of scientific water quality criteria guidance
documents.    Early  Federal  efforts  were  the
"Green  Book" (FWPCA,  1968)  and the "Red
Book" (USEPA, 1976).  EPA also sponsored a
contract effort that resulted in the "Blue Book"
(NAS/NAE,  1973).   These early efforts were
premised on the use of literature reviews and the
collective  scientific  judgment  of Agency and
advisory panels. However, when faced with the
need to develop criteria for human health as well
as aquatic life, the Agency determined that new
procedures were necessary.  Continued reliance
solely on existing scientific literature was deemed
inadequate because essential information was not
available for  many pollutants.  EPA  scientists
developed formal methodologies for establishing
scientifically  defensible criteria.   These were
subjected  to  review by  the Agency's  Science
Advisory Board of outside experts and the public.
This effort culminated on November 28,  1980,
when the Agency published criteria development
guidelines for aquatic life and for human health,
along  with criteria  for 64   toxic  pollutants
(USEPA, 1980a,b).  Since that initial publication,
the  aquatic  life  methodology  was   amended
(Appendix  H),  and additional  criteria  were
proposed for public comment and  finalized  as
Agency criteria guidance. EPA summarized the
available criteria information in the "Gold Book"
(USEPA, 1986a), which is updated from time to
time. However, the individual criteria documents
(see Appendix  I), as updated,  are the official
guidance documents.

EPA's   criteria   documents   provide  a
comprehensive lexicological evaluation  of each
chemical.   For toxic pollutants, the documents
tabulate the relevant acute and chronic toxicity
information for aquatic life and derive the criteria
maximum  concentrations (acute criteria) and
criteria   continuous  concentrations    (chronic
criteria) that the Agency  recommends  to protect
aquatic  life resources.  The methodologies for
these processes are described in Appendices H
and J and outlined in sections 3.1.2 and  3.1.3 of
this Handbook.

3.1.1    State Use of EPA Criteria Documents

EPA's  water  quality criteria  documents  are
available to assist States in:

•    adopting water quality standards that include
     appropriate numeric  water quality criteria;

•    interpreting existing  water quality standards
     that include  narrative  "no  toxics in toxic
     amounts" criteria;
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 Water Quality Standards Handbook - Second Edition
 *    making listing decisions under section 304(1)
      oftheCWA;

 •    writing water quality-based NPDES permits
      and individual control strategies; and

 *    providing certification under section 401 of
      the CWA for any Federal permit or license
      (e.g.,  EPA-issued NPDES permits,  CWA
      section 404 permits,  or Federal Energy
      Regulatory Commission licenses).

 In these situations, States have primary authority
 to determine the appropriate  level to protect
 human health  or welfare  (in accordance  with
 section 303(c)(2)  of the CWA) for each  water
 body.  However, under the Clean Water Act,
 EPA must also review and approve State  water
 quality standards;  section 304(1) listing decisions
 and draft and final State-issued individual control
 strategies;  and in  States  where EPA  writes
 NPDES permits, EPA  must develop appropriate
 water quality-based permit limitations. The States
 and EPA therefore  have a strong interest  in
 assuring that the decisions are legally defensible,
 are based on the best information available, and
 are subject to full and meaningful public comment
 and participation.  It is very important  that each
 decision be supported  by an  adequate record.
 Such a record is critical to meaningful comment,
 EPA's  review  of the State's decision,  and any
 subsequent administrative or judicial review.

 Any human health criterion for a toxicant is based
 on at least three interrelated considerations:

 *    cancer potency or systemic toxicity,

 •    exposure, and

 *    risk characterization.

 States may make their own judgments on each of
 these factors within reasonable scientific bounds,
 but documentation to support  their judgments,
 when different from EPA's recommendation, must
 be clear and in the public record. If a State relies
on EPA's section 304(a) criteria  document (or
 other EPA documents), the State may reference
 and rely on the data in these documents and need
 not create  duplicative  or  new  material   for
 inclusion in their records. However, where site-
 specific issues arise or the State decides to adopt
 an approach to any one of these three factors that
 differs  from  the approach  in EPA's  criteria
 document, the State must explain its reasons in a
 manner sufficient for a reviewer to determine that
 the approach chosen is based on sound scientific
 rationale (40 CFR 131.ll(b)).

 3.1.2     Criteria for Aquatic Life Protection

 The development of national  numerical water
 quality  criteria  for  the protection  of  aquatic
 organisms  is  a  complex  process  that uses
 information  from  many   areas  of   aquatic
 toxicology.   (See Appendix H for  a detailed
 discussion of this process.)  After a decision is
 made that a  national criterion  is needed for a
 particular  material,  all available  information
 concerning toxicity to, and bioaccumulation by,
 aquatic organisms is collected and reviewed  for
 acceptability. If enough acceptable data for 48- to
 96-hour  toxicity tests  on  aquatic plants  and
 animals are available, they are used to derive  the
 acute criterion.  If sufficient data on the ratio of
 acute to  chronic toxicity  concentrations  are
 available, they are used to derive the chronic or
 long-term exposure criteria. If justified,  one or
 both of the criteria may be related to other water
 quality characteristics,  such as pH, temperature,
 or hardness.  Separate  criteria are developed for
 fresh and salt waters.

The Water Quality Standards Regulation allows
States to develop  numerical criteria or modify
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                                                                   Chapter 3 - Water Quality Criteria
 EPA's  recommended  criteria  to  account  for
 site-specific  or other  scientifically  defensible
 factors. Guidance on modifying national criteria
 is  found  in  sections  3.6  and  3.7.   When  a
 criterion must be developed for a chemical for
 which   a  national  criterion  has   not  been
 established, the regulatory authority should refer
 to the EPA guidelines (Appendix H).

      Magnitude for Aquatic Life Criteria

 Water quality criteria for aquatic life contain two
 expressions of allowable magnitude: a criterion
 maximum concentration (CMC) to protect against
 acute  (short-term)  effects;  and   a  criterion
 continuous concentration (CCC) to protect against
 chronic (long-term)  effects.  EPA derives acute
 criteria from  48- to 96-hour tests of lethality or
 immobilization.  EPA derives  chronic criteria
 from longer term (often greater than 28-day) tests
 that measure  survival,  growth, or reproduction.
 Where appropriate, the calculated criteria may be
 lowered  to   be  protective  ofcomercially  or
 recreationally important species.

     Duration for Aquatic Life Criteria

 The quality of an ambient water typically varies in
 response to variations of effluent quality, stream
 flow,  and other  factors.   Organisms in  the
 receiving water are not  experiencing constant,
 steady  exposure but  rather  are experiencing
 fluctuating exposures,  including periods of high
 concentrations, which may have adverse effects.
 Thus, EPA's criteria indicate a time  period over
 which exposure is to be averaged, as well as an
 upper limit on the average concentration, thereby
 limiting  the  duration  of exposure  to  elevated
 concentrations.   For   acute   criteria,   EPA
 recommends an averaging period of 1 hour.  That
 is, to protect against acute effects,  the 1-hour
 average exposure should not exceed  the CMC.
For  chronic  criteria,  EPA  recommends  an
 averaging period of  4 days.  That is, the 4-day
average exposure should not exceed the CCC.
      Frequency for Aquatic Life Criteria

 To predict or ascertain the attainment of criteria,
 it is necessary to specify the allowable frequency
 for exceeding the criteria.  This is because it is
 statistically impossible to project that criteria will
 never be exceeded.  As ecological communities
 are naturally subjected to  a series of stresses, the
 allowable frequency of pollutant stress may be set
 at a value that does not significantly increase the
 frequency or severity of all stresses combined.

 EPA  recommends an average frequency  for
 excursions of both acute and chronic criteria not
 to exceed once in 3  years.   In all cases,  the
 recommended frequency applies to actual ambient
 concentrations,  and excludes  the  influence of
 measurement  imprecision.  EPA established its
 recommended frequency as part of its guidelines
 for deriving criteria (Appendix H). EPA selected
 the   3-year   average  frequency  of  criteria
 exceedence  with  the  intent  of providing  for
 ecological  recovery from a variety  of  severe
 stresses.    This  return   interval is  roughly
 equivalent to a  7Q10 design  flow  condition.
 Because of the nature of the  ecological recovery
 studies  available,  the   severity  of  criteria
 excursions could not be rigorously related to the
 resulting ecological impacts.  Nevertheless, EPA
 derives its criteria intending that a single marginal
 criteria excursion (i.e., a slight excursion over a
 1-hour period for acute or over a 4-day period for
 chronic) would  require  little  or no  time for
 recovery. If  the frequency of marginal criteria
 excursions is not high, it  can be shown that the
 frequency of severe stresses, requiring measurable
 recovery periods,  would be extremely  small.
 EPA  thus expects the 3-year return interval to
 provide a very high degree of protection.

 3.1.3  Criteria for Human Health Protection

This  section reviews EPA's procedures used to
develop assessments of human  health effects in
developing water quality  criteria and reference
ambient concentrations. A more complete human
health  effects discussion  is  included  in  the
Guidelines and Methodology Used in the
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 Water Quality Standards Handbook - Second Edition
 Preparation of Health Effects Assessment Chapters
 of  the  Consent  Decree  Water  Documents
 (Appendix J).  The procedures contained in this
 document are  used  in  the development and
 updating of EPA water quality criteria and may be
 used in updating State criteria and in developing
 State criteria for those pollutants lacking EPA
 human health criteria.   The procedures  may also
 be  applied  as  site-specific  interpretations of
 narrative standards and as a basis for permit limits
 under 40 CFR 122.44 (d)(l)(vi).

     Magnitude and Duration

 Water  quality criteria  for human health contain
 only a  single expression of allowable magnitude;
 a criterion concentration generally to protect
 against long-term (chronic) human health effects.
 Currently, national policy and prevailing opinion
 in  the  expert  community  establish   that the
 duration for human health criteria for carcinogens
 should  be derived assuming lifetime exposure,
 taken to be a 70-year time period. The duration
 of  exposure assumed  in  deriving  criteria for
 noncarcinogens is more complicated owing to a
 wide variety of endpoints:  some developmental
 (and  thus  age-specific  and perhaps  gender-
 specific), some  lifetime,  and some,   such  as
 organoleptic effects, not duration-related at all.
 Thus,   appropriate  durations  depend  on the
 individual  noncarcinogenic pollutants   and the
 endpoints or adverse effects being considered.

     Human Exposure Considerations

 A complete human exposure evaluation for toxic
 pollutants of concern for bioaccumulation would
 encompass not only estimates of exposures due to
 fish   consumption  but   also  exposure   from
 background  concentrations and  other exposure
 routes,   The more important of these include
 recreational  and  occupational  contact,   dietary
 intake  from  other  than fish, intake from air
 inhalation, and drinking water consumption. For
 section 3Q4(a) criteria development, EPA typically
 considers only exposures to a pollutant that occur
 through the ingestion of water and contaminated
fish and shellfish.  This  is the exposure default
 assumption, although the human health guidelines
 provide for considering other sources  where data
 are available (see  45  F.R. 79354).   Thus the
 criteria are  based on  an assessment  of risks
 related to the surface water exposure route only
 (57 F.R. 60862-3).

 The consumption of contaminated fish tissue is of
 serious concern  because the  presence of even
 extremely   low   ambient   concentrations  of
 bioaccumulative pollutants (sublethal to aquatic
 life) in surface  waters can  result  in  residue
 concentrations in fish tissue that can pose a human
 health risk.  Other exposure  route information
 should be considered and incorporated in human
 exposure evaluations to the extent available.

 Levels  of  actual  human   exposures   from
 consuming contaminated fish vary depending upon
 a number of case-specific consumption factors.
 These  factors  include  type   of  fish  species
 consumed, type of fish tissue consumed, tissue
 lipid content, consumption rate and pattern, and
 food preparation practices. In addition, depending
 on the spatial variability in the fishery area, the
 behavior of the fish  species,  and  the point of
 application of the criterion, the average exposure
 of fish may be  only  a small fraction of the
 expected exposure at the point of application of
 the  criterion.   If an effluent attracts fish, the
 average exposure  might be  greater  than the
 expected exposure.

 With  shellfish,  such  as oysters,  snails, and
 mussels,   whole-body   tissue   consumption
 commonly  occurs,  whereas with fish, muscle
 tissue and roe are most commonly  eaten.   This
 difference in  the types of tissues  consumed has
 implications  for   the  amount  of   available
 bioaccumulative   contaminants  likely  to  be
 ingested.   Whole-body shellfish consumption
 presumably means ingestion of the entire burden
 of bioaccumulative contaminants. However, with
 most fish,  selective cleaning  and  removal of
internal organs, and sometimes body fat as well,
 from edible tissues, may result in removal of
 much   of   the   lipid  material  in   which
bioaccumulative contaminants tend to concentrate.
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                                                                 Chapter 3 - Water Quality Criteria
     Fish Consumption Values

EPA's human health criteria  have assumed  a
human body weight of 70 kg and the consumption
of 6.5 g of fish and shellfish per day.  Based on
data collected in 1973-74, the national per capita
consumption of freshwater and estuarine fish was
estimated  to average 6.5  g/day.   Per  capita
consumption  of all  seafood (including marine
species) was estimated  to average 14.3 g/day.
The 95th percentile for consumption of all seafood
by  individuals over  a period  of 1  month  was
estimated to be 42 g/day. The mean lipid content
of fish and shellfish tissue consumed in this study
was estimated to be 3.0 percent  (USEPA, 1980c).
Currently,  four  levels of  fish  and  shellfish
consumption  are provided  in EPA guidance
(USEPA, 1991a):

•    6.5 g/day to represent an estimate of average
     consumption of fish and  shellfish  from
     estuarine and freshwaters by the entire U.S.
     population. This consumption level is based
     on the  average of  both consumers  and
     nonconsumers of.

•    20 g/day  to represent  an estimate of the
     average  consumption of fish and  shellfish
     from marine, estuarine, and freshwaters by
     the  U.S.   population.     This  average
     consumption  level   also  includes  both
     consumers and nonconsumers of.

•    165 g/day to represent consumption of fish
     and shellfish from marine, estuarine,  and
     freshwaters by the 99.9th percentile of the
     U.S. population consuming the most fish or
     seafood.

•    180 g/day to represent a  "reasonable worst
     case"  based on the assumption that some
     individuals would consume fishand shellfish
     at a rate equal to the combined consumption
     of red meat, poultry, fish, and  shellfish in
     the United States.
EPA is currently updating the national estuarine
and freshwater fish  and shellfish  consumption
default values  and  will  provide  a  range  of
recommended national consumption values.  This
range will include:

•   mean values appropriate to the population at
    large; and

•   values appropriate for those individuals who
    consume a relatively large proportion of fish
    and   shellfish  in their  diets  (maximally
    exposed individuals).

Many States use EPA's 6.5 g/day consumption
value.   However, some States use the above-
mentioned 20  g/day value and,  for  saltwaters,
37 g/day.  In general, EPA recommends that the
consumption values used in deriving criteria from
the formulas in  this chapter  reflect  the  most
current, relevant, and/or site-specific information
available.

    Bioaccumulation Considerations

The ratio of the contaminant concentrations in fish
tissue versus that in water is termed either  the
bioconcentration   factor  (BCF)    or   the
bioaccumulation factor (BAF).  Bioconcentration
is defined as involving contaminant uptake from
water only (not from food).  The bioaccumulation
factor (BAF)  is defined similarly to the  BCF
except that it includes contaminant uptake from
both  water  and  food.    Under  laboratory
conditions,   measurements   of  tissue/water
partitioning are generally considered  to involve
uptake from water only.  On the other hand, both
processes are likely to apply in the field since the
entire food chain is exposed.

The BAF/BCF ratio ranges from 1 to  100, with
the highest ratios applying to organisms in higher
trophic levels, and to chemicals with logarithm of
the octanol-water  partitioning coefficient (log P)
close to 6.5.

Bioaccumulation considerations are integrated into
the criteria equations  by  using food  chain
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                                         3-5

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  Water Quality Standards Handbook - Second Edition
 multipliers (FMs) in conjunction with the BCF.
 The bioaccumulation and bioconcentration factors
 for a chemical are related as follows:

               BAF = FM x BCF

 By incorporating the FM and BCF terms into the
 criteria  equations,   bioaccumulation  can  be
 addressed.

 In Table 3-1,  FM values derived from the work
 of Thomann (1987, 1989) are listed according to
 log P value and trophic level of the organism.
 For chemicals with log P values  greater than
 about 7, there is additional uncertainty regarding
 the degree of bioaccumulation,  but generally,
 trophic level  effects appear  to decrease due to
 slow transport kinetics of these chemicals in fish,
 the growth rate  of the fish,  and the chemical's
 relatively low bioavailability.  Trophic  level 4
 organisms are typically the most desirable species
 for sport fishing and, therefore, FMs for trophic
 level 4 should  generally be used in the equations
 for calculating  criteria.    In those  very rare
 situations  where  only   lower  trophic  level
 organisms are  found, e.g.,  possibly oyster beds,
 an FM for a lower trophic  level might  be
 considered.

 Measured BAFs  (especially for those chemicals
 with log  P values  above 6.5) reported in the
 literature should be used when available.  To use
 experimentally measured BAFs in calculating the
 criterion, the (FM x BCF) term is replaced by the
 BAF in the equations in the following-section.
 Relatively  few  BAFs  have been  measured
 accurately and  reported, and their application to
 sites other than the specific ecosystem where they
 were developed  is problematic and subject  to
 uncertainty.    The option is also available  to
 develop BAFs  experimentally, but this  will be
 extremely resource intensive if done on  a site-
 specific basis with all the necessary experimental
and quality controls.
                                                                        c .Levels
                                                     LogP

                                                       3.5

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                                                       44
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                                                                   Chapter 3 - Water Quality Criteria
 health criteria.  The Integrated Risk Information
 System  (IRIS)  (Barns  and  Dourson,  1988;
 Appendix  N) is an electronic data base of the
 USEPA  that  provides  chemical-specific  risk
 information on the relationship between chemical
 exposure and estimated human health effects. Risk
 assessment information contained in IRIS, except
 as  specifically  noted,  has been  reviewed  and
 agreed upon  by  an  interdisciplinary group of
 scientists representing various Program  Offices
 within the Agency and represent an Agency-wide
 consensus.   Risk assessment information  and
 values are updated on  a  monthly basis and  are
 approved for Agency-wide use.  IRIS is intended
 to  make  risk  assessment information  readily
 available to those individuals  who must perform
 risk assessments and also  to increase consistency
 among   risk   assessment/risk   management
 decisions.

 IRIS contains  two types of quantitative risks
 values:  the oral Reference Dose (RfD) and  the
 carcinogenic potency estimate or  slope factor.
 The RfD (formerly known as the acceptable daily
 intake or  ADI) is the  human health  hazard
 assessment  for  noncarcinogenic (target  organ)
 effects.    The  carcinogenic  potency estimate
 (formerly  known  as  qi*) represents the upper
 bound cancer-causing potential resulting from
 lifetime exposure to a substance. The RfD or the
 oral carcinogenic potency  estimate is used in the
 derivation of EPA human  health criteria.

 EPA  periodically  updates  risk   assessment
 information,  including  RfDs,  cancer  potency
 estimates, and related information on contaminant
 effects, and reports the current information  on
 IRIS.  Since IRIS Contains the Agency's most
 recent quantitative risk assessment values,  current
 IRIS values should be used by States in updating
 or developing new human health criteria.  This
 means that the 1980 human health criteria should
be  updated with the  latest IRIS  values.  The
procedure for deriving an updated human health
water quality criterion would require inserting the
current Rfd or carcinogenic potency estimate on
IRIS into the equations in  Exhibit 3.1 or 3.2, as
appropriate.
                    EPA's
                  water quality
                    criterion
                   available
                             Evaluate other
                             sources of data,
                             e.g.. FDA action
                             levels, MCLs, risk
                             assessment, fish
                             consumption
                             advisory levels
Figure 3-1.   Procedure  for determining  an
              updated  criterion  using  IRIS
              data.

Figure 3-1 shows the procedure for determining
an  updated criterion  using  IRIS  data.   If a
chemical   has   both  carcinogenic   and  non-
carcinogenic effects, i.e., both a cancer potency
estimate  and a  RfD, both  criteria  should  be
calculated. The  most stringent criterion applies.

     Calculating Criteria for Non-carcinogens

The RfD is an estimate of the daily exposure to
the human population that is likely to  be without
appreciable risk of causing  deleterious effects
during a lifetime. The RfD is expressed in units
of mg toxicant per kg human body weight per
day.

RfDs are derived from the "no-observed-adverse-
effect level" (NOAEL) or the "lowest-observed-
adverse-effect level"  (LOAEL)  identified  from
chronic or subchronic human epidemiology studies
or animal exposure studies.   (Note:  "LOAEL"
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 Water Quality Standards Handbook - Second Edition
 and  "NOAEL"  refer to  animal  and  human
 toxicology and are therefore  distinct from the
 aquatic   toxicity   terms   "no-observed-effect
 concentration" (NOEC)  and  "lowest-observed-
 effect  concentration"  (LOEC).)   Uncertainty
 factors are then applied to the NOAEL or LOAEL
 to account for uncertainties in the data associated
 with variability among individuals, extrapolation
 from nonhuman test species to humans, data on
 other than long-term exposures, and the use of a
 LOAEL  (USEPA,  1988a).    An  additional
 uncertainty factor may be applied to account for
 significant weakness or gaps in the database.

 The RfD is  a threshold  below  which systemic
 toxic  effects are  unlikely  to  occur.   While
 exposures above the RfD  increase the probability
 of adverse effects, they do not produce a certainty
 of adverse effects.   Similarly,  while exposure at
 or below the RfD reduces the probability, it does
 not guarantee the absence of effects in all persons.
 The  RfDs contained  in  IRIS are  values that
 represent EPA's consensus (and have uncertainty
 spanning perhaps an order of magnitude). This
 means an RfD of 1.0 mg/kg/day could range from
 0.3 to 3.0 mg/kg/day.

 For noncarcinogenic effects, an updated criterion
 can be derived using the equation in Exhibit 3-1.

 If the receiving  water body is  not used as  a
 drinking water source,  the factor  WI  can be
 deleted.    Where  dietary  and/or   inhalation
 exposure values are unknown,  these  factors may
 be deleted from the above calculation.

     Calculating Criteria for Carcinogens

 Any human health  criterion  for a carcinogen is
 based on at least three interrelated considerations:
 cancer   potency,   exposure,   and   risk
 characterization. When developing State criteria,
 States may make their own judgments on each of
 these factors  within reasonable  scientific bounds,
 but  documentation to support their judgments
 must be clear and in the public record.
Maximum protection of human health from the
potential  effects of exposure  to  carcinogens
through  the  consumption of  contaminated fish
and/or other aquatic life would require a criterion
of zero.   The zero level is based  upon  the
assumption of non-threshold effects (i.e., no safe
level exists below which any increase in exposure
does not result in an increased risk of cancer) for
carcinogens.    However,  because a  publicly
acceptable policy for safety does not require the
absence  of all  risk, a numerical  estimate of
pollutant   concentration   (in   jig/1)   which
corresponds  to  a  given level of risk  for a
population of a specified size is selected instead.
A cancer risk level is defined as the number of
new cancers  that may result in a population of
specified  size due  to an increase in  exposure
(e.g., 10"6 risk level  =  1 additional cancer in a
population of 1 million).  Cancer risk is calculated
by multiplying the experimentally derived cancer
potency  estimate by the concentration of  the
chemical in the fish and the average daily human
consumption of contaminated fish.  The risk for a
specified population (e.g., 1 million people or 10"
6) is then calculated by dividing the risk level by
the specific cancer  risk.  EPA's ambient water
quality  criteria  documents  provide risk  levels
ranging from 10"5 to 10~7 as  examples.

The cancer potency  estimate, or  slope  factor
(formerly known as  the c^*), is derived using
animal  studies.     High-dose  exposures   are
extrapolated  to  low-dose  concentrations  and
adjusted to a lifetime exposure period through the
use of a linearized multistage model. The model
calculates the upper 95 percent confidence limit of
the slope of a  straight line  which the model
postulates to occur at low doses.  When based on
human (epidemiological) data,  the slope factor is
based on the observed increase in cancer risk and
is not extrapolated.   For  deriving criteria  for
carcinogens, the oral cancer potency estimates or
slope factors from IRIS are used.

It is important to note that cancer potency factors
may overestimate or underestimate the actual risk.
Such  potency  estimates are  subject  to  great
uncertainty because of two primary factors:
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                                                                   Chapter 3 - Water Quality Criteria
    where;
          "t   '='

            s
           IN

           TO    *=
           BCF
                  ,-wi
aj(dated water quality criterion (mg/J.)

oral reference dose (nag toxicant/kg human body weight/day)

weight of an average human adult (70 kg)
     s    j  -f  y
dietary ^ expoiswre  (oilier  than fish)  (mg toxicant/kg body human
weight/day)    .

inltialation exposure (mg toxicant/kg body human weight/day)

average human adult water intake (2 I/day)

daily fish consumption (kg fish/day)

ratio of lipid traction of fish tissue ^consumed to 3%

food chaitt multiplier (from Table 3-1}

bioconceatradoa factor (tag  toxicant/kg fish divided by mg toxicant/L
water) for fish with 3% lipid content
  Exhibit 3-1.  Equation for Deriving Human Health Criteria Based on Noncarcinogenic Effects
•    adequacy  of the  cancer  data base  (i.e.,
     human vs. animal data); and

•    limited information regzirding the mechanism
     of cancer causation.

Risk levels of 10'5, 10'6, and 10'7 are often used
by States as minimal risk levels hi interpreting
their  standards.   EPA  considers  risks  to  be
additive, i.e., the risk from individual chemicals
is not necessarily the overall risk from exposure
to water. For example, an individual risk level of
10'6  may yield a higher  overall risk  level if
multiple carcinogenic chemicals are present.

For  carcinogenic  effects,  the  criterion can  be
determined by using the equation in Exhibit 3-2.
                        If the receiving water body is not designated as a
                        drinking water  source,  the  factor WI  can be
                        deleted.

                             Deriving Quantitative Risk Assessments in
                             the Absence of IRIS Values

                        The RfDs or cancer potency estimates  comprise
                        the existing dose-response factors for developing
                        criteria.    When  IRIS  data are  unavailable,
                        quantitative  risk  level  information  may  be
                        developed according  to a  State's own procedures.
                        Some   States  have  established  their  own
                        procedures whereby dose-response factors can be
                        developed  based upon  extrapolation  of acute
                        and/or chronic animal  data to concentrations of
                        exposure  protective of  fish consumption  by
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 Water Quality Standards Handbook - Second Edition
          C(mg/I) «
    where:
                    %* [WI Hh FC x L x (FM x
C     =    updated water quality criterion (rag/1)


RL    =    risk level (10*) where x Is usually in the fangeTof 4 to 6
      "   	                                "      ^ •%$ * "S f " >J'        ^ ±   "'*'••  <•
                                                 "  "^ •• / /,        ,/^S,
WT   —    weight of an average human adult (70 kg)
                                            f A    <     A V*          J -wiwi     '• v ^ ff
                                                       «,            *s
qt*    =    carcinogenic potency factor (kg day/mg)


WI    =    average human adult water intake (2 I/day)


FC    =    daily fish consumption (kg fish/day)


L     »    ratio of lipid fraction of fish tissue consumed to 3 % assume! by EPA
                                            ,       u. vu, w, v ™ ™ ^    ^   ' X "*

FM    as    food chain multiplier (from Table 3-1)


BCF   =    bioconCentration factor  (mg  loxicant/kg fish divided by mg toxicant/L
             water) for fish with 3% lipid content
                                  ^  *v       fv~f  s «! i ii-v wvi
                                                                                             II	I	
  Exhibit 3-2.  Equation for Deriving Human Health Criteria Based on Carcinogenic Effects
humans.

13.21 Relationship of Section 304(a) Criteria
T"""11" to State Designated Uses

The section 304(a)(l) criteria published by EPA
from time to time  can be used to support the
designated uses found  in State standards.  The
following sections briefly discuss the relationship
between  certain  criteria  and individual  use
classifications.  Additional information on this
subject also can be  found  in  the "Green Book"
(FWPCA, 1968);  the "Blue Book" (NAS/NAE,
1973); the "Red Book"  USEPA, 1976); the EPA
Water Quality Criteria Documents (see Appendix
I); the"Gold Book"  (USEPA,  1986a); and future
EPA  section  304(a)(l) water quality criteria
publications.
                                     Where a water body is designated for more than
                                     one use, criteria  necessary to protect the most
                                     sensitive use must be applied. The following four
                                     sections discuss the major types of use categories.
                                    3.2.1  Recreation

                                    Recreational uses of water include activities such
                                    as  swimming,  wading,  boating,  and fishing.
                                    Often insufficient data exist on the human health
                                    effects  of physical  and  chemical  pollutants,
                                    including most toxics, to make a determination of
                                    criteria  for  recreational  uses. However, as  a
                                    general guideline, recreational waters that contain
                                    chemicals in concentrations  toxic  or  otherwise
                                    harmful to man  if ingested, or irritating  to the
                                    skin or  mucous membranes of the human body
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upon brief immersion, should be avoided.  The
section  304(a)(l) human  health effects criteria
based on direct human drinking water intake and
fish consumption might provide useful guidance in
these  circumstances.   Also,  section  304(a)(l)
criteria  based on human  health effects may be
used to  support this designated use where fishing
is included in the State definition of "recreation."
In this  latter situation, only the portion of the
criterion based on  fish consumption should be
used.   Section  304(a)(l)   criteria  to  protect
recreational uses are also available for certain
physical,  microbiological, and  narrative  "free
from" aesthetic criteria.

Research regarding  bacteriological indicators has
resulted in EPA recommending that States use
Escherichia coli or enterococci  as indicators of
recreational water quality (USEPA, 1986b) rather
than  fecal coliform  because  of  the  better
correlation with gastroenteritis in swimmers.

The "Green  Book" and  "Blue Book" provide
additional information on protecting  recreational
uses such as pH criteria to prevent eye irritation
and microbiological criteria  based on aesthetic
considerations.

3.2.2  Aquatic Life

The section  304(a)(l) criteria  for  aquatic life
should be used directly to support this designated
use.  If subcategories of this use are adopted
(e.g., to  differentiate between coldwater  and
warmwater fisheries), then appropriate  criteria
should be set to reflect the varying needs of such
subcategories.

3.2.3  Agricultural and Industrial Uses

The "Green Book" (FWPCA,  1968) and "Blue
Book"   (NAS/NAE,   1973)   provide   some
information  on  protecting  agricultural   and
industrial uses.  Section 304(a)(l)  criteria for
protecting  these uses have not been specifically
developed for numerous parameters pertaining to
these uses, including most toxics.
Where  criteria  have  not  been   specifically
developed for these uses,  the criteria developed
for human health and aquatic life  are  usually
sufficiently stringent to protect these uses.  States
may also establish criteria specifically designed to
protect these uses.

3.2.4  Public Water Supply

The drinking water exposure component of the
section 304(a)(l) criteria based  on human health
effects can apply directly to this use classification.
The criteria also may be appropriately modified
depending upon whether the specific water supply
system  falls  within  the  auspices  of the Safe
Drinking Water Act's (SDWA) regulatory control
and the type and level of treatment imposed upon
the supply before delivery to the consumer. The
SDWA controls the presence of contaminants in
finished ("at-the-tap") drinking water.

A brief description of relevant sections  of the
SDWA is necessary to explain how the Act will
work in conjunction with section 304(a)(l) criteria
in protecting human health  from the effects of
toxics due to consumption of water.  Pursuant to
section 1412 of the SDWA, EPA has promulgated
"National Primary Drinking Water Standards" for
certain radionuclide, microbiological, organic, and
inorganic substances.  These standards establish
maximum  contaminant  levels  (MCLs),  which
specify  the maximum  permissible  level  of a
contaminant in water  that may be delivered to a
user of a public  water system  now defined as
serving  a minimum  of 25 people.    MCLs are
established based  on consideration of a range of
factors including not only the health  effects of the
contaminants  but  also  treatment  capability,
monitoring availability, and costs. Under section
1401(l)(D)(i) of the SDWA, EPA is also allowed
to establish the minimum quality criteria for water
that may  be taken into  a public water supply
system.

Section  304(a)(l)  criteria provide  estimates of
pollutant  concentrations  protective  of  human
health, but do not consider treatment technology,
costs, and other feasibility factors.   The section
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 304(a)(l)   criteria   also   include  fish
 bioaccumulation  and  consumption  factors  in
 addition to direct human drinking water intake.
 These numbers were not developed to serve as
 Mat-the-tap"  drinking water standards, and they
 have no regulatory significance under the SDWA.
 Drinking water standards are established based on
 considerations,   including  technological   and
 economic feasibility,  not  relevant  to  section
 304(a)(l) criteria.  Section 304(a)(l) criteria are
 more analogous to  the  maximum contaminant
 level  goals  (MCLGs)  (previously  known  as
 RMCLs)   under section  1412(b)(l)(B)  of the
 SDWA in which, based  upon a report from the
 National Academy of Sciences, the Administrator
 should set  target  levels  for contaminants  in
 drinking water at which "no known or anticipated
 adverse effects occur and which allow an adequate
 margin of safety." MCLGs do  not take treatment,
 cost,   and   other   feasibility  factors  into
 consideration.  Section 304(a)(l) criteria are, in
 concept, related to the health-based goals specified
 in the MCLGs.

 MCLs of the SDWA, where they exist, control
 toxic  chemicals in   finished   drinking  water.
 However,  because  of variations in  treatment,
 ambient water criteria may be  used by the States
 as a supplement to  SDWA regulations.  When
 setting water quality criteria  for public water
 supplies,  States  have  the option  of applying
 MCLs, section 304(a)(l) human health effects
 criteria, modified section 304(a)(l) criteria, or
 controls more stringent than these three to protect
 against the effects of contaminants by ingestion
 from drinking water.

 For  treated drinking water supplies serving 25
 people  or   greater,   States   must  control
 contaminants down  to levels at least as stringent
 as MCLs  (where they exist for the pollutants of
 concern)   in   the   finished   drinking   water.
 However, States also have the options to control
 toxics  in the ambient water by choosing section
 304(a)(l)   criteria,  adjusted  section  304(a)(l)
 criteria resulting from the reduction of the direct
 drinking water exposure component hi the criteria
 calculation to the extent that the treatment process
 reduces the level of pollutants, or a more stringent
 contaminant level than the former three options.
        State Criteria Requirements
 Section  131.11(a)(l) of the Regulation  requires
 States to adopt water quality criteria to protect the
 designated  use(s).   The State criteria must  be
 based on sound  scientific  rationale  and  must
 contain  sufficient parameters or constituents  to
 protect the designated use(s).  For waters with
 multiple  use  designations,  the  criteria   must
 support the most sensitive use.

 In section 131.11, States are encouraged  to adopt
 both numeric and narrative criteria.  Aquatic life
 criteria  should  protect against  both short-term
 (acute) and long-term (chronic) effects. Numeric
 criteria are particularly important where the cause
 of toxicity  is  known  or for protection against
 pollutants with potential human health impacts  or
 bioaccumulation potential. Numeric water quality
 criteria may also be  the best way  to  address
 nonpoint source pollution problems.   Narrative
 criteria can be the basis for limiting toxicity  in
 waste discharges where a specific pollutant can be
 identified as causing or contributing to the toxicity
 but  where there  are no  numeric criteria in the
 State standards.  Narrative  criteria also can be
 used where toxicity  cannot be traced  to  a
 particular pollutant.

 Section 131.11(a)(2) requires States to develop
 implementation procedures which explain how the
 State will ensure that narrative toxics criteria are
 met.

 To more fully protect aquatic habitats, it is EPA's
policy that States fully integrate chemical-specific,
 whole-effluent,    and   biological   assessment
approaches in State water quality programs (see
Appendix R).  Specifically,  each of these  three
methods can provide a valid  assessment of non-
attainment of designated aquatic life uses  but can
rarely  demonstrate  use  attainment  separately.
Therefore, EPA supports  a policy of independent
application of these three water quality assessment
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                                                                   Chapter 3 - Water Quality Criteria
approaches.  Independent application means that
the validity  of the results of any one  of the
approaches does not depend  on confirmation by
one or both of the other methods.  This policy is
based on the unique attributes, limitations, and
program  applications  of each  of  the  three
approaches. Each method alone can provide valid
and  independently  sufficient evidence of  non-
attainment of water quality standards, irrespective
of any evidence, or lack thereof, derived from the
other two approaches.  The failure of one method
to confirm impacts identified by another method
does  not negate  the  results  of  the   initial
assessment.

It is  also  EPA's  policy  that  States  should
designate aquatic  life uses  that  appropriately
address biological integrity and adopt biological
criteria  necessary  to  protect those  uses (see
section 3.5.3 and Appendices C, K, and R).
       Criteria for Toxicants
Applicable  requirements  for State  adoption of
water quality criteria for toxicants vary depending
upon the toxicant.  The reason for this is that the
1983  Water  Quality   Standards   Regulation
(Appendix A) and the Water Quality Act of 1987
which amended the Clean Water Act (Public Law
100-4) include more specific requirements for the
particular  toxicants  listed  pursuant  to  CWA
section 307(a). For regulatory purposes, EPA has
translated  the 65  compounds  and families of
compounds listed pursuant to section 307(a) into
126 more specific substances, which EPA refers
to as "priority toxic pollutants."  The 126 priority
toxic pollutants are listed in the WQS regulation
and in Appendix  P of this Handbook. Because of
the more  specific requirements for priority toxic
pollutants,  it  is convenient  to organize the
requirements  applicable  to  State  adoption of
criteria for toxicants into  three categories:

•    requirements  applicable to  priority  toxic
     pollutants that have been the subject of CWA
     section  304(a)(l)  criteria  guidance  (see
     section 3.4.1);
•    requirements  applicable to  priority  toxic
     pollutants that have not been the subject of
     CWA section 304(a)(l) criteria guidance (see
     section 3.4.1);  and

•    requirements applicable to all other toxicants
     (e.g.,  non-conventional   pollutants  like
     ammonia and chlorine) (see section 3.4.2).

3.4.1  Priority Toxic Pollutant Criteria

The criteria requirements  applicable to priority
toxic pollutants (i.e., the first two  categories
above) are specified in CWA section 303(c)(2)(B).
Section 303(c)(2)(B),  as added  by the Water
Quality Act of 1987, provides that:

     Whenever a State reviews water quality
     standards pursuant to paragraph (1) of
     this  subsection,  or revises or adopts
     new   standards  pursuant  to   this
     paragraph,   such  State  shall  adopt
     criteria for all toxic pollutants listed
     pursuant to section 307(a)(l) of this Act
     for which criteria have been published
     under section 304(a), the discharge or
     presence  of  which  in the  affected
     waters could reasonably be expected to
     interfere  with  those designated uses
     adopted by the State, as necessary to
     support such designated uses.   Such
     criteria  shall  be specific numerical
     criteria  for  such   toxic   pollutants.
     Where such numerical criteria are not
     available,  whenever  a  State reviews
     water  quality  standards  pursuant to
     paragraph (1), or revises or adopts new
     standards pursuant  to this  paragraph,
     such State shall adopt criteria based on
     biological monitoring  or   assessment
     methods  consistent  with  information
     published pursuant to section 304(a)(8).
     Nothing  in  this  section  shall  be
     construed  to limit or delay the use of
     effluent limitations  or  other  permit
     conditions  based  on  or  involving
     biological monitoring  or   assessment
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      methods   or   previously   adopted
      numerical criteria.

  EPA,   in   devising   guidance  for   section
  303(c)(2)(B), attempted to provide States with the
  maximum  flexibility that  complied  with  the
  express  statutory language but  also  with  the
  overriding  congressional  objective:    prompt
  adoption  and implementation of numeric toxics
  criteria.     EPA  believed  that  flexibility  was
  important so that each State could comply with
  section 303(c)(2)(B)  and to the extent possible,
  accommodate its existing water quality standards
  regulatory approach.

      General Requirements

 To  carry  out  the   requirements   of  section
 303(c)(2)(B), whenever a State revises its water
 quality standards, it must  review all  available
 information and data to  first determine whether
 the discharge or the presence of a toxic pollutant
 is interfering with or is likely to interfere with the
 attainment of the designated uses of any water
 body segment.

 If the data indicate that it is reasonable to expect
 the toxic pollutant to interfere with the use, or it
 actually is interfering  with the use, then the State
 must adopt a  numeric  limit  for the specific
 pollutant.  If a State is  unsure whether a toxic
 pollutant is interfering  with,  or is likely  to
 interfere with, the designated use and therefore is
 unsure that control of the pollutant is necessary to
 support the  designated  use,  the  State  should
 undertake to develop sufficient information upon
 which to make such a determination. Presence of
 facilities that manufacture  or use the. section
 307(a)   toxic  pollutants  or other  information
 indicating that such pollutants are discharged  or
 will  be discharged strongly suggests  that such
 pollutants  could  be interfering  with  attaining
 designated uses.  If a State expects the pollutant
 not to  interfere  with the designated  use, then
 section 303(1)(2)(B) does not require a numeric
 standard for that pollutant.

 Section  303(c)(2)(B) addresses  only  pollutants
 listed as "toxic" pursuant to section  307(a) of the
 Act,  which are codified  at  40 CFR  131.36(b).
 The section 307(a) list contains 65 compounds and
 families of compounds, which potentially include
 thousands of  specific compounds.   The Agency
 has interpreted that list to include 126  "priority"
 toxic   pollutants    for   regulatory  purposes.
 Reference in this guidance to toxic pollutants or
 section  307(a) toxic pollutants refers to the  126
 priority toxic  pollutants unless otherwise noted.
 Both  the list of  priority  toxic  pollutants and
 recommended criteria levels are subject to change.

 The national criteria recommendations published
 by EPA under section  304(a)  (see  section 3.1,
above) of the  Act include values for both acute
and chronic aquatic life protection; only chronic
criteria recommendations have been established to
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                                                                  Chapter 3 - Water Quality Criteria
protect  human  health.    To  comply  with the
statute,  a State  needs to  adopt aquatic life and
human health criteria where necessary to support
the appropriate designated uses.  Criteria for the
protection of human health are needed for water
bodies designated for public water supply.  When
fish ingestion is  considered an important activity,
then  the human  health-related  water  quality
criteria recommendation developed under section
304(a) of the CWA should be used; that is, the
portion of the criteria recommendation based on
fish consumption. For those pollutants designated
as carcinogens, the recommendation for a human
health criterion  is generally more stringent  than
the aquatic life  criterion for the same pollutant.
In   contrast,    the  aquatic   life   criteria
recommendations    for   noncarcinogens   are
generally more  stringent  than the human health
recommendations. When  a State adopts a human
health criterion for a carcinogen,  the State needs
to select a risk level.  EPA  has estimated risk
levels  of  10'5,  10'6,  and  10'7  in  its  criteria
documents under one set of exposure assumptions.
However, the State is  not limited to choosing
among the risk levels published in the section
304(a) criteria documents, nor is the State limited
to the base case exposure assumptions; it must
choose the risk level for its conditions and explain
its rationale.
                 /
EPA  generally  regulates  pollutants  treated as
carcinogens in the range of 10"6 to 10"4 to protect
average  exposed  individuals and more highly
exposed  populations. However, if a State selects
a criterion that represents an upper bound risk
level less protective than 1 in 100,000 (e.g., 10'5),
the State needs to have substantial support in the
record for this level. This support focuses on two
distinct issues.  First, the record must include
documentation that the decision maker considered
the public interest of the State in selecting the risk
level,   including   documentation  of   public
participation in the  decision making  process as
required  by   the  Water  Quality   Standards
Regulation at 40 CFR  13L20(b).  Second, the
record must include an analysis showing that the
risk level selected, when combined with other risk
assessment variables, is a balanced and reasonable
estimate of actual risk posed,  based oh the best
and  most representative information available.
The  importance  of the estimated  actual risk
increases as the degree of  conservatism  in the
selected risk level  diminishes.   EPA carefully
evaluates all assumptions used by a State if the
State chose to alter any one  of the standard EPA
assumption values (57 F.R. 60864, December 22,
1993).

EPA does not intend to propose changes to the
current requirements regarding the bases on which
a  State can  adopt numeric  criteria (40  CFR
131.11(b)(l)).  Under  EPA's   regulation,  in
addition  to  basing  numeric criteria  on EPA's
section 304(a) criteria documents, States may also
base  numeric   criteria   on   site-specific
determinations or other scientifically defensible
methods.

EPA expects each State to comply with the new
statutory requirements in any section 303 (c) water
quality standards review initiated after enactment
of the Water Quality Act of 1987. The structure
of section 303(c) is to require States to review
their water quality standards at least once each 3
year period. Section 303(c)(2)(B) instructs States
to include  reviews  for toxics criteria whenever
they initiate a triennial review.  Therefore, even
if a State has complied with  section 303(c)(2)(B),
the State must review its standards each triennium
to ensure that section  303(c)(2)(B) requirements
continue to be  met, considering that EPA may
have published additional section 304(a) criteria
documents  and  that  the  State  will have new
information on  existing water  quality  and  on
pollution sources.

It should be noted that nothing in the Act or in the
Water Quality Standards Regulation restricts the
right of a State to adopt numeric criteria for any
pollutant not listed pursuant to section 307(a)(l),
and  that  such  criteria  may be expressed  as
concentration limits for an individual pollutant or
for a toxicity parameter itself  as measured  by
whole-effluent toxicity testing. However, neither
numeric toxic criteria nor whole-effluent toxicity
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  should be used as a surrogate for, or to supersede
  the other.

      State Options

  States may meet the requirements of CWA section
  303(c)(2)(B)   by   choosing   one  of  three
  scientifically and technically sound options (or
  some combination thereof):

  (1)  Adopt statewide numeric  criteria in State
      water quality standards for all section 307(a)
      toxic  pollutants  for  which   EPA  has
      developed criteria guidance, regardless  of
      whether  the pollutants are known to be
      present;

  (2)  Adopt  specific  numeric criteria  in State
      water quality standards for section  307(a)
      toxic pollutants  as  necessary  to  support
      designated uses  where  such pollutants are
      discharged  or are present  in the affected
      waters and could reasonably be expected to
      interfere with designated uses;

 (3)  Adopt a "translator procedure" to be applied
      to a  narrative  water  quality   standard
      provision that prohibits toxicity in receiving
      waters. Such a procedure is to  be used by
      the  State  in calculating derived  numeric
      criteria, which shall be used for all purposes
      under section 303(c) of the CWA.  At  a
      minimum, such criteria need to be developed
      for  section  307(a)  toxic  pollutants, as
      necessary to  support designated uses, where
      these pollutants are discharged or present in
      the affected waters and could reasonably be
     expected to interfere with designated uses.

Option  1   is consistent  with  State authority to
establish water quality standards.  Option 2 most
directly reflects the CWA requirements and is the
option recommended by EPA. Option 3,  while
meeting the requirements of the CWA, is best
suited to supplement numeric criteria from option
1 or 2.  The three options are discussed in more
detail below.
      OPTION 1

  Adopt statewide numeric criteria in State water
  quality standards for  all section 307(a)  toxic
  pollutants for which EPA has developed criteria
  guidance, regardless of whether the pollutants
  are known to be present.

  Pro:

  •    simple, straightforward implementation

  •    ensures that States  will satisfy statute

  •    makes   maximum   uses   of   EPA
      recommendations

  •    gets specific numbers into State water quality
      standards fast, at first

 Con:

 •    some priority toxic pollutants may  not be
      discharged in State

 •    may cause unnecessary monitoring by States

 •    might result in "paper standards"

 Option 1 is within a State's legal authority under
 the CWA to adopt broad water quality standards.
 This  option is the most comprehensive approach
 to satisfy the statutory requirements because it
 would include all of the  priority toxic pollutants
 for which EPA has  prepared section  304(a)
 criteria guidance for  either or both aquatic life
 protection  and  human  health protection.    In
 addition to a simple adoption of EPA's section
 304(a) guidance as standards, a State must select
 a risk level for those toxic pollutants which are
 carcinogens (i.e., that cause or may cause cancer
 in humans).

 Many States find this option attractive because it
 ensures comprehensive coverage of the priority
 toxic  pollutants  with scientifically  defensible
criteria without the need  to conduct a resource-
intensive evaluation of the particular segments and
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                                                                   Chapter 3 - Water Quality Criteria
pollutants requiring criteria.   This option also
would not be  more  costly to dischargers than
other options because  permit limits  would  be
based only  on the regulation of the particular
toxic pollutants in their  discharges and not on the
total listing in the water quality standards.  Thus,
actual permit limits should be the same under any
of the options.

The State may also exercise; its authority to use
one or more of the techniques for adjusting water
quality standards:

•    establish or revise designated stream uses
     based  on  use  attainability  analyses (see
     section 2.9);

•    develop site-specific criteria; or

•    allow short-term variances (see section 5.3)
     when appropriate.

All  three  of  these  techniques  may  apply  to
standards developed under  any  of  the  three
options  discussed in  this guidance.  It is  likely
that States electing to use option 1 will rely more
on  variances because the other two options are
implemented with more  site-specific data being
available.   It  should be noted,  however, that
permits  issued pursuant to such  water quality
variances still must comply with any applicable
antidegradation and antibacksliding requirements.

     OPTION 2

Adopt specific numeric criteria in State  water
quality  standards  for section  307(a)  toxic
pollutants as necessary to support designated
uses where such pollutants  are discharged or
are present in the affected  waters and  could
reasonably  be  expected  to  interfere  with
designated uses.
Pro:
     directly reflects statutoiry requirement
•    standards based on  demonstrated need  to
     control problem pollutants

•    State can use EPA's  section 304(a) national
     criteria   recommendations   or    other
     scientifically acceptable alternative, including
     site-specific criteria

•    State can consider current or potential toxic
     pollutant problems

•    State can go beyond section 307(a)  toxics
     list, as desired

Con:

•    may be  difficult and time  consuming  to
     determine  if,  and   which, pollutants  are
     interfering with the designated use

•    adoption of standards can require lengthy
     debates on  correct  criteria  limit  to  be
     included in standards

•    successful State toxic control programs based
     on narrative criteria may be halted or slowed
     as the  State applies its limited  resources to
     developing numeric standards

•    difficult to update criteria once adopted as
     part of standards

•    to be absolutely technically defensible, may
     need site-specific criteria in many situations,
     leading to a  large workload for  regulatory
     agency

EPA recommends that a State  use this option to
meet the statutory requirement.  It directly reflects
all  the  Act's  requirements  and  is flexible,
resulting in adoption of  numeric water quality
standards as needed. To  assure that the State is
capable of  dealing  with  new problems as they
arise, EPA  also recommends that States adopt a
translator procedure the same  as, or similar to,
that described in option 3, but applicable to  all
chemicals causing toxicity and not  just priority
pollutants as is the case for option 3.
(8/15/94)
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 Water Quality Standards Handbook - Second Edition
 Beginning  in  1988, EPA provided States with
 candidate lists of priority toxic pollutants and
 water bodies in support of CWA section 304(1)
 implementation.   These lists were developed
 because States were required to evaluate existing
 and readily available water-related data to comply
 with section 304(1), 40 CFR 130.10(d). A similar
 "strawman"  analysis  of  priority  pollutants
 potentially requiring adoption of numeric criteria
 under section 303(c)(2)(B) was furnished to most
 States in September or October of 1990 for their
 use in ongoing and subsequent triennial  reviews.
 The primary differences between the "strawman"
 analysis and the section 304(1) candidate lists were
 that  the  "strawman" analysis (1)  organized the
 results by chemical rather than by water body, (2)
 included data for certain  STORET monitoring
 stations  that were not used in constructing the
 candidate lists, (3) included data from the Toxics
 Release   Inventory  database,  and  (4)  did not
 include  a  number of  data  sources  used  in
 preparing the candidate lists (e.g., those, such as
 fish  kill  information,   that   did  not  provide
 chemical-specific information).

 EPA intends for States, at a minimum, to use the
 information gathered in support of section 304(1)
 requirements as a starting point for identifying (1)
 water segments that will need new and/or revised
 water quality standards  for section 307(a) toxic
 pollutants, and (2) which priority toxic pollutants
 require adoption  of numeric  criteria.  In the
 longer term, EPA expects similar determinations
 to occur  during  each  triennial review of water
 quality standards as required by section 303(c).

 In identifying the need for numeric criteria, EPA
 is encouraging States to use information and data
 such as:

 •    presence  or   potential   construction  of
     facilities that  manufacture or use  priority
     toxic pollutants;

 *    ambient water  monitoring data, including
     those for sediment and aquatic life (e.g., fish
     tissue data);
 •    NPDES permit applications and permittee
      self-monitoring reports;

 •    effluent guideline development  documents,
      many of which  contain  section >307(a)(l)
      priority pollutant scans;

 •    pesticide   and   herbicide   application
      information and other records of pesticide or
      herbicide inventories;

 •    public water supply source monitoring data
      noting   pollutants   with   Maximum
      Contaminant Levels (MCLs); and

 •    any other  relevant information on  toxic
      pollutants   collected  by   Federal,  State,
      interstate agencies,  academic  groups,  or
      scientific organizations.

 States are also  expected  to take  into  account
 newer information as it became available, such as
 information  in annual  reports from the Toxic
 Chemical Release Inventory requirements of the
 Emergency Planning and Community Right-To-
 Know Act of 1986 (Title III, Public Law 99-499).

 Where the State's review indicates a reasonable
 expectation of a  problem from the discharge or
 presence  of toxic  pollutants,  the  State should
 identify   the pollutant(s)  and   the  relevant
 segment(s).   In  making these determinations,
 States should use their own EPA-approved criteria
 or  existing  EPA  water  quality  criteria  for
 purposes  of  segment identification.  After the
 review, the State may use other means to establish
 the final  criterion as it revises its standards.

 As  with  option 1,  a State using  option  2 must
 follow   all   its   legal   and   administrative
requirements  for  adoption  of  water  quality
 standards. Since the resulting numeric criteria are
part of a  State's water quality standards, they are
required to be submitted by the State to EPA for
review and either approval or disapproval.

EPA believes this  option offers the State optimum
flexibility.   For section  307(a) toxic pollutants
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                                                                  Chapter 3 - Water Quality Criteria
adversely affecting  designated  uses,  numeric
criteria are available for permitting purposes. For
other situations,  the  State has  the  option  of
defining site-specific criteria..

     OPTION 3

Adopt  a procedure  to  be  applied to  the
narrative water quality standard provision that
prohibits toxicity in receiving waters. Such a
procedure  would   be used by  a   State  in
calculating derived numeric criteria to be used
for all purposes of water quality criteria under
section  303(c) of the CWA.  At  a  minimum
such criteria need  to be derived for section
307(a) toxic pollutants where the discharge or
presence  of such  pollutants  in the affected
waters   could  reasonably  be  expected  to
interfere with designated uses,  as necessary to
support such designated uses.
Pro:
     allows a State flexibility to control priority
     toxic pollutants

     reduces time  and cost required  to adopt
     specific numeric  criteria as  water  quality
     standards regulations

     allows immediate use of  latest  scientific
     information  available at  the time a  State
     needs to develop derived numeric criteria

     revisions and additions to derived numeric
     criteria can be made without need to revise
     State law

     State can deal more easily  with a situation
     where  it did  not establish  water  quality
     standards  for  the  section  307(a)  toxic
     pollutants during  the most recent triennial
     review

     State can address problems from non-section
     307(a) toxic pollutants
Con:

•    EPA is  currently on notice that a derived
     numeric criterion may invite legal challenge

•    once the necessary procedures are adopted to
     enhance legal defensibility (e.g., appropriate
     scientific methods  and  public participation
     and review), actual savings in time and costs
     may be less than expected

•    public   participation in   development  of
     derived  numeric  criteria  may  be  limited
     when  such criteria  are not addressed in  a
     hearing on water quality standards

EPA believes that adoption of a narrative standard
along with a translator  mechanism as part of a
State's  water  quality   standard  satisfies  the
substantive requirements of the statute.   These
criteria  are subject to all the State's legal  and
administrative  requirements  for  adoption  of
standards plus  review  and  either  approval or
disapproval   by  EPA,   and   result  in  the
development  of  derived numeric  criteria  for
specific section  307(a) toxic pollutants. They are
also  subject  to  an  opportunity   for  public
participation.   Nevertheless,  EPA believes the
most  appropriate use  of option  3  is as  a
supplement to either option 1 or 2. Thus, a State
would have formally adopted numeric criteria for
toxic  pollutants that occur frequently; that have
general  applicability statewide  for  inclusion in
NPDES permits, total maximum daily loads, and
waste load allocations; and that also  would have
a  sound  and  predictable method   to  develop
additional numeric criteria  as  needed.    This
combination  of  options  provides  a complete
regulatory scheme.

Although the approach in option 3 is similar to
that currently  allowed  in  the Water   Quality
Standards Regulation (40 CFR 131.11(a)(2)), this
guidance  discusses several  administrative  and
scientific  requirements  that  EPA believes  are
necessary to comply with section 303(c)(2)(B).
(8/15/94)
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  Water Quality Standards Handbook - Second Edition
.  (1)  The Option 3 Procedure Must Be Used To
       Calculate Derived Numeric Water Quality
       Criteria

  States  must adopt a specific procedure to be
  applied to a narrative water quality criterion.  To
  satisfy section 303(c)(2)(B), this procedure shall
  be  used by  the  State  in  calculating derived
  numeric  criteria,  which shall  be used  for all
  purposes under section 303(c) of the CWA.  Such
  criteria need to be developed for section 307(a)
  toxic pollutants as necessary to support designated
  uses, where these pollutants are discharged or are
  present  in  the   affected   waters   and  could
  reasonably  be  expected  to  interfere  with the-
  designated uses.

  To assure protection from short-term exposures,
  the State procedure should ensure development of
  derived numeric water quality criteria based on
  valid acute aquatic  toxicity tests that are lethal to
  half the affected organisms (LC50) for the species
  representative of or similar to those found in the
  State.   In addition, the State procedure  should
  ensure  development  of derived numeric  water
  quality criteria  for protection  from  chronic
  exposure  by using an appropriate safety factor
  applicable to  this  acute limit.    If  there  are
  saltwater  components  to  the  State's  aquatic
  resources, the State should establish appropriate
  derived numeric criteria for saltwater in addition
  to those for freshwater.

  The State's documentation  of the tests  should
  include a detailed discussion of its quality control
  and  quality assurance procedures.   The State
  should also include a description (or reference
  existing technical agreements with EPA)  of the
 procedure it will use to calculate derived acute
 and chronic numeric criteria from the test data,
 and how these derived criteria will be used as the
 basis for  deriving appropriate TMDLs, WLAs,
 and NPDES permit  limits.

 As discussed above, the procedure for calculating
 derived numeric criteria needs to protect aquatic
 life from  both  acute and  chronic exposure to
 specific chemicals.  Chronic  aquatic life criteria
 are to be met at the edge of the mixing zone.
 The acute criteria are to be met (1) at the end-of-
 pipe if mixing is not rapid and complete and a
 high rate diffuser is not present;  or (2) after
 mixing if mixing is rapid and complete or a high
 rate diffuser is present. (See EPA's  Technical
 Support Document for Water Quality-based Toxics
 Control,  USEPA  1991a.)

 EPA  has  not established  a  national  policy
 specifying the point of application in the receiving
 water  to be used with  human health criteria.
 However, EPA has approved State standards that
 apply human health criteria for fish consumption
 at the  mixing zone boundary and/or apply the
 criteria for  drinking  water  consumption,  at  a
 minimum, at the  point  of use.   EPA has also
 proposed more stringent  requirements for the
 application  of human health  criteria for highly
 bioaccumulative pollutants in the Water Quality
 guidance  for the  Great  Lakes System  (50 F.R.
 20931,  21035,   April   16,   1993)  including
 elimination of mixing zones.

 Li addition, the  State should  also include an
 indication  of  potential  bioconcentration  or
 bioaccumulation by providing for:

 •    laboratory tests that measure the steady-state
     bioconcentration  rate   achieved   by   a
     susceptible organism; and/or

 •    field data in  which ambient concentrations
     and  tissue loads  are  measured to give an
     appropriate factor.

 In  developing  a  procedure  to  be   used in
 calculating  derived  numeric  criteria  for the
 protection  of  aquatic  life,   the  State  should
 consider the potential impact that bioconcentration
 has on aquatic and terrestrial food chains.

The  State   should    also  use  the  derived
bioconcentration factor and food chain multiplier
to calculate chronically protective numeric criteria
for humans that consume aquatic organisms.  In
calculating this derived  numeric criterion, the
State should indicate data requirements to be met
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                                                                   Chapter 3 - Water Quality Criteria
when dealing with either threshold (toxic) or non-
threshold  (carcinogenic) compounds.   The State
should describe the species and the minimum
number of tests, which may generally be met by
a single mammalian chronic: test if it is of good
quality and if the weight of evidence indicates that
the results  are  reasonable.   The  State  should
provide the method to calculate a derived numeric
criterion from the appropriate test result.

Both the threshold and non-threshold criteria for
protecting human health should contain exposure
assumptions, and the State  procedure should be
used to calculate derived numeric criteria that
address the consumption of water, consumption of
fish, and  combined  consumption of  both  water
and  fish.     The  State  should  provide  the
assumptions regarding  the amount of fish and the
quantity of water consumed per person per day,
as  well  as  the rationale  used  to  select  the
assumptions.  It needs to include the number of
tests, the  species necessary to establish a dose-
response relationship,  and  the procedure  to be
used to calculate the  derived numeric criteria.
For non-threshold contaminants, the State should
specify the model used to extrapolate to low dose
and  the  risk level.    It  should  also  address
incidental  exposure  from other water  sources
(e.g.,  swimming).   When calculating  derived
numeric   criteria  for  multiple  exposure  to
pollutants, the  State  should  consider additive
effects,  especially for carcinogenic  substances,
and should factor in the contribution to the daily
intake of toxicants from other sources (e.g., food,
air) when  data are available,

(2)  The  State Must Demonstrate  That the
     Procedure Results  in Derived Numeric
     Criteria Are Protective

The State needs to demonstrate that its procedures
for  developing  criteria,   including  translator
methods, yield fully protective criteria for human
health and for aquatic life. EPA's review process
will proceed according to EPA's regulation of 40
CFR 131.11, which requires that criteria be based
on sound  scientific rationale and be protective of
all designated uses.  EPA will use the expertise
and experience it has gamed in developing section
304(a) criteria for toxic pollutants by application
of its  own translator method (USEPA, 1980b;
USEPA, 1985b).

Once EPA has approved the  State's procedure,
the Agency's review of derived numeric criteria,
for example, for pollutants  other  than section
307(a) toxic pollutants resulting from the State's
procedure, will focus on the adequacy of the data
base rather than  the calculation  method.   EPA
also  encourages States to apply such a procedure
to calculate derived numeric criteria to be used as
the  basis for  deriving permit  limitations  for
nonconventional  pollutants   that   also   cause
toxicity.

(3)  The State Must Provide Full  Opportunity
     for Public Participation in Adoption of the
     Procedure

The Water Quality Standards Regulation requires
States to hold public hearings to review and revise
water  quality  standards  in  accordance   with
provisions  of  State law and  EPA's Public
Participation Regulation (40 CFR 25).  Where a
State plans to adopt a procedure to  be applied to
the  narrative   criterion,  it must  provide  full
opportunity   for  public  participation  in  the
development and adoption of the procedure as part
of the  State's water quality standards.

While  it is not necessary for  the State to  adopt
each derived numeric  criterion  into its  water
quality standards and submit it to EPA for review
and  approval,  EPA is  very  concerned that all
affected  parties  have   adequate  opportunity  to
participate in  the  development of a derived
(8/15/94)
                                         3-21

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 Water Quality Standards Handbook - Second Edition
 numeric  criterion  even though it is  not  being
 adopted directly as a water quality standard.

 A State  can  satisfy the need  to provide an
 opportunity  for  public  participation  in  the
 development of derived numeric criteria in several
 ways, including:

 •   a specific hearing on the derived numeric
     criterion;

 *   the opportunity for a public  hearing on an
     NPDES permits as long as public notice is
     given that a criterion for a toxic pollutant as
     part  of  the  permit  issuance  is   being
     contemplated; or

 *   a hearing coincidental with any other hearing
     as long as it is made clear that development
     of a  specific  criterion  is  also   being
     undertaken.

 For example,  as  States develop their lists and
 individual control strategies (ICSs) under section
 304(1), they may seek full public participation.
 NPDES   regulations   also   specify  public
 participation requirements related to State permit
 issuance.  Finally, States have public participation
 requirements  associated  with  Water  Quality
 Management Plan updates.    States may take
 advantage  of any of these public participation
 requirements to fulfill the requirement for public
 review of any resulting derived numeric criteria.
 In such cases, the State must give prior notice that
 development   of   such   criteria  is   under
 consideration.

 (4)  The Procedure Must Be Formally Adopted
     and Mandatory

 Where a State  elects to supplement its narrative
 criterion with  an accompanying  implementing
 procedure,  it  must  formally  adopt  such a
 procedure as a part of its water quality standards.
 The procedure  must be used by the State to
 calculate derived numeric criteria that will be used
 as the basis for  all standards' purposes,  including
 the following: developing TMDLs, WLAs, and
 limits in NPDES permits; determining whether
 water  use designations  are being  met;  and
 identifying potential  nonpoint source pollution
 problems.

 (5)   The Procedure Must Be Approved by EPA
      as  Part  of the State's Water  Quality
      Standards Regulation

 To be consistent with the requirements of the Act,
 the State's procedure to be applied to the narrative
 criterion  must be submitted  to EPA  for review
 and approval, and will become a part of the
 State's  water  quality  standards.   (See 40 CFR
 131.21  for further discussion.) This requirement
 may be satisfied by a reference in the standards to
 the procedure, which may be contained in another
 document, which has  legal effect and is binding
 on the State, and all the requirements for public
 review,  State  implementation, and EPA  review
 and approval are satisfied.

     Criteria  Based on Biological Monitoring

 For priority toxic pollutants for which EPA has
 not issued section  304(a)(l)  criteria guidance,
 CWA section 303(c)(2)(B) requires States to adopt
 criteria   based  on  biological  monitoring  or
 assessment methods.   The  phrase  "biological
 monitoring or  assessment methods" includes:

 •    whole-effluent toxicity control methods;

 •    biological criteria methods; or

 •    other  methods    based  on   biological
     monitoring or assessment.

 The phrase "biological monitoring or assessment
 methods" in   its broadest  sense  also includes
 criteria developed through translator procedures.
 This  broad interpretation of that  phrase  is
 consistent  with.  EPA's  policy   of applying
 chemical-specific, biological,  and whole-effluent
 toxicity  methods independently in an  integrated
 toxics control program. It is also consistent with
 the intent of Congress to expand State standards
programs beyond chemical-specific approaches.
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                                                                   Chapter 3 - Water Quality Criteria
States should also consider developing protocols
to derive and adopt numeric criteria for priority
toxic pollutants (or other pollutants) where EPA
has not issued  section 304(a) criteria  guidance.
The State  should consider  available laboratory
toxicity test data that may be sufficient to support
derivation of chemical-specific criteria.  Existing
data need  not  be  as  comprehensive as  that
required to meet EPA's 1985 guidelines in order
for a State to  use its own protocols  to  derive
criteria.  EPA has described such protocols in the
proposed Water Quality  Guidance for  the Great
Lakes System (58 F.R. 20892, at 21016, April 16,
1993.) This is particularly important where other
components  of  a  State's  narrative   criterion
implementation procedure (e.g., WET controls or
biological criteria) may not ensure full protection
of  designated  uses.   For  some pollutants,  a
combination  of   chemical-specific  and  other
approaches is  necessary  (e.g.,  pollutants  where
bioaccumulation   in   fish   tissue  or  water
consumption by humans is a primary concern).

Biologically  based  monitoring  or assessment
methods serve as the basis for control  where no
specific numeric criteria exist or where calculation
or  application  of pollutant-by-pollutant criteria
appears  infeasible.  Also,  these methods may
serve  as   a   supplemental  measurement  of
attainment of water quality standards in addition
to  numeric  and  narrative  criteria.     The
requirement  for  both  numeric   criteria  and
biologically based methods demonstrates  that
section  303(c)(2)(B)  contemplates  that  States
develop a comprehensive toxics control program
regardless of the  status of EPA's section  304(a)
criteria.

The  whole-effluent  toxicity   (WET)  testing
procedure is the principal biological monitoring
guidance developed by  EPA to date. The purpose
of the WET procedure is to control point  source
dischargers of toxic pollutants.  The procedure is
particularly useful for monitoring and controlling
the toxicity of complex effluents that may  not be
well controlled through chemical-specific numeric
criteria.   As such,  biologically based effluent
testing procedures are a necessary component of
a  State's toxics control program under section
303(c)(2)(B)  and   a   principal   means   for
implementing a  State's  narrative  "free  from
toxics" standard.

Guidance documents EPA considers to serve the
purpose of section 304(a)(8) include the Technical
Support Document for Water Quality-based Toxics
Control (USEPA, 1991a; Guidelines for Deriving
National Water Quality Criteria for the Protection
of Aquatic Organisms and Their Uses (Appendix
H);  Guidelines  and  Methodology  Used  in  the
Preparation of Health Effect Assessment Chapters
of the Consent Decree Water Criteria Documents
(Appendix  J); Methods for Measuring  Acute
Toxicity of Effluents to Freshwater and Marine
Organisms (USEPA, 1991d); Short-Term Methods
for Estimating the Chronic Toxicity of Effluents
and Receiving Waters to Freshwater Organisms
(USEPA, 1991e); and  Short-Term Methods for
Estimating the Chronic  Toxicity of Effluents and
Receiving  Waters  to  Marine   and  Estuarine
Organisms (USEPA, 199If).

3.4.2   Criteria for Nonconventional Pollutants

Criteria requirements applicable to toxicants that
are not priority toxic pollutants (e.g., ammonia
and  chlorine), are specified  in  the  1983  Water
Quality  Standards   Regulation   (see  40  CFR
131.11).  Under these requirements, States must
adopt criteria based on  sound scientific rationale
that  cover  sufficient  parameters  to  protect
designated uses.   Both numeric  and narrative
criteria (discussed in sections 3.5.1  and  3.5.2,
below)  may  be   applied   to   meet   these
requirements.
       Forms of Criteria
States are required to adopt water quality criteria,
based on sound scientific rationale, that contain
sufficient parameters or constituents to protect the
designated  use.  EPA believes that an effective
State water  quality standards program should
include both parameter-specific  (e.g.,  ambient
numeric criteria) and narrative approaches.
(8/15/94)
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 Water Quality Standards Handbook - Second Edition
 3.5.1  Numeric Criteria

 Numeric criteria are required where necessary to
 protect designated uses.   Numeric criteria  to
 protect aquatic life should be developed to address
 both short-term (acute)  and long-term (chronic)
 effects.  Saltwater species, as well as freshwater
 species, must be adequately protected.  Adoption
 of numeric criteria is particularly  important for
 toxicants known to be impairing surface waters
 and  for toxicants with  potential  human health
 impacts (e.g., those  with  high bioaccumulation
 potential).   Human health should be protected
 from exposure  resulting from consumption  of
 water and fish or other aquatic life (e.g., mussels,
 crayfish). Numeric water quality criteria also are
 useful in addressing nonpoint  source  pollution
 problems.

 In evaluating  whether chemical-specific numeric
 criteria for toxicants that  are not  priority toxic
 pollutants are required,  States should consider
 whether other approaches (such as whole-effluent
 toxicity criteria or biological controls) will ensure
 full protection of designated uses.  As mentioned
 above, a combination of independent approaches
 may be required  in some cases to support the
 designated uses and comply with the requirements
 of the Water Quality Standards Regulation (e.g.,
 pollutants where bioaccumulation in fish tissue or
 water  consumption  by  humans is a primary
 concern).

 3.5.2  Narrative Criteria

 To supplement numeric criteria for toxicants, all
 States  have also  adopted  narrative criteria for
 toxicants.  Such narrative criteria are statements
 that describe the desired  water quality goal,  such
 as the following:

     All waters,  including those within
     mixing  zones,   shall  be  free from
     substances  attributable  to  wastewater
     discharges  or other pollutant sources
     that:
     (1)  Settle   to   form   objectional
          deposits;

     (2)  Float  as  debris,  scum,  oil,  or
          other matter forming nuisances;

     (3)  Produce objectionable color, odor,
          taste, or turbidity;

     (4)  Cause injury to, or are toxic to,
          or produce adverse physiological
          responses in humans, animals, or
          plants; or

     (5)  Produce undesirable or nuisance
          aquatic life (54 F.R. 28627, July
          6, 1989).

EPA considers that the narrative criteria apply to
all designated  uses at all flows and are necessary
to meet the  statutory  requirements  of section
303(c)(2)(A) of the CWA.

Narrative toxic criteria (No, 4, above) can be the
basis for establishing chemical-specific limits for
waste discharges where a specific pollutant can be
identified as causing or contributing to the toxicity
and  the State  has not  adopted chemical-specific
numeric criteria. Narrative toxic criteria are cited
as a basis for  establishing whole-effluent toxicity
controls in EPA permitting regulations at 40 CFR
122.44(d)(l)(v).

To ensure that narrative criteria for toxicants are
attained, the Water Quality Standards Regulation
requires   States  to   develop  implementation
procedures (see 40  CFR 131.11(a)(2)).   Such
implementation procedures (Exhibit 3-3) should
address all mechanisms to be used by the State to
ensure  that   narrative  criteria  are   attained.
Because   implementation of  chemical-specific
numeric  criteria is a  key component  of State
toxics   control  programs,   narrative  criteria
implementation  procedures   must describe  or
reference  the  State's procedures to implement
such  chemical-specific  numeric  criteria  (e.g.,
procedures  for  establishing  chemical-specific
permit  limits   under  the NPDES   permitting
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                                                                   Chapter 3 - Water Quality Criteria
    State implementation procedures for narrative toxics criteria should describe tile following;


    «    Specific, scientilteatly defeasible methods by which the State will implement its narrative
         toxics standard for all toxicants, including:

         -  methods for chemical-specific criteria, including mei&ods for applying chemical-spedfie
           criteria in permits, developing or modifying chemical-spedfic criteria via a "translator
           procedure" (defined and discussed below), and calculating $ite*spe£ific criteria based
           on local water chemistry or biology);

         -  methods for developing and implementing  whole-effluent toxicity criteria and/or
           controls; and

         -  methods for developing and implementing biological criteria.
    «    How these methods will be integrated in the State's toxics control program (le,, how the
         State will proceed when the specified methods produce conflicting or inconsistent results).
         Application criteria and information needed to apply numerical criteria, for examples

         -  methods the State will uSf to Meatiiy those pollutants to, be regulated in a specific
           discharge;

         -  an incremental estncer risk level for carcinogens;

         -  methods for identifying compliance thresholds in permits where calculated limits are
           below detection;

         -  methods for selecting appropriate hardness, pH, and temperature variables for criteria
           expressed  as functions;

         -  methods or policies controlling the size and in~zone quality of mixing zones;

         -  design flows to be used in translating chemical-specific numeric criteria for aquatic life
          . aad human health into permit limits; aad

         -  other methods and information needed to apply standards on a case-by-case basis.
  Exhibit 3-3.   Components of a State Implementation Procedure for Narrative Toxics Criteria


(8/15/94)                                                                                   3-25

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 program).  Implementation procedures must also
 address State programs to control whole-effluent
 toxicity  (WET)  and may  address programs to
 implement   biological  criteria,   where   such
 programs  have  been developed  by the  State.
 Implementation  procedures therefore  serve  as
 umbrella documents that describe how the State's
 various toxics control programs are integrated to
 ensure adequate protection for aquatic  life and
 human health and  attainment of the  narrative
 toxics criterion.  In essence, the procedure should
 apply the  "independent  application"  principle,
 which provides  for  independent  evaluations  of
 attainment of a designated use based on chemical-
 specific, whole-effluent toxicity,  and biological
 criteria   methods   (see   section  3.5.3  and
 Appendices C, K, and R).

 EPA encourages, and may  ultimately  require,
 State implementation procedures to provide for
 implementation of biological criteria. However,
 the regulatory basis for requiring whole-effluent
 toxicity (WEI) controls is clear. EPA regulations
 at  40  CFR   122.44(d)(l)(v) require   NPDES
 permits to contain WET limits where a permittee
 has  been shown to cause,  have the reasonable
 potential to cause, or contribute to an in-stream
 excursion of a narrative criterion. Implementation
 of chemical-specific controls is also required by
 EPA regulations  at 40 CFR 122.44(d)(l).  State
 implementation procedures should, at a minimum,
 specify or  reference methods to be  used  in
 implementing chemical-specific and whole-effluent
 toxicity-based  controls,   explain   how  these
 methods  are  integrated,  and  specify  needed
 application criteria.

 In addition to EPA's regulation at 40 CFR 131,
 EPA has regulations at 40 CFR 122.44 that cover
 the  National   Surface  Water Toxics   Control
 Program.   These  regulations are  intrinsically
 linked to  the requirements  to  achieve  water
 quality standards, and  specifically address the
 control of  pollutants both with  and  without
 numeric   criteria.     For   example,   section
 122.44(d)(l)(vi) provides the permitting authority
 with several options for establishing effluent limits
 when a State  does not have a chemical-specific
 numeric criterion for a pollutant present  in  an
 effluent at  a  concentration  that  causes  or
 contributes to a violation of the State's narrative
 criteria.

 3.5.3   Biological Criteria

 The Clean Water Act  of  1972 directs EPA  to
 develop programs that will evaluate, restore, and
 maintain the chemical, physical, and biological
 integrity of the Nation's waters.  In response to
 this directive, States and EPA have implemented
 chemically based water quality  programs that
 address  significant  water pollution  problems.
 However, over the past 20 years, it has become
 apparent that these programs alone cannot identify
 and address all surface water pollution problems.
 To help create a more comprehensive program,
 EPA is setting a priority for the development  of
 biological criteria as part of State water quality
 standards.  This effort will help States and EPA
 (1) achieve the biological integrity objective of the
 CWA  set forth  in section  101, and (2) comply
 with the statutory requirements under sections 303
 and 304 of the Act (see Appendices C  and K).

    Regulatory Bases for Biocriteria

 The primary statutory basis for EPA's policy that
 States  should develop  biocriteria  is  found  in
 sections  101(a)  and 303(c)(2)(B)  of the  Clean
 Water  Act. Section 101(a) of the CWA gives the
 general goal of biological criteria.  It establishes
 as the objective of the Act the restoration and
 maintenance  of  the chemical,  physical,  and
 biological integrity of the Nation's waters.  To
 meet this objective, water quality criteria should
 address  biological integrity.    Section 101(a)
 includes the  interim water quality  goal for the
protection and propagation of fish, shellfish, and
 wildlife.

 Section 304(a) of the Act provides the legal basis
for the development of informational criteria,
including biological criteria.  Specific  directives
for the development of regulatory biocriteria can
be found in section 303(c), which requires EPA  to
develop criteria  based on biological assessment
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                                                                   Chapter 3 - Water Qualify Criteria
methods  when  numerical  criteria  are  not
established.

Section 304(a) directs EPA to develop and publish
water quality criteria and information on methods
for measuring water quality and establishing water
quality criteria for toxic pollutants on bases other
than pollutant-by-pollutant,  including biological
monitoring and assessment methods that assess:

•    the  effects   of  pollutants   on   aquatic
     community  components (".  .  .  plankton,
     fish, shellfish, wildlife, plant life .  . .") and
     community  attributes  (".   .   . biological
     community   diversity,  productivity,  and
     stability . . .") in any body of water; and

•    factors  necessary  "...  to  restore and
     maintain  the   chemical,   physical,  and
     biological integrity of all navigable waters .
     .."  for "...  the protection of shellfish,
     fish, and wildlife for classes and categories
     of receiving waters . .  . ."

Once biocriteria are formally adopted into State
standards,  biocriteria   and  aquatic  life  use
designations  serve as direct., legal endpoints for
determining  aquatic  life  use  attainment/non-
attainment.   CWA section 303(c)(2)(B) provides
that when numeric  criteria, are  not  available,
States shall  adopt criteria  for toxics based on
biological monitoring or assessment methods;
biocriteria can be used to meet this requirement.

     Development  and  Implementation   of
     Biocriteria

Biocriteria  are numerical  values   or  narrative
expressions that describe the expected reference
biological  integrity   of  aquatic   communities
inhabiting waters of a designated  aquatic life use.
In the  most desirable scenario,  these would be
waters  that  are  either in pristine  condition or
minimally impaired.   However, in some areas
these conditions no longer exist and may not be
attainable.   In these situations, the reference
biological  communities  represent  the  best
attainable conditions. In either case, the reference
conditions then become the basis for developing
biocriteria for major surface water types (streams,
rivers,  lakes,  wetlands,  estuaries,  or  marine
waters).
                              e
Biological criteria support designated aquatic life
use  classifications  for  application  in  State
standards (see chapter 2).  Each State develops its
own designated use classification system based on
the generic uses cited in the Act (e.g., protection
and propagation of fish, shellfish, and wildlife).
Designated   uses   are   intentionally  general.
However,  States  may  develop   subcategories
within use designations to refine and clarify the
use  class.    Clarification of the  use class  is
particularly helpful  when a variety of surface
waters with distinct  characteristics  fit within the
same use  class, or  do  not  fit well into any
category.

For example, subcategories of aquatic life uses
may be  on the basis of attainable  habitat (e.g.,
coldwater versus warmwater  stream systems  as
represented  by distinctive trout  or  bass fish
communities, respectively).   Special uses may
also be designated to protect particularly unique,
sensitive,    or  valuable   aquatic   species,
communities, or habitats.

Resident biota  integrate  multiple  impacts over
time and can detect impairment from known and
unknown causes.  Biological criteria can be used
to  verify  improvement   in  water  quality  in
response to  regulatory and  other  improvement
efforts   and   to  detect  new  or  continuing
degradation  of waters.   Biological criteria also
provide  a  framework for developing improved
best  management  practices  and   management
measures for nonpoint source impacts.  Numeric
biological    criteria   can   provide   effective
monitoring criteria for more definitive evaluation
of the health of an aquatic ecosystem.

The assessment of the biological  integrity of a
water body should include  measures  of the
structure and function of the  aquatic community
within a specified habitat. Expert  knowledge of
the system  is required  for  the   selection  of
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 Water Quality Standards Handbook - Second Edition
 appropriate   biological   components   and
 measurement  indices.    The  development  and
 implementation of biological criteria requires:

 *    selection  of  surface  waters  to   use  in
      developing reference conditions  for  each
      designated use;

 *    measurement of the structure and function of
      aquatic  communities in  reference  surface
      waters to establish biological criteria;

 •    measurement of  the physical habitat  and
      other environmental characteristics  of the
      water resource; and

 *    establishment of a protocol to compare the
      biological criteria to  biota in comparable test
      waters to determine whether impairment has
      occurred.

 These elements serve as  an interactive network
 that  is  particularly   important  during  early
 development  of biological criteria where rapid
 accumulation   of  information  is  effective  for
 refining both  designated  uses and  developing
 biological  criteria values and  the  supporting
 biological monitoring and assessment techniques.

 3.5.4  Sediment Criteria

 While ambient water quality criteria are playing
 an  important  role in assuring  a  healthy aquatic
 environment, they alone have not been sufficient
 to  ensure  appropriate  levels  of environmental
 protection.  Sediment contamination,  which can
 involve deposition of toxicants  over long periods
 of time, is responsible for water  quality impacts
 in some areas.

 EPA  has authority to pursue  the development of
 sediment criteria  in  streams,  lakes  and other
 waters of the United States under sections 104 and
 304(a)(l) and  (2) of the CWA as follows:

 *    section   104(n)(l)   authorizes   the
     Administrator to establish national programs
      that study the effects of pollution, including
      sedimentation, in estuaries on aquatic life;

 •    section 304(a)(l) directs the Administrator to
      develop  and publish  criteria  for water
      quality, including information on the factors
      affecting  rates of organic  and  inorganic
      sedimentation for varying types of receiving
      waters;

 •    section 304(a)(2) directs the Administrator to
      develop and publish information on, among
      other issues, "the  factors necessary for the
      protection and propagation of shellfish, fish,
      and  wildlife  for classes and  categories of
      receiving waters.  ..."

 To  the extent that sediment criteria  could be
 developed that address the concerns of the section
 404(b)(l) Guidelines for discharges of dredged or
 fill  material under the CWA  or  the  Marine
 Protection,  Research, and Sanctuaries Act, they
 could also be incorporated into those regulations.

 EPA's  current  sediment  criteria  development
 effort, as described below, focuses on criteria for
 the protection of aquatic life.  EPA anticipates
 potential future expansion of this effort to include
 sediment  criteria  for the protection of human
 health.

     Chemical Approach to Sediment Criteria
     Development

 Over the  past  several  years, sediment  criteria
 development activities have centered on evaluating
 and   developing  the Equilibrium  Partitioning
 Approach  for generating sediment  criteria.  The
 Equilibrium Partitioning Approach  focuses  on
 predicting   the  chemical   interaction  between
 sediments  and  contaminants.    Developing  an
 understanding   of  the  principal  factors  that
 influence  the sediment/contaminant  interactions
 will  allow predictions to be made  regarding the
level  of contaminant concentration that benthic
and other organisms may be exposed to.  Chronic
water  quality   criteria,   or  possibly   other
toxicological endpoints, can then  be  used  to
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                                                                  Chapter 3 - Water Quality Criteria
predict potential biological effects.  In addition to
the development of sediment criteria, EPA is also
working  to  develop a  stamdardized  sediment
toxicity  test  that  could  be  used   with  or
independently of  sediment  criteria  to assess
chronic effects in fresh and marine waters.

     Equilibrium  Partitioning (EqP) Sediment
     Quality  Criteria  (SQC)  are  the  U.S.
     Environmental Protection Agency's  best
     recommendation of the concentration of a
     substance  in  sediment  that  will   not
     unacceptably affect  benthic  organisms or
     their uses.

Methodologies  for deriving;  effects-based  SQC
vary for different classes  of compounds.   For
non-ionic organic chemicals,  the  methodology
requires  normalization  to organic carbon.  A
methodology for deriving effects-based sediment
criteria  for  metal  contaminants  is  under
development  and  is   expected  to   require
normalization to acid volatile sulfide.  EqP SQC
values can  be derived for varying degrees of
uncertainty   and  levels   of  protection,  thus
permitting   use  for ecosystem protection  and
remedial programs.

     Application of Sediment Criteria

SQC would provide a basis for  making  more
informed decisions on the environmental impacts
of contaminated  sediments.   Existing  sediment
assessment  methodologies are limited  in  their
ability   to   identify  chemicals  of   concern,
responsible  parties, degree of contamination, and
zones  of impact.  To make the most informed
decisions, EPA believes  that a comprehensive
approach using SQC and biological test methods
is preferred.

Sediment criteria will be particularly valuable in
site-monitoring  applications   where   sediment
contaminant   concentrations   are  gradually
approaching a  criterion  over time  or  as  a
preventive tool to ensure that point and  nonpoint
sources of contamination  are controlled and that
uncontaminated sediments remain uncontaminated.
Also  comparison  of  field  measurements  to
sediment criteria will be a reliable method for
providing early warning of a potential problem.
An early warning would provide an opportunity to
take corrective action before adverse impacts
occur.   For the reasons mentioned above, it has
been identified that SQC are essential to resolving
key contaminated  sediment  and  source  control
issues in the Great Lakes.

     Specific Applications

Specific applications  of sediment criteria are
under development.  The primary use of EqP-
based sediment criteria will  be to assess risks
associated with contaminants  in sediments.  The
various  offices and programs concerned  with
contaminated sediment have different regulatory
mandates and, thus,  have different  needs and
areas for potential application of sediment criteria.
Because each regulatory need is different, EqP-
based    sediment   quality   criteria   designed
specifically  to meet the needs of one office or
program may have to be implemented in different
ways to meet the needs of another office or
program.

One mode of application of EqP-based numerical
sediment quality  criteria would  be  in a tiered
approach.    In  such  an    application,  when
contaminants in sediments exceed the sediment
quality criteria the sediments would be considered
as causing unacceptable impacts.  Further testing
may or may not be required depending  on site-
specific conditions and the  degree in which a
criterion has been violated.   (In locations where
contamination significantly exceeds a criterion, no
additional testing  would be  required.   Where
sediment contaminant  levels are close  to  a
criterion, additional testing might be necessary.)
 Contaminants in a sediment at concentrations less
than the sediment criterion would  not be of
concern.  However, in some cases the sediment
could not be considered safe because it might
contain other contaminants above safe levels for
which no sediment criteria exist.   In addition, the
synergistic,  antagonistic, or  additive  effects of
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 Water Quality Standards Handbook - Second Edition
 several contaminants in the sediments may be of
 concern.

 Additional testing in other tiers of an evaluation
 approach, such astoxicity tests, could be required
 to determine if the sediment is safe.  It is likely
 that such testing would incorporate  site-specific
 considerations. Examples of specific applications
 of  sediment criteria  after they  are developed
 include the following:

 •    Establish permit limits for point sources to
      ensure that uncontaminated sediments remain
      uncontaminated   or  sediments   already
      contaminated have an opportunity to cleanse
      themselves.  Of course,  this would  occur
      only after criteria and the means to tie point
      sources   to  sediment  contamination  are
      developed.

 *    Establish  target levels for nonpoint sources
      of sediment contamination.

 *    For  remediation  activities, SQC would be
      valuable in identifying:

      -  need for remediation,

      -  spatial extent of remediation area,

      -  benefits  derived   from   remediation
        activities,

      -  responsible parties,
ttt/H/l/ll/UtHltittt
      -  impacts  of   depositing   contaminated
        sediments in water environments, and

      -  success of remediation activities.,

 In tiered testing sediment evaluation processes,
 sediment criteria and biological testing procedures
 work very well together.

      Sediment Criteria Status

      Science Advisory Board Review

 The  Science Advisory Board has  completed a
 second review of the EqP approach to deriving
 sediment   quality   criteria   for  non-ionic
 contaminants.    The  November   1992  report
 (USEPA, 1992c) endorses the EqP approach to
 deriving criteria as  "...  sufficiently valid to be
 used  in the regulatory process if the uncertainty
 associated   with the  method  is   considered,
 described,  and  incorporated,"   and that  "EPA
 should  .  .  .  establish criteria on  the  basis of
 present  knowledge  within  the  bounds  of
 uncertainty. ..."

 The Science Advisory Board also identified the
 need  for  ".  .  .a  better understanding of the
 uncertainty around the assumptions inherent in the
 approach, including assumptions of equilibrium,
 bioavailability,  and kinetics, all critical to the
 application of the EqP."

     Sediment   Criteria  Documents   and
     Application Guidance

 EPA  efforts  at producing  sediment  criteria
 documents   are  being  directed first  toward
 phenanthrene,   fluoranthene,   dieldrin,
 acenaphthene, and endrin.  Efforts are also being
 directed towards producing a guidance document
 on the derivation and interpretation  of sediment
 quality criteria.   The  criteria documents were
 announced  in  the Federal Register in  January
 1994; the public comment  period  ended June
 1994.   Final  documents  and  implementation
guidance should be available in early 1996.
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                                                                   Chapter 3 - Water Quality Criteria
     Methodology  for  Developing  Sediment
     Criteria for Metal Contaminants

EPA is proceeding to develop a methodology for
calculating sediment criteria for benthic toxicity to
metal contaminants, with key work focused on
identifying and understanding the role of acid
volatile sulfides (AVS), and other binding factors,
in  controlling  the   bioavailability  of  metal
contaminants.  A variety of field and laboratory
verification  studies  are  under  way  to add
additional support to the methodology.  Standard
AVS  sampling and  analytical  procedures  are
under  development.  Presentation of the metals
methodology to the SAB for review is anticipated
for Fall 1994.

     Biological Approach to Sediment Criteria
     Development

Under the Contaminated Sediment  Management
Strategy, EPA programs have committed to using
consistent  biological  methods  to  determine  if
sediments  are contaminated.    In  the  water
program, these biological methods will be used as
a complement to the sediment-chemical criteria
under development.    The biological  methods
consist of both toxicity and bioaccumulation tests.
Freshwater and saltwater benthic species, selected
to represent  the  sensitive  range  of species'
responses  to toxicity,  are used in toxicity tests  to
measure sediment toxicity.  Insensitive freshwater
and saltwater benthic species that form the base of
the food  chain are  used in  toxicity tests  to
measure   the  bioaccumulation  potential   of
sediment.  In  FY  1994, acute toxicity tests and
bioaccumulation tests selected by all the Agency
programs should be standardized and available for
use.   Training for States amd  EPA Regions on
these methods is expected to begin in FY1995.

In the next few years, research will be conducted
 to develop standardized chronic toxicity tests for
 sediment  as  well   as  toxicity  identification
 evaluation (TIE) methods, Ittie TIE approach will
 be used to identify  the specific chemicals in a
 sediment causing acute or chronic toxicity in the
 test   organisms.     Under  the  Contaminated
Sediment Management Strategy, EPA's programs
have  also  agreed to incorporate these chronic
toxicity and TIE methods into  their  sediment
testing when they are available.

3.5.5  Wildlife Criteria

Terrestrial  and  avian  species  are  useful  as
sentinels for the health of the ecosystem as a
whole.    In many  cases,  damage  to wildlife
indicates that the ecosystem  itself  is  damaged.
Many wildlife species that are heavily dependent
on the  aquatic  food web reflect the  health of
aquatic systems.  In the case  of toxic chemicals,
terminal predators such  as  otter,  mink, gulls,
terns, eagles, ospreys,  and turtles are useful as
integrative indicators of the status or health of the
ecosystem.

      Statutory and Regulatory Authority

Section 101(a)(2) of the CWA sets,  as an interim
goal  of,

      .  . . wherever attainable . .  .  water
      quality  which   provides   for   the
      protection  and  propagation  of  fish,
      shellfish,  and wildlife .  . .  (emphasis
      added).

Section 304(a)(l) of the Act also requires EPA to:

      .  . . develop and publish . .  . criteria for
      water quality accurately reflecting ...  the
      kind and extent of all identifiable effects on
      health and welfare including .  . .  wildlife.

The  Water Quality Standards Regulation reflect
 the statutory goals and  requirements by requiring
 States  to adopt,  where  attainable,  the  CWA
 section  101(a)(2)  goal uses  of protection and
 propagation of fish, shellfish, and wildlife (40
 CFR 131.10), and to adopt water quality criteria
 sufficient to protect  the designated  use (40 CFR
 131.11).
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  Water Quality Standards Handbook - Second Edition
      Wildlife Protection in  Current  Aquatic
      Criteria

 Current  water quality  criteria  methodology  is
 designed to protect fish, benthic invertebrates, and
 zooplankton; however, there is a provision in the
 current aquatic life criteria guidelines (Appendix
 H) that  is  intended  to protect wildlife  that
 consume   aquatic  organisms   from   the
 bioaccumulative potential of a compound.   The
 final residue value can be based on either the
 FDA  Action Level or a wildlife feeding study.
 However,   if   maximum  permissible   tissue
 concentration is not  available from a  wildlife
 feeding study,  a final residue value cannot be
 derived and the criteria quantification procedure
 continues without further consideration of wildlife
 impacts.     Historically,  wildlife   have  been
 considered   only  after  detrimental  effects  on
 wildlife populations have been observed in  the
 environment (this occurred with  relationship to
 DDT, selenium, and PCBs).

     Wildlife Criteria Development

 EPA's national wildlife  criteria  effort began
 following  release  of  a  1987   Government
 Accounting   Office   study   entitled  Wildlife
 Management - National Refuge Contamination Is
 Difficult To Confirm and Clean Up (GAO, 1987).
 After waterfowl deformities observed at Kesterson
 Wildlife  Refuge  were   linked  to  selenium
 contamination in the water, Congress requested
 this  study   and   recommended   that  "the
 Administrator of EPA, in close coordination with
 the  Secretary  of the Interior,  develop water
 quality  criteria for protecting wildlife and their
 refuge habitat."

 In  November of 1988,  EPA's  Environmental
 Research  Laboratory in Corvallis sponsored a
 workshop  entitled  Water  Quality Criteria  To
 Protect Wildlife Resources,  (USEPA,  1989g)
 which was co-chaired by EPA  and the Fish and
 Wildlife Service (FWS).  The workshop brought
 together 26  professionals from  a variety  of
institutions,    including   EPA,   FWS,   State
governments, academia, and consultants who had
 expertise  in  wildlife toxicity,  aquatic toxicity,
 ecology,  environmental  risk  assessment,   and
 conservation.  Efforts at he workshop focused on
 evaluating the need for, and developing a strategy
 for  production  of  wildlife  criteria.     Two
 recommendations came out of that workshop:

      (1)  The process by which  ambient
          water   quality   criteria   are
          established should be modified to
          consider effects on wildlife; and

      (2)  chemicals  should  be prioritized
          based  on  their   potential   to
          adversely impact wildlife species.
 Based  on  the  workshop  recommendations,
 screening  level wildlife criteria (SLWC)  were
 calculated  for priority pollutants and chemicals of
 concern submitted by the FWS to gauge the extent
 of the problem by:

     (1)  evaluating  whether  existing  water
          quality criteria  for  aquatic  life are
          protective of wildlife, and

     (2)  prioritizing chemicals for their potential
          to adversely impact wildlife species.

 There  were 82  chemicals for which EPA had the
 necessary toxicity information as well as ambient
 water  quality  criteria,  advisories,  or lowest-
 observed-adverse-effect  levels    (LOAELs)  to
 compare with the SLWC values.  As would be
 expected,  the majority of chemicals  had SLWC
 larger   than  existing  water  quality  criteria,
 advisories,  or  LOAELs   for  aquatic  life.
 However,  the  screen   identified   classes  of
 compounds for which  current  ambient  water
 quality criteria may not be  adequately protective
 of  wildlife:    chlorinated   alkanes,  benzenes,
phenols, metals, DDT,  and dioxins. Many  of
 these compounds are produced in  very large
amounts and  have  a variety of  uses (e.g.,
 solvents, flame retardants,  organic syntheses  of
fungicides  and  herbicides,  and manufacture  of
plastics and textiles.  The manufacture and use of
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                                                                  Chapter 3 - Water Quality Criteria
these materials produce waste byproduct).  Also,
5 of the  21  are among  the  top 25 pollutants
identified at Superfund sites in 1985 (3 metals, 2
organics).

Following this initial effort,, EPA held a national
meeting in April 19921 to constructively discuss
and evaluate proposed methodologies for deriving
wildlife criteria to build consensus among the
scientific  community as  to the most defensible
scientifically approaches) to be pursued by EPA
in developing useful and effective wildlife criteria.

The conclusions of this national meeting were as
follows:

•    wildlife criteria should have a tissue-residue
     component when appropriate;

•    peer-review of wildlife criteria and data sets
     should be used in their derivation;

•    wildlife criteria should incorporate methods
     to establish site-specific wildlife criteria;

•    additional amphibian and reptile toxicity data
     are needed;

•    further   development    of  inter-species
     lexicological sensitivity factors are needed;
     and
•    criteria methods should measure biomarkers
     in conjunction with other studies.

On  April  16,  1993,  EPA proposed  wildlife
criteria  in the Water Quality Guidance for the
Great Lakes  System (58  F.R. 20802).   The
proposed wildlife criteria are based on the current
EPA noncancer  human health criteria approach.
In  this  proposal,  in  addition  to  requesting
comments on  the proposed Great  Lakes criteria
and  methods,  EPA also requested comments on
possible modifications  of the proposed Great
Lakes   approach   for   consideration  in  the
development of national wildlife criteria.

3.5.6  Numeric Criteria for Wetlands

Extension of  the EPA  national 304(a) numeric
aquatic  life  criteria to wetlands is recommended
as part of a program to  develop  standards and
criteria for wetlands.   Appendices D and  E
provide an overview of the need for standards and
criteria for wetlands. The 304(a) numeric aquatic
life  criteria are designed  to  be protective  of
aquatic life  for  surface waters  and are generally
applicable to  most wetland types.   Appendix E
provides a possible approach, based on the site-
specific guidelines,  for detecting  wetland types
that might not be protected by direct application
of national 304(a) criteria.  The evaluation can be
 simple  and  inexpensive for those wetland types
for  which sufficient water chemistry and species
assemblage  data are available, but  will be less
 useful for wetland types for which these data are
 not  readily  available.  In  Appendix E, the site-
 specific approach is described  and recommended
 for  wetlands for which modification of the 304(a)
 numeric criteria are considered necessary.  The
 results  of this type of evaluation,  combined with
 information on  local or regional environmental
 threats, can be used to prioritize wetland types
 (and individual criteria) for further site-specific
 evaluations and/or additional data collection.
 Close coordination among regulatory  agencies,
 wetland scientists, and criteria experts will  be
 required.
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  Water Quality Standards Handbook - Second Edition
         Policy on Aquatic Life  Criteria for
         Metals
  It is the policy of the Office of Water that the use
  of dissolved metal to set and measure compliance
  with water quality standards is the recommended
  approach, because dissolved metal more closely
  approximates the bioavailable fraction of metal in
  the  water  column  than does  total recoverable
  metal.    This  conclusion  regarding  metals
  bioavailability is supported by a majority of the
  scientific community within and outside  EPA.
  One reason is that a primary mechanism for water
  column toxicity is adsorption at the gill surface
  which requires metals to be in the dissolved form.

  Until  the   scientific  uncertainties   are  better
  resolved, a  range of different risk management
  decisions can  be justified by  a State.   EPA
  recommends that State water quality standards be
 based on  dissolved  metal—a conversion factor
  must be used in order to express the EPA criteria
 articulated as total recoverable as dissolved. (See
 the paragraph  below for  technical  details  on
 developing  dissolved criteria.)   EPA will also
 approve a State risk management decision to adopt
 standards based on  total recoverable metal,  if
 those standards  are  otherwise  approvable as a
 matter of law.   (Office of Water  Policy and
 Technical   Guidance  on   Interpretation  and
 Implementation of Aquatic Life  Metals Criteria
 USEPA, 1993f)

 3.6.1 Background

 The implementation of metals criteria is complex
 due to the site-specific nature of metals toxicity.
 This issue covers a number of areas including the
 expression of aquatic  life criteria; total maximum
 daily   loads   (TMDLs),    permits,   effluent
 monitoring,   and  compliance;   and   ambient
 monitoring.  The following Sections, based on the
 policy memorandum  referenced  above, provide
 additional guidance  in   each of these areas.
 Included in this Handbook as  Appendix J are
 three guidance documents issued along with the
 Office  of Water  policy  memorandum  with
 additional technical details.  They are:  Guidance
 Document on Expression of Aquatic Life Criteria
 as Dissolved Criteria (Attachment #2), Guidance
 Document on Dynamic Modeling and Translators
 (Attachment #3),  and  Guidance Document on
 Monitoring  (Attachment  #4).   These will be
 supplemented as additional information becomes
 available.

 Since metals toxicity is significantly affected by
 site-specific factors, it presents a  number of
 programmatic challenges.   Factors that must be
 considered  in the management of metals  in the
 aquatic environment include:  toxicity specific to
 effluent chemistry;  toxicity specific to ambient
 water chemistry; different patterns of toxicity for
 different metals;  evolution  of the  state of the
 science  of  metals  toxicity,  fate,  and transport;
 resource limitations for  monitoring,  analysis,
 implementation, and research functions; concerns
 regarding some of the analytical data currently on
 record due to  possible  sampling  and analytical
 contamination; and lack of standardized protocols
 for  clean and ultraclean metals analysis.   The
 States have the key role in the risk management
 process  of  balancing  these  factors  in  the
 management of water programs. The site-specific
 nature  of this  issue  could  be  perceived as
 requiring  a  permit-by-permit  approach   to
 implementation.  However, EPA believes that this
 guidance can be effectively implemented on a
 broader level, across any waters with roughly the
 same physical and  chemical characteristics, and
 recommends  that States work with the EPA with
 that  perspective in mind.

 3.6.2  Expression of Aquatic Life Criteria

     Dissolved vs.  Total Recoverable Metal

 A  major issue  is  whether, and  how,  to use
 dissolved metal concentrations ("dissolved metal")
 or total recoverable  metal  concentrations ("total
recoverable metal") in setting State water quality
standards.  In the past, States  have used both
approaches when applying the same EPA Section
304(a) criteria guidance.  Some  older  criteria
documents may  have facilitated these different
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approaches to interpretation of the criteria because
the documents were somewhat  equivocal with
regards to analytical methods.  The May  1992
interim guidance continued the policy that either
approach was acceptable.

The position that the dissolved metals approach is
more accurate has  been questioned because it
neglects the possible toxicity of paniculate metal.
It is true that some studies have indicated that
paniculate metals  appear to contribute to the
toxicity of metals, perhaps because of factors such
as desorption of metals at  the gill surface, but
these  same   studies indicate the  toxicity  of
paniculate metal is substantially less than that of
dissolved metal.

     Furthermore,   any  error   incurred  from
excluding the contribution of paniculate metal will
generally be compensated by other factors which
make criteria conservative.  For example, metals
in toxicity  tests are added as  simple salts to
relatively clean water. Due to the likely presence
of a significant concentration of metals binding
agents in many discharges  and ambient  waters,
metals  in  toxicity  tests would  generally  be
expected to be more bioavailable than  metals in
discharges or in ambient waters.

     If total recoverable metal is used  for the
purpose of specifying water quality standards, the
lower  bioavailability  of paniculate metal and
lower bioavailability of sorbed metals as they are
discharged may result in an overly conservative
water  quality standard.  The use  of  dissolved
metal  in  water quality  standards gives a  more
accurate result in the water column.  However,
total recoverable measurements in ambient water
have value, in that exceedences  of criteria on a
total recoverable basis are an indication that metal
loadings  could be  a stress  to  the ecosystem,
particularly  in  locations other than the water
column (e.g., in the sediments).

The reasons for the potential consideration of total
recoverable   measurements   include   risk
management  considerations  not   covered  by
evaluation of water column toxicity alone.  The
ambient water quality criteria are neither designed
nor intended to protect sediments, or to prevent
effects in  the  food webs  containing  sediment
dwelling organisms. A risk manager, however,
may consider sediments and food chain effects
and may decide to take a conservative  approach
for metals,  considering  that  metals are  very
persistent chemicals. This conservative approach
could include the use of total recoverable metal in
water  quality   standards.     However,   since
consideration  of  sediment  impacts   is  not
incorporated into  the  criteria  methodology, the
degree  of  conservatism  inherent in  the total
recoverable  approach  is   unknown.     The
uncertainty  of metal impacts in  sediments stem
from  the  lack of sediment criteria  and  an
imprecise understanding of the fate and transport
of metals.  EPA will continue to pursue research
and other activities to close these knowledge gaps.

     Dissolved Criteria

In the toxicity tests used to develop EPA metals
criteria for aquatic life, some fraction of the metal
is dissolved while  some fraction is bound to
particulate  matter.  The present  criteria  were
developed    using   total    recoverable   metal
measurements  or  measures  expected  to give
equivalent  results in  toxicity  tests,  and are
articulated as total recoverable.  Therefore, in
order to express the EPA criteria as dissolved, a
total recoverable to dissolved conversion factor
must  be used.   Attachment #2 in Appendix J
provides guidance for  calculating EPA  dissolved
criteria   from  the published  total recoverable
criteria.  The data expressed as percentage metal
dissolved are presented as  recommended  values
and ranges. However, the choice within ranges is
a State  risk management  decision.    EPA has
recently  supplemented the data for copper and is
proceeding  to  further supplement the  data  for
copper and other metals. As testing is completed,
EPA will make this information available and this
is expected to reduce the magnitude of the ranges
for some  of the conversion  factors provided.
EPA  also strongly encourages the application of
dissolved   criteria  across   a   watershed  or
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  waterbody, as technically sound and the best use
  of resources.

      SUe-Spectfic Criteria Modifications

  While the above methods will correct some  site-
  specific factors affecting metals toxicity, further
  refinements  are  possible.    EPA  has issued
  guidance   for   three   site-specific   criteria
  development   methodologies:      recalculation
  procedure, water-effect ratio  (WER) procedure
  (called the indicator species procedure in previous
  guidance) and resident species procedure.  (See
  Section 3.7 of this Chapter.)

  In the National  Toxics  Rule (57  PR  60848,
 December  22,  1992), EPA recommended  the
 WER as  an  optional method for  site-specific
 criteria development  for  certain  metals.  EPA
 committed  in the  NTR  preamble  to  provide
 additional guidance  on determining  the WERs.
 The Interim Guidance on the Determination  and
 Use of Water-Effect  Ratios for Metals was issued
 by EPA on February 22,  1994  and is intended to
 fulfill that commitment.   This interim guidance
 supersedes all guidance concerning water-effect
 ratios and the recalculation procedure previously
 issued by EPA.   This guidance is included as
 Appendix L to this Handbook.

 In order  to meet current needs,  but allow  for
 changes suggested by protocol users, EPA issued
 the guidance  as "interim."    EPA will  accept
 WERs developed using this guidance, as well as
 by using other scientifically defensible protocols.
 3.6.3  Total Maximum Daily Loads (TMDLs)
        and  National   Pollutant  Discharge
        Elimination System (NPDES) Permits

      Dynamic Water Quality Modeling

 Although not specifically part of the reassessment
 of water quality criteria for metals, dynamic or
 probabilistic models are another useful tool for
 implementing water quality criteria, especially for
 those criteria  protecting aquatic  life.   These
 models provide another  way to  incorporate site-
 specific data.  The Technical Support Document
for Water Quality-based Toxics Control  (TSD)
 (USEPA, 1991a) describes  dynamic, as well as
 static (steady-state) models.  Dynamic models
 make the best use of the specified magnitude,
 duration, and frequency  of water quality criteria
 and,  therefore,  provide  a   more   accurate
 representation  of the  probability  that a water
 quality  standard exceedence  will  occur.    In
 contrast, steady-state models frequently apply a
 number  of  simplifying,  worst case assumptions
 which makes them  less complex but also  less
 accurate than dynamic models.

Dynamic models have received increased attention
over the last  few  years  as a result  of  the
widespread  belief that steady-state modeling is
over-conservative   due    to    environmentally
conservative dilution assumptions. This belief has
led to the misconception that dynamic models will
always lead to less stringent regulatory controls
(e.g., NPDES  effluent limits) than steady-state
models, which is not true in every application of
dynamic models.  EPA considers  dynamic models
to be a more accurate approach to implementing
water quality criteria and continues to recommend
their use.   Dynamic modeling  does require a
commitment of resources to develop appropriate
data.  (See Appendix J,  Attachment #3 and the
USEPA, 1991a for details on the use of dynamic
models.)

     Dissolved-Total Metal Translators

Expressing ambient  water quality  criteria  for
metals as the dissolved form of a metal poses a
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need to be able to translate from dissolved metal
to  total  recoverable  metal  for TMDLs  and
NPDES permits.  TMDLs for metals must be able
to calculate:   (1)  dissolved  metal  in order to
ascertain  attainment of water quality standards,
and (2) total recoverable metal in order to achieve
mass balance necessary for permitting purposes.

EPA's NPDES regulations require that limits of
metals in  permits be stated as total recoverable in
most cases (see 40 CFR §122.45(c)) except when
an  effluent guideline  specifies  the  limitation in
another form of the metal, the approved analytical
methods  measure only dissolved metal, or the
permit writer expresses a nietals limit in another
form  (e.g., dissolved, valent specific,  or  total)
when  required  to  carry out provisions of the
Clean  Water Act.  This is because  the chemical
conditions in ambient waters  frequently differ
substantially from those in the effluent, and there
is no  assurance that  effluent  particulate metal
would not dissolve after discharge.  The NPDES
rule does not require that  State  water quality
standards  be  expressed  as  total  recoverable;
rather, the rule requires permit writers to translate
between different metal forms in the calculation of
the permit limit so that a total  recoverable limit
can be established. Both the TMDL and NPDES
uses of water quality criteria require the ability to
translate  between  dissolved   metal  and total
recoverable metal.  Appendix J, Attachment #3
provides  guidance on  this translation.

3.6.4   Guidance on Monitoring

     Use  of Clean  Sampling and Analytical
     Techniques

In assessing waterbodies to determine the potential
for toxicity problems due to metals,  the quality of
the data used is  an important issue.  Metals data
are used  to determine attainment status for water
quality standards, discern trends in water quality,
estimate  background loads for TMDLs, calibrate
 fate  and transport   models,   estimate  effluent
 concentrations  (including effluent variability),
 assess permit compliance, and  conduct  research.
 The quality of trace level metal data, especially
below  1  ppb,  may be  compromised due  to
contamination  of  samples  during  collection,
preparation, storage, and analysis. Depending on
the level of metal present, the use of "clean" and
"ultraclean" techniques for sampling and analysis
may   be   critical   to   accurate  data   for
implementation of aquatic life criteria for metals.

The significance of the  sampling and analysis
contamination problem  increases as the ambient
and effluent metal concentration decreases and,
therefore, problems are more likely in ambient
measurements.  "Clean" techniques refer to those
requirements (or practices for sample  collection
and handling)  necessary  to  produce reliable
analytical data in the part per billion (ppb) range.
"Ultraclean"    techniques   refer   to    those
requirements  or practices necessary to produce
reliable analytical data in the part per trillion (ppt)
range.  Because typical concentrations  of metals
in  surface waters and  effluents vary  from one
metal to another,  the effect of contamination on
the quality  of metals monitoring data  varies
appreciably.

EPA plans to develop protocols on the use of
clean   and   ultra-clean    techniques   and   is
coordinating with the  United States Geological
Survey (USGS) on this project, because  USGS has
been doing work on these techniques  for some
time, especially the  sampling procedures.   Draft
protocols for clean  techniques were presented at
the Norfolk, VA analytical methods conference in
the Spring  of  1994  and  final  protocols  are
expected to be available in early 1995.   The
development  of comparable protocols  for  ultra-
clean techniques is underway and are expected to
be available in late 1995.  In developing these
protocols, we  will consider the costs of these
techniques  and will give guidance   as  to  the
situations where their use is necessary.  Appendix
L, pp.  98-108 provide  some general guidance.on
the use  of clean  analytical  techniques.    We
recommend that this guidance be used by  States
and Regions  as an  interim step, while the clean
 and ultra-clean protocols  are being developed.
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      Use of Historical Data

 The concerns about metals sampling and analysis
 discussed above raise  corresponding  concerns
 about the validity of historical data.   Data on
 effluent  and ambient metal concentrations  are
 collected by a variety of organizations including
 Federal  agencies (e.g.,  EPA,  USGS),  State
 pollution control agencies and health departments,
 local  government   agencies,   municipalities,
 industrial dischargers, researchers,  and others.
 The data are collected for a variety of purposes as
 discussed above.

 Concern  about  the  reliability  of  the sample
 collection and  analysis  procedures is greatest
 where they have been used  to monitor very low
 level metal concentrations.  Specifically, studies
 have shown data sets with contamination problems
 during sample collection and laboratory  analysis,
 that  have resulted in inaccurate  measurements.
 For example, in  developing a TMDL for New
 York Harbor,  some historical  ambient data
 showed extensive metals problems in the harbor,
 while other  historical ambient data showed only
 limited metals problems.  Careful resampling and
 analysis in 1992/1993 showed the latter view was
 correct.   The key to producing accurate data is
 appropriate quality assurance  (QA)  and quality
 control (QC) procedures.  EPA believes that most
 historical data for metals, collected and analyzed
 with appropriate QA and QC at levels of 1 ppb or
 higher,  are  reliable.    The  data  used  in
 development of EPA criteria are also considered
 reliable,  both because they  meet  the above test
 and because the toxicity test solutions are created
 by adding known amounts of metals.

 With respect to effluent monitoring reported by an
 NPDES permittee, the permittee is responsible for
 collecting  and  reporting   quality  data  on  a
 Discharge Monitoring Report (DMR). Permitting
 authorities  should continue to  consider  the
 information reported  to  be  true,  accurate, and
 complete as certified by the permittee. Where the
 permittee  becomes aware of  new  information
 specific to the effluent discharge that questions the
quality of previously  submitted DMR data,  the
 permittee must promptly submit that information
 to  the  permitting  authority.   The  permitting
 authority will consider all information submitted
 by  the  permittee  in  determining  appropriate
 enforcement responses  to monitoring/reporting
 and  effluent  violations.    (See  Appendix J,
 Attachment #4 for additional details.)
        Site-Specific Aquatic Life Criteria
 The purpose of this section is to provide guidance
 for the development of site-specific water quality
 criteria   which   reflect  local   environmental
 conditions.  Site-specific criteria are allowed by
 regulation and are subject to EPA review  and
 approval.  The Federal water quality standards
 regulation at  section  131.11(b)(l)(ii)  provides
 States with the opportunity to adopt water quality
 criteria that are "... modified to reflect site-specific
 conditions."   Site-specific  criteria,  as with  all
 water quality criteria, must be based on a sound
 scientific  rationale   in  order  to  protect  the
 designated use.  Existing guidance and practice
 are that EPA will approve site-specific criteria
 developed using appropriate procedures.

 A site-specific criterion is intended to come closer
 than  the  national criterion  to   providing  the
 intended level of protection to the aquatic life at
 the site,  usually by taking  into account  the
 biological  and/or  chemical  conditions (i.e.,  the
 species  composition  and/or   water   quality
 characteristics)  at the  site. The fact that the U.S.
 EPA  has made these procedures available  should
 not be interpreted as implying that the agency
 advocates that  states  derive site-specific  criteria
 before setting state standards. Also, derivation of
 a  site-specific  criterion does  not  change  the
 intended level of protection of the aquatic life at
 the site.

 3.7.1   History    of   Site-Specific   Criteria
       Guidance

National water quality criteria for aquatic life may
be under- or over-protective if:
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(1)   the  species  at  the site are  more  or less
     sensitive than those included in the national
     criteria  data set (e.g.,, the national criteria
     data set contains  data  for trout, salmon,
     penaeid shrimp, and  other aquatic species
     that  have  been  shown to  be  especially
     sensitive to some materials), or

(2)   physical and/or chemical  characteristics of
     the   site alter  the biological availability
     and/or  toxicity  of  the   chemical   (e.g.,
     alkalinity, hardness, pH,  suspended  solids
     and salinity influence the concentration(s) of
     the  toxic  form(s) of some  heavy metals,
     ammonia and other chemicals).

Therefore,  it is  appropriate  that  site-specific
procedures  address   each  of  these  conditions
separately as well as the combination of the two.
In  the  early   1980's,  EPA   recognized that
laboratory-derived water quality criteria might not
accurately reflect site-specific conditions and, in
response, created three procedures to derive site-
specific  criteria.  This  Handbook contains the
details of these procedures, referenced below.

1.   The Recalculation Procedure is intended to
     take  into   account  relevant  differences
     between the  sensitivities of  the aquatic
     organisms  in the  national dataset  and the
     sensitivities of  organisms that occur  at the
     site (see Appendix L, pp.  90-97).

2.   The Water-Effect Ratio Procedure (called the
     Indicator  Species  Procedure  in USEPA,
     1983a;  1984f ) provided for the use of a
     water-effect ratio (WER) that is intended to
     take  into  account  relevant  differences
     between the toxicities  of the chemical in
     laboratory  dilution water  and in site water
     (see Appendix  L).

3.   The Resident Species Procedure intended to
     take into account  both  kinds of differences
     simultaneously (see Section 3.7.6).

These procedures were first published in the 1983
Water Quality  Standards Handbook (USEPA,
1983a) and expanded upon in the Guidelines for
Deriving Numerical Aquatic Site-Specific Water
Quality Criteria by Modifying National Criteria
(USEPA, 1984f). Interest has increased in recent
years as states have devoted more attention  to
chemical-specific water quality criteria for aquatic
life.  In addition, interest in water-effect  ratios
increased when they were integrated into some of
the aquatic life  criteria  for metals that  were
promulgated  for  several  states  in  the National
Toxics Rule (57 FR 60848, December 22, 1992).
The  Office  of  Water  Policy  and  Technical
Guidance on Interpretation and Implementation of
Aquatic Life Criteria for Metals (USEPA, 1993f)
(see  Section  3.6  of  this Handbook) provided
further guidance on site-specific criteria for metals
by recommending the use of dissolved metals for
setting  and measuring compliance with  water
quality standards.

The early guidance concerning WERs (USEPA,
1983a;  1984f) contained few details and needed
revision, especially to take  into account newer
guidance concerning metals.   To meet this need,
EPA   issued  Interim   Guidance   on   the
Determination and  Use of Water-Effect Ratios for
Metals in 1994  (Appendix L).    Metals  are
specifically addressed in Appendix L because of
the National Toxics Rule and because of current
interest in aquatic life criteria for metals; although
most  of this guidance  also applies  to  other
pollutants, some obviously applies only to metals.
Appendix L  supersedes  all guidance concerning
water-effect  ratios  and  the Indicator  Species
Procedure given  in  Chapter 4  of the  Water
Quality Standards Handbook (USEPA, 1983a) and
in Guidelines for Deriving Numerical Aquatic Site-
Specific Water Quality  Criteria   by  Modifying
National Criteria (USEPA, 1984f). Appendix L
(p. 90-98) also supersedes the guidance in these
earlier documents for the Recalculation Procedure
for performing site-specific criteria  modifications.
The   Resident  Species   Procedure   remains
essentially unchanged since 1983 (except for
changes in the averaging periods to conform  to
the 1985 aquatic life criteria guidelines (USEPA,
 1985b) and is presented in Section  3.7.6, below.
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 The previous guidance  concerning site-specific
 procedures  did  not  allow  the  Recalculation
 Procedure and the WER procedure to be used
 together in the derivation of a site-specific aquatic
 life criterion; the only way to take into account
 both  species  composition and water quality
 characteristics in  the determination  of a site-
 specific criterion was to use the Resident Species
 Procedure. A specific change contained Appendix
 L is that, except in jurisdictions that are subject to
 the National  Toxics  Rule,  the  Recalculation
 Procedure and the WER Procedure may now be
 used  together provided that  the  recalculation
 procedure  is  performed   first.     Both  the
 Recalculation Procedure and the WER Procedure
 are based directly on the guidelines for deriving
 national aquatic life criteria (USEPA 1985 ) and,
 when the two are  used together,  use of the
 Recalculation Procedure must  be performed first
 because the Recalculation Procedure has specific
 implications concerning the determination  of the
 WER.

 3.7.2   Preparing  to  Calculate  Site-Specific
        Criteria

 Adopting  site-specific  criteria  in water quality
 standards  is a State option—not a  requirement.
 Moreover, EPA is not advocating that States use
 site-specific criteria development procedures for
 setting all aquatic life criteria as opposed to using
 the  National   Section    304(a)    criteria
 recommendations.  Site-specific criteria are  not
 needed  in all situations.  When a State considers
 the possibility of developing site-specific criteria,
 it is essential  to involve the  appropriate EPA
 Regional office at the start of the project.

 This early  planning is also essential  if it appears
 that data generation and testing  may be conducted
 by a party other than the State or EPA.  The State
 and EPA need to apply the procedures judiciously
 and must consider the complexity of the problem
 and the extent of knowledge available concerning
 the fate  and  effect  of  the   pollutant under
 consideration.    If  site-specific  criteria  are
 developed without early EPA involvement in the
planning and design of the  task, the State may
expect EPA  to take additional time to  closely
scrutinize the results before granting any approval
to the formally adopted standards.

The following sequence of decisions need to be
made before any of the procedures are initiated:

4  verify that site-specific criteria are actually
    needed (e.g., that the use of clean sampling
    and/or analytical techniques, especially for
    metals,  do  not result in  attainment  of
    standards.)

4  Define the site boundaries.

4  Determine  from   the   national  criterion
    document  and  other  sources if physical
    and/or chemical characteristics are known to
    affect  the  biological  availability  and/or
    toxicity of a material of interest.

4  If data  in the national criterion document
    and/or from other sources indicate that the
    range of sensitivity of the selected resident
    species to the material of interest is different
    from the range for the species in the national
    criterion document, and variation in physical
    and/or chemical characteristics of the site
    water is not expected to be a factor, use the
    Recalculation Procedure (Section 3.7.4).

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4   If data  in  the  national criterion document
     and/or  from  other sources  indicate  that
     physical and/or chemical characteristics of
     the site water  may affect  the biological
     availability and/or toxicity of the material of
     interest, and the selected  resident  species
     range of sensitivity is similar to that for the
     species  in the national  criterion document,
     use  the  Water-Effect  Ratio  Procedure
     (Section 3.7.5).

4   If data  in  the  national criterion document
     and/or  from other  sources  indicated  that
     physical and/or chemical characteristics of
     the site water  may affect  the biological
     availability and/or toxicity of the material of
     interest, and the selected  resident  species
     range of sensitivity  is different from that for
     the  species  in   the   national  criterion
     document, and if both these differences are
     to  be   taken  into   account,   use  the
     Recalculation Procedure in conjunction with
     the Water-Effect Ratio  Procedure or  use the
     Resident Species Procedure (Section 3.7.6).

3.7.3  Definition of a Site

Since the rationales for  site-specific criteria are
usually based on potential differences in  species
sensitivity, physical and chemical characteristics
of the water, or a combination of the two, the
concept  of  site  must  be  consistent with  this
rationale.

In the general context of site-specific criteria, a
"site"   may  be  a   state,   region,  watershed,
waterbody, or segment of a waterbody.  The site-
specific  criterion is  to  be  derived  to provide
adequate protection  for the entire  site, however
the site is defined.

If water quality effects  on toxicity are  not  a
consideration, the  site  can be as  large as  a
generally consistent biogeographic  zone permits.
For example, large portions of the  Chesapeake
Bay, Lake Michigan, or the Ohio River may be
considered as one site if their respective  aquatic
communities  do not vary substantially. However,
when a site-specific criterion is derived using the
Recalculation Procedure, all species that "occur at
the site"  need to be  taken into  account when
deciding what species, if any, are to be deleted
from  the dataset.  Unique  populations  or less
sensitive  uses   within   sites  may  justify   a
designation as a distinct site.

If the  species   of  a  site  are  lexicologically
comparable to those in the national criteria data
set for a material of interest, and physical and/or
chemical water characteristics are the only factors
supporting modification  of the  national criteria,
then  the  site  can be defined  on the basis  of
expected  changes in  the material's  biological
availability and/or toxicity due to physical and
chemical variability of the site water.  However,
when a site-specific criterion is derived  using a
WER, the WER is to be adequately protective of
the entire site.   If,  for  example,  a site-specific
criterion is being derived for an estuary, WERs
could be determined using samples of the surface
water obtained from various sampling  stations,
which, to avoid confusion, should not be called
"sites". If all the WERs were sufficiently similar,
one site-specific criterion could  be derived  to
apply to the whole estuary.   If the WERs were
sufficiently different, either the lowest WER could
be used to derive a site-specific criterion for the
whole estuary, or the data might indicate that the
estuary should be divided into two or more sites,
each with its own criterion.

3.7.4  The Recalculation Procedure

The Recalculation Procedure is intended to cause
a  site-specific  criterion  to  appropriately differ
from a national aquatic life criterion if justified by
demonstrated pertinent toxicological differences
between the aquatic species that occur at  the site
and those that were used in the  derivation of the
national criterion. There are at least three reasons
why such differences might exist between the two
sets of species.

4  First, the national dataset  contains  aquatic
     species that are sensitive to many pollutants,
(8/15/94)
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 Water Quality Standards Handbook - Second Edition
     but these and comparably sensitive species
     might not occur at the site.

 +   Second, a species that is critical at the site
     might  be  sensitive  to  the  pollutant  and
     require a lower criterion. (A critical species
     is  a  species  that  is  commercially  or
     recreationally important  at the site, a species
     that exists at the site and  is  listed  as
     threatened or endangered under section 4 of
     the Endangered Species Act, or a species for
     which there is evidence that the loss of the
     species from  the  site is likely to  cause an
     unacceptable impact  on a commercially or
     recreationally important species, a threatened
     or endangered species,  the abundances of a
     variety of other species, or the structure or
     function of the community.)

 +   Third,  the  species that occur at the  site
     might represent a narrower mix of species
     than those in the national dataset  due to a
     limited  range  of  natural   environmental
     conditions.

The procedure presented in Appendix L, pp. 90-
98  is structured so that corrections and additions
can be made to the national  dataset without the
deletion process being  used to take into account
taxa that do not occur at the site;  in effect, this
procedure makes it possible to update the national
aquatic  life  criterion.    All  corrections  and
additions  that have been approved by EPA are
required,  whereas use of the deletion process  is
optional.  The deletion process may not be used
to remove species from  the criterion calculation
that are not currently present at a  site due  to
degraded  conditions.

The Recalculation Procedure is  more likely  to
result in lowering a criterion if the net result  of
addition and deletion is to decrease the number  of
genera in the dataset, whereas the procedure  is
more likely to result  in raising a criterion if the
net result of addition and deletion is to increase
the number of genera in  the dataset.

For the lipid soluble chemicals  whose national
Final Residue Values are based on Food and Drug
Administration (FDA) action levels, adjustments
in those values based  on  the percent lipid content
of resident aquatic species is appropriate for the
derivation of  site-specific Final Residue Values.
For lipid-soluble materials,  the national Final
Residue Value is based on an average 11 percent
lipid content for edible portions for the freshwater
chinook salmon and lake trout and an average of
10  percent lipids  for the  edible  portion  for
saltwater  Atlantic herring.  Resident species of
concern may  have  higher (e.g.,  Lake Superior
siscowet,  a race of lake trout)  or lower (e.g.,
many sport fish) percent lipid content than used
for the national Final Residue Value.
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                                                                   Chapter 3 - Water Quality Criteria
For   some   lipid-soluble   materials  such  as
polychlorinated biphenyls (PCS) and DDT,  the
national Final Residue Value is based on wildlife
consumers of fish and aquatic invertebrate species
rather than an  FDA action  level because  the
former provides a more stringent residue level.
See the National Guidelines (USEPA, 1985b) for
details.

For  the  lipid-soluble materials whose  national
Final Residue Values  are  based  on  wildlife
effects, the limiting wildlife species (mink  for
PCB and brown pelican for DDT) are considered
acceptable surrogates for  resident  avian and
mammalian species  (e.g., herons,  gulls, terns,
otter, etc.) Conservatism is appropriate for those
two chemicals, and no less restrictive modification
of the national Final Residue Value is appropriate.
The  site-specific  Final Residue Value would be
the same as the national value.

3.7.5  The   Water-Effect   Ratio   (WER)
Procedure

The guidance on the Water-Effect Ratio Procedure
presented in Appendix L  is intended to  produce
WERs that may  be used to derive site-specific
aquatic life criteria from most national and state
aquatic life  criteria that  were derived  from
laboratory toxicity data.

     As   indicated   in   Appendix   L,    the
determination of a water-effect ratio may require
substantial resources.    A  discharger should
consider   cost-effective,  preliminary measures
described in this Appendix L (e.g., use of "clean"
sampling  and  chemical  analytical  techniques
especially for metals, or  in non-NTR States, a
recalculated criterion) to determine if an indicator
species site-specific criterion is really needed. In
many instances, use of these other measures may
eliminate the need for deriving water-effect ratios.
The   methods  described  in  the  1994  interim
guidance  (Appendix L) should be sufficient to
develop site-specific criteria that resolve concerns
of dischargers when  there appears to be no
instream  toxicity but,  where  (a)  a  discharge
appears to exceed existing  or proposed  water
quality-based permit limits, or  (b) an  instream
concentration appears to exceed an existing or
proposed water quality criterion.

WERs obtained using the methods described in
Appendix L should only be used to adjust aquatic
life criteria that were derived using laboratory
toxicity  tests.   WERs  determined  using the
methods described  herein cannot be used to adjust
the residue-based mercury Criterion Continuous
Concentration (CCC) or the field-based  selenium
freshwater  criterion.

Except  in  jurisdictions  that are subject to the
NTR,  the  WERs  may  also be used with  site-
specific aquatic life criteria that are derived using
the   Recalculation  Procedure  described  in
Appendix L (p. 90).

     Water-Effect  Ratios in the Derivation of
     Site-Specific Criteria

A central question concerning WERs is whether
their  use by a State results in a  site-specific
criterion subject to  EPA review and  approval
under Section 303(c) of the  Clean Water Act?

Derivation  of a water-effect ratio by a State is a
site-specific criterion adjustment subject to EPA
review  and approval/disapproval under Section
303(c).   There are  two options by  which this
review can be accomplished.

     Option 1:

A State may derive  and submit each individual
water-effect ratio determination to EPA for review
and  approval.   This  would be accomplished
through the normal review  and  revision process
used by a State.

     Option 2:

A State can amend its water quality standards to
provide  a  formal procedure  which  includes
derivation  of  water-effect  ratios,  appropriate
definition of sites,  and enforceable  monitoring
provisions  to assure that  designated  uses are
(8/15/94)
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 Water Quality Standards Handbook - Second Edition
 protected.  Both this procedure and the resulting
 criteria   would   be   subject  to  full  public
 participation requirements.  EPA would review
 and approve/disapprove this protocol as a revised
 standard   as  part  of  the  State's  triennial
 review/revision.  After adoption of the procedure,
 public review of a site-specific criterion could be
 accomplished  in  conjunction with  the  public
 review required for permit issuance.  For public
 information, EPA recommends that once a year
 the State publish a list  of site-specific  criteria.

 An exception to this policy applies to the waters
 of the jurisdictions included  in the  National
 Toxics Rule.  The EPA review is not required for
 the jurisdictions included in the National Toxics
 Rule where EPA established the procedure for the
 State for application to the criteria promulgated.
 The  National  Toxics  Rule  was  a  formal
 rulemaMng process (with notice and comment) in
 which EPA pre-authorized the use of  a correctly
 applied water-effect ratio.  That same process has
 not yet taken place in  States not included in the
 National Toxics Rule.

 However,  the National Toxics  Rule does not
 affect  State authority  to  establish  scientifically
 defensible   procedures  to  determine   Federally
 authorized  WERs,  to  certify those  WERs in
 NPDES  permit proceedings, or  to deny  their
 application based on the State's risk management
 analysis.

 As described in Section 131.36(b)(iii) of the water
 quality standards regulation (the official regulatory
 reference to the National Toxics Rule), the water-
 effect  ratio is a  site-specific calculation.    As
 indicated on page 60866 of the preamble to the
 National Toxics Rule, the rule was constructed as
 a rebuttable presumption. The water-effect ratio is
 assigned a value of 1.0 until a different water-
 effect  ratio  is   derived  from   suitable  tests
 representative  of  conditions  in  the  affected
 waterbody.  It is the responsibility of the State to
 determine whether to rebut the assumed value of
 1.0 in the National Toxics Rule and apply another
 value of the water-effect ratio in order to establish
a site-specific criterion.  The site-specific criterion
 is then used to develop appropriate NPDES permit
 limits. The rule thus provides a State with the
 flexibility  to derive an  appropriate site-specific
 criterion for specific waterbodies.

 As a point of emphasis, although a water-effect
 ratio  affects   permit  limits   for   individual
 dischargers, it  is  the State in all cases  that
 determines if derivation of a site-specific criterion
 based on the water-effect ratio is allowed and it is
 the  State that ensures that the calculations and
 data analysis are done completely and correctly.

 3.7.6 The Resident Species Procedure

 The resident Species Procedure for the derivation
 of a site-specific criterion accounts for differences
 in resident species  sensitivity and differences in
 biological availability and/or toxicity of a material
 due  to  variability  in  physical and  chemical
 characteristics of a  site water.  Derivation of the
 site-specific  criterion  maximum concentration
 (CMC)  and  site-specific  criterion  continuous
 concentration (CCC) are accomplished after the
 complete   acute  toxicity  minimum  data  set
 requirements have been  met by conducting tests
 with resident species in site water.  Chronic tests
 may  also  be  necessary.    This procedure is
 designed to compensate concurrently for any real
 differences  between  the  sensitivity  range  of
 species represented in the national data set and for
 site   water  which  may markedly  affect  the
 biological  availability and/or toxicity  of  the
 material of interest.

 Certain families of organisms have been specified
 in the National Guidelines acute toxicity minimum
 data  set  (e.g., Salmonidae in fresh  water and
 Penaeidae or Mysidae in salt water); if this or any
 other requirement  cannot  be  met because the
 family or other group (e.g., insect or  benthic
 crustacean) in fresh water is not represented by
resident  species, select  a substitute(s)  from  a
 sensitive family represented  by one  or  more
resident species and meet the 8 family minimum
data set requirement. If all the families at the site
have been  tested  and the minimum data set
requirements have not been  met, use the most
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                                                                   Chapter 3 - Water Quality Criteria
sensitive resident family mean acute value as the
site-specific Final Acute Value.

To derive the criterion maximum concentration
divide the site-specific Final Acute Value by two.
The site-specific Final Chronic Value  can be
obtained as described in the Appendix L.  The
lower of the site-specific Final Chronic Value (as
described  in  the  recalculation   procedure  -
Appendix L,  p.  90) and  the  recalculated  site-
specific Final Residue  Value becomes the  site-
specific criterion continuous concentration unless
plant or other data (including data obtained from
the site-specific tests) indicates a lower  value is
appropriate.  If a problem is identified, judgment
should be  used in establishing the site-specific
criterion.

The frequency  of testing  (e.g.,  the need  for
seasonal testing) will be related to the variability
of the physical and chemical characteristics of site
water as it is expected to affect the biological
availability  and/or toxicity of the material  of
interest.     As  the  variability  increases,  the
frequency  of testing will  increase.  Many of the
limitations  discussed  for the  previous  two
procedures would also apply to this procedure.
                                          Endnotes

1. Proceedings in production.

        Contact:   Ecological Risk Assessment Branch (4304)
                   U.S. Environmental Protection Agency
                   401 M Street, S.W.
                   Washington, DC 20460
                   Telephone (202) 260-1940
(8/15/94)                                                                                  3-45

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                                                                 Chapter 4 - Antidegradation
                                 CHAPTER 4

                            ANTIDEGRADATION

                                (40 CFR 131.12)


                               Table of Contents


4.1  History of Antidegradation	4-1

4.2  Summary of the Antidegradation Policy	 4-1

4.3  State Antidegradation Requirements	4-2

4.4  Protection of Existing Uses - 40 CFR 131.12(a)(l)	4-3

     4.4.1     Recreational Uses  	4-4

     4.4.2     Aquatic Life/Wildlife Uses	4-5

     4.4.3     Existing Uses and Physical Modifications	4-5

     4.4.4     Existing Uses and Mixing Zones  	4-6

4.5  Protection of Water Quality in High-Quality Waters  - 40 CFR 131.12(a)(2)  	4-6

4.6  Applicability of Water Quality Standards to Nonpoint Sources Versus Enforceability
     of Controls	4-9

4.7  Outstanding National Resource Waters (ONRW) - 40 CFR 131.12(a)(3)   	  4-10

4.8  Antidegradation Application and Implementation	4-10

     4.8.1     Antidegradation,  Load Allocation, Waste Load Allocation, Total Maximum
              Daily Load, and Permits  	4-12

     4.8.2     Antidegradation and the Public Participation Process	4-13

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                                                                        Chapter 4 - Antidegradation
                                        CHAPTER 4
                                  ANO0EGRADATION
This  chapter   provides  guidance   on   the
antidegradation  componenf;   of water  quality
standards,  its application  in conjunction  with
the other parts  of the water quality standards
regulation,  and  its  implementation   by  the
States. Antidegradation  implementation  by the
States  is based  on a  set of procedures  to  be
followed when  evaluating activities  that  may
impact the quality of the waters of the  United
States.  Antidegradation   implementation is an
integral   component   of   a   comprehensive
approach  to protecting  and enhancing  water
quality.
         History of Antidegradation
The first antidegradation  policy statement  was
released  on February 8,1968, by the Secretary
of the U.S. Department  of the Interior.  It was
included in EPA1 s first Water Quality Standards
Regulation (40 CFR 130.17,40 F.R. 55340-41,
November 28, 1975), and was  slightly refined
and re-promulgated  as  part  of  the  current
program regulation  published on November  8,
1983  (48  F.R.  51400,  40  CFR   131.12).
Antidegradation  requirements and  methods for
implementing  those  requirements are minimum
conditions  to be included  in a State's  water
quality   standards.      Antidegradation    was
originally based on  the spirit, intent, and goals
of the Act, especially the clause "... restore
and maintain  the  chemical,   physical   and
biological  integrity   of  the  Nation's  waters"
(101(a))  and the provision of 303(a) that made
water  quality standards  under  prior law the
"starting  point"  for  CWA  water   quality
requirements.    Antidegradation  was  explicitly
incorporated  in the  CWA through:

•    a  1987  amendment  codified  in section
     303(d)(4)(B)    requiring    satisfaction   of
     antidegradation
     making   certain
     permits; and
requirements
changes   in
 before
NPDES
     the  1990 Great  Lakes  Critical Programs
     Act codified in  CWA section 118(c)(2)
     requiring  EPA  to publish  Great  Lakes
     water   quality   guidance   including
     antidegradation     policies    and   imple-
     mentation  procedures.
          Summary  of the Antidegradation
          Policy
Section  131.12(a)(l),  or  "Tier  1," protecting
"existing uses," provides the  absolute  floor of
water quality in all waters  of the United States.
This paragraph   applies a minimum   level of
protection  to all  waters.

Section  131.12(a)(2),  or  "Tier  2," applies to
waters whose quality exceeds that necessary to
protect  the section 101(a)(2)  goals of the Act.
In this case, water quality  may not be lowered
to less than the level necessary to fully protect
the  "fishable/swimmable"   uses  and  other
existing uses and  may be lowered even to those
levels  only after  following all  the provisions
described in section 131.12(a)(2).

Section  131.12(a)(3),  or  "Tier  3," applies to
Outstanding    National   Resource    Waters
(ONRW)  where the ordinary use classifications
and supporting  criteria  may not be sufficient or
appropriate.  As described in the preamble to
the Water Quality Standards Regulation, "States
may allow some  limited activities which result
in temporary and short-term  changes  in water
quality," but  such  changes  in  water  quality
should  not impact  existing uses or  alter  the
essential character or  special use that makes
the water an ONRW.
(9/15/93)
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 Water Quality Standards Handbook - Second Edition
 The  requirement   for potential  water  quality
 impairment associated with thermal discharges
 contained   in  section   131.12 (a)(4)   of  the
 regulation   is  intended  to  coordinate   the
 requirements  and   procedures   of   the
 antidegradation  policy with those established in
 the   Act   for   setting  thermal   discharge
 limitations. Regulations  implementing  section
 316 may be  found at 40  CFR 124.66.  The
 statutory scheme and legislative history indicate
 that limitations developed  under  section  316
 take precedence over other  requirements of the
 Act.

 As the States  began to focus more attention on
 implementing  their antidegradation  policies, an
 additional  concept was developed by the States,
 which EPA  has  accepted   even  though  not
 directly mentioned in previous EPA guidance or
 in the  regulation.  This concept,  commonly
 known as  "Tier 21A,"is an application  of the
 antidegradation  policy that has implementation
 requirements  that are more stringent than for
 HTier2" (high-quality waters), but somewhat less
 stringent   than  the  prohibition  against   any
 lowering of water  quality in "Tier3"(ONRWs).
 EPA  accepts  this  additional  tier in  State
 antidegradation  policies because it is clearly  a
 more  stringent  application  of  the  Tier  2
 provisions  of the  antidegradation   policy  and,
 therefore,  permissible under section 510 of the
 CWA.

 Tile  supporting   rationale   that  led  to   the
 development  of the Tier 2l/z concept  was  a
 concern by the  States that  the  Tier  3 ONRW
 provision  was so  stringent that its application
 would likely prevent States from taking actions
 in  the  future   that   were  consistent   with
 important social and economic development  on,
 or upstream  of, ONRWs.  This concern  is  a
 major reason  that  relatively few water  bodies
 are designated  as  ONRWs.   The Tier  2Vz
 approach  allows States to provide  a very high
 level  of   water   quality protection  without
precluding   unforeseen   future  economic  and
social development considerations.
          State Antidegradation Requirements
 Each State must develop, adopt, and retain  a
 statewide  antidegradation   policy  regarding
 water   quality   standards    and    establish
 procedures for its implementation  through the
 water quality management process.  The State
 antidegradation   policy  and  implementation
 procedures   must   be  consistent   with  the
 components  detailed in 40 CFR  131.12.  If not
 included in the standards  regulation of a State,
 the policy must be specifically referenced  in the
 water quality standards  so  that  the  functional
 relationship   between  the   policy  and  the
 standards is clear. Regardless of the location of
 the   policy,   it  must  meet  all  applicable
 requirements.      States   may   adopt
 antidegradation   statements   more   protective
 than   the   Federal   requirement.       The
 antidegradation   implementation   procedures
 specify how the State will determine on a case-
 by-case basis whether,  and to what extent, water
 quality may be lowered.

 State  antidegradation   polices   and   imple-
 mentation  procedures  are subject to  review by
 the Regional Administrator.   EPA  has clear
 authority to  review and approve  or disapprove
 and promulgate an antidegradation  policy for a
 State.   EPA's review  of the  implementation
 procedures   is   limited   to  ensuring   that
 procedures are included that  describe how the
 State will implement the  required elements  of
 the   antidegradation    review.     EPA   may
 disapprove and federally promulgate all or part
 of  an    implementation  process   for
 antidegradation   if, in the  judgment  of  the
 Administrator,  the State's process (or certain
 provisions thereof)  can be implemented  in such
 a way as to circumvent the intent and purpose
 of the antidegradation  policy. EPA encourages
 submittal of  any amendments  to  the  statement
 and implementing procedures to the Regional
 Administrator for pre-adoption  review so that
 the State may take EPA comments into account
prior to final action.
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                                                                          Chapter 4 -
If a  State's antidegradation  policy does not
meet  the  Federal  regulatory  requirements,
either through State actioiQ to revise its policy
or through revised Federal  requirements, the
State would be given the opportunity to make
its policy consistent with the regulation.   If this
is  not  done,  EPA  has   the   authority   to
promulgate the policy for the State pursuant  to
section 303(c)(4)  of the  Clean Water Act (see
section 6.3, this Handbook).
          Protection of Existing Uses - 40 CFR
This section requires  the protection of existing
uses and the level  of water quality to protect
those uses.  An "existing use" can be established
by demonstrating  that:

•    fishing,  swimming, or other  uses  have
     actually   occurred  since   November   28,
     1975; or

•    that the   water quality is suitable  to allow
     the use  to be attained—unless  there are
     physical problems,  such  as substrate  or
     flow, that prevent the use  from  being
     attained.

An example  of the  latter  is an  area where
shellfish  are  propagating  and  surviving  in a
biologically suitable habitat  and are  available
and suitable for harvesting  although, to date, no
one has attempted  to harvest them. Such facts
clearly  establish that  shellfish  harvesting  is an
"existing"   use,   not    one   dependent    on
improvements   in  water quality.   To  argue
otherwise would be to  say that the only tune an
aquatic  protection  use  "exists" is if  someone
succeeds in catching fish.

Full protection  of the  existing  use   requires
protection of the entire  water body with a few
limited  exceptions  such  as certain   physical
modifications  that  may  so  alter a water  body
that  species composition cannot be maintained
(see section  4.4.3,this Handbook), and mixing
zones  (see section  4.4.4,this Handbook).   For
example, an activity that lowers water quality
such  that  a buffer zone must be  established
within a previous shellfish harvesting  area  is
inconsistent  with the antidegradation  policy.

Section  131.12(a)(l) provides the absolute floor
of water quality in all  waters of the  United
States. This paragraph  applies a minimum level
of protection to  all waters. However, it is most
pertinent to waters having beneficial uses that
are less  than the section 101(a)(2)  goals of the
Act.  If it can be proven, in that  situation,  that
water quality  exceeds that necessary to fully
protect the existing use(s)  and exceeds water
quality standards but is not of sufficient quality
to cause a better use to  be achieved, then that
water quality  may  be  lowered  to  the  level
required to fully protect the existing use as long
as  existing  water  quality   standards   and
downstream  water quality  standards  are not
affected.  If this does  not involve  a change  in
standards,  no public hearing would be required
under   section    303(c).   However,    public
participation   would  still   be  provided   in
connection  with the  issuance of a  NPDES
permit or amendment  of a section 208 plan or
section  319 program.    If, however,  analysis
indicates  that  the  higher water  quality does
result in a better use, even if not  up to the
section 101(a)(2) goals, then the water quality
standards must be upgraded to reflect the uses
presently being attained  (131.10(i)).

If a  planned  activity will foreseeably  lower
water quality to  the extent that it  no longer is
sufficient to protect  and  maintain  the existing
(9/15/93)
                                           4-3

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 Water Quality Standards Handbook - Second Edition
 uses  in  that  water  body,  such an  activity is
 inconsistent with EPA's antidegradation policy,
 which requires  that  existing  uses are  to be
 maintained.    In  such  a  circumstance,   the
 planned  activity must be avoided  or  adequate
 mitigation   or preventive  measures  must be
 taken to ensure  that the existing uses and the
 water   quality   to  protect   them   will  be
 maintained.

 Section  4.4.1, this Handbook,  discusses  the
 determination  and protection   of recreational
 "existing"  uses,   and   section  4.4.2,    this
 Handbook,  discusses  aquatic   life protection
 "existing" uses (of  course, many other types of
 existing uses may occur in a water body).

 4.4.1    Recreational Uses

 Recreational uses traditionally  are divided into
 primary   contact   and   secondary   contact
 recreation  (e.g., swimming  vs. boating; that is,
 recreation  "in" or  "on" the water.)  However,
 these   two  broad  uses   can   logically  be
 subdivided  into a variety of  subcategories  (e.g.,
 wading, sailing, power boating,  rafting).   The
 water quality  standards  regulation  does  not
 establish  a  level of specificity  that each State
 must  apply in determining  what  recreational
 "uses" exist. However,  the following principles
 apply.

 •    The State selects the level of specificity it
     desires for identifying recreational existing
     uses (that is,  whether  to  treat secondary
     contact  recreation  as a single use  or to
     define   subcategories   of   secondary
     recreation).  The State has two limitations:

          the State  must be  at  least as specific
          as the uses listed  in  sections  101(a)
          and  303(c)  of the  Clean  Water  Act;
          and

          the State  must be  at least as specific
          as  the  written  description   of  the
          designated use classifications  adopted
          by the State.
 •    If the  State  designated use classification
      system  is  very  specific   in  describing
      subcategories    of  a   use,  then   such
      specifically defined uses, if they exist, must
      be protected fully under antidegradation.
      A State  with  a  broadly  written  use
      classification system may, as a matter of
      policy, interpret  its classifications  more
      specifically   for   determining    existing
      uses—as long as it is done consistently. A
      State   may   also   redefine    its   use
      classification   system,   subject   to  the
      constraints  in  40 CFR  131.10, to  more
      adequately reflect existing uses.

 •    If the use  classification  system in a State is
      defined  in broad terms  such as primary
      contact   recreation,   secondary   contact
      recreation, or  boating, then it is a State
      determination  whether  to allow changes in
      the type of  primary or secondary contact
      recreation  or boating activity that would
      occur on a specific water body as long as
      the basic  use  classification  is  met.   For
      example, if a State defines a use simply as
      "boating,"it is the State's decision whether
      to allow  something  to occur  that  would
      change the type of boating from canoeing
      to power boating as long as the  resulting
      water quality allows the "boating" use to be
      met.  (The public record used originally to
      establish  the use  may  provide  a clearer
      indication  of  the  use intended  to be
      attained  and protected  by the State.)

The rationale is that the required  water quality
will allow  a boating  use  to  continue and that
use meets the goal of the  Act.  Water quality is
the key. This interpretation  may allow a State
to  change   activities  within  a  specific   use
category but it does  not create a mechanism to
remove use classifications; this latter action is
governed   solely  by  the provisions   of  the
standards  regulation  (CWA section  131.10(g)).

One situation where  EPA might conceivably be
called  upon  to  decide  what  constitutes  an
existing use is where  EPA is writing an NPDES
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                                                                         Chapter 4 - Antidegradatioa
permit. EPA has the responsibility under CWA
section  301(b)(l)(C)   to  determine  what  is
needed  to  protect  existing  uses  under  the
State's   antidegradation    requirement,    and
accordingly  may  define  "existing uses"  or
interpret  the State's  definition  to  write  that
permit if the State has not done so.  Of course,
EPA's determination  would be subject  to State
section 401 certification  in such a case.

4.4.2     Aquatic Life/Wildlife Uses

No   activity  is    allowable   under   the
antidegradation  policy which would  partially or
completely eliminate  any existing use whether
or not that use  is designated  in a State's water
quality standards.  The aquatic protection use is
a broad category requiring farther explanation.
Non-aberrational   resident   species  must  be
protected,  even if not prevalent  in  number or
importance.  Water quality should be such that
it  results  in no  mortality and  no  significant
growth or reproductive impairment  of resident
species.   Any lowering of water quality  below
this fall level of protection is not allowed.

A State  may develop subcategories  of aquatic
protection  uses but  cannot  choose  different
levels of protection  for like uses.  The fact that
sport or commercial  fish are not present does
not mean  that the water  may not be supporting
an aquatic life protection  function.  An existing
aquatic   community   comi>osed  entirely  of
invertebrates  and plants, such as may be found
in a pristine alpine tributary stream,  should still
be  protected whether or not  such a  stream
supports a fishery.

Even   though    the   shorthand   expression
"fishable/swimmable"  is  often  used, the  actual
objective of the Act is to "restore and maintain
the chemical, physical, and biological integrity
of our Nation's waters"  (section  101 (a)).  The
term   "aquatic  life"  would   more  accurately
reflect the protection  of the aquatic  community
that was intended in section 101(a)(2)  of the
Act.
Section 131.12(a)(l) states, "Existing instream
water uses and level of water quality necessary
to protect the existing uses shall be maintained
and protected." For example, while sustaining a
small coldwater fish population, a stream  does
not  support  an  existing  use  of a  "coldwater
fishery."The existing stream temperatures  are
unsuitable  for a thriving coldwater fishery. The
small marginal  population  is  an artifact and
should not be employed  to mandate  a more
stringent  use (true  coldwater  fishery) where
natural conditions are not suitable for that use.

A use attainability  analysis or other  scientific
assessment   should  be   used  to  determine
whether the aquatic life population  is in fact an
artifact or is a stable population requiring water
quality protection.   Where species appear  in
areas not normally  expected,  some  adaptation
may have occurred and site-specific criteria may
be  appropriately    developed.   Should   the
coldwater   fish  population   consist  of   a
threatened   or  endangered  species,  it  may
require   protection  under  the  Endangered
Species Act.  Otherwise, the stream need only
be protected as a warmwater fishery.

4.4.3    Existing   Uses   and   Physical
         Modifications

A literal interpretation  of40CFR 131.12(a)(l)
could prevent certain physical modifications to
a  water  body that  are clearly allowed by the
Clean   Water  Act,  such  as   wetland   fill
operations  permitted  under section 404 of the
Clean  Water  Act.   EPA interprets   section
131.12(a)(l) of the antidegradation  policy to be
satisfied  with regard to fills in wetlands if the
discharge   did   not  result   in   "significant
degradation"  to  the  aquatic  ecosystem  as
defined under section  230.10(c) of the section
404(b)(l) Guidelines.

The section 404(b)(l) Guidelines state that the
following  effects  contribute   to  significant
degradation,  either  individually or collectively:
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 Water Quality Standards Handbook - Second Edition
      . . . significant adverse effects on (1)
      human  health or  welfare,  including
      effects on municipal  water supplies,
      plankton, fish, shellfish, wildlife, and
      special aquatic  sites (e.g., wetlands);
      (2) on the life  stages of aquatic life
      and   other   wildlife  dependent   on
      aquatic   ecosystems,  including  the
      transfer,  concentration,  or spread of
      pollutants or their byproducts beyond
      the site  through biological, physical,
      or chemical process; (3) on ecosystem
      diversity, productivity, and stability,
      including loss of  fish  and  wildlife
      habitat or loss  of the capacity  of a
      wetland to assimilate nutrients, purify
      water, or reduce wave energy; or (4)
      on   recreational,    aesthetic,    and
      economic values.

 These  Guidelines   may be used by  States  to
 determine  "significant degradation"  for wetland
 fills.  Of course, the  States are  free  to adopt
 stricter  requirements   for wetland fills in then-
 own antidegradation  polices, just as  they may
 adopt  any other  requirement  more   stringent
 than  Federal   law requires.    For  additional
 information  on  the  linkage   between  water
 quality standards  and  the section 404 program,
 see Appendix  D.

 If any wetlands were found to have better water
 quality  than   "fishable/swimmable,"  the  State
 would be allowed to lower water quality to the
 no significant degradation level as long as the
 requirements  of section  131.12(a)(2)  were
 followed.    As  for  the  ONRW  provision of
 antidegradation   (131.12(a)(3)),  there   is  no
 difference in the way it applies to wetlands and
 other  water bodies.

 4.4.4     Existing Uses and Mixing Zones

 Mixing zones are another  instance  when the
 entire extent of  the water body is not required
 to be  given full existing  use protection.  The
 area within  a properly designated  mixing zone
 (see  section 5.1) may  have  altered  benthic
 habitat  and  a  subsequent   alteration   of the
 portions of the aquatic community.  Any effect
 on the existing use must be limited to the area
 of the regulatory mixing zone.
          Protection of Water Quality in High-
          Quality Waters - 40 CFR 131.12(a)(2)
This section provides general program guidance
in  the development   of procedures  for  the
maintenance   and protection  of water quality
where the quality of the water exceeds levels
necessary  to  support   propagation   of  fish,
shellfish, and wildlife and recreation in and on
the  water.    Water  quality  in  "high-quality
waters" must be maintained  and  protected  as
prescribed  in section  131.12(a)(2) of the WQS
regulation.
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                                                                        Chapter 4 - Antidegradation
High-quality waters  are those  whose  quality
exceeds  that necessary  to  protect  the  section
101(a)(2) goals of the  Act,  regardless  of use
designation.  All parameters do not need to be
better quality than the State's ambient criteria for
the water to be deemed a "high-quality  water."
EPA   believes   that   it  is   best  to  apply
antidegradation  on  a  parameter-by-parameter
basis.  Otherwise, there is potential for  a large
number of waters not  to receive antidegradation
protection, which is  important to  attaining the
goals of the Clean Water Act to  restore  and
maintain the integrity  of the Nation's  waters.
However, if a State has an official interpretation
that differs from this interpretation, EPA  will
evaluate  the State interpretation for conformance
with the statutory and regulatory intent of the
antidegradation  policy.    EPA  has  accepted
approaches that do not use a  strict pollutant-by-
pollutant basis (USEPA, 1989c).

In  "high-quality waters," under  131.12(a)(2),
before any lowering of water quality occurs, there
must be an antidegradation review consisting of:

•    a finding that it is necessary to accommodate
     important economical or social development
     in the area in which the  waters are located
     (this phrase is intended to convey a general
     concept regarding what level of social and
     economic  development  could be  used to
    justify a change in high-quality waters);

•    full  satisfaction  of all  intergovernmental
     coordination   and  public   participation
     provisions (the intent here is to ensure that
     no activity that will cause water quality to
     decline  in existing  high-quality waters is
     undertaken without adequate public review
     and intergovernmental coordination); and

•    assurance  that  the  highest statutory  and
     regulatory requirements  for point sources,
     including new source performance standards,
     and best management practices for nonpoint
     source pollutant controls  are achieved (this
     requirement  ensures   that   the   limited
     provision for lowering water quality of high-
     quality waters down to "fishable/swimmable"
     levels will not be used to undercut the Clean
     Water Act requirements for point source and
     nonpoint   source    pollution    control;
     furthermore, by ensuring  compliance with
     such statutory and regulatory controls, there
     is  less chance that a lowering of water
     quality will be sought to accommodate new
     economic and social development).

In addition, water quality may not be lowered to
less than the level necessary to fully  protect  the
"fishable/swimmable"  uses and  other existing
uses.  This provision is intended to provide relief
only in a few extraordinary circumstances where
the economic  and  social need for the activity
clearly outweighs the benefit of maintaining water
quality   above   that  required  for
"fishable/swimmable" water, and  both cannot be
achieved.   The burden of demonstration on  the
individual proposing such  activity will be very
high.   In any case, moreover, the existing  use
must  be maintained and the  activity shall  not
preclude   the   maintenance   of   a
"fishable/swimmable"  level  of  water  quality
protection.

The antidegradation review requirements of this
provision   of  the  antidegradation  policy   are
triggered by any action that would result in  the
lowering of water quality in a high-quality water.
Such activities as new discharges or expansion of
existing facilities would presumably lower water
quality and would not be permissible unless  the
State  conducts a   review consistent  with  the
previous paragraph.  In addition,  no permit may
be issued, without an antidegradation review, to
a discharger to high-quality waters with effluent
limits greater than actual  current loadings if such
loadings will cause a lowering of water quality
(USEPA,  1989c).

Antidegradation is not a "no growth" rule and was
never designed or intended to be such.  It is a
policy that allows public decisions to be made on
important environmental actions. Where the State
intends to provide for development, it may decide
under   this   section,   after   satisfying    the
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 Wtter Quality Standards Handbook - Second Edition
 requirements for intergovernmental coordination
 and public participation, that some lowering of
 water quality in "high-quality waters" is necessary
 to  accommodate important  economic or  social
 development.  Any such lower water quality must
 protect existing uses fully,  and the State must
 assure that the highest statutory and regulatory
 requirement for all new and existing point sources
 and all cost-effective and reasonable BMPs for
 nonpoint source control are being achieved on the
 water body.

 Section 131.12(a)(2) does not REQUIRE a State
 to  establish BMPs for nonpoint sources  where
 such BMP requirements  do  not exist.   We
 interpret Section 131.12(a)(2) as REQUIRING
 States to adopt an antidegradation policy that
 includes a provision that will assure that all cost-
 effective and reasonable BMPs established under
 State authority are implemented for nonpoint
 sources before the State authorizes degradation of
 high quality waters by point sources (see USEPA,
 1994a.)

 Section 131.12(a)(2) does not mandate that States
 establish controls on nonpoint sources. The Act
 leaves it to the States to determine what, if any,
 controls  on nonpoint  sources  are needed  to
 provide for attainment of State water  quality
 standards (See  CWA Section 319.)  States may
 adopt  enforceable  requirements,  or voluntary
 programs to address nonpoint source pollution.
 Section 40 CFR 131.12(a)(2) does not require that
 States  adopt  or implement best  management
 practices for nonpoint sources prior to allowing
 point source degradation of a high quality water.
 However,   States  that have  adopted nonpoint
 source controls must assure that such controls are
 properly implemented  before  authorization  is
 granted to allow point source degradation of water
 quality.

The  rationale   behind   the   antidegradation
regulatory  statement regarding  achievement of
statutory requirements  for point sources and  all
cost effective and reasonable BMPs for nonpoint
sources is to assure that, in high quality waters,
where there are existing point or nonpoint source
 control compliance problems, proposed  new or
 expanded  point  sources  are  not  allowed to
 contribute additional pollutants that could result in
 degradation.  Where such compliance problems
 exist, it would be inconsistent with the philosophy
 of the antidegradation policy  to authorize the
 discharge of additional pollutants in the absence of
 adequate assurance that any existing compliance
 problems will be resolved.

 EPA's regulation also requires maintenance of
 high quality waters except where the State finds
 that degradation  is "necessary to accommodate
 important economic and social development in the
 area in which the waters  are located." (40 CFR
 Part 131.12(a) (Emphasis added)).   We believe
 this phrase should be interpreted to prohibit point
 source   degradation   as  unnecessary   to
 accommodate important  economic  and  social
 development if it could be partially or completely
 prevented  through implementation  of existing
 State-required BMPs.

 EPA   believes  that its  antidegradation  policy
 should be interpreted on a pollutant-by-pollutant
 and waterbody-by-waterbody basis. For example,
 degradation of a high quality  waterbody  by  a
 proposed   new    BOD   source   prior   to
 implementation of required BMPs on  the same
 waterbody that are related  to BOD loading should
 not be allowed.  However, degradation by the
 new point source of BOD should not be barred
 solely  on the basis that BMPs unrelated to BOD
 loadings, or which relate to  other waterbodies,
 have not been implemented.

 We recommend  that  States  explain  in  their
 antidegradation polices or procedures how, and to
 what extent, the State will require implementation
 of otherwise non-enforceable (voluntary) BMPs
 before allowing point source degradation of high
 quality   waters.      EPA   understands   this
recommendation exceeds the Federal requirements
 discussed  in  this  guidance.    For example,
nonpoint   source   management  plans   being
developed under section 319 of the Clean Water
Act are likely to identify potential problems and
certain  voluntary  means  to  correct   those
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                                                                         Chapter 4 - Antidegradation
problems.  The State should consider how these
provisions will be implemented in  conjunction
with the water quality standards program.
          Applicability  of   Water   Quality
          Standards   to   Nonpoint   Sources
          Versus Enforceability of Controls
The  requirement  in  Section  131.21(a)(2) to
implement  existing  nonpoint  source  controls
before  allowing degradation of a  high quality
water,  is a subset of  the  broader  issue of the
applicability of water quality standards versus the
enforceability of controls designed to implement
standards.   A  discussion of the broader issue is
included here with the intent of further clarifying
the nonpoint source antidegradation  question. In
the following discussion, the central message is
that water quality standards apply broadly and it
is  inappropriate  to  exempt whole  classes of
activities from standards and thereby  invalidate
that broader,  intended  purpose of adopted State
water quality standards.

Water quality standards serve the dual function of
establishing water quality  goals  for a specific
waterbody and providing the basis for regulatory
controls.  Water quality stamdards apply to both
point and nonpoint sources!.   There  is a direct
Federal implementation mechanism to regulate
point sources  of pollution but no parallel Federal
regulatory process for  nonpoint sources.  Under
State law,  however, States can and do  adopt
mandatory nonpoint source controls.

State water quality standards play the central role
in a  State's water quality management program,
which identifies the overall mechanism States use
to integrate the various Clean Water Act  water
quality  control   elements  into  a   coherent
management  framework.   This  includes,  for
example: (1)  setting and  revising water quality
standards   for  all  surface  waterbodies,  (2)
monitoring water quality to provide information
upon which water quality-based decisions will be
made, progress evaluated, amd success measured,
(3)  preparing  a water quality inventory report
under section  305(b) which documents the status
of the States'SL water  quality,  (4)  developing a
water quality management plan  which lists the
standards,  and  prescribes  the  regulatory  and
construction  activities  necessary  to  meet the
standards,  (5)  calculating  total maximum  daily
loads and wasteload allocations for point sources
of pollution  and load allocations  for nonpoint
sources of pollution in the implementation of
standards,(6)  implementing  the  section   319
management  plan  which  outlines the  State's
control strategy for nonpoint sources of pollution,
and (7) developing  permits under Section 402.

Water quality standards  describe the  desired
condition of the aquatic environment,  and, as
such,  reflect any   activity  that  affects  water
quality.   Water quality standards have broad
application and use  in evaluating potential impacts
of water quality from a broad range of causes and
sources and are not limited to evaluation of effects
caused by the discharge of pollutants  from point
sources.   In this regard, States  should have in
place methods by which the State can determine
whether or not their standards have been achieved
(including uses, criteria, and implementation of an
antidegradation policy).  Evaluating attainment of
standards is  basic  to successful application of a
State's water quality standards program.  In the
broad application of standards, these evaluations
are  not  limited  to those activities  which  are
directly controlled  through a mandatory process.
Rather,  these  evaluations  are  an  important
component of a State's water quality management
program  regardless  of  whether  or  not  an
enforcement  procedure is in place for the activity
under review.

Water quality standards are implemented through
State or EPA-issued water quality-based permits
and  through  State  nonpoint  source  control
programs.     Water    quality  standards   are
implemented through enforceable NPDES permits
for point sources and through the installation and
maintenance  of BMPs for  nonpoint  sources.
Water quality standards usually are not considered
self-enforcing except where they are established as
enforceable under State law. Application of water
quality standards in the overall context of a water
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                                                                                          4-9

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 Water Quality Standards Handbook - Second Edition
 quality management program, however,  is not
 limited  to  activities  for  which   there  are
 enforceable implementation mechanisms.

 In simple terms, applicability and enforceability
 are two distinctly separate functions in the water
 quality standards  program.    Water  quality
 standards  are applicable to all waters and in all
 situations,  regardless of  activity  or source of
 degradation.  Implementation  of those standards
 may not be possible in all circumstances; in such
 cases,  the use attainability  analysis  may  be
 employed.  In describing the desired condition of
 the environment, standards establish a benchmark
 against which all activities which might affect that
 desired condition are, at a minimum, evaluated.
 Standards  serve as the  basis  for  water quality
 monitoring and there is value in identifying the
 source and cause  of  a  exceedance even  if, at
 present, those sources of impact are not regulated
 otherwise controlled.

 It is  acceptable for a State to specify particular
 classes  of  activities  for   which  no  control
 requirements  have been  established in  State law.
 It is not acceptable,  however, to specify that
 standards do  not apply  to particular  classes of
 activities (e.g.  for purposes of monitoring and
 assessment).  To do so would abrogate one  of the
 primary functions of water quality standards.
          Outstanding   National   Resource
          Waters   (ONRW)   -   40   CFR
Outstanding National Resource Waters (ONRWs)
are provided the highest level of protection under
the antidegradation policy. The policy provides
for protection  of water quality in high-quality
waters that  constitute an ONRW by prohibiting
the lowering of water quality.  ONRWs are often
regarded as highest quality waters of the United
States: That is clearly the thrust of 131.12(a)(3).
However, ONRW designation also offers special
protection for waters of • "exceptional ecological
significance."  These are water bodies that are
important, unique, or sensitive ecologically, but
whose  water   quality,  as   measured  by  the
 traditional parameters such as dissolved oxygen or
 pH, may  not  be particularly high  or whose
 characteristics cannot be adequately described by
 these parameters (such as wetlands).

 The regulation  requires  water  quality to  be
 maintained and protected  in  ONRWs.    EPA
 interprets this  provision  to  mean no  new  or
 increased discharges  to ONRWs and no new or
 increased discharge to tributaries to ONRWs that
 would  result  in lower  water  quality  in the
 ONRWs.  The only exception to this prohibition,
 as discussed in the preamble to the Water Quality
 Standards Regulation (48  F.R. 51402), permits
 States to allow some limited activities that result
 in temporary and short-term changes in the water
 quality of  ONRW.   Such activities must not
 permanently degrade water quality or result  in
 water quality lower than that necessary to protect
 the existing uses in the ONRW.  It is difficult to
 give an  exact  definition  of  "temporary"  and
 "short-term" because of the variety of activities
 that might be considered.   However, in rather
 broad terms, EPA's view of temporary is weeks
 and months, not  years.  The intent  of  EPA's
 provision  clearly  is to  limit   water  quality
 degradation to the shortest possible time.   If a
 construction activity  is involved, for example,
 temporary is  defined  as   the  length  of  time
 necessary to construct the  facility and make it
 operational.  During  any  period of time when,
 after opportunity for  public participation  in the
 decision, the State allows temporary degradation,
 all  practical    means   of  minimizing    such
 degradation shall be implemented.  Examples of
 situations in which flexibility is appropriate are
 listed in Exhibit 4-1.
          Antidegradation
          Implementation
Application   and
Any one or a combination of several activities
may trigger the  antidegradation policy analysis.
Such activities include a scheduled water quality
standards review,  the establishment of new or
revised load allocations, waste load allocations,
total maximum daily loads, issuance of NPDES
permits,  and  the  demonstration  of need  for
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                                                                          Chapter 4 - AnMegra&afion
   Example 1  A notional park wishes to replace <* defective septic tank-dratnfieM
                  system  in a campground. The campground is located immediately
                            to a matt stream with the ON&W me designation*
                  Under the- regulation, the construction could occur if best management practices were
                             followed to minimize any disturbance of water quality of aquatic habitat.
   Example 2  Same situation except the campground is served by a small sewage
                  treatment plant already discharging to the 0NRW. It is desired to
                  enlarge the treatment system and provide higher levels of treatment.
                  Under theregulation, this vtetBr-qadifc^-fedfaanoingfUStida WOUtd b6pertnittfed if fhene Was
                  only teiapOfary increase ia S6dim6nt aadf perhaps^ in organic loading;, which W&ttld
                  dwlng (lie ^stflal wBstniottoa phase,
   Example 3  A National forest with a mature, second growth of trees which are
                  suitable for harvesting* with associated road repair and
                  re-staMtteation.  Streams in the area are designated as ONRWand
                  support trout fishing.
                  The regulatioa intends that best management practices for timber harvesting be followed
                  and might include preventive measures more stringeat than for similar logging ia less
                  ensiranmeaially SensitrVfe areas.  Of eotirs&, if flife lands were being, considered, for
                  designation as wilderness areas or other similar designations, EPA*s regulation should not
                  &6 fconstraed as encouraging or condoning timbering operations. The regulation allows
                  only temporary and short-term Water quality degradation while maintaining existing Use*
                  or new uses consistent with tiie purpose pf the management of the ON&W area.
   Other examples of these types of activities Include maintenance and/or repair of existing boat lamps or boat
   doefeSj, restoration of existiag sea walls, repair of existing stormwater pipes, and replacement or repair of
   existing bridges.
 Exhibit 4-1.   Examples  of  Allowable  Temporary  Lowering  of Water  Quality  in
                Outstanding National Resource Waters
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 Water Quality Standards Handbook - Second Edition
 advanced treatment or request by private or public
 agencies or individuals for a special study of the
 water body.

 Nonpoint source activities are not exempt  from
 the provisions of the antidegradation policy. The
 language  of  section  131.12  (a)(2)  of  the
 regulation:   "Further, the State shall assure that
 there shall  be  achieved the highest statutory and
 regulatory requirements for  all new and existing
 point sources and all cost-effective and reasonable
 best management practices  for nonpoint source
 control ..."  reflects statutory provisions of the
 Clean Water Act.  While it is true that the Act
 does not establish a federally  enforceable program
 for nonpoint sources, it clearly intends that the
 BMPs  developed and  approved under sections
 20S(j), 208,  303(e),  and 319  be  aggressively
 implemented by the States.

 4.8.1  Antidegradation,    Load   Allocation,
        Waste Load Allocation, Total Maximum
        Daily Load, and Permits

 In developing or revising a load allocation (LA),
 waste load allocation (WLA), or total maximum
 daily load (TMDL) to reflect new information or
 to   provide  for  seasonal  variation,     the
 antidegradation policy, as an integral part of the
 State water  quality  standards, must be applied as
 discussed in this section.

 The  TMDL/WLA/LA process distributes   the
 allowable pollutant loadings to a water body. Such
 allocations  also  consider the  contribution to
 pollutant loadings from nonpoint sources.  This
 process must reflect applicable State water quality
 standards including the antidegradation policy.
 No waste load allocation  can be developed or
 NPDES  permit  issued  that would  result in
 standards being  violated.    With  respect to
 antidegradation, that means existing uses must be
 protected, water quality  may not be lowered in
 ONRWs, and in the case of waters whose quality
 exceeds that necessary for the section 101(a)(2)
 goals of the Act, an  activity cannot result in a
 lowering of water  quality unless the applicable
public participation, intergovernmental review,
 and   baseline  control   requirements   of  the
 antidegradation policy have been met. Once the
 LA, WLA, or TMDL revision is completed, the
 resulting permits  must  incorporate  discharge
 limitations based on this revision.

 When a pollutant discharge ceases for any reason,
 the  waste  load  allocations  for  the  other
 dischargers in the area may be adjusted to reflect
 the additional loading available consistent with the
 antidegradation policy under two circumstances:

 •   In "high-quality waters" where after the full
     satisfaction  of all public participation and
     intergovernmental review requirements, such
     adjustments are  considered  necessary  to
     accommodate important economic or social
     development,  and  the  "threshold"  level
     requirements (required point and nonpoint
     source controls) are met.

 •   In less than  "high-quality waters," when the
     expected improvement in water quality (from
     the ceased  discharge)  would  not  cause a
     better use to be achieved.

 The adjusted loads  still must meet water quality
 standards,  and the new waste  load  allocations
 must be at least as stringent as technology-based
 limitations.      Of  course,    all   applicable
 requirements of the section 402 NPDES permit
 regulations would have to be  satisfied before a
 permittee could increase its discharge.

 If a permit is being renewed, reissued or modified
 to include less  stringent limitations based on the
 revised   LA/WLA/TMDL,  the    same
 antidegradation  analysis  applied  during  the
 LA/WLA/TMDL stage  would apply during the
 permitting stage.  It would be reasonable to allow
 the showing made during the LA/WLA/TMDL
 stage to satisfy the antidegradation showing at the
permit stage.  Any restrictions to less stringent
limits based on antibacksliding  would also apply.

If a State issues an  NPDES permit that violates
the required antidegradation policy,  it would be
subject to a discretionary EPA veto under section
   4-12
                                                                                  (8/15/94)

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                                                                        Chapter 4 - Antidegradation
402(d) or to a citizen challenge.  In addition to
actions on permits, any waste load allocations and
total  maximum  daily  loads   violating   the
antidegradation  policy  are  subject  to  EPA
disapproval and  EPA  promulgation  of a new
waste load  allocation/total maximum daily load
under section 303 (d) of the Act.  If a significant
pattern  of  violation  was  evident, EPA could
constrain the award of grants or possibly revoke
any Federal permitting capability  that had been
delegated  to the State.  Where EPA  issues an
NPDES permit,  EPA  will,  consistent with its
NPDES regulations, add any additional or more
stringent effluent limitations required  to ensure
compliance with the State antidegradation policy
incorporated  into   the  State  water  quality
standards.  If a State fails to require compliance
with its antidegradation policy through section 401
certification  related  to  permits issued by  other
Federal agencies (e.g., a Corps  of  Engineers
section  404  permit),   EPA  could  comment
unfavorably upon permit issuance.  The public, of
course,  could bring pressure  upon the permit
issuing agency.

For example applications of ;antidegradation in the
WLA and permitting process, see Exhibit 4-2.

4.8.2  Antidegradation   and  the  Public
       Participation Process

Antidegradation,  as with  other  water quality
standards  activities, requires public participation
and  intergovernmental coordination  to be  an
effective tool in the water  quality management
process.   40 CFR 131.12(a)(2) contains explicit
requirements   for   public   participation   and
intergovernmental coordination  when determining
whether to allow lower water quality in  high-
quality  waters.   Nothing in  either  the water
quality  standards or  the waste load  allocation
regulations  requires the same  degree  of public
participation or intergovernmental coordination for
such non-high-quality  waters as is required  for
high-quality waters. However public participation
would still be provided in  connection with  the
issuance of a NPDES permit or amendment of a
208  plan.    Also,  if the  action that causes
reconsideration of the existing waste loads (such
as dischargers withdrawing from the area) will
result in an improvement  in water  quality that
makes a better use attainable, even if not up to the
"fishable/swimmable" goal, then the water quality
standards must be upgraded and full public review
is required for any  action affecting changes in
standards.  Although not specifically required by
the standards  regulation  between the  triennial
reviews, we recommend that the State conduct a
use attainability analysis to  determine  if water
quality improvement will result in attaining higher
uses than currently designated in situations where
significant changes in waste loads are expected.

The   antidegradation   public   participation
requirement may be satisfied  in several  ways.
The State may hold a public hearing or hearings.
The State may also satisfy the requirement by
providing public notice and the opportunity for the
public to request  a hearing.  Activities that may
affect several water bodies in a river basin or sub-
basin  may be considered in a single hearing.  To
ease the resource burden on both the  State and
public, standards  issues may be combined  with
hearings  on  environmental  impact  statements,
water management plans, or permits.  However,
if this  is  done, the  public  must be clearly
informed that  possible changes in water quality
standards are being considered along with other
activities. It is inconsistent with the water quality
standards regulation to  "back-door" changes in
standards through actions on EIS's, waste load
allocations, plans, or permits.
    (8/15/94)
                                      4-13

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Water Quality Standards Handbook - Second Edition
      Example 1
                                                                   ! --"*„'!
           Several facilities on a stream segment discharge phosphorus-containing wastes.
           Ambient phosphorus concentrations meet the designated class & (non*
           jfishabie/swimmabh) standards,^bui farefy.  Three dischargers achieve
           elimination by developing land treatment systems^ Asa resul^ actual water
           quality improves (i.e+, phosphorus levels decline) but not quite to the level
           needed to meet class A (ftshable/swbnmable) standards* Can the remaining
           dischargers now be allowed to increase their phosphorus discharge without an
           antidegradation analysis with the result that water quality declines (phosphorus
           levels increase) to previous levels?          '              ,\.          *•
                                                                     f         **    ' <  f
           Nothing in the water quality standards regulation explicitly prohibits this. Ofeourse, changes in their
           NPDES permit limits may be subject to non-water quality constraints, such as BFT, BAT, or the
           NPDES antibacfcsliding provisions, which may restrict the increased loads.
      Example 2

           Suppose, in the above situation, water quality improves to $e point that actual
           water qualify now meets class A requirements. Is the answer different?


           Yes, The standards must be upgraded (see section 2.8).


      Examples

           As an alternative case, suppose phosphorus loadings go down and water quality
           improves because of a change in farming practices (e.g., initiation of a
           successful nonpoint source program.) Are the above answers the same?
                     •  ; ;?-.                              >~       <•      ^ •y?t™         "   ^ V
          ^es* Whether the improvement results from, a change in point or nonpowit source activity is immaterial
          to how any aspect pf the standards regulation operates,  Section t3L10(d) clearly indicates that uses
          are deemed attainable if they can be achieved by "... cost-effective and reasonable best management
          practices for nonpoint source control,* Section 131,12
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                                                              Chapter 5 - General Policies
                                CHAPTERS

                           GENERAL POLICIES

                              (40 CFR 131.13)


                              Table of Contents


5.1 Mixing Zones	5-1
    5.1.1    State Mixing Zone Methodologies  	5-2
    5.1.2    Prevention of Lethality to Passing Organisms	5-6
    5.1.3    Human Heailth Protection	5-7
    5.1.4    Where Mixing Zones Are Not Appropriate	5-8
    5.1.5    Mixing Zones for the Discharge of Dredged or Fill Material	5-9
    5.1.6    Mixing Zones for Aquaculture Projects  	5-9

5.2 Critical Low-Flows	5-9

5.3 Variances From Water Quality Standards  	5-11

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                                                                       Chapter 5 - General Policies
                                        CHAPTER 5
                                  GENERAL POLICIES
States  may, at their discretion,  adopt  certain
policies   in   their  standards   affecting  the
application  and implementation   of standards.
For example, policies concerning mixing zones,
water quality  standards  variances, and  critical
flows for water quality-based permit limits may
be adopted.  Although thesie are areas of State
discretion, EPA retains authority to review and
approve  or disapprove  such policies (see  40
CFR 131.13).
        Mixing Zones
It  is not  always necessary to meet all  water
quality  criteria  within the discharge  pipe to
protect  the integrity of the  water body as a
whole. Sometimes it is appropriate to allow for
ambient  concentrations  above  the criteria in
small areas  near outfalls.   These  areas  are
called  mixing zones.  Whether  to establish  a
mixing  zone  policy  is   a   matter   of  State
discretion, but  any State  policy allowing for
mixing zones must be consistent with the  Clean
Water  Act and is subject to approval of the
Regional  Administrator.

A  series of guidance documents  issued by EPA
and its predecessor agencies have addressed the
concept of a mixing zone  as  a limited area or
volume of water where  initial  dilution  of a
discharge  takes place.  Mixing zones have been
applied  in the water quality standards  program
since its inception.  The present  water quality
standards   regulation  allows  States' to  adopt
mixing zones as a matter  of  States discretion.
Guidance  on defining mixing zones previously
has been  provided in  sevei^l  EPA documents,
including  FWPCA (1968); NAS/NAE (1972);
USEPA (1976); and USEPA  (1983a).
EPA1 s current mixing zone guidance, contained
in this  Handbook  and  the  Technical Support
Document   for  Water  Quality-based  Toxics
Control  (USEPA,  1991a),  evolved  from  and
supersedes these sources.

Allowable mixing zone characteristics should be
established  to ensure that:

•  mixing zones do not  impair  the  integrity of
   the water body as a whole,

•  there is  no lethality  to organisms passing
   through the mixing zone  (see  section 5.1.2,
   this Handbook);  and

•  there  are  no  significant   health   risks,
   considering likely pathways of exposure (see
   section 5.1.3, this Handbook).

EPA   recommends   that   mixing   zone
characteristics  be  defined  on  a case-by-case
basis after  it has  been  determined  that  the
assimilative  capacity of the receiving system can
safely   accommodate  the   discharge.    This
assessment  should  take  into  consideration  the
physical, chemical, and biological characteristics
of the discharge  and the receiving  system; the
life history  and behavior of organisms  in the
receiving system;  and the desired uses of the
waters.   Mixing zones should not  be permitted
where they  may endanger  critical  areas (e.g.,
drinking  water  supplies,  recreational  areas,
breeding grounds, areas  with sensitive biota).

EPA has developed  a holistic  approach  to
determine whether  a mixing zone is tolerable
(Brungs, 1986). The method considers  all the
impacts  to the water body and  all the impacts
that  the drop in water quality will have on the
surrounding ecosystem and water  body uses. It
is  a  multistep  data  collection  and analysis
(9/15/93)
                                          5-1

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 Water Quality Standards Handbook - Sec6nd Edition
procedure  that  is  particularly  sensitive  to
overlapping   mixing  zones.     This  method
includes the identification  of all upstream  and
downstream  water bodies  and the  ecological
and  cultural  data pertaining  to  them;  the
collection  of data  on  all present  and future
discharges to the water  body; the assessment of
relative  environmental   value  and  level  of
protection  needed  for the  water  body;  and,
finally, the allocation  of environmental  impact
for  a discharge  applicant.   Because  of the
difficulty in  collecting  the  data necessary for
this  procedure   and   the  general  lack  of
agreement   concerning   relative  values,   this
method  will be  difficult to implement  in full.
However,  the method does  serve as a guide on
how to proceed  in allocating a mixing zone.

Mixing zone allowances will increase  the mass
loadings of the pollutant to the water body and
decrease   treatment   requirements.     They
adversely  impact  immobile  species, such  as
benthic communities,  in the immediate vicinity
of  the  outfall.   Because  of these  and other
factors, mixing zones must be applied carefully,
so as not to impede progress toward the Clean
Water Act goals of maintaining  and improving
water quality.    EPA  recommendations   for
allowances for  mixing zones, and appropriate
cautions about their use, are  contained  in this
section.
              MIXING ZONES

   A limited area or volume of water where
   initial dilution of a discharge takes place
   and where  numeric water quality criteria
   can  be  exceeded  but  acutely  toxic
   conditions  are prevented.
 sections 2.2, 4.3, 4.4) discusses  mixing zone
 analyses for situations  in which the discharge
 does not  mix  completely  with the receiving
 water within a  short  distance.   Included  are
 discussions of  outfall  designs  that  maximize
 initial  dilution   in the  mixing  zone,  critical
 design  periods  for mixing zone analyses, and
 methods to  analyze and model  nearfield and
 farfield mixing.

 5.1.1 State Mixing Zone Methodologies

 EPA recommends  that  States have a definitive
 statement  in their  standards on  whether or not
 mixing zones are allowed. Where mixing zones
 provisions  are part of the State  standards,  the
 State  should   describe  the  procedures   for
 defining mixing zones.  Since  these areas  of
 impact,   if   disproportionally   large,   could
 potentially adversely impact the productivity of
 the   water  body  and  have   unanticipated
 ecological   consequences,   they   should  be
 carefully evaluated and appropriately  limited in
 size.  As our understanding  of pollutant  impacts
 on  ecological systems evolves, cases could be
 identified where no mixing zone is appropriate.

 State water  quality standards should describe
 the  State's methodology for determining   the
 location, size, shape, outfall design,  and  in-zone
 quality  of mixing zones.   The methodology
 should  be  sufficiently  precise   to   support
 regulatory  actions, issuance   of permits,  and
 determination  of BMPs  for nonpoint  sources.
 EPA recommends  the following:

 •  Location

Biologically important areas are to be identified
and protected.   Where necessary to preserve  a
zone  of passage  for migrating  fish or other
organisms  in a  water  course,  the standards
should specifically identify  the portions of the
waters to be kept free from mixing zones.
                                                 Where a mixing zone is allowed, water quality
The Technical  Support  Document  for Water   standards  are met at the edge of that regulatory
Quality-based Toxics Control (USEPA,  1991a,
5-2
                                                                                       (9/15/93)

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                                                                       Chapter 5 - General Policies
mixing zone during design flow conditions and   created by water  with inadequate  chemical or
generally provide:                               physical quality.
•  a continuous  zone  of passage that meets
   water quality criteria for free-swimming and
   drifting organisms;  and

•  prevention of impairment  of critical resource
   areas.

Individual State mixing  zone dimensions  are
designed  to limit the impact of a mixing zone
on the water body.  Furthermore,  EPA's review
of State waste load allocations (WLAs) should
evaluate   whether assumptions of complete or
incomplete  mixing are appropriate  based  on
available  data.

In river systems, reservoirs, lakes,  estuaries, and
coastal waters, zones of passage are defined as
continuous  water routes  of  such  volume,  area,
and   quality   as   to   allow   passage   of
free-swimming and drifting organisms so that no
significant  effects  are   produced  on  their
populations.     Transport   of a  variety  of
organisms  in  river   water   and  by  tidal
movements in estuaries is biologically important
for a number of reasons:

•  food is carried  to  the sessile  filter feeders
   and other  nonmotile organisms;

•  spatial  distribution   of  organisms   and
   reinforcement of weakened populations are
   enhanced;  and

•  embryos  and larvae  of  some fish species
   develop while drifting.

Anadromous  and catadromous  species must be
able  to reach suitable spawning  areas.  Their
young (and in some cases the adults)  must be
assured  a return route  to  their  growing and
living areas. Many species make  migrations for
spawning and  other   purposes.   Barriers or
blocks that prevent or interfere with these types
of essential transport  and  movement  can be
   Size

Various  methods  and techniques for defining
the surface area and volume of mixing zones for
various types of waters have been formulated.
Methods that  result in  quantitative  measures
sufficient for permit actions  and that protect
designated  uses of a water body as a whole are
acceptable.     The  area  or  volume  of  an
individual  zone  or group  of zones  must  be
limited  to  an  area or  volume as  small  as
practicable  that will not  interfere   with the
designated   uses   or  with  the  established
community  of  aquatic life  in the segment for
which the uses are designated.

To ensure  that mixing zones do not impair the
integrity of the  water  body,  it  should  be
determined  that the mixing zone will not cause
lethality  to   passing  organisms  and   that,
considering likely pathways  of exposure,  no
significant human  health risks exist. One means
to achieve these objectives is to limit the size of
the area affected by the mixing zones.

In  the general case, where a State  has  both
acute and chronic aquatic life criteria, as well as
human   health    criteria,  independently
established  mixing  zone  specifications  may
apply to each of the three types of criteria.  For
application  of  two-number  aquatic life criteria,
there  may be  up to two types of mixing zones
(see  Figure 5-1).   In the  zone immediately
surrounding the outfall, neither  the acute nor
the chronic criteria  are met. The acute criteria
are met at  the edge of this zone. In the next
mixing zone,   the acute,  but not the  chronic,
criteria are met.  The chronic criteria are met
at the edge of the second mixing zone.  The
acute  mixing  zone may be  sized  to prevent
lethality  to passing  organisms, the  chronic
mixing zone sized to protect the ecology of the
water body as a whole,  and the  health criteria
mixing zone sized to prevent  significant human
risks.   For any particular  pollutant from any
 (9/15/93)
                                           5-3

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 Water Quality Standards Handbook - Second Edition
                               Chronic criteria
                               (e.g., CCC) met
 Figure 5-1. Diagram  of the Two Parts of the
            Aquatic Life Mixing Zone
 particular  discharge, the  magnitude, duration,
 frequency,  and  mixing  zone  associated  with
 each of the three  types  of criteria  (acute and
 chronic  aquatic  life, and  human health) will
 determine  which one most limits the allowable
 discharge.

 Concentrations  above  the chronic criteria are
 likely to prevent sensitive  taxa from taking up
 long-term residence in the mixing zone.  In this
 regard,  benthic   organisms   and   territorial
 organisms  are likely to be of greatest concern.
 The higher the concentrations occurring within
 certain  isopleths, the more taxa are likely to be
 excluded, thereby  affecting  the  structure and
 function of the ecological community. It is thus
 important  to minimize the overall size of the
 mixing   zone   and   the   size   of   elevated
 concentration isopleths within the mixing zone.

 To determine that, for  aquatic life protection, a
 mixing zone is appropriately  sized, water quality
 conditions   within  the mixing  zone  may be
 compared to laboratory-measured  or predicted
 toxicity benchmarks as follows:
 It is not necessary  to meet chronic criteria
 within the  mixing zone,  only at the edge of
 the  mixing zone.   Conditions  within the
 mixing zone would thus  not be adequate to
 assure survival, growth, and reproduction of
 all organisms  that might otherwise  attempt
 to  reside  continuously  within the  mixing
 zone.

 If   acute  criteria   (criterion   maximum
 concentration,  or CMC,  derived from 48- to
 96-hour exposure tests) are met throughout
 the  mixing zone, no  lethality  should result
 from temporary  passage  through the mixing
 zone.  If acute  criteria are exceeded no more
 than  a  few minutes  hi  a parcel of water
 leaving  an  outfall (as assumed in deriving
 the  section 5.1.2  options  for  an  outfall
 velocity of 3 m/sec,  and a size of 50 times
 the  discharge  length  scale),   this likewise
 assures no  lethality  to passing organisms.

 If a  full analysis  of concentrations   and
 hydraulic residence  times within the  mixing
 zone  indicates   that   organisms   drifting
 through the centerline of the  plume along
 the path of maximum exposure  would not be
 exposed  to concentrations  exceeding   the
 acute criteria when averaged over the 1-hour
 (or   appropriate   site-specific)   averaging
 period  for  acute criteria, then lethality to
 swimming  or   drifting  organisms   should
 ordinarily not  be expected, even for rather
 fast-acting  toxicants.   In many  situations,
 travel  time through the  acute  mixing zone
 must be less than roughly 15 minutes if a 1-
 hour average exposure is not to exceed the
 acute criterion.

 Where  mixing zone  toxicity  is  evaluated
 using the probit  approach described  in the
 water   quality   criteria   'Blue   Book"
 (NAS/NAE,  1973),  or  using  models of
 toxicant   accumulation    and   action   in
 organisms  (such as described  by Mancini,
 1983,  or   Erickson  et   al.,  1989),   the
phenomenon of delayed mortality should be
5-4
                                                                                       (9/15/93)

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                                                                        Chapter 5 - General Policies
   taken into account before judging the mixing
   zone concentrations  to be safe.

 The above recommendations  assume that the
 effluent is repulsive, such that  free-swimming
 organisms would avoid the mixing zones. While
 most toxic effluents  are  repulsive, caution is
 necessary  in evaluating attractive mixing zones
 of known effluent toxicity, and denial of such
.mixing zones  may well be  appropriate.   It is
 also  important  to  assure that  concentration
 isopleths  within any plume; will not  extend to
 restrict passage of  swimming organisms into
 tributary  streams.

 In all cases, the size  of the mixing zone and the
 area  within  certain  concentration   isopleths
 should  be evaluated  for their  effect on the
 overall biological integrity of the water body. If
 the   total   area    affected    by   elevated
 concentrations    within   all   mixing   zones
 combined  is small compared with the total area
 of a water body (such as a river segment), then
 mixing zones are likely to have little  effect on
 the  integrity  of the  water  body as  a  whole,
 provided  that they do not impinge on unique or
 critical  habitats.    EPA   has  developed   a
 multistep  procedure  for evaluating the overall
 acceptability of mixing zones (Brungs, 1986).

   Shape

 The shape of a mixing zone should be a simple
 configuration that is easy to locate in a body of
 water   and  that  avoids  impingement  on
 biologically important  area:s.  In lakes, a circle
with a specified radius is generally preferable,
but other shapes may be specified in the case of
unusual  site requirements.   Most States allow
mixing  zones  as  a policy  issue  but provide
spatial dimensions  to limit the area!  extent of
the mixing zones.  The mixing zones are then
allowed  (or not  allowed)   after  case-by-case
determinations.  State regulations  dealing with
streams  and rivers generally limit mixing zone
widths, cross-sectional areas, and flow volumes,
and  allow  lengths  to  be  determined  on a
case-by-case basis.  For lakes,  estuaries,  and
coastal waters, dimensions are usually specified
by surface area, width, cross-sectional  area, and
volume.   "Shore-hugging"  plumes should  be
avoided  in all water bodies.

   Outfall Design

Before designating any  mixing zone,  the State
should   ensure  that   the   best   practicable
engineering  design is used and that the location
of the existing or proposed outfall will avoid
significant adverse  aquatic resource and water
quality impacts of the wastewater discharge.

   In-Zone Quality

Mixing   zones  are  areas  where  an  effluent
discharge undergoes  initial dilution  and  are
extended  to cover the secondary  mixing in the
ambient  water body.   A mixing zone is an
allocated  impact zone where acute and chronic
water quality criteria can be exceeded as long
as a  number  of protections  are maintained,
including freedom from the  following:

(1)    materials  in  concentrations   that   will
      cause acutely  toxic conditions to aquatic
      life;

(2)    materials in concentrations  that settle to
      form objectionable deposits;

(3)    floating  debris,  oil,  scum,  and  other
      material  in  concentrations  that  form
      nuisances;
 (9/15/93)
                                          5-5

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Water Quality Standards Handbook - Second Edition
(4)   substances in concentrations  that produce
      objectionable   color,  odor,  taste,   or
      turbidity; and

(5)   substances in concentrations  that produce
      undesirable  aquatic  life or result in a
      dominance  of nuisance species.

Acutely  toxic conditions are defined  as those
lethal  to  aquatic  organisms  that  may pass
through  the  mixing  zone.   As  discussed  in
section  5.1.2 below, the underlying assumption
for allowing a mixing zone is that  a small area
of concentrations in excess of acute and chronic
criteria  but  below  acutely  toxic  releases  can
exist  without causing adverse effects to the
overall  water body.    The State  regulatory
agency  can decide to allow or deny a mixing
zone on a site-specific basis. For a mixing zone
to be permitted, the discharger  should  prove  to
the  State   regulatory  agency  that all State
requirements  for a mixing zone are  met.

5.1.2 Prevention  of  Lethality  to  Passing
      Organisms

Lethality  is a function of the magnitude   of
pollutant  concentrations  and the  duration  an
organism  is exposed  to those  concentrations.
Requirements for wastewater plumes that tend
to  attract  aquatic  life  should  incorporate
measures   to reduce  the  toxicity (e.g., via
pretreatment,  dilution) to minimize lethality or
any irreversible  toxic effects on aquatic life.

EPA's water  quality criteria provide guidance
on  the  magnitude and duration  of pollutant
concentrations  causing lethality.  The  CMC  is
used as a  means  to prevent lethality  or other
acute effects. As explained in Appendix D  to
the  Technical Support Document  for  Water
Quality-based Toxics Control (USEPA, 1991a),
the CMC is a toxicity level and should not be
confused  with an  LC50 level.   The  CMC  is
defined as one-half  of the final  acute  value
(FAV)  for  specific  toxicants  and  0.3 acute
toxicity unit (TUJ for effluent toxicity (USFJPA,
1991a,  chap. 2).   The CMC describes  the
condition under which lethality will not occur if
the duration of the exposure to the CMC level
is  less   than  1  hour.     The  CMC   for
whole-effluent toxicity is  intended  to prevent
lethality  or acute effects in the aquatic  biota.
The  CMC for individual toxicants  prevents
acute effects  in all but a small percentage of
the tested  species.  Thus,  the areal extent and
concentration  isopleths of the mixing zone must
be  such  that  the  1-hour average  exposure of
organisms  passing  through the mixing zone is
less than the CMC. The organism must be able
to  pass  through   quickly  or flee the   high-
concentration  area.   The objective  of mixing
zone  water  quality   recommendations   is to
provide  time-exposure histories  that produce
negligible   or  no  measurable   effects   on
populations of critical species in the  receiving
system.

Lethality to passing organisms can be prevented
in the mixing zone in one of four ways.  The
first method  is to prohibit  concentrations  in
excess of the  CMC  in  the pipe   itself, as
measured directly at the end of the pipe.  As an
example, the  CMC should be met in the pipe
whenever a continuous discharge is made to an
intermittent stream. The second approach is to
require  that the CMC be met  within  a very
short  distance from the outfall during chronic
design flow conditions for receiving waters (see
section 5.2, this Handbook).

If the second alternative  is selected,  hydraulic
investigations  and calculations indicate that the
use of a high-velocity discharge  with  an  initial
velocity of 3 m/sec, or greater, together with a
mixing zone spatial limitation of 50 times the
discharge length  scale in any direction,  should
ensure  that  the CMC is met  within  a  few
minutes under practically all conditions.

The discharge length  scale  is defined  as the
square root of the  cross-sectional  area  of any
discharge pipe.

A third  alternative  (applicable  to any  water
body) is not to use a high-velocity discharge.
5-6
                                      (9/15/93)

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                                                                         Chapter 5 - General Policies
Rather  the discharger  should provide  data  to
the State regulatory agency showing that the
most restrictive of the following conditions are
met for each outfall:

•  The CMC should be met within 10 percent
   of the distance from the edge of the outfall
   structure  to  the edge  of the  regulatory
   mixing zone in any spatial  direction.

•  The CMC should be met  within a distance
   of 50 times  the discharge length scale in any
    spatial direction.  In the case  of a multiport
    diffuser, this requirement  must be met  for
    each port using the  appropriate  discharge
    length  scale  of  that port.  This  restriction
    will ensure  a dilution factor  of at  least  10
    within  this  distance   under  all  possible
    circumstances, including situations  of severe
    bottom  interaction,  surface interaction,  or
    lateral  merging.

 •  The CMC  should  be met within a distance
    of 5 times  the local  water  depth  in  any
    horizontal   direction  from  any  discharge
    outlet.   The  local water depth is defined as
    the natural water depth (existing prior to the
    installation    of  the   discharge   outlet)
    prevailing    under    mixing-zone    design
    conditions  (e.g., low-flow for rivers).  This
    restriction will prevent locating the discharge
    in very shallow environments or very close to
    shore,   which  would  result   in  significant
    surface and bottom  concentrations.

 A fourth alternative  (applicable  to any  water
 body)  is for the discharger to provide data to
 the  State  regulatory   agency showing  that  a
 drifting organism would not be  exposed to  1-
 hour  average  concentrations   exceeding  the
 CMC, or would not receive harmful  exposure
 when  evaluated  by other  valid lexicological
 analysis (USEPA,  1991a, chap. 2).  Such data
 should  be  collected   during  environmental
 conditions that replicate critical conditions.

 For the third and fourth alternatives, examples
 of such data include monitoring studies, except
for those situations where collecting chemical
samples  to develop monitoring  data  would be
impractical, such as at deep outfalls in oceans,
lakes,  or embayments.   Other types  of data
could  include  field  tracer  studies using dye,
current  meters,  other  tracer  materials,  or
detailed    analytical    calculations,   such  as
modeling  estimations   of concentration   or
dilution  isopleths.

The following outlines a method,  applicable to
the fourth alternative,  to determine whether a
mixing zone is tolerable for a free-swimming or
drifting  organism.   The  method  incorporates
mortality rates (based on toxicity studies for the
pollutant  of  concern  and a representative
organism)   along   with   the   concentration
isopleths of the mixing zone and  the  length of
time the organism may spend in each isopleth.
The  intent of the method  is  to prevent the
actual  time of exposure  from exceeding the
exposure time required to elicit an effect:
                                <; 1
                 ET(X) at C(l
 where T(n)  is the exposure tune an organism is
 in isopleth  n, and  ET(X)  is the "effect time."
 That is, ET(X) is the exposure time required to
 produce  an  effect (including a delayed effect) in
 X  percent   of  organisms  exposed  to   a
 concentration equal to C(n),the concentration in
 isopleth   n.      ET(X)    is   experimentally
 determined;  the effect is usually mortality.  If
 the summation  of ratios  of exposure  time to
 effect tune  is  less than  1, then the  percent
 effect will not occur.

 5.1.3 Human Health Protection

 For protection of human health,  the presence of
 mixing zones  should not  result in significant
 health risks when evaluated using  reasonable
 assumptions about  exposure pathways.  Thus,
 where   drinking  water  contaminants   are  a
 concern, mixing zones should not encroach on
  (9/15/93)
                                                                                              5-7

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 Water Quality Standards Handbook - Second Edition
 drinking  water  intakes.   Where  fish tissue
 residues  are  a concern  (either  because  of
 measured  or predicted residues), mixing zones
 should not be projected  to result in significant
 health  risks to average consumers  of fish and
 shellfish, after considering exposure duration  of
 tile  affected aquatic  organisms in the mixing
 zone and  the  patterns of fisheries  use  hi the
 area.

 While fish tissue contamination tends to be a
 far-field problem affecting entire water bodies
 rather than a narrow-scale problem  confined to
 mixing zones, restricting  or eliminating mixing
 zones  for  bioaccumulative pollutants  may be
 appropriate   under   conditions  such  as  the
 following:

 *  Mixing zones should be restricted such that
   they do not encroach on areas often  used for
   fish  harvesting  particularly  of  stationary
   species such as shellfish.

•  Mixing zones might be denied  (see section
   5.1.4) where such denial is used as a device
   to  compensate  for uncertainties  in  the
   protectiveness of the water quality criteria or
   uncertainties  in the  assimilative capacity of
   the  water body.
 5.1.4 Where   Mixing
       Appropriate
Zones   Are  Not
 States  are  not  required  to  allow  mixing zones
 and,  if  mixing zones  are  allowed, a  State
 regulatory  agency may decide to deny a mixing
 zone   in  a   site-specific   case.     Careful
 consideration    must   be    given   to    the
 appropriateness  of a  mixing  zone  where  a
 substance   discharged    is   bioaccumulative,
 persistent,   carcinogenic,   mutagenic,   or
 teratogenic.

 Denial   should   be   considered  when
 bioaccumulative pollutants are in the discharge.
 The potential for a pollutant to bioaccumulate
 in living organisms  is measured  by:

 •  the bioconcentration  factor (BCF), which is
   chemical-specific and describes the degree to
   which  an organism  or tissue can acquire a
   higher contaminant  concentration  than  its
   environment  (e.g., surface water);

 •  the duration  of exposure; and

 •  the concentration of the chemical of interest.

While any BCF value greater  than 1 indicates
that   bioaccumulation  potential   exists,
bioaccumulation  potential  is   generally  not
considered  to  be significant unless the  BCF
exceeds 100 or more.  Thus, a chemical that is
discharged to a receiving stream  resulting  in
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                                                                         Chapter 5 - General Policies
low concentrations  and has  a low BCF value
will not result  in a bioaccumulation  hazard.
Conversely, a chemical  that  is discharged to a
receiving    stream   resulting   in   a   low
concentration  but having a high BCF value may
result in a bioaccumulation hazard. Also, some
chemicals of relatively low toxicity, such as zinc,
will  bioconcentrate  in  fish  without harmful
effects resulting from human  consumption.

Factors  such as  size  of zone,  concentration
gradient within the zone, physical habitat,  and
attraction of aquatic life are important  in this
evaluation.  Where unsafe fish tissue levels or
other evidence  indicates  a lack of assimilative
capacity  in a  particular  water  body  for  a
bioaccumulative pollutant, care should be taken
in calculating discharge limits for this pollutant
or the additivity of multiple pollutants.   In such
instances,   the  ecological  or  human  health
effects  may be so adverse that a mixing zone is
not appropriate.

Another  example  of when a regulator  should
consider  prohibiting  a  mixing zone  is  in
situations where an effluent  is known to attract
biota.  In such cases, provision of a continuous
zone of passage around the mixing area  will not
serve the purpose  of protecting aquatic  life. A
review   of  the    technical   literature   on
avoidance/attraction  behavior revealed  that the
majority  of toxicants elicited  an avoidance  or
neutral response at low concentrations  (Versar,
 1984).  However,  some  chemicals  did elicit an
attractive   response,  but  the data  were  not
 sufficient to  support  any predictive  methods.
Temperature   can be  an attractive  force and
may  counter   an  avoidance response  to  a
pollutant, resulting in attraction  to the toxicant
discharge.  Innate  behavior  such as migration
may  also supersede  an avoidance response and
 cause a fish to incur a significant exposure.

 5.1.5 Mixing  Zones  for  the  Discharge  of
       Dredged or Fill Material

 EPA,  in conjunction  with the Department  of
 the  Army, has  developed   guidelines  to  be
applied in evaluating the discharge of dredged
or fill material  in navigable waters (see 40 CFR
230).  The  guidelines  include  provisions  for
determining    the   acceptability   of   mixing
discharge  zones   (section  230.11(f)).    The
particular   pollutant    involved   should   be
evaluated  carefully  in establishing  dredging
mixing  zones.    Dredged  spoil  discharges
generally  result   in   temporary   short-term
disruption and do not represent continuous
discharge that  will affect beneficial uses over a
long term. Disruption of beneficial uses should
be the primary consideration   in establishing
mixing zones for dredge and fill activities. State
water  quality  standards  should  reflect these
principles if mixing zones for dredging activities
are referenced.

5.1.6  Mixing  Zones for Aquaculture Projects

The Administrator  is authorized,  after  public
hearings, to permit certain discharges associated
with approved  aquaculture  projects (section 318
of the  Act).    The  regulations  relating  to
aquaculture   (40  CFR  122.56  and   125.11)
provide  that the aquaculture  project area  and
project   approval   must   not   result   in   the
enlargement of any previously approved mixing
zone.    In  addition,   aquaculture  regulations
provide  that designated project areas must  not
include  so large a portion  of the body of water
that  a substantial  portion  of  the indigenous
biota  will be  exposed to  conditions  within  the
designated  projects area  (section 125.11(d)).
Areas  designated  for approved  aquaculture
projects  should be treated in the  same manner
as other  mixing  zones.    Special allowances
 should not be made for these areas.
          Critical Low-Flows
 Water quality  standards  should protect water
 quality for designated uses in critical low-flow
 situations.     In  establishing   water  quality
 standards,  States may designate a critical  low-
 flow  below  which  numerical  water quality
 criteria  do not apply.  At all tunes, waters  shall
 (9/15/93)
                                                                                             5-9

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  Water Quality Standards Handbook - Second Edition
 be free from  substances  that settle  to  form
 objectionable deposits; float as debris, scum, oil,
 or other matter; produce  objectionable  color,
 odor,  taste,  or turbidity;  cause  acutely  toxic
 conditions; or produce undesirable or nuisance
 aquatic life.

 To  do  steady-state  waste   load  allocation
 analyses, these low-flow values become design
 flows for sizing treatment  plants,  developing
 waste  load allocations,  and developing  water
 quality-based effluent limits.  Historically, these
 so-called "design" flows were  selected  for the
 purposes of waste load allocation  analyses that
 focused   on    instream    dissolved   oxygen
 concentrations  and protection  of aquatic life.
 EPA introduced hydrologically and biologically
 based analyses  for the protection of aquatic life
 and human health  with  the publication of the
 Technical Support Document for Water  Quality-
 based  Toxics Control   These  concepts  have
 been   expanded   subsequently  in  guidance
 entitled  Technical  Guidance  Manual   for
 Performing  Wasteload  Allocations,  Book  6,
 Design Conditions, (USEPA, 1986c). These new
 developments  are included in Appendix  D of
 the 1991 Technical Support Document for Water
 Quality-based Toxics Control (USEPA,  199la).
 The discussion  here is greatly simplified;  it is
 provided to support EPA's recommendation  for
 baseline application values for instream flows
 and thereby maintain the intended  stringency of
 the criteria for priority toxic pollutants.  EPA
 recommended   either  of  two  methods   for
 calculating acceptable low-flows, the traditional
 hydrologic  method  developed   by  the  U.S.
 Geological  Survey  and  a biologically based
 method  developed  by EPA.

 Most States  have  adopted  specific low-flow
 requirements  for streams and  rivers to  protect
 designated uses against  the  effects of toxics.
 Generally, these have followed the guidance in
 the TSD.   EPA  believes  it is essential  that
 States   adopt   design flows  for  steady-state
 analyses  so  that  criteria  are  implemented
 appropriately.   The  TSD  also recommends  the
 use of three dynamic models to perform waste
 load allocations.  Because  dynamic  waste load
 models  do not  generally  use specific steady-
 state  design  flows but  accomplish  the  same
 effect  by  factoring   in  the  probability   of
 occurrence   of  stream  flows based  on  the
 historical   flow   record,   only  steady-state
 conditions  will be discussed here.   Clearly, if
 the criteria are implemented using inadequate
 design flows, the resulting toxics controls would
 not be  fully effective because  the resulting
 ambient  concentrations  would  exceed  EPA's
 criteria.

 In the  case  of aquatic  life,  more frequent
 violations than the assumed exceedences  once
 in 3 years would result in diminished vitality of
 stream ecosystems  characteristics  by the loss of
 desired  species  such  as sport  fish.   Numeric
 water, quality criteria  should apply at all  flows
 that are  equal to or greater  than flows specified
 in Exhibit 5-1.

 EPA is recommending  the harmonic mean flow
 to  be applied  with human  health criteria  for
 carcinogens. The concept of a harmonic  mean
 is a standard statistical  data  analysis technique.
 EPA's model for human health effects assumes
 that such effects  occur because of a  long-term
 exposure  to  low  concentration   of  a   toxic
 pollutant   (for example,  2 liters  of  water per
 day  for  70  years).     To  estimate   the
 concentrations  of the toxic pollutant in those 2
 liters per day by  withdrawal from streams with
 a high daily variation  in flow, EPA believes the
 harmonic mean flow is the  correct  statistic to
use in computing such design flows rather  than
other averaging techniques.   For  a description
of harmonic means, refer to Rossman (1990).
5-10
                                                                                      (9/15/93)

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                                                                         Chapter 5 - General Policies
             r  -  AQUATIC LIFE

  Acute Criteria 
-------
 Water Quality Standards Handbook - Second Edition
 Variance   procedures    involve  the   same
 substantive  and  procedural  requirements  as
 removing a designated use (see  section 2.7,this
 Handbook), but unlike use removal, variances
 are both discharger and pollutant  specific, are
 time-limited,  and  do not forego  the  currently
 designated use.

 A variance should  be used instead of removal
 of a use where the State believes the standard
 can ultimately be attained.   By maintaining the
 standard rather than  changing it, the State  will
 assure   that   further  progress  is  made  in
 improving  water   quality   and   attaining  the
 standard.   With  a variance,  NPDES  permits
 may be written such that reasonable progress is
 made  toward  attaining  the standards  without
 violating section  402(a)(l)  of the Act,  which
 requires  that NPDES permits  must  meet  the
 applicable water quality standards.

 State  variance procedures,  as  part   of State
 water quality standards,  must be consistent with
 the substantive requirements  of 40 CFR 131.
 EPA has approved  State-adopted  variances in
 the past and will continue to do so if:

 *   each  individual variance  is included as part
    of the water quality standard;

 *   the  State  demonstrates  that meeting  the
    standard is unattainable  based on one or
    more  of the  grounds outlined  in  40 CFR
    131.10(g) for removing a designated use;

 *   the justification  submitted  by the  State
    includes documentation   that treatment
    more  advanced  than that  required   by
    sections  303(c)(2)(A> and  (B)  has been
    carefully considered,  and that alternative
    effluent  control  strategies   have  been
    evaluated;

 •  the    more  stringent  State   criterion   is
   maintained  and  is binding upon  all  other
   dischargers   on   the   stream   or  stream
   segment;
•  the discharger who is given a variance  for
   one  particular  constituent  is  required  to
   meet   the  applicable   criteria  for  other
   constituents;

•  the variance  is granted  for a specific period
   of  time  and  must  be  rejustified  upon
   expiration but  at least every 3 years (Note:
   the 3-year limit is derived from the triennial
   review requirements of section 303(c) of the
   Act.);

•  the discharger either must meet the standard
   upon  the  expiration of this time period  or
   must   make    a   new   demonstration   of
   "unattainability";

•  reasonable progress is being made toward
   meeting the standards; and

•  the variance was subjected to public  notice,
   opportunity   for   comment,   and   public
   hearing. (See section 303(c)(l) and 40 CFR
   131.20.) The public notice should contain a
   clear  description   of  the  impact  of the
   variance   upon  achieving  water  quality
   standards  in the affected stream  segment.
5-12
                                                                                       (9/15/93)

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                            Chapter 6 - Procedures for Review and Revision of Water Quality Standards
                                CHAPTER 6

                      PROCEDURES FOR REVIEW
                            AND REVISION OF
                     WATER QUALITY STANDARDS

                         (40 CFR 131 - Subpart C)


                              Table of Contents
6.1 State Review and Revision  	6-1
    6.1.1     Consultation with EPA  	6-1
    6.1.2     Public Notice Soliciting Suggestions for Additions or Revisions to
             Standards   	6-1
    6.1.3     Review of General Provisions   	6-3
    6.1.4    Selection of Specific Water Bodies for Review	6-3
    6.1.5     Evaluation of Designated Uses	6-4
    6.1.6    Evaluation of Criteria	6-6
    6.1.7    Draft Water Quality Standards Submitted to EPA for Review	6-7
    6.1.8    Public Hearing on Proposed Changes to Standards   	6-7
    6.1.9    State Adopts Revisions; Submits Standards Package to EPA for Review  . . 6-7

6.2 EPA Review and Approval	6-8
    6.2.1     Policies and Procedures Related to Approvals	6-11
    6.2.2    Policies and Procedures Related to Disapprovals	6-11
    6.2.3    Policies and Procedures Related to Conditional Approvals   	  6-12

6.3 EPA Promulgation ,	6-13

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-------
                                  Chapter 6 - Procedures for Review and Revision of Water Quality Standards
                                       CHAPTER 6
            PROCEDURES FOR REVIEW AND REVISION OF WATER
                                QUALITY STANDARDS
State  review  and  revision  of water  quality
standards  are discussed  in section 6.1. of this
chapter.     Guidance   is  provided   on  the
administrative and regulatory requirements  and
procedures that should be followed in the State
review and submittal  process as  well as the
implication  of  a  State's  failure to  submit
standards.     EPA   review  and  approval
procedures are discussed in section 6.2, and the
procedures   for   promulgation   of  Federal
standards  are described in section  6.3.
         State Review and Revision
Section  303(c)(l)  of the  Clean  Water  Act
requires  that a State shall, from time to time,
but at least  once  every 3 years,  hold  public
hearings  to  review applicable  water quality
standards and, as appropriate,  to  modify and
adopt  standards.    The  3-year  period  is
measured from the date of the letter  in which
the State informs  EPA  that  revised or  new
standards have been adopted  for the affected
waters and are being submitted for EPA review
or, if no changes were made in the standards
for those waters, from the date of the letter in
which the State informs EPA that the standards
were  reviewed  and no changes were made.

States identify additions or revisions necessary
to  existing  standards  based  on  their 305(b)
reports,   other    available   water   quality
monitoring   data,   previous   water  quality
standards reviews, or requests from  industry,
environmental  groups, or the public.   Water
quality  standards reviews  and revisions  may
take  many  forms,  including  additions to and
modifications   in  uses,  in  criteria,  in  the
antidegradation   policy, in the antidegradation
implementation procedures, or in other general
policies.

6.1.1    Consultation with EPA

State consultation  with  EPA regional offices
should occur  when States  begin activities  to
revise or adopt new water quality standards and
long before the  State standards  are  formally
submitted for EPA review.  Reasons for early
consultation with EPA include the following:

•    States will benefit from early identification
     of potential areas  of disagreement  between
     EPA  and  the   States,  and  EPA  can
     determine   where   assistance   may  be
     provided;

•    EPA must be in  a position to respond  to
     litigation  and to  congressional  and  other
     inquiries  relating  to actions on the revised
     State water quality  standards;

•    Headquarters  must  be ready to support
     promulgation actions when State standards
     have been disapproved;

•    early consultation with EPA  allows issues
     to  be  discussed  well before   a formal
     review request is received  from the State;
     and

•    EPA  actions  related  to  State  standards
     should receive as comprehensive  a review
     as possible.

6.1.2  Public Notice Soliciting  Suggestions for
       Additions or Revisions to Standards

An important  component  of the water quality
standards  setting  and  review  process   is  a
 (9/15/93)
                                          6-1

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 Water Quality Standards Handbook - Second Edition
                Consultation with EPA
               , PubHo Notice Soliciting
               Suggestions for Additions
               or Revisions to Standards
             Review of Genera! Provisions
            Appropriate Use Designations
              (Chapter 2)
            Criteria review and Development
              (Chapters)
            AnlfdsgYadation Policy
            Implamofitation (Chapter 4)
            Downgrade/Variance Provisions
              (Section 5.3)
            Inclusion of AM Waters of the U.S.
              (Section 1.3)
            Low Flow Provisions (Section 5.2)
            Mixing Zone Provisions (Section 5.1)
            DaflnWons
            Other
                 Selection of Specific
               Waterbodtea for Review
             CWA §305(b) Report
             CWA §304(0 Ust
             CWA §303(d) Waters
             CWA §319 Waters
             Construction Grants Priority List
             Expired Major Permits
             Waters Not Meeting CWA
             §101 (a){8) Goals
             Unclassified Waterbodtes
             Public Input
            Evaluation of Designated Uses
                    (Chapter 2)
                Evaluation of Criteria
                    (Chapters)
   Draft Water Quality
 Standards Submitted to
    EPA for Review
   Public Hearing on
  Proposed Changes to
Water Quality Standards
 State Adopts Revisions
 State Attorney General
 Certifies Water Quality
      Standards
State Submits Revisions,
 Methods, Justifications
 and Attorney General
 Certification to EPA for
       Review
        EPA
      Approves
      Standards
     (Section 6.2)
                                            Yes
State Proposes Revisions
                                                                                                   No
                                EPA Promulgates Federal
                                 Water Quality Standards
                                      (Section 6.3)
 Standards to Permits
       Process
  Figure 6-1. Simplified Flow Chart of a Typical State Water Quality Standards Review Process
6-2
                                                                                                            (9/15/93)

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                                    Chapter 6 - Procedures for Review and Revision of Water Quality Standards
-meaningful involvement of those affected by the
standards  decisions.   At a  minimum,  section
303(c) of the Clean Water Act requires  States
to  hold a public  hearing   in reviewing  and
revising water quality standards. (State law may
require  more than  one  hearing.)   However,
States are  urged  to  involve the public more
actively  in the review process.  Involvement  of
the public includes the .involvement  of citizens
affected by standards  decisions, the  regulated
community (municipalities  and  industry),  and
inter-governmental   coordination  with  local,
State, and Federal agencies,  and Indian Tribes
with  an interest  in water quality issues.   This
partnership will ensure  the  sharing  of ideas,
data,  and  information, which will increase the
effectiveness   of   the   total   water   quality
management  process.

Public  involvement  is  beneficial  at  several
points in the water quality  standards  decision
making  process.    Enlisting  the support  of
municipalities,  industries,   environmentalists,
universities,  other  agencies,,  and the  affected
public in collecting and evaluating information
for the decision making  process  should assist
the State in improving the  scientific  basis for,
and hi building support for, standards decisions.
The more  that people  and groups are involved
early in  the process  of sietting  appropriate
standards,  the more support  the State will have
in implementing  the standards.

6.1.3  Review of General Provisions

In each  3-year water quality standards  review
cycle, States  review the general provisions  of
the   standards   for   adequacy   taking   into
consideration:

•    new Federal  or State statutes, regulations,
     or guidance;

•    legal  decisions involving  application   of
     standards; or

•    other  necessary clarifications or revisions.
     Inclusion  of All Waters of the  United
     States

Water  quality  standards  are needed  for all
"waters of the United States,"  defined  in the
National   Pollution   Discharge   Elimination
System Regulations at 40 CFR 122.2 to include
all interstate waters, including wetlands, and all
intrastate   lakes,  rivers,  streams   (including
intermittent  streams),  wetlands, natural ponds,
etc.,  the  use, degradation   or destruction  of
which would affect or could affect interstate  or
foreign commerce.  The term "waters of the
United States" should be read broadly during
the standards  review  process.   States  should
ensure that all waters under this definition are
included in the States' water quality  standards,
are   assigned   designated   uses,  and   have
protective  criteria.

   Definitions

Terms  used in  the  Water Quality  Standards
Regulation  are defined in 40 CFR 131.3.  The
glossary of this  document contains  these  and
other  water  quality standards-related   terms
defined  by  the  Clean  Water  Act,   EPA
regulation, or guidance. States, when reviewing
their   water quality  standards,   should  at  a
minimum  define  those terms  included  in the
Definitions  section  of the  regulation  to  be
synonymous with the EPA definitions.

6.1.4  Selection of Specific Water Bodies for
       Review

The Water Quality Standards Regulation allows
States to establish procedures  for identifying
and reviewing the standards on specific water
bodies  in  detail.    Any  procedures  States
establish   to   revise  standards   should   be
articulated   in the  continuing  planning process
consistent  with the water quality  management
regulation.   Water bodies  receiving a detailed
standards  review are most likely to  be those
where:
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Water Quality Standards Handbook - Second Edition
*  combined  sewer  overflow  (CSO)  funding
   decisions are pending;

*  water quality-based permits are scheduled to
   be issued or reissued;

•  CWA goal uses are not being met;

*  toxics   have   been   identified  and   are
   suspected of precluding a  use or may be
   posing  an  unreasonable   risk to  human
   health;  or
   there   may  be   potential   impacts
   threatened  or endangered species.
on
States  may have other reasons  for  wishing to
examine a water body in detail,  such as human
health   problems,  court  orders,  or costs  or
economic and  social impacts of implementing
the existing water  quality  standards.    States
must reexamine any water body with standards
not consistent  with the section  101(a)(2)  goals
of the Act every 3 years, and if new information
indicates that  section 101(a)(2) goal uses  are
attainable,  revise its standards  to  reflect  those
uses.

States are encouraged to  review standards for a
large  enough  area  to consider  the interaction
between  both  point  and   nonpoint  source
discharges.  In carrying out standards  reviews,
the States  and  EPA  should  ensure  proper
coordination of all water quality programs.
6.1.5  Evaluation of Designated Uses

Once priority water bodies have been selected
for  review,   the  designated   uses  must  be
evaluated.  This may involve some level of data
collection up to and including a full water body
survey and  assessment;  however,  an intensive
survey of the  water body is not  necessary if
adequate  data are available.   The purpose  of
the evaluation is  to pinpoint problems and to
characterize present uses, attainable uses (uses
that could exist in the absence of anthropogenic
effects),  uses  impaired  or precluded,  and  the
reasons why uses are impaired or precluded.
Information generated in the survey also can be
used to establish the basis for seasonal uses and
subcategories  of uses.

Included in section  2.9 of this Handbook  are
examples  of a range of physical, chemical, and
biological characteristics of the  water body that
may  be  surveyed  when  evaluating   aquatic
protection uses.  This information  is then used
in determining the existing species in the water
body and the health  of those species, as well as
what species could be in the water body  given
the physical characteristics of the water body, or
what species might be in the water  if the quality
of the  water were improved.

   Review of the Cause of Uses Not Being Met

If the survey indicates that designated  uses  are
impaired,  the  next  step  is to  determine  the
cause.  In many situations, physical conditions
and/or the presence  of pollutants   prevent  the
water  body from meeting its  designated  use.
Physical  limitations   refer  to   such factors  as
depth,  flow, habitat,  turbulence,  or structures
such as dams that might make a use unsuitable
or impossible  to  achieve regardless  of water
quality.

If uses  are  precluded   because   of  physical
limitations  of the water body, the State  may
wish to examine modifications that  might  allow
a habitat suitable  for a species  to thrive where
it could  not before.   Some of the techniques
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                                   Chapter 6 - Procedures for Review and Revision of Water Quality Standards
which   have   been    used   include   bank
stabilization, current deflectors, construction  of
oxbows, or installation  of spawning  beds.   A
State also might wish to consider improving the
access to the water body, improving  facilities
nearby  so  that it can  be used for recreational
purposes,  or  establishing  seasonal   uses   or
subcategories  of a use.

If uses are not  being  met because  of water
pollution problems, the first step in the process
is to determine  the  cause.  If the  standards
review process is well coordinated with the total
maximum  daily  load   (TMDL)  determination
and  the  permit process,  permitees   may   be
required  to  conduct   some of the  analyses
necessary  to  determine   why  uses   are  not
attained (For more information  on the TMDL
process, see chapter 7, this Handbook.) When
background levels of pollutants  are irreversible
and   criteria  cannot  be  met,  States should
evaluate other more appropriate  uses and revise
the water quality standards  appropriately.

   Determination of Attainable Uses

Consideration  of the  suitability  of the water
body to attain a use is an integral part of the
water quality standards  review and  revision
process.  The data  and iriformation  collected
from the water body survey provide a  firm basis
for  evaluating  whether  the  water  body   is
suitable for  the  particulair  use.   Suitability
depends   on  the  physical,  chemical,   and
biological  characteristics of the  water body,  its
geographic setting and scenic qualities, and the
socioeconomic  and cultural characteristics  of
the   surrounding  area.   Suitability  must   be
assessed through the  professional judgment  of
the  evaluators.   It  is their  task to  provide
sufficient  information   to  the  public and  the
State decision makers.

In some instances, physical factors may preclude
the   attainment   of  uses   regardless    of
improvements in the chemistry of the  receiving
water.   This is particularly  true  for fish and
wildlife protection uses where the  lack of a
proper substrate  may preclude certain  forms of
aquatic  life   from  using   the  stream   for
propagation,  or the lack of cover, depth, flow,
pools, riffles, or impacts from channelization,
dams, or diversions may preclude  particular
forms  of  aquatic  life  from   the   stream
altogether.     While   physical  factors   may
influence   a   State's   decision   regarding
designation  of uses  for a water  body. States
need  to give consideration to the incidental uses
that  may  be  made    of  the   water  body
notwithstanding  the  use  designation.    For
example, even though it may not make sense to
encourage   use  of a   stream   for  swimming
because  of the flow, depth, or velocity of the
water, the States and EPA  must recognize that
swimming and/or  wading may, in fact, occur.
To protect public health,  States  must set criteria
to reflect swimming if it appears  that primary
contact  recreation   will, in  fact, occur  in the
stream.

While   physical  factors  are  important   in
evaluating  whether a use is  attainable,  physical
limitations  of the  stream  may not be  an
overriding factor.   Common  sense and good
judgment play an  important  role  in  setting
appropriate  uses and criteria. In setting criteria
and uses, States  must assure the attainment  of
downstream  standards.   The downstream  uses
may  not be   affected   by the  same  physical
limitations as the upstream  uses.

If a change in the  designated  use is warranted
based on a use attainability  analysis, States may
modify the uses currently assigned.  In  doing so,
the State  should designate  uses that can  be
supported   given the  physical,  chemical,  or
biological limitations of the water body.  Or, a
State may designate uses on a seasonal  basis.
Seasonal use designations  may be appropriate
for streams  that lack adequate  water volume to
support  aquatic life year round, but can be used
for  fish spawning,  etc., during  higher  flow
periods.  In setting seasonal uses, care must be
taken not to allow the  creation of conditions
instream that  preclude uses in another season.
EPA encourages  the designation  of seasonal
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 Water Quality Standards Handbook - Second Edition
 uses   as   an   alternative   to   completely
 downgrading the use of a water body.

    Economic Impact Assessment

 The Water Quality Standards Regulation allows
 States  to establish uses that  are  inconsistent
 with the section  101(a)(2)  goals of the Act if
 the more stringent technology required to meet
 the goals will cause substantial and widespread
 economic and social impact. These are impacts
 resulting  specifically from imposition  of the
 pollution  controls and  reflect such factors as
 unemployment, plant closures, and changes in
 the governmental  fiscal  base.  The  analysis
 should address the incremental effects of water
 quality standards beyond technology-based  or
 other  State requirements.   If the requirements
 are not demonstrated to have an incremental,
 substantial,  and  widespread   impact  on  the
 affected  community, the   standard   must  be
 maintained or made compatible with the goals
 of the Act.

 6.1.6   Evaluation of Criteria

 Changes  in  use designations  also  must  be
 accompanied  by consideration  of the  need for
 a  change in criteria.  If a use is removed,  the
 criteria to protect  that  use  may be deleted  or
 revised to assure protection of the remaining
 uses. If a use is added, there must be adequate
 water   quality  criteria  to  protect  the  use.
 Regardless  of whether changes or modifications
 in uses are made, criteria protective of the  use
 must be adopted.   Certain criteria are deemed
 essential  for inclusion  in all State  standards,
 and criteria for section 307(a) toxic pollutants
 must  be  addressed   consistent   with  section
 303(c)(2)(B)  (see chapter 3, this  Handbook).
 All State  standards  should  contain the  "free
 froms" narrative statements  (see  section 3.5.2)
 in addition to numerical limits that can be used
 as a basis  for regulating discharges into surface
 waters. Also, water quality parameters  such as
 temperature,    dissolved   oxygen,   pH,  and
 bacteriological  requirements  are  basic to  all
 State standards.

 EPA's  laboratory-derived  criteria  may  not
 always accurately  reflect  the   bioavailability
 and/or  toxicity of  a  pollutant because  of the
 effect   of  local   physical   and  chemical
 characteristics   or varying sensitivities of  local
 aquatic   communities.      Similarly,  certain
 compounds may be more or less toxic in some
 waters  because of differences in temperature,
 hardness,  or other  conditions.    Setting  site-
 specific criteria is appropriate where:

 •  background  water quality parameters,  such
    as pH,  hardness, temperature,  color, appear
    to  differ significantly  from the laboratory
    water used  in developing the section  304(a)
    criteria; or

 •  the  types of local aquatic  organisms differ
    significantly from those actually tested  in
    developing  the section 304(a)  criteria.

 Developing site-specific criteria is a method  of
 taking  local conditions into  account so  that
 criteria are adequate  to protect the designated
 use without being more or less stringent  than
 needed.   A three-phase  testing  program  that
 includes water quality sampling and analysis, a
 biological  survey, and acute bioassays provides
 an approach for developing site-specific criteria.
 Much of the data and  information for the water
 quality sampling and analysis and  the biological
 survey can be obtained while conducting the
 assessment  of the  water  body.   Included  in
 section  3.10 of this Handbook  are scientifically
 acceptable  procedures for setting  site-specific
pollutant   concentrations   that   will protect
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                                   Chapter 6 - Procedures for Review and Revision of Water Quality Standard
designated uses. EPA believes that setting site-
specific criteria will occur on only a limited
number  of stream  segments  because  of the
resources  required  to conduct  the analyses and
the  basic  soundness   of the  section  304(a)
recommendations.

6.1.7  Draft   Water   Quality   Standards
       Submitted to EPA for Review

While not a regulatory requirement, prudence
dictates that draft  State water quality standards
be  submitted  to EPA for  review.   The  EPA
regional  office and  Headquarters  will conduct
concurrent reviews of draft standards and make
comments  on proposed revisions to assist the
State  hi   producing   standards   that   are
approvable  by the  Regional  Administrator.
Continuing cooperation  between the State and
EPA is essential  to timely  approval of  State
standards.

6.1.8  Public Hearing on Proposed Changes to
       Standards

Before  removing  or  modifying any use or
changing criteria, the Clean Water Act requires
the State  to hold  a public hearing.  More than
one hearing  may  be required  depending  on
State regulations.    It  may be appropriate to
have EPA review  the adequacy of justifications
including   the data  and  the  suitability  and
appropriateness  of the  analyses  and how the
analyses   were  applied  prior to  the  public
hearing.  In cases where the analyses are judged
to be inadequate,  EPA  will identify how the
analyses  could  be unproved and suggest the
additional types of evaluations or data needed.
By consulting with EPA frequently  throughout
the review process, States can be better assured
that  EPA will be able to expeditiously review
State submissions and make the determination
that  the standards meet the requirements  of the
Act.

The analyses and supporting  documentation
prepared  hi  conjunction   with  the  proposed
water quality standards revision should be made
available  to  the  interested  public prior to the
hearing.    Open  discussion  of the  scientific
evidence  and  analysis  supporting   proposed
revisions  in  the water  quality  standards  will
assist the State in making its decision.

6.1.9  State   Adopts   Revisions;   Submits
       Standards Package to EPA for Review

Within  30 days of their final  administrative
action,  States  submit to EPA  water  quality
standards revisions,  supporting  analyses,  and
State Attorney  General  certification that the
standards were  duly adopted  pursuant to  State
law. Final administrative action is meant  to be
the  last  action  a  State  must take  before its
revision  becomes  a rule under State law and it
can  officially transmit State-adopted   standards
to EPA for review. This last action might be a
signature, a review by a legislative committee or
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Water Quality Standards Handbook - Second Edition
State Board,  or a delay  mandated  by a State
administrative procedures  act.

In   reviewing  changes   in   uses   that   are
inconsistent with the section 101(a)(2) goals of
the  Act  or  changes  in criteria,  EPA  will
carefully consider the adequacy of the analyses
and  the  public  comments received  during the
hearing  process.   Standards  are to meet  the
goals of the Act unless the  State  can  clearly
demonstrate that the uses reflected in the goals
are unattainable.
       EPA Review and Approval
When States adopt new or revised water quality
standards,  the State is  required  under  CWA
Section 303(c) to submit such standards to EPA
for review and approval/disapproval.   Section
131.20(c)  of the  Water  Quality   Standards
Regulation  requires  the submittal  to EPA to
occur within 30 days of the final State  action.
Figure 6.2 outlines  EPA's review process. EPA
reviews and approves/disapproves  the standards
based on  whether  the standards   meet  the
requirements  of  the CWA and  the  Water
Quality  Standards  Regulation.     States  are
encouraged  to provide early drafts to the EPA
Regional Office so that  issues can be resolved
during  the  water  quality  standards   review
process, prior to  formal  State  proposal  or
adoption of revised or new standards.

When reviewing State water quality standards,
EPA  ensures  that the  standards  meet  the
minimum requirements   of the Act  and Water
Quality  Standards  Regulation.    Pursuant  to
section 510 of the  Act,  State  water  quality
standards may be  more stringent than  EPA's
minimum requirements.

The  general  elements   of an  EPA  review
include, but are not limited to, the following:

*  EPA   determines   whether   "fishable/
   swimmable"  designated  uses  have  been
   assigned  to  all  State  waters  or  a  use
   attainability analysis  (UAA) is available to
   support  the  designation   of  other  uses.
   Other uses may satisfy the  CWA section
   101(a)(2) goal if properly  supported  by a
   UAA.  EPA  reviews the  adequacy of the
   analyses.

•  EPA determines  whether the  State's water
   quality criteria are sufficient to protect  the
   designated uses by ensuring that all numeric
   criteria  are based on CWA Section 304(a)
   guidance,  304(a)  guidance   modified   to
   reflect  site-specific  conditions,  or other
   scientifically  defensible  methods.  EPA's
   decision  to accept criteria based on  site-
   specific calculations  or alternative scientific
   procedures  is based  on a determination  of
   the validity and adequacy of the supporting
   scientific  procedures  and assumptions  and
   not  on  whether  the  resulting  criterion is
   more  or  less  stringent  than  the  EPA
   guideline.

•  EPA ensures  that uses and/or  criteria  are
   consistent  throughout the water  body  and
   that  downstream standards  are protected.  A
   review   to  determine  compliance  with
   downstream  standards  is  most  likely  to
   involve  bodies  of water  on,  or crossing,
   interstate  and international  boundaries.

•  Where the analyses supporting any changes
   in the   standards  are  inadequate,   EPA
   identifies  how  the   analyses  need to  be
   improved   and  suggests   the  type   of
   information or analyses needed.

•  For  waters  where   uses  have  not been
   designated  in  support  of the  fishable/
   swimmable   goal  of  the   CWA,  EPA
   determines whether the alternative uses  are
   based on an acceptable UAA  and whether
   such  UAAs have been reviewed every 3
   years as required by 40 CFR 131.20(a).

•  EPA ensures  that  general   "free  from"
   narrative  criteria are included that  protect
   all waters at all flows from substances  that
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                                    Chapter 6 • Procedures for Review and Revision of Water Quality Standards
                         State Submits Draft
                         WQS to Region for
                          Informal Review
                        Region Reviews Draft
                               WQS
                    HQ Reviews Draft WQS
                         Comments Given to
                               State
                          State Adopts or
                           Revises WQS
             State Submits Revisions, Methods, Justifications
              and Attorney General Certification to Regional
                       Administrator for Review
                                or
                 X- (60 days)
                                                              or
            (90 days)
         Regional Administrator
            Approves WQS
Regional Administrator
  Disapproves WQS
                                                   (90 days)
                            Yes
          te
      Adopts
      Required
      Changes
                                           EPA Begins
                                           Promulgation
                              Concurrent HQ Review
Regional Administrator
Conditionally Approves
        WQS
 If Conditions Not Met
    by State, WQS
     Considered
     Disapproved
  Figure 6-2. Overview of EPA Water Quality Standards Review Process
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Water Quality Standards Handbook - Second Edition
    settle  to form objectionable  deposits; float
    as  debris,   scum,  oil,  or  other   matter;
    produce objectionable  color, odor, taste,  or
    turbidity;  are  acutely  toxic;  or  produce
    undesirable  or nuisance aquatic life.

*   EPA  determines  whether  the  State  has
    included  criteria for CWA  section  307(a)
    "priority" pollutants sufficient to satisfy the
    requirements of CWA section 303(c)(2)(B).

•   For toxic pollutants  where  EPA  has not
    issued  guidance or it is not known which
    toxicant  or toxicants  are  causing  the
    problem,   EPA   ensures   that   the  State
    standards include or reference a method  for
    implementing   the  narrative  toxics  "free
    from" criterion.

•   EPA ensures that the State's antidegradation
    policy  meets the  requirements   of section
    131.12 of  the  Water  Quality  Standards
    Regulation.

•   EPA reviews whether  the State has provided
    or referenced a procedure for implementing
    the antidegradation  policy.

*   Where  (optional)   general   policies  are
    included in the State water quality standards
    (e.g.,  mixing  zone  provisions,   variance
    policies, low-flow exemption  policies), EPA
    reviews whether the policies are consistent
    with the latest EPA guidance.

*   EPA reviews comments and  suggestions on
    previous State water  quality standards   to
    ensure that  any areas for  improvement   or
    conditions  attached  to previous approvals
    have been acted upon satisfactorily.

•   EPA  reviews  whether  the  policies  are
    consistent with the latest EPA guidance and
    regulatory  requirements.

•   EPA ensures that  the  State  has  met the
    minimum  requirements  for a  standards
    submission  as outlined  in section  131.6 of
    the Water Quality Standards Regulation.

•   EPA  reviews   whether   the  State  has
    complied with the procedural  requirements
    (e.g., public  participation)  for conducting
    water quality standards  reviews.

Since   1972,  EPA   review  and  approval/
disapproval includes  concurrent reviews by the
Regions and Headquarters.   However, because
the  EPA   regional   Administrator   has  the
responsibility for approving/disapproving water
quality   standards   and   because    of  the
decentralized  structure  of EPA,  the  regional
offices are  the primary point of contact with the
States.   The EPA  regional  offices,  not the
States, are responsible for providing  copies  of
State   water   quality   standards   to   EPA
Headquarters   for review  and  for  acting  as
liaison between  States and EPA Headquarters
on  most matters affecting  the water  quality
standards  program.  The basic internal  EPA
review  procedures   have been  described   in
various guidance documents  over  the years; the
most was a memorandum  dated December  17,
1984. This  memorandum  also made one minor
change  to  the  process.    It required   that
Headquarters  be  consulted   immediately  for
possible  advice  and   assistance  when  the
Regional Office learns that a State:

•   is proposing  to lower designated water uses
    below the section  101(a)(2) goals of the Act;

•   is not raising water uses to meet the section
    101(a)(2) goals of the Act; or

•   is considering  adopting  a water  quality
    criterion  less  stringent  than,   currently
    included in a State's  standard.

To  expedite Headquarters   review,  copies  of
State water  quality standards revisions (draft
and final)  must  be provided  to  the  Director,
Standards  and Applied Science Division, at the
time they  are  received  by  the Region.  The
Standards   and Applied   Science  Division  will
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                                   Chapter 6 - Procedures for Review and Revision of Water <2waficy Standards
involve other  EPA  offices  in  the review  as
appropriate,   and  provide   comments   and
suggestions,  if any,  to  regional  offices  for
consideration  in  State-EPA  negotiations  and
final standards decisions.  Their review will be
expeditiously  accomplished  so as  not to  slow
regional  approval/disapproval.     Neither  the
regional  nor Headquarters  review  need  be
limited only to revisions to existing standards  or
to new standards.

In general, three outcomes are possible:

•  EPA approval, in whole  or  in  part,  of the
   submitted  State water quality standards;

•  EPA disapproval, in whole or in part, of the
   submitted State water quality standards; and

•  EPA conditional  approval,  in whole  or in
   part, of the submitted  State  water quality
   standards.

Unconditional   approval   or disapproval   of
State-adopted  water quality standards within the
statutory time limits is the preferred approach.
Conditional approvals should be used only as a
limited exception  to this general  policy for
correcting minor deficiencies  in State  standards
and  only  if a State provides assurance that  it
will  submit corrections  on a specified, written
schedule.   Failure of a State to respond  in a
timely manner to  the  conditions expressed  in
the  letter  means   that  the   standards   are
disapproved  and  the  Region  must  promptly
request Headquarters to initiate a promulgation
action.  Where this occurs,, the  Region should
formally notify the State  in  writing that their
failure  to  meet  the  conditions   previously
specified  results  in the  standards  now being
disapproved  as  of the  original date  of  the
conditional approval  letter.

6.2.1  Policies  and  Procedures  Related  to
       Approvals

Authority to approve or disapprove  State water
quality   standards   is   delegated   by   the
Administrator  to each Regional Administrator.
The  Administrator  retains  the  authority  to
promulgate standards.  Revisions to State water
quality standards that meet the requirements of
the  Act  and  the  Water  Quality   Standards
Regulation  are approved  by  the  appropriate
EPA Regional  Administrator.    The Regional
Administrator  must, within 60 days, notify the
Governor  or  his  designee  by  letter   of the
approval and forward a copy of the letter to the
appropriate  State  agency.  The letter  should
contain any information that might be helpful in
understanding  the scope of the approval  action.
If particular events  (e.g., State implementation
decisions, pending Federal legislation pertaining
to water quality standards  requirements)  could
result in a failure of the approved standards to
continue to meet  the requirements of the Act,
these  events  should  be  identified  in  the
approval   letter.     Such  events  should be
identified for the record to guide future  review
and revision activities.

When only a portion of the revisions  submitted
meet the  requirements  of the  Act and the
Water  Quality   Standards   Regulation,   the
Regional  Administrator may approve only that
portion.  If only a partial approval is made, the
Region  must,  hi  notifying the  State,  be  as
specific  as  possible  in   identifying  what is
disapproved    and   why.      The   Regional
Administrator  must  also clearly  indicate  what
action  the State  could   take  to  make  the
disapproved item acceptable.

6.2.2  Policies  and  Procedures  Related  to
       Disapprovals

If the Regional Administrator  determines that
the revisions submitted are not consistent with
or do not meet the requirements  of the  Act or
the Water Quality  Standards   Regulation,  the
Regional  Administrator must disapprove  such
standards   within  90 days.  Such  disapproval
must be via written notification  to the Governor
of the State  or his designee.   The letter  must
state  why the revisions are not consistent with
the  Act  or  the  Water  Quality   Standards
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Water Quality Standards Handbook - Second Edition
Regulation and specify the revisions that  must
be adopted to  obtain full approval.  The letter
must   also   notify  the  Governor  that   the
Administrator   will   initiate   promulgation
proceedings  if the  State  fails to  adopt   and
submit the necessary revisions within 90 days
after notification.

A State   water quality standard  remains  in
effect, even though disapproved  by EPA,  until
the State  revises it or EPA promulgates a rule
that   supersedes   the   State  water   quality
standard.     This   is  because  water  quality
standards  are State laws, not Federal laws, and
once  the  law  is  amended by the  State, the
previously   adopted   and   EPA-approved
standards  no longer legally exist.
6,23  Policies  and  Procedures  Related
       Conditional Approvals
                                           to
Conditional  approvals  are  EPA  approvals
contingent  on the  performance  of  specified
actions  on the part  of a State in  a timely
manner.    There   is  an  implicit  or explicit
statement  in the letter to the State  that failure
to satisfy the identified  conditions  will nullify
the conditional  approval and lead  to Federal
promulgation action. Problems have arisen with
inconsistent use of conditional approvals among
the regions and with foUowup actions to ensure
that a State is responding to the conditions  in a
timely  manner.
Because  promulgation of Federal  standards  is
inherently   a  lengthy  process,  the  use  of
conditional  approvals evolved over the years as
another   mechanism   to   maintain   the
State-Federal    relationship   in   establishing
standards.   When  used  properly, conditional
approvals can result in standards that  fully meet
the requirements   of the Act  without undue
Federal  intervention  and  promote  smooth
operation of the national  program.

If used improperly,  conditional approvals can be
an unacceptable delaying tactic to establishing
standards and can be construed as EPA failing
to properly  exercise its  duty  to  review  and
either  approve  or disapprove  and   promptly
initiate  promulgation action after  the allotted
90-day period for State action.  This improper
use of conditional  approvals must be  avoided.

It is  incumbent on  a   Region  that uses  a
conditional  approval to ensure that State action
is timely.   When  a State  fails  to  meet  the
agreed-upon  schedule,  EPA   should initiate
promulgation  action. Conditional approvals are
to be used  only to correct minor deficiencies
and  should  be the  exception, not  the  rule,
governing regional responses to State standards.
Note that requests for clarification  or additional
information  are not approval  actions  of any
type.

This policy is modeled  after  that applied to
EPA  approval of State  implementation  plans
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                                   Chapter 6 - Procedures for Review and Revision of Water Quality Standards
(SIPs) in the air program. (See 44 F.R. 38583,
July 2, 1979.  See also Mississippi Commission
on Natural Resources v. Costle, 625 F. 2d 1269
(5th Cir.) 1980.)

   Necessary   Elements    of  Conditional
   Approvals

First, conditional approvals are appropriate only
for "minor deficiencies." Blatant disregard of
Federal statutory or regulatory requirements or
changes that will affect major permit  issuance
or reissuance  are not  minor  deficiencies.  In
addition, the State's standards submission  as a
whole must be  in substantial  compliance with
FJPA's regulation.   Major deficiencies  must be
disapproved    to    allow   prompt    Federal
promulgation  action.

Second, the State must commit, in writing, to a
mutually  satisfactory,  negotiated  schedule to
correct the identified regulatory deficiencies in
as short  a time period  as possible.  The time
allowed should  bear a reasonable  relationship
to   the   required    action.     However,  in
consideration  of the first element above,  it is
expected  that the time period for compliance
will be limited to a few months.  It is definitely
not  expected  that  a  year or  more  will be
required.  If that is the cases, disapproval  would
be   more    appropriate.      Headquarters
concurrence  in the schedule  is required  if it
extends for more than  3 months.
       EPA Promulgation
As a matter  of policy, EPA prefers that States
adopt their  own standards.   However, under
section  303(c)(4)  of  the  Act,  FJPA   may
promulgate Federal standards:

•   if a revised or new  water quality  standard
    submitted by a State is determined by the
    Administrator  not to be; consistent  with the
    requirements  of the  Clean Water  Act, or
•  in  any  case   where  the   Administrator
   determines that a new or revised standard  is
   necessary to meet  the  requirements  of the
   Act.

Under the latter provision of the statute,  FJPA
would be able to promulgate  standards  for a
State,  or  States,   that  failed  to  conduct  a
triennial   review and  submit  new  or  revised
standards  to FJ?A for review  so long as the
Administrator determined  new standards  were
necessary.   Where one of these conditions  is
met,  the  Administrator  has  the authority  to
publish proposed  revisions  to  the  State(s)
standards  in the Federal Register. Generally, a
public hearing  will be held  on  the proposed
standards.  Final  standards  are  promulgated
after   giving  due  consideration   to   written
comments received and statements made at any
public hearings  on the proposed  revisions.

Although    only   the   Administrator   may
promulgate State standards, the Regional Office
has a major  role  in the promulgation  process.
The Regional   Office provides  the necessary
background  information  and   conducts  the
public hearings. The Regional Office prepares
drafts of the rationale  supporting EPA's action
included in the proposed and final rulemakings.
The rationale  should clearly state  the reason  for
the disapproval  of the State standard.

If conditions  warrant (e.g., a State remedies the
deficiencies in its  water quality standards  prior
to  promulgation),  the   Administrator  may
terminate   the rulemaking  proceeding  at any
time.  However, if a proposed  rulemaking has
been  published  hi the  Federal Register, then the
Regional  Administrator must  not approve the
State's changes  without obtaining concurrence
from Headquarters.

Whenever   promulgation   proceedings   are
terminated,   a  notice  of  withdrawal  of the
proposed  rulemaking  will be published in the
Federal Register.   The Regional  Offices are
responsible   for  initiating  such  action  and
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Water Quality Standards Handbook - Second Edition
furnishing a rationale for use in preparing  the
notice for the Administrator's signature.

An   EPA-proinulgated    standard   will  be
withdrawn when revisions to State water quality
standards are made that meet the requirements
of the Act.  In such a situation, the Regional
Office should initiate the withdrawal action by
notifying the Standards  and Applied Science
Division  (WH-585)  that  it  is  requesting  the
withdrawal,  specifying  the   rationale  for  the
withdrawal,   and    obtaining   Headquarters
concurrence  on the acceptability of the State's
water  quality   standards.    EPA's  action  to
withdraw  a federally promulgated  standard
requires  both a proposed and final rulemaking
if the State-adopted  standards are less stringent
than federally promulgated standards but, in the
Agency's judgment, fully meet the requirements
of the Act. EPA will withdraw the Federal rule
without a notice and comment rulemaking  when
the State standards are no  less stringent than
the Federal rule (i.e.,standards  that provide, at
least,  equivalent  environmental  and  human
health protection).

Withdrawal of a Federal promulgation is based
on  a determination  that  State-adopted  water
quality standards meet the requirements  of the
Clean   Water  Act.    Such   State-adopted
standards may be the same  as,  more stringent
than, or less stringent than the  Federal  rule.
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                                 Chapter 7 - The Water Quality-Based Approach to Pollution Control
                               CHAPTER 7

                     THE WATER QUALITY-BASED
                             APPROACH TO
                         POLLUTION CONTROL
                             Table of Contents


7.1 Determine Protection Level	7-2

7.2 Conduct Water Quality Assessment	7-3

    7.2.1    Monitor Water Quality  	7-3

    7.2.2    Identify Impaired (Water Quality-Limited) Waters	7-3

7.3 Establish Priorities	7-5

7.4 Evaluate Water Quality Standards for Targeted Waters	7-6

7.5 Define and Allocate Control Responsibilities	 7-7

7.6 Establish Source Controls	7-8

    7.6.1    Point Source Control - the NPDES Process	7-9

    7.6.2    Nonpoint Source Controls	7-10

    7.6.3    CWA Section 401 Certification	7-10

7.7 Monitor and Enforce Compliance	7-12

7.8 Measure Progress .	7-13

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                                         Chapter 7 - The Water Quality-Based Approach to Pollution Control
                                        CHAPTER 7
                     THE WATER QUAOTY-BASED APPROACH
                              TO POLLUTION CONTROL
This chapter briefly describes the overall water
quality-based  approach and its relationship  to
the water quality standards program. The water
quality-based  approach emphasizes  the  overall
quality  of  water   within  a  water  body and
provides  a  mechanism   through   which  the
amount of pollution  entering  a water body is
controlled based on the intrinsic conditions  of
that body of water and  the standards  set  to
protect  it.

As shown in Figure 7.1, the water quality-based
approach  contains  eight  stages.  These stages
each  represent  a major  Clean  Water  Act
program with specific regulatory requirements
and guidance. The presentations  in this chapter
summarize how the different programs  fit into
the overall  water  quality  control scheme and
are not intended as implementation  guidance.
Implementation  of these  programs should be
consistent   with  the   specific  programmatic
regulations  and guidance  documents  provided
by  the  appropriate  program  office,  many  of
which are cited  herein.

The first stage, "Determining Protection  Level,"
involves State development  of water  quality
standards, the subject of the preceding chapters
of this Handbook.

In the second stage, "Monitoring and Assessing
Water Quality," States  identify impaired waters,
determine if water quality standards  are being
met, and detect pollution  trends.  Sections  of
the Clean Water Act  require  States  to compile
data, assess, and report on the status of their
water bodies.   States  generally use  existing
information   and  new  data  collected  from
ongoing  monitoring programs to assess their
waters.  This stage is discussed in section 7.2.
of this Handbook.
In  the third stage,  "Establishing  Priorities,"
States  rank water  bodies  according  to  the
severity of the pollution, the uses to be made of
the   waters,   and   other    social-economic
considerations,   and  determine  how best  to
utilize available  resources to solve  problems.
Section 7.3 of  this  Handbook  discusses  the
ranking and targeting of water bodies.

In  the fourth  stage,  "Evaluating   WQS  for
Targeted  Waters," the  appropriateness  of the
water  quality standards for specific  waters is
evaluated.   States may  revise or reaffirm their
water quality standards.  A State may choose,
for example, to develop site-specific  criteria for
a particular  stream because a particular  species
needs to be protected.  This  stage is discussed
in section 7.4 of this Handbook.

In  the  fifth stage  "Defining and  Allocating
Control Responsibilities,"  the level  of  control
needed  to  meet  water  quality  standards  is
established,   and  control  responsibilities   are
defined and allocated.  States  use mathematical
models  and/or   monitoring to determine total
maximum  daily  loads  (TMDLs)  for water
bodies;   the  TMDLs   include  waste load
allocations  (WLAs)  for point  sources, load
allocations (LAs)  for nonpoint  sources, and  a
margin of safety.  The TMDL is the amount of
a pollutant that may be  discharged into a water
body and  still maintain  water quality  standards.
Pollutant  loadings above this amount generally
will result in waters  exceeding the   standards.
Allocations  for  pollution limits for point and
nonpoint  sources are calculated to ensure that
water  quality  standards   are  not   exceeded.
Section 7.5  discusses  the TMDL process  in
greater detail.
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Water Quality Standards Handbook - Second Edition
                                  Determine Protection Level
                                  Review/Revise State WQS
                       8
                Measure Progress
              Modify TMDL if needed
         Monitor and Enforce
             Compliance
            Self-Monitoring
          Agency Monitoring
             Enforcement
         Conduct WQ Assessment
          (a) Monitor Water Quality
          (b) Identify Impaired Waters
                                                                        \
                 Establish Priorities
               Rank/ Target Waterbodies
                      I
         Establish Source Controls
            Pofnt Source Permits
              NFS Programs
             §401 Certification
               Evaluate WQS for
               Targeted Waters
             Reaffirm / Revise WQS
                           Define and Allocate Control Responsibilities
                                       TMDL/WLA/LA
    Figure 7-1. Water Quality-Based Approach to Pollution Control
In the sixth stage, "Establishing Source Control,"
States   and  EPA  implement   point  source
controls  through  NPDES permits,  State  and
local governments implement nonpoint  source
management programs through State laws and
local ordinances, and  States assure attainment
of water quality standards  through  the  CWA
section  401  certification  process.    Control
actions  are  discussed in Section 7.6.

In the seventh stage, "Monitoring and Enforcing
Compliance," States  (or EPA)  evaluate  self-
monitoring  data reported by dischargers to see
that the conditions of the NPDES permit are
being   met  and  take  actions   against   any
violators.     Dischargers  are  monitored  to
determine   whether  or  not they  meet permit
conditions  and  to ensure that expected  water
quality  improvements   are  achieved.    State
nonpoint  source  programs  are  monitored and
enforced  under  State  law and  to  the extent
provided by State law.

In the  final  stage,  "Measuring  Progress," the
States (and EPA) assess the effectiveness  of the
controls  and  determine  whether water quality
standards have  been  attained,  water quality
standards need to be revised, or more stringent
controls  should be applied.
         Determine Protection Level
The water quality-based approach  to pollution
control   begins  with  the   identification   of
problem  water bodies.   State  water  quality
standards  form the  basis  and  "yardstick" by
which States can assess the water body status
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                                         Chapter 7 - The Water Quality-Based Approach to Foffulion Control
 and implement needed pollution  controls.   A
 water quality standard defines the water quality
 goals of a water  body, or portion  thereof, by
 designating the use or uses to be  made  of the
 water, by  setting  criteria  necessary  to protect
 the  uses,  and  by preventing degradation  of
 water   quality   through   antidegradation
 provisions. States adopt water quality standards
 to protect public health or welfare, enhance the
 quality of water, and serve the purposes  of the
 Clean Water Act.  "Serve the purposes  of the
 Act" (as defined in sections  101(a), 101(a)(2),
 and 303(d) of the Act) means that water quality
 standards  should  (1)  include provisions for
 restoring  and  maintaining  chemical, physical,
 and biological  integrity  of  State  waters; (2)
 provide,  wherever attainable, water quality for
 the protection and propagation of fish, shellfish,
 and wildlife, and recreation in and on the water
 ("fishable/swimmable"); and (3)  consider the
 use  and value  of State waters for public water
 supplies,  propagation  of fish  and wildlife,
 recreation,  agricultural and industrial purposes,
 and navigation.  The preceding chapters of this
 Handbook   provide  EPA's guidance  on the
 water quality standards program.
          Conduct Water Quality Assessment
Once  State  water  quality   standards   have
determined  the appropriate  levels of protection
to be  afforded  to State  water bodies, States
conduct  water quality monitoring and identify
those waters that are "waterquality limited,"or
not meeting  the standards.

7.2.1    Monitor Water Quality

Monitoring  is an important element throughout
the  water   quality-based   decision   making
process.  In this step, monitoring provides  data
for identifying impaired  waters.   The Clean
Water  Act specifies that  States and  Interstate
Agencies, in cooperation  with EPA,  establish
water quality monitoring  systems necessary  to
review and revise water quality  standards, assess
designated  use attainment,  calculate  TMDLs,
 assess compliance  with permits, and  report on
 conditions and trends in ambient waters.  EPA
 issued   guidance  in  1985  for  State  Water
 Monitoring and Waste load Allocation (USEPA,
 1985d).  Guidance for preparing CWA section
 305(b) reports is contained in the Guidelines for
 the Preparation of the 1994 State Water Quality
 Assessments  (305 (b) Reports) (USEPA,  1993a).
 Both of these  documents discuss monitoring as
 an  information  collection   tool   for  many
 program needs.  The Intergovernmental  Task
 Force on Monitoring  Water  Quality report
 (ITFM,  1992) proposes  actions  to  improve
 ambient  water quality monitoring in the United
 States to  allow  better  management  of water
 resources.

 Sections 208(b)(2)(F)  through (K) of the CWA
 require  the development of a State  process to
 identify, if appropriate, agricultural, silvicultural,
 and other  nonpoint  sources of pollution.  NPS
 monitoring concerns  are discussed  in several
 NPS guidance documents along with methods to
 monitor    and   evaluate   nonpoint   sources
 (Watershed   Monitoring   and   Reporting
 Requirements   for   Section   319   National
 Monitoring Program Projects (USEPA,  199 Ig)
 and Guidance  Specifying Management Measures
for Sources of Nonpoint  Pollution in Coastal
 Waters (USEPA, 1993b).

 7.2.2     Identify Impaired (Water Quality-
          Limited) Waters

 EPA's   Water   Quality   Planning   and
 Management  Regulation  (40 CFR  Part  130)
 establishes  the process  for identifying  water
 quality-limited   water   still   requiring   total
 maximum  daily  loads   (TMDLs).    Waters
 require TMDLs when certain pollution control
 requirements  (see Exhibit 7.1) are not stringent
 enough to  maintain water quality standards for
 such waters.

 The  most  widely  applied  water   pollution
 controls  are   the  technology-based   effluent
 limitations  required by sections 301 (b) and 306
 of the Clean Water Act. In some cases, a State
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Water Quality Standards Handbook - Second Edition
  (b)(l) Each State shall identify those water
  segments still requiring WLAs/LAs and TMDLs
  within its boundaries for which:

       (i) Technology-based effluent limitations
       required by sections 301(b), 306,307, or
       other section of the Act;

       (ii) More stringent effluent limitations
       (including prohibitions) required by either
       State or local authority preserved by section
       510 of the Act, of Federal authority («,#.,
       law, regulation, or treaty); and

       (Hi) Other pollution control requirements
       (e.g., best management practices) required by
       local, State, or Federal authority

  are not stringent enough to implement any water
  quality standard applicable to such waters.
Exhibit 7-1. Identifying Waters Still Requiring
             TMDLs: 40 CFR 130.7(b)
or  local  authority  may establish  enforceable
requirements beyond technology-based controls.
Examples  of such requirements  may be those
that (1) provide more stringent NPDES permit
limitations to protect a valuable water resource,
or (2) provide for the management  of certain
types of nonpoint source pollution.

Identification of  good quality waters that  are
threatened   is  an  important   part  of  this
approach.  Adequate control of new discharges
from either point  or nonpoint sources should be
a  high  priority  for  States  to  maintain   the
existing  use or uses of these water bodies. In
the  identification  of threatened  waters, it is
important  that the 303(d)  process consider all
parts  of the  State  water  quality standards
program    to    ensure   that   a  State's
antidegradation  policy and narrative provisions,
as  well  as  parameter-specific   criteria,   are
maintained.
Section 303(d) requires States  to identify those
water  quality-limited  waters needing TMDLs.
States  must regularly update their lists of waters
as assessments are made  and report these  lists
to EPA  once every 2 years.  In their biennial
submission,  States  should  identify  the water
quality-limited  waters  targeted   for  TMDL
development  in  the  next  2  years, and   the
pollutants  or stressors  for  which the  water is
water  quality-limited.

Each  State  may have different  methods  for
identifying  and compiling information  on  the
status  of its water  bodies,  depending on its
specific  programmatic  or cross-programmatic
needs    and   organizational   arrangements.
Typically,   States   utilize   both   existing
information   and  new  data  collected  from
ongoing  monitoring programs to assess whether
water  quality standards are  being  met, and to
detect  trends.

States  assess  their   waters  for a  variety of
purposes, including targeting cleanup  activities,
assessing  the  extent  of   contamination   at
potential Superfund sites, and meeting federally
mandated  reporting  requirements.    While  the
identification of water  quality-limited  waters
may appear  to be a major task for the States,  a
significant  amount  of this  work  has  already
begun  or has been  completed  under sections
305(b), 304(1), 314(a), and 319(a) of the Clean
Water  Act  as amended in 1987.

Section  305(b)  requires  States  to  prepare  a
water  quality  inventory  every   2  years  to
document the status of water bodies  that have
been  assessed.   Under  section  304(1), States
identified all surface  waters adversely affected
by  toxic   (65   classes   of   compounds),
conventional  (such as BOD,  total  suspended
solids, fecal coliform, and oil and  grease), and
nonconventional   (such as ammonia, chlorine,
and iron)  pollutants   from  both  point  and
nonpoint sources.  Under section 314(a), States
identify publicly owned lakes for which uses  are
known to be impaired by point and nonpoint
sources,  and report  those  identified  in their
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                                         Chapter 7 -The Water Quality-Based Approach to Pollution Control
305(b)  reports.   Section  319  of the  CWA
requires   each  State  to  develop   an  NFS
assessment report. Guidance on the submission
and approval process for Section 319 reports is
contained   hi  Nonpoint  Source  Guidance
(USEPA, 1987c).

Lists  prepared  to  satisfy nsquirements  under
section 305(b), 304(1), 314(a) and 319 should be
very useful in preparing  303 (d) lists. Appendix
B   of   Guidance  for   Water  Quality-based
Decisions: The TMDL Process (USEPA, 199 Ic)
provides a summary  of these  supporting CWA
programs.
          Establish Priorities
Once waters needing  additional controls  have
been  identified,  a State prioritizes  its list of
waters using established ranking processes that
should  consider  all  water pollution  control
activities within the State.  Priority ranking has
traditionally been a process defined by the State
and  may vary in  complexity  and design.  A
priority  ranking   should  enable the  State  to
make efficient use of its available resources and
meet  the objectives of the Clean Water Act.

The  Clean  Water Act states  that  the priority
ranking for such waters must take into account
the severity of the pollution and the uses to be
made  of  such   waters.    Several  documents
(USEPA, 1987e, 1988c,d, 1989d, 1990c, 1993c)
are  available from EPA  to  assist  States  in
priority setting.

According  to EPA's State Clean Water  Strategy
document:   "Where all water quality problems
cannot be addressed immediately, EPA and the
States will, using multi-year  approaches,   set
priorities and direct efforts and resources  to
maximize  environmental  benefits  by dealing
with  the most  serious  water quality problems
and the most valuable  and  threatened  resources
first."
Targeting  high-priority  waters  for  TMDL
development  should reflect an evaluation  of the
relative  value and benefit of water  bodies
within the State and take into consideration the
following:

•    risk to  human health, aquatic  life,  and
     wildlife;

•    degree of public interest and support;

•    recreational,   economic,   and   aesthetic
     importance of a particular water body;

•    vulnerability  or fragility  of a  particular
     water body as an aquatic  habitat;

•    immediate  programmatic   needs  such as
     waste load  allocations  needed for permits
     that are coming up for revisions or for new
     or   expanding   discharges,    or   load
     allocations  for needed  BMPs;

•    waters and pollution  problems  identified
     during the  development   of  the section
     304(1) "longlist";

•    court  orders  and  decisions  relating  to
     water quality; and

•    national  policies  and  priorities  such as
     those    identified   in   EPA's   Annual
     Operating Guidance.

States  are required  to submit their  priority
rankings to EPA for review.  EPA expects all
waters  needing  TMDLs to be ranked,  with
"high" priority waters — targeted  for initiation
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 Water Quality Standards Handbook - Second Edition
 of TMDL development within 2 years following
 the listing process — identified.  (See USEPA
 (1991c)  for further  details on submission  of
 priorities to EPA.)

 To effectively develop and implement TMDLs
 for all waters identified, States  should establish
 multi-year   schedules   that   take    into
 consideration   the   immediate   TMDL
 development for targeted  water bodies and the
 long-range  planning  for  addressing  all water
 quality-limited waters still requiring TMDLs.

 While the CWA  section  319 NFS assessment
 report identifies  the overall dimensions  of the
 State's NFS water quality problems and States
 are to develop  statewide  program  approaches
 for specific  categories of pollution to address
 NTS  problems,  States  are also encouraged  to
 target subsets of waters for concerted  action on
 a  watershed-by-watershed   basis.   EPA  has
 issued guidance   on NFS targeting  (USEPA,
 1987e).
          Evaluate  Water Quality  Standards
          for Targeted Waters
At this point in the water quality management
process, States have identified  and  targeted
priority water quality-limited water bodies.  It is
often   appropriate,   to   re-evaluate   the
appropriateness of the water quality  standards
for  the  targeted   waters  for several reasons
including, but  not limited to, the following.

First, many States have not conducted  in-depth
analyses of appropriate uses and criteria for all
water  bodies  but  have  designated  general
fishable/swimmable   use   classifications   and
statewide  criteria  on  a  "best  professional
judgment"  basis to many waters.  In addition,
many  States make general assumptions  about
the antidegradation  status  of State waters  (e.g.,
all  waters  not  specifically  assigned  to  an
antidegradation  category will be considered tier
2  or high-quality  waters).  It is possible  that
these  generally  applied  standards,  although
meeting  the  minimum  requirements  of the
CWA   and   WQS   regulation,   may   be
inappropriate  (either over- or under-protective)
for a specific water body that has not had an in-
depth standards  analysis.  For example,  if a
water body was classified as a coldwater fishery
based solely on its proximity to other coldwater
fisheries, a water  body-specific  analysis  may
show that  only  a  warmwater  fishery use  is
existing or attainable.  If the listing of the water
body was based on exceedences of criteria  that
are more stringent for coldwater fish  (such as
ammonia or  dissolved oxygen),  changing the
designated  use  through  a  use  attainability
analysis  and applying appropriate  criteria  may
allow standards to be met without further water
quality controls.

Second,  even if an in-depth analysis has been
done in the past, changes  in the uses of the
water body  since that time  may have made
different   standards   more  appropriate   or
generated  an  additional  "existing use" which
must be  protected.  For example,  a water body
designated for fish, aquatic  life, and recreation
in the past may now be used  as a public water
supply, without that use and protective  criteria
ever  being formally adopted  in the  standards.
Another   example   might  be   a  designated
warmwater  fishery that, due to  the removal of
a thermal discharge,  now supports a coldwater
fishery as the existing use.

Third, monitoring  data  used to  identify  the
water body as impaired  may be historical,  and
subsequent  water quality improvements  have
allowed  standards  to be met.  And fourth,  site-
specific criteria may be appropriate because of
specific  local  environmental conditions.   For
example, the species capable of living at the site
are more or less sensitive than  those included
in the national criteria  data  set, or  physical
and/or chemical characteristics of the site alter
the biological availability  and/or  toxicity of the
chemical.
7-6
                                      (9/15/93)

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                                         Chapter 7 - The Water Quality-Based Approach to Pollution Control
          Define   and
          Responsibilities
Allocate   Control
For  a  water  quality-limited  water  that  still
requires a TMDL, a State must establish a TMDL
that quantifies pollutant sources, and a margin of
safety,  and  allocates allowable  loads  to the
contributing point and nonpoint source discharges
so that the water quality standards are attained.
The   development   of   TMDLs   should  be
accomplished by setting priorities, considering the
geographic  area  impacted  by   the  pollution
problem,  and in  some cases  where  there are
uncertainties from lack of adequate data,  using a
phased approach to establishing control measures
based on the TMDL.

Many  water  pollution concerns  are areawide
phenomena  caused   by   multiple dischargers,
multiple pollutants (with potential synergistic and
additive   effects),    or   nonpoint  sources.
Atmospheric  deposition   and  ground   water
discharge may also result  in significant pollutant
loadings  to  surface waters.  As a result,  EPA
recommends that States  develop TMDLs  on  a
watershed basis  to  efficiently  and  effectively
manage the quality of surface waters.

The  TMDL process  is a rational  method for
weighing  the  competing pollution concerns and
developing  an  integrated pollution  reduction
strategy  for point and nonpoint  sources.  The
TMDL process  allows States  to take a  holistic
view of  their water quality problems from the
perspective  of instream  conditions.   Although
States  may  define a water body to correspond
with their current programs,  it is expected that
States  will  consider  the  extent  of  pollution
problems  and  sources  when   defining  the
geographic  area  for  developing TMDLs.   In
general, the geographical approach for  TMDL
development  supports  sound   environmental
management and efficient use of limited water
quality  program  resources.   In  cases  where
TMDLs are  developed on watershed levels, States
should consider organizing permitting  cycles so
that all permits in a given watershed expire at the
same time.

Mathematical  modeling is a valuable tool for
assessment  of  all  types  of  water  pollution
problems.   Dissolved oxygen  depletion  and
nutrient enrichment from point  sources  are the
traditional modeling problems of the past.  They
continue to  be problems and are joined by such
new challenges as nonpoint source loadings, urban
stormwater  runoff,   toxics,    and  pollutants
involving sediment and bioaccumulative pathways.
These new pollutants and pathways require the
use of new models.

All models  are simplifications  of reality  that
express our  scientific  understanding   of the
important  processes.    Where  we  don't  fully
understand the processes), or cannot collect the
data that would be required to set parameters in a
model  that  would simulate the process(es), we
make simplifying  assumptions.    All  of  these
   (8/15/94)
                                                             7-7

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 Water Quality Standards Handbook - Sefcond Edition
 simplifications increase  the  uncertainty of our
 ability to predict responses  of already highly-
 variable systems. While the  use of conservative
 assumptions   does  reduce   the  possibility  of
 underestimating  pollutants   effects   on  the
 waterbody, the use of conservative assumptions
 does not reduce the uncertainty.  Calibration of a
 model to given waterbody does more to reduce
 uncertainty surrounding the system's response to
 reduced pollutant loadings.   Sensitivity  analyses
 can further this process.

 For TMDLs  involving  both  traditional and
 nontraditional problems, the margins of safety can
 be increased and additional monitoring required to
 verify attainment of water quality standards, and
 provide data needed to recalculate the TMDL if
 necessary (the phased approach).

 EPA regulations provide that load allocations for
 nonpoint sources and natural background "are best
 estimates  of  the loading which may range from
 reasonably accurate estimates to gross allotments
 ..." (40 CFR 130.2(g)). A phased approach to
 developing TMDLs  may be appropriate  where
 nonpoint sources are involved and where estimates
 are based on limited information.  Under the
 phased  approach,  TMDL includes  monitoring
 requirements  and a  schedule for  reassessing
 TMDL allocations to ensure attainment of water
 quality standards.  Uncertainties that cannot be
 quantified may also  exist for certain pollutants
 discharged primarily by point sources.  In such
 situations a large margin of safety and follow-up
 monitoring are appropriate.

 By  pursuing  the  phased   approach   where
 applicable,  a  State  can  move   forward  to
 implement water quality-based control measures
 and adopt an explicit schedule for implementation
 and assessment. States  can  also use the phased
 approach to address a greater number of water
 bodies including threatened waters or watersheds
 that would otherwise not be managed.  Specific
 requirements  relating to  the phased approach are
 discussed  in  Guidance for Water Quality-based
Decisions: The TMDL Process (USEPA 1991c).
          Establish Source Controls
 Once a TMDL has been established for a water
 body (or watershed) and the appropriate source
 loads  developed,   implementation  of   control
 actions should  proceed.   The State or  EPA is
 responsible  for implementation,  the  first step
 being  to update the water quality management
 plan.  Next, point and nonpoint source  controls
 should  be  implemented  to  meet  waste  load
 allocations  and load allocations, respectively.
 Various  pollution   allocation   schemes  (i.e.,
 determination of allowable loading from different
 pollution sources in the same water body) can be
 employed by States to optimize alternative point
 and nonpoint source management strategies.

 The NPDES permitting  process is used  to limit
 effluent  from  point  sources.    Section  7.6.1
 provides a  more  complete description  of  the
 NPDES process and how it fits  into  the water
 quality-based   approach   to   permitting.
 Construction decisions regarding publicly owned
 treatment  works (POTWs),  including advanced
 treatment  facilities, must also be based  on  the
 more  stringent  of technology-based  or  water
 quality-based limitations. These decisions should
 be coordinated  so  that the facility plan for  the
 discharge is consistent with the limitations in the
 permit.

 In the case  of nonpoint  sources, both State and
 local laws may authorize the implementation of
 nonpoint source controls such as the installation of
 best management  practices  (BMPs)  or  other
 management measures.  CWA  section 319 and
 Coastal Zone Act Reauthorization Amendments of
 1990  (CZARA)  section  6217 State management
programs  may  also be  utilized  to  implement
nonpoint source control measures and practices to
ensure improved water quality. Many BMPs may
be implemented through section  319  programs
even where State  regulatory programs  do  not
exist.  In such cases, a State needs to  document
the coordination that may be necessary  among
State and local agencies, landowners, operators,
and   managers   and   then   evaluate   BMP
   7-8
                                                                                 (8/15/94)

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                                         Chapter 7 -The Water Quality-Based Approach to Pollution Control
implementation,   maintenance,   and   overall
effectiveness to ensure that load allocations  are
achieved.  Section 7.6.2 discusses some of  the
programs  associated  with  implementation   of
nonpoint source control measures.

States  may  also  grant,  condition,  or  deny
"certification"  for  a  federally  permitted   or
licensed activity that may result in a discharge to
the waters of the United States, if it is the State
where  the discharge  will originate.   The State
decision  is based  on a State's determination of
whether  the proposed activity  will comply with
the requirements of certain sections of the Clean
Water  Act,  including  water  quality  standards
under  section  303.    Section  7.6.3    of  this
Handbook contains further discussion  of section
401 certification.

7.6.1     Point Source Control - the NPDES
          Process

Both technology-based and water  quality-based
controls  are  implemented through the National
Pollutant Discharge Elimination System (NPDES)
permitting process.   Permit  limits  based  on
TMDLs are called water quality-based  limits.

Waste  load  allocations establish  the level  of
effluent quality necessary to protect water quality
in the receiving water and to ensure attainment of
water quality standards.  Once allowable loadings
have been developed  through WLAs for specific
pollution  sources,  limits are  incorporated  into
NPDES permits.  It is important to ensure that the
WLA  accounts for the fact that effluent quality
is often highly variable.  The  WLA and permit
limit should be calculated to prevent water quality
standards impairment at all times. The reader is
referred  to the Technical Support Document for
Water  Quality-based Toxics Control  (USEPA,
199 la)  for additional  information on deriving
permit limits.

As a result of the 1987 Amendments to the Act,
Individual  Control  Strategies   (ICSs)   were
established under section 304(1)(1) for  certain
point  source   discharges  of  priority   toxic
pollutants. ICSs consist of NPDES permit limits
and  schedules  for achieving such  limits, along
7with  documentation  showing  that  the control
measures selected are appropriate and adequate
(e.g., fact sheets including information on  how
water quality-based limits were developed,  such
as total  maximum daily  loads and waste  load
allocations).  Point sources with approved ICSs
are to be in compliance with those ICSs as  soon
as possible or in no case later than 3 years from
the establishment of the ICS (typically by 1992 or
1993).

When establishing WLAs for point sources in a
watershed, the TMDL record should show that, in
the case  of any credit for future nonpoint source
reductions (1) there is reasonable assurance that
nonpoint source controls will be implemented and
maintained, or (2) that nonpoint source reductions
are demonstrated through an effective monitoring
program. Assurances may include the application
or   utilization  of   local   ordinances,   grant
conditions, or other enforcement authorities. For
example, it may be appropriate to provide that a
permit may be reopened when  a WLA  requiring
more  stringent  limits  is   necessary  because
attainment of a nonpoint source load  allocation
was not demonstrated.

Some compliance implementation time may,  in
certain situations,  be necessary and appropriate
for permittees to meet new permit limits based on
new standards.  Under the Administrator's April
16, 1990 decision in an  NPDES appeal (Star-Kist
Caribe  Inc..  NPDES  Appeal  No. 88-5),  the
Administrator stated that the only basis in which
a permittee may delay  compliance after July  1,
1977 (for a post July  1977 standard), is pursuant
to a schedule of compliance established in the
permit which is authorized by the State in the
water quality standard  itself or in other State
implementing regulations.   Standards  are made
applicable to  individual  dischargers  through
NPDES  permits which reflects the applicable
Federal or State water quality standards. When a
permit is issued, a schedule of compliance for
water quality-based limitations  may be included,
as necessary.
   (8/15/94)
                                       7-9

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 Water Quality Standards Handbook - Second Edition
 7,6.2     Nonpoint Source Controls

 In addition to permits for point sources, nonpoint
 sources controls such as management measures or
 best management practices (BMPs) are also to be
 implemented  so  that  surface  water  quality
 objectives are met.  To fully address water bodies
 impaired  or  threatened  by nonpoint  source
 pollution, States should implement their nonpoint
 source management programs and ensure adoption
 of   control  measures  or  practices  by  all
 contributors of nonpoint source  pollution to  the
 targeted watersheds.

 Best  management  practices  are the  primary
 mechanism in section 319 of the CWA to enable
 achievement of water quality standards.  Section
 319 requires each State, in addition to developing
 the assessment reports discussed  in section 7.2.1
 of  this Handbook, to adopt NFS  management
 programs to control NFS pollution.

 Sections 208(b)(2)(F) through (K) of the CWA
 also require States to set  forth  procedures and
 methods including land  use requirements,  to
 control to the extent feasible nonpoint sources of
 pollution reports.

 Section 6217 of the Coastal Zone Reauthorization
 Amendments of  1990  (CZARA)  requires  that
 States  with  federally  approved  coastal  zone
 management programs develop Coastal Nonpoint
 Pollution Control Programs to be approved by
 EPA and NOAA.  EPA and NOAA  have issued
 Coastal Nonpoint Pollution Control Program;
 Program Development and Approval Guidance
 (NOAA/EPA,  1993),   which  describes   the
program development and approval process and
 requirements.  State programs are to employ an
 initial  technology-based  approach   generally
 throughout the coastal management  area, to be
 followed by a more stringent water quality-based
 approach   to  address   known   water  quality
 problems.  The Management Measures generally
 implemented throughout the coastal management
 area  are  described  in  Guidance  Specifying
 Management Measures for Sources of Nonpoint
 Pollution in Coastal Waters (USEPA, 1993b).

 7.6.3     CWA Section 401 Certification

 States  may  grant,    condition,    or   deny
 "certification"  for  a  federally  permitted  or
 licensed activity that may result in a discharge to
 the waters  of the United  States, if it is the  State
 where the discharge will originate. The language
 of section 401(a)(l) is very broad  with respect to
 the activities  it covers:

     [A]ny  activity,  including,  but  not
     limited to, the construction or operation
     of facilities, which  may result in any
     discharge  . . .

 requires water quality certification.

 EPA  has identified five Federal permits and/or
 licenses that authorize activities that may result in
 a discharge to the waters:   permits for point
 source discharge under section 402 and discharge
 of dredged and fill material under section 404 of
 the Clean Water Act;  permits for  activities in
 navigable waters that may affect navigation under
 sections 9 and 10 of the Rivers and Harbors Act
 (RHA);  and  licenses required for hydroelectric
projects issued under the Federal Power  Act.
There  are likely other  Federal permits   and
licenses, such as permits  for activities on public
lands,   and  Nuclear  Regulatory Commission
licenses, which  may result in a discharge and thus
require 401 certification. Each  State should work
with EPA and the Federal agencies active in its
State to  determine whether 401 certification  is in
fact applicable.
   7-10
                                                                                  (8/15/94)

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                                          Chapter 7-The Water Quality-Based Approach to Pollution Control
 Congress intended for the States to use the water
 quality certification  process to ensure  that  no
 Federal license or permits would  be issued that
 would violate State standards or become a source
 of pollution in the future.   Also,  because the
 States'  certification of a construction permit or
 license also  operates  as  certification  for  an
 operating  permit  (except  in  certain instances
 specified in section 401(a)(3)), it is imperative for
.a State review  to consider  all potential  water
 quality impacts  of the project, both direct and
 indirect, over the life of the project.

 In addition,  when  an  activity  requiring 401
 certification in one State (i.e. the State in which
 the discharge originates) will have an impact  on
 the water quality of another State,  the statute
 provides that after receiving notice of application
 from a Federal  permitting or licensing  agency,
 EPA will notify any States whose water quality
 may be affected.  Such States  have the  right to
 submit their objections and  request  a hearing.
 EPA  may  also  submit  its   evaluation  and
 recommendations. If the use of conditions cannot
 ensure compliance with the affected State's water
 quality requirements, the Federal permitting  or
 licensing  agency shall  not Issue such permit  or
 license.

 The  decision   to grant,  condition,  or  deny
 certification is based on a State's determination
 from data submitted by am  applicant (and any
 other information available to the State) whether
 the proposed  activity  will  comply  with  the
 requirements  of  certain  sections  of the Clean
 Water  Act  enumerated in  section  401(a)(l).
These requirements address  effluent limitations
for conventional and nonconventional pollutants,
water quality standards, new source performance
standards, and toxic pollutants (sections 301, 302,
303,   306,   and  307).    Also  included  are
requirements of State law or regulation more
stringent  than those  sections or  their  Federal
implementing regulations.

States adopt surface  water  quality  standards
pursuant to section 303 of the Clean Water Act
and have broad authority to base those standards
on the waters'  use and value for "... public
water supplies, propagation of fish and wildlife,
recreational purposes, and  . .  .  other purposes"
(33 U.S.C.  section 1313 (c)(2)(A)).  All permits
must include  effluent  limitations  at  least  as
stringent  as  needed  to  maintain  established
beneficial uses and to attain the  quality of water
designated by States for their waters. Thus, the
States'  water  quality  standards are a critical
concern of the 401 certification process.

If a State grants  water quality certification to an
applicant  for a Federal license or permit, it is in
effect saying that  the proposed  activity will
comply with State water quality standards (and the
other CWA and State law provisions enumerated
above).   The State may thus  deny  certification
because the applicant has not  demonstrated that
the project will comply with those requirements.
Or it may place whatever limitations or conditions
on the certification it determines  are necessary to
ensure compliance with those provisions, and with
any other "appropriate" requirements of State law.

If  a   State  denies  certification,  the   Federal
permitting or licensing agency is  prohibited from
issuing a permit or license.  While  the procedure
varies from State to  State,  a State's decision to
grant or deny certification is ordinarily subject to
an administrative appeal, with review in  the State
courts designated for appeals of agency decisions.
Court review is typically limited to the question of
whether the State agency's  decision is supported
by the record and is  not arbitrary or capricious.
The courts generally presume regularity in agency
procedures and defer to agency expertise in their
    (8/15/94)
                                       7-11

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Water Quality Standards Handbook - Second Edition
review. (If the  applicant is  a Federal agency,
however, at least one Federal court has ruled that
the State's certification decision may be reviewed
by the Federal courts.)

States may also waive water quality certification,
either  affirmatively or  involuntarily.   Under
section 401(a)(l),  if the State fails to act  on a
certification request "within  a reasonable  time
(which shall not  exceed one  year)"  after the
receipt of an application, it forfeits its authority to
grant conditionally or to deny certification.

The  most  important  regulatory  tools for the
implementation of 401 certification are the States'
water quality standards regulations and their 401
certification   implementing   regulations  and
guidelines.  Most  Tribes do  not yet have water
quality standards, and developing them would be
a  first step  prior to  having  the  authority  to
conduct water quality certification.  Also, many
States have not adopted regulations implementing
their authority to grant, deny,  and condition water
quality  certification.      Wetland   and  401
Certification: Opportunities and  Guidelines for
States and Eligible  Indian Tribes (USEPA, 1989a)
discusses  specific  approaches,  and elements  of
water  quality standards and 401  certification
regulations  that  EPA views  as  effective  to
implement the States'  water quality certification
authority.
         Monitor and Enforce Compliance
As noted  throughout  the  previous  sections,
monitoring  is  a  crucial  element  of  water
quality-based  decision   making.    Monitoring
provides data for assessing compliance with water
quality-based controls and for evaluating whether
the TMDL and control actions that are based on
the TMDL protect water quality standards.

With  point sources, dischargers are required to
provide reports  on  compliance  with  NPDES
permit limits.  Their discharge monitoring reports
(DMR)  provide  a key source of effluent quality
data.  In some instances,  dischargers may also be
required in the permit to assess the impact of their
discharge on the receiving water.  A monitoring
requirement can be put into  the permit as  a
special condition as long  as the information is
collected for purposes of writing a permit limit.

States should also ensure that effective monitoring
programs  are in place  for evaluating  nonpoint
source  control  measures.    EPA  recognizes
monitoring as a high-priority activity in a State's
nonpoint source management program  (55 F.R.
35262,  August 28,  1990).   To  facilitate  the
implementation  and evaluation of NPS controls,
States should consult current guidance (USEPA,
199 Ig);  (USEPA,  1993b).    States  are  also
encouraged to use innovative monitoring programs
(e.g., rapid bioassessments (USEPA, 1989e), and
volunteer monitoring (USEPA,  1990b) to provide
for adequate point and nonpoint source monitoring
coverage.

Dischargers are monitored to determine whether
or not they are meeting their  permit conditions
and  to  ensure that  expected  water  quality
improvements are  achieved.  If a State has not
been delegated  authority for the NPDES permit
program, compliance reviews of all permittees in
that State are the  responsibility of EPA.  EPA
retains   oversight   responsibility   for   State
compliance programs in NPDES-delegated States.
NPDES  permits   also  contain  self-monitoring
requirements  that  are  the  responsibility  of the
individual discharger.  Data obtained through self-
monitoring  are reported  to   the  appropriate
regulatory agency.

Based  on a  review of data,  EPA or a State
regulatory agency  determines  whether or not a
NPDES   permittee  has   complied  with  the
requirements  of the NPDES permit.  If a facility
has been identified as having apparent violations,
EPA  or  the State  will  review  the  facility's
compliance history. This review focuses on the
magnitude, frequency, and duration of violations.
A determination of the appropriate enforcement
response is then made.  EPA and States  are
authorized to bring civil or criminal action against
facilities that violate their NPDES permits. State
   7-12
                                   (8/15/94)

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                                         Chapter 7 - The Water Quality-Based Approach to Pollution Control
 nonpoint source programs are enforced  under
 State law and to the extent provided by State law.

 Once control measures have been implemented,
 the  impaired  waters  should  be  assessed  to
 determine  if water quality standards have been
 attained or  are no longer  threatened.   The
 monitoring program used to gather the  data for
 this  assessment should be designed based on the
 specific pollution  problems or sources.   For
 example, it is difficult to ensure, a priori, that
 implementing  nonpoint  source  controls  will
 achieve expected   load   reductions   due   to
 inadequate selection  of practices or  measures,
 inadequate design or implementation, or lack of
 full  participation by all contributing nonpoint
 sources (USEPA, 1987e).  As a result, long-term
 monitoring efforts must be consistent over time to
 develop a data base  adequate for analysis  of
 control actions.
          Measure Progress
If the water body achieves the applicable State
water quality standards,  the water body may be
removed  from  the  303(d) list of  waters  still
needing TMDLs.  If the water quality standards
are not met, the TMDL and allocations of load
and  waste   loads  must  be  modified.    This
modification should  be bascxl on  the additional
data and information gathered as required by the
phased approach for developing a TMDL, where
appropriate;  as  part  of  routine  monitoring
activities; and when assessing the water  body for
water quality standards attainment.
   (8/15/94)                                                                            7.43

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       REFERENCES
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                                                                                  References


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Barnes, D.G., and M. Dourson.  1988. Reference Dose (RfD): Description and Use in Health Risk
     Assessments. Regulatory Toxicology and Pharmacology 8,  471-486.

Battelle Ocean Sciences. 1992.  Evaluation of Trace-Metal Levels in Ambient Waters and
     Tributaries to New York/New Jersey Harbor for Waste Load Allocation.  U.S. EPA, Office of
     Wetlands, Oceans, and Watersheds, Washington, DC and Region II, New York, NY.   (Source
     #1.)

Brown, D.S., and J.D. Allison.  1987.  MINTEQAl, An Equilibrium Metal Speciation Model-
     User's Manual.  U.S. EPA, Environmental Research Laboratory, Athens, GA. EPA 600/3-87-
     012.  (Source #2.)

Brungs, W.A. 1986.  Allocated Impact Zones for Areas of Non-Compliance.  USEP A, Region 1.
     Water Management Division, Boston, MA. (Source #3.)

Brungs, W.A., T.S. Holderman, and M.T. Southerland.  1992.  Synopsis of Water-effect Ratios for
     Heavy Metals as Derived for Site-specific Water Quality Criteria.  Draft.  U.S. EPA Contract
     68-CO-0070. (Source #4.)

Carlson, A.R., W.A. Brungs, G.A.  Chapman, and DJ. Hansen.  1984. Guidelines for Deriving
     Numerical Aquatic Site-specific Water Quality Criteria by Modifying National Criteria.  U.S.
     EPA, Environmental Research Laboratory, Duluth, MN.  EPA 600/3-84-099.  NTIS #PB 85-
     121101.  (Source #2 or #9.)

Cole, G.A.  1979.  Textbook of Limnology.  The C.V. Mosby Co.  St. Louis MO

Erickson, R., C. Kleiner, J. Fiandt, and T. Hignland. 1989.  Report on the Feasibility of
     Predicting the Effects of Fluctuating Concentrations on Aquatic Organisms.  USEPA, ERL,
     Duluth, MN.  (Source #16.)

FWPCA (Federal Water Pollution Control Administration). 1968. Water Quality Criteria (the
     "Green Book"), Report of the National Technical Advisory  Committee to the Secretary of the
     Interior.  U.S. Department of the Interior, Washington, DC. (Out of Print.)

GAO (U.S. General Accounting Office) 1987. Wildlife Management; National Refuge
     Contamination is Difficult to Confirm and Clean Up.  Report to the Chairman, Subcommittee
     on Oversight and Investigations, Committee on Energy and  Commerce, House of
     Representatives.  Washington, DC.   GAO/RCED-87-128. (Source #6.)

ITFM. 1992. Ambient Water-quality Monitoring in the United States: First Year Review,
     Evaluation,  and Recommendations.  Intergovermental Task Force on Monitoring Water
     Quality. Washington, IDC.  (Source #15.)
   (9/15/93)                                                                       REF-1

-------
Water Quality Standards Handbook - Second Edition
Karr, J.R.  1981. Assessment ofBiotic Integrity Using Fish Communities. Fisheries, Vol. 6, No.6,
     pp. 21-27.

Mancini, J.L.  1983. A Method for Calculating Effects on Aquatic Organisms of Time-Varying
     Concentrations.  Water Res. 17:1355-61.

Martin, T.D., J.W. O'Dell, E.R. Martin, and G.D. McKee.  1986.  Evaluation of Method 200.1
     Determination of Acid-Soluble Metals.  Environmental Monitoring and Support Lab,
     Cincinnati, OH. (Source #4.)

McLusky, D.S.  1971. Ecology of Estuaries.  Heinemann Educational Books, Ltd.  London.

NAS/NAE.  1973.  Water Quality Criteria 1972 (the "Blue Book"), a Report of the Committee on
     Water Quality Criteria.  National Academy of Science and National Academy of Engineering,
     Washington, DC. NTIS-PB 236199.  USGPO #5501-00520.  (Source #2  or #7.)

NOAA/EPA. 1993.  Coastal Nonpoint Pollution Control Program; Program Development and
     Approval Guidance. National Oceanic and Atmospheric Administration and Environmental
     Protection Agency, Washington, DC.  (Source #8.)

Puls, R.W., and MJ. Barcelona.  1989. Ground Water Sampling for Metals Analyses.  EPA
     Superfund Ground Water Issue.  U.S. EPA, Office of Research and Development.  EPA
     540/4-89-001. (Source #9.)

Rossman, Lewis J.  1990. Design Stream Flows Based on Harmonic Means.  J. of Hydraulics
     Engineering, Vol. 116, No. 7.

Thomann, R.V.  1987. A Statistical Model of Environmental Contaminants Using Variance
     Spectrum Analysis.  Report to National Science Foundation.  NTTS #PB 88-235130/A09.
     (Source #2.)

Thomann, R.V.  1989. Bioaccumulation Model of Organic Chemical Distribution in Aquatic Food
     Chains. Environ. Sci. Technol. 23: 699-707.

U.S. Department of Agriculture.  1984.  Agricultural Statistics.  USDA, Washington, DC.  p. 506.

USEPA (U. S.  Environmental Protection Agency).  1972.  Biological Field and Laboratory Methods
    for Measuring the Quality of Surface Waters and Effluents. Office of Research and
     Development, Washington, DC.  EPA 670/4-73-001.  (Source #9.)

       _.  1976.  Quality Criteria for Water 1976 (the "Red Book").  Office of Water and Hazardous
    Materials, Washington, DC.  GPO #055-001-01049-4. (Source #7.)

    	. 1980a.  Notice of Water Quality Criteria Documents.  Criteria and Standards Division,
    Washington, DC.  45 F.R. 79318, November 28, 1980.
   REF-2                                                                     (9/15/93)

-------
                                                                                   References
     	. 1980b.  Guidelines and Methodology Used in the Preparation of Health Effects Assessment
      Chapters of the Consent Decree Water Documents.  Criteria and Standards Division,
      Washington, DC.  45 F.R. 79347, November 28, 1980.
                                    ^         .      I               '      '
     	. 1980c. Seafood Consumption Data Analysis.  Stanford Research Institute International,
      Menlo Park, CA.  Final Report, Task 11, Contract No. 68-01-3887.  Office of Water
      Regulations and Standards, Washington, DC.  (Source #10.)

        _. 1981. Notice of Water Quality Criteria Documents.  Criteria and Standards Division,
     Washington, DC. 46 F.R. 40919, August 13, 1981.

    	. 1983a. Water Quality Standards Handbook.  Office of Water Regulations and Standards,
     Washington, DC. (Out of Print.)

    	. 1983b. Methods for Chemical Analysis of Water and Wastes (Sections 4.1.1, 4.1.3, and
     4.1.4).  Environmental Monitoring and Support Laboratory, Cincinnati, OH.  EPA 600/4-79-
     020.  (Source #9.)

        _. 1983c. Technical Support Manual: Waterbody Surveys and Assessments for Conducting
     Use Attainabilty Analyses,  Volume I.  Criteria and Standards Division, Washington, DC.
     (Source #10.)

    	•  1983d.  Technical Guidance Manual for Performing Waste Load Allocations - Book II
     Streams and Rivers - Chapter 1 Biochemical Oxygen Demand/Dissolved Oxygen.  Monitoring
     and Data Support Division, Washington, DC.  EPA 440/4-84-020.  (Source #10.)

    	.  1983e.  Technical Guidance Manual for Performing Waste Load Allocations - Book II
     Streams and Rivers - Chapter 2 Nutrient/Eutrophication Impacts. Monitoring and Data Support
     Division, Washington, DC. EPA 440/4-84-021.  (Source #10.)

    	•  1983f.  Technical Guidance Manual for Performing Waste Load Allocations - Book IV
     Lakes and Impoundments - Chapter 2 Nutrient/Eutrophication Impacts.  Monitoring and Data
     Support Division, Washington, DC. EPA 440/4-84-019. (Source #10.)

    	•  1984a.  Technical Support Manual: Waterbody Surveys and Assessments for Conducting
     Use Attainability Analyses, Volume II, Estuarine Systems.  Criteria and Standards Division,
     Washington, DC. (Source #10.)

    	•  1984b.  Technical Support Manual: Waterbody Surveys and Assessments for Conducting
     Use Attainability Analyses, Volume III, Lake Systems. Criteria and Standards Division,
     Washington, DC. (Source #10.)

    	•  1984d.  State Water Quality Standards Approvals: Use Attainability  Analysis Submittals.
     (Memorandum from Director, Criteria and Standards Division to Director, Water Management
     Division, Region I; November 28.)  Washington, DC.  (Source #11.)
(8/15/94)                                                                              REp.3

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Water Quality Standards Handbook - Second Edition
    	. 1984e. Technical Guidance Manual for Performing Waste Load Allocations.  Book II
    Streams and Rivers.  Chapter 3 Toxic Substances. Office of Water Regulations and Standards,
    Washington, DC.  EPA 440/4-84-022. (Source #10.)
        . 1984f.  Guidelines for Deriving Numerical Aquatic Site-Specific Water Quality Criteria by
    Modifying National Criteria. Office of Research and Development.  Duluth, MN.  (Out of
    Print.)

    	. 1985a. Methods for Measuring Acute Toxicity of Effluents to Freshwater and Marine
    Organisms. Office of Research and Development. Washington, DC.  EPA 600-4-85-013.
    (Source #9.)

       _. 19855. Guidelines for Deriving National Water Quality Criteria for the Protection of
    Aquatic Organisms and Their Uses.  Office of Water Regulations and Standards, Washington,
    DC.  45 F.R. 79341, November 28, 1980, as amended at 50 F.R. 30784, July 29, 1985.
    NTIS #PB 85-227049.  (Source #2.)

    	. 1985c.  Short-Term Methods for Estimating the Chronic Toxicity of Effluents and
    Receiving Waters to Freshwater Organisms.  Office of Research and Development, Cincinnati,
    OH. EPA 600-4-85-0145.

       _. 1985d.  Guidance for State Water Monitoring and Waste Load Allocation Programs.
     Office of Water Regulations and Standards.  Washington, DC. EPA 440/4-85-031. (Out of
     Print.)

    	. 1985e. Interpretation of the Term "Existing Use".  (Memorandum from Director, Criteria
     and Standards Division to Water Quality Standards Coordinator, Region IV; February 21.)
     Washington, DC.  (Source #11.)

       _. 1985f. Selection of Water Quality Criteria in State Water Quality Standards.
     (Memorandum from Director, Office of Water Regulations and Standards to Water Division
     Directors, Region I - X; February 28.)  Washington, DC. (Source #11.)

    	. 1985g.  Variances in Water Quality Standards.  (Memorandum from Director, Office of
     Water Regulations and Standards to Water Division Directors; March 15.)  Washington, DC.
     (Source #11.)

       _. 1985h.  Antidegradation, Waste Loads, and Permits. (Memorandum from Director,
     Office of Water Regulations and Standards to Water Management Division Directors, Region I
     -X.) Washington, DC.  (Source #11.)

    	, 1985L Antidegradation Policy.  (Memorandum from Director, Criteria and Standards
     Division to Water Management Division Directors,  Region I - X; November 22.)
     Washington, DC.  (Source #11.)

    	. 1986a.  Quality Criteria for Water (the "Gold Book") Office of Water Regulations and
     Standards, Washington DC.  EPA 440/5-86-001.  USGPO #955-002-00000-8. (Source #7.)
REF-4                                                                             (8/15/94)

-------
                                                                                  References
       _. 1986b. Ambient Water Quality Criteria for Bacteria. Office of Water Regulations and
    Standards, Washington DC.   EPA 440/5-84-002. PB 86-158045.  (Source #2.)

    	. 1986c. Technical Guidance Manual for Performing Waste Load Allocations, Book 6,
    Design Conditions.  Office of Water Regulations and Standards, Washington, DC. EPA 440/4-
    87-002.  (Source #10.)

    	. 1986d. Technical Guidance Manual for Performing Waste Load Allocations, Book VI,
    Design Conditions: Chapter 1 - Stream Design Flow for Steady-State Modeling.  Office of
    Water Regulations and Standards, Washington, DC.  EPA 440/4-87-004. (Source #10.)

    	. 1986e. Answers to Questions on Nonpoint Sources and WQS.  (Memorandum from
    Assistant Administrator for Water to Water Division Director, Region X; March  7.)
    Washington, DC. (Source #11.)

    	. 1986f.  Determination of "Existing Uses" for Purposes of Water Quality Standards
    Implementation. (Memorandum from Director, Criteria and Standards Division to Water
    Management Division Directors, Region I - X, WQS Coordinators, Region I - X; April 7.)
    Washington, DC.  (Source #11.)

    	. 1986.  Technical Guidance Manual for Performing Waste Load Allocations.  Book IV
    Lakes, Reservoirs, and Impoundments.  Chapter 3 Toxic Substances.  Office of Water
    Regulations and Standards, Washington, DC.  EPA 440/4-87-002.  (Source #10.)

    	. 1987d.  Nonpoint Source Controls and Water Quality Standards.  (Memorandum from
    Chief, Nonpoint Source Branch to Regional Water Quality Branch Chiefs; August 19.)
    Washington, DC.  (Source #11.)

    	. 1987e.  Setting Priorities: The Key to Nonpoint Source Control.  Office of Water
    Regulations and Standards.  Washington, DC.  (Source #8.)

    	. 1988a.  Short-term Methods for Estimating the Chronic Taxicity of Effluents and Receiving
    Waters to Marine and Estuarine Organisms.  Office of Research and Development,  Cincinnati,
    OH.  EPA 600/4-87-028.

    	. 1988d.  State Clean Water Strategies; Meeting the Challenges for the Future.  Office of
    Water.  Washington, DC.  (Source #5.)

       _. 1988e.  Guidance for State Implementation of Water Quality StandardSfor CWA Section
    303(c)(2)(B).  Office of Water.  Washington, DC.  (Source #10.)

    	. 1989a. Wetlands and 401 Certification: Opportunities for States and Eligible Indian
    Tribes.  Office of Wetlands Protection, Washington, DC.  (Source #12.)

        . 1989b. Exposure Factors Handbook.  Office of Health and Environmental Assessment,
    Washington, DC.  EPA 600/8-89-043. (Source #9.)
(8/15/94)'                                                                            REF-5

-------
 Water Qualify Standards Handbook - Second Edition
     	. 1989c. Application of Antidegradation Policy to the Niagara River.  (Memorandum from
     Director, Office of Water Regulations and Standards to Director, Water Management Division,
     Region IE; August 4.) Washington, DC.  (Source #11.)
    	. 1989d. Selecting Priority Nonpoint Source Projects: You Better Shop Around.  Office of
     Water; and Office of Policy, Planning and Evaluation.  Washington, DC.  EPA 506/2-89-003.
     (Source #13.)

    	. 1989e. Rapid Bioassessment'Protocols for Use in Streams and Rivers.  Assessment and
     Watershed Protection Division.  Washington, DC.  EPA 444/4-89-001.  (Source #14.)

        _. 1989f.  EPA Designation of Outstanding National Resource Waters. (Memorandum from
     Acting Director, Criteria and Standards Division to Regional Water Management Division
     Directors; May 25.)  Washington, DC.  (Source #11.)

    	. 1989g.  Guidance for the Use of Conditional Approvals for State WQS. (Memorandum
     from Director, Office of Water Regulations and Standards to Water Division Directors,
     Regions I - X; June 20.)  Washington, DC.  (Source #11.)

    	. 1989h.  Designation of Recreation Uses. (Memorandum from Director, Criteria and
     Standards Division to Director, Water Management Division, Region IV; September 7.)
     Washington, DC. (Source #11.)

    	. 1989L  Water Quality Criteria to Protect Wildlife Resources.  Environmental Research
     Laboratory.  CoralUs, OR. EPA 600/3-89-067. NTIS #PB 89-220016.  (Source #2.)

       _. 1989J. Assessing Human Health Risks from Chemically Contaminated Fish and Shellfish:
     a Guidance Manual.  Office of Water Regulations and Standards.  Washington, DC.  EPA
     503/8-89-002.  (Source #10.)

    	.  1990a.  Biological Criteria, National Program  Guidance for Surface Waters.  Office of
     Water Regulations and Standards, Washington, DC.  EPA 440/5-90-004. (Source #10)

       _.  1990b.  Volunteer Water Monitoring:  A Guide for State Managers.  Office of Water.
     Washington, DC.  EPA 440/4-90-010.  (Source #14.)

    	. 1990c.  The Lake and Reservoir Restoration Guidance Manual, Second Edition.  Office of
     Water. Nonpoint Source Branch. Washington, DC. EPA 440/4-90-006.  (Source #14.)

       _. 1991a.  Technical Support Document for Water Quality-based Toxics Control.  Office of
     Water, Washington, DC.  EPA 505/2-90-001. NITS #PB 91-127415.  (Source #2.)

    	. 199 Ib.  Methods for the Determination of Metals in Environmental Samples.
     Environmental Monitoring Systems Laboratory, Cincinnati, OH 45268. EPA 600/4-91-010.
     (Source #9.)

       _. 1991c.  Guidance for Water Quality-based Decisions: The TMDL Process.  Office of
     Water, Washington, DC.  EPA 440/4-91-001  (Source #14.)
REF-6                                                                             (8/15/94)

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                                                                                   References

    	. 1991d. Methods for Measuring the Acute Toxicity of Effluents to Aquatic Organisms. 4th.
    ed.  Office of Research and Development, Cincinnati, OH.  EPA 600/4-90-027.  (Source #9.)

    	. 199 le. Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving
    Waters to Freshwater Organisms. 3d. ed. Office of Research and Development, Cincinnati,
    OH.  EPA 600/4-91-002.  (Source #9.)

    	. 1991f. Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving
     Waters to Marine and Estuarine Organisms. 2d. ed. Office of Research and Development,
     Cincinnati, OH. EPA 600/4-91-003. (Source #9.)

    	. 1991g.  Watershed Monitoring and Reporting Requirements for Section 319 National
     Monitoring Program Projects.  Assessment and Watershed Protection Division. Washington
     DC.  (Source #8.)

    	. 199 Ih.  Section 401 Certification and FERC Licenses.  (Memorandum from Assistant
     Administrator, Office of Water to Secretary, Federal Energy Regulatory Commission; January
     18.)  Washington, DC.  (Source #11.)

   	. 199 li.  Policy on the Use of Biological Assessments and Criteria in the Water Quality
     Program. (Memorandum from Director, Office of Science and Technology to Water
     Management Division Directors, Regions I - X; June 19.)  (Source #4.)

   	. 1992b.  Interim Guidance on Interpretation and Implementation of Aquatic Life Criteria
    for Metals.  57 F.R. 24041. Office of Science and Technology.  Washington, DC.  (Source
     #4.)

   	. 1993a.   Guidelines for Preparation of the 1994 State Water Quality Assessments 305(b)
     Reports.  Office of Wetlands, Oceans and Watersheds.  Washington, DC.  (Source #14.)

   	. 1993b.  Guidance Specifying  Management Measures for Sources ofNonpoint Pollution in
     Coastal Waters. Office of Water.  Washington, DC.  840-B-92-002.  (Source #8.)

    	. 1993c.  Geographic Targeting: Selected State Examples.  Office of Water. Washington,
     DC.  EPA 841-B-93-001. (Source #14.)

    	. 1993d.  Final Guidance on the Award and Management ofNonpoint Source Program
    Implementation Grants Under Section 319(h) of the Clean Water Act for Fiscal Year 1994 and
    Future Years. Office of Water.  Washington, DC. (Source #8.)

    	. 1993e.  Guidance for Assessing Chemical Contaminant Data for Use in Fish Advisories;
    Volume 1 - Fish Sampling and Analysis (in preparation). Office of Water.  Washington, DC.
    EPA 823-R-93-002.  (Source #9.)

    	. 1993f.  Office of Water Policy and Technical Guidance on Interpretation and
    Implementation of Aquatic Life Metals Criteria.  Office of Water.  Washignton, DC.
    (Source #10.)
(8/15/94)                                                                              REF-7

-------
 Water Quality Standards Handbook - Second Edition
        _. 1994a.  Interpretation of Federal Antidegradation Regulatory Requirement.  Office of
     Science and Technology. Washington, DC.  (Source 11.)

 	.  1994b.  Interim Guidance on Determination and Use of Water-Effect Ratios for Metals.
     Office of Water.  Washington, DC.  EPA-823-B-94-001.  (Source #10.)

 Vernberg, W.B.  1983.  Responses to Estuarine Stress.  In: Ecosystems of the World: Estuaries and
     Enclosed Seas. B.H. Ketchum, ed.  Elsevier Scientific Publishing Company, New York, pp.
     43-63.

 Versar. 1984.  Draft Assessment of International Mixing Zone Policies. Avoidance/Attraction
     Characteristics, and Available Prediction Techniques.  USEPA, Office of Water Regulations
     and Standards and USEPA Office of Pesticides and Toxic Substances, Washington, DC.

 Windom, H.L., J.T. Byrd, R.G. Smith, and F. Huan. 1991. Inadequacy of NASQAN Data for
     Assessing Metals  Trends in the Nation's Rivers.  Environ. Sci. Technol. 25, 1137.
                            SOURCES OF DOCUMENTS
(1)  Seth Ausubel
     U.S. Environmental Protection Agency
     Region 2
     26 Federal Plaza
     New York, NY  10278
     Ph: (212) 264-6779

(2)  National Technical Information Center
     (NTIS)
     5285 Front Royal Road
     Springfield, VA  22161
     Ph: (703)487-4650

(3)  U. S. Environmental Protection Agency
     Region 1
     Water Quality Standards Coordinator
     Water Division
     JFK Federal Building
     One Congress Street
     Boston, MA 02203
     Ph: (617) 565-3533
(4)  U. S. Environmental Protection Agency
    Health and Ecological Criteria Division
    401 M Street, S.W. (4304)
    Washington, DC 20460
    Ph:  (202)260-5389
    (See Appendix V)

(5)  U. S. Environmental Protection Agency
    Office of Water
    401 M Street, S.W. (4301)
    Washington, DC 20460
    Ph:  (202)260-5700
REF-8
                                                                                  (8/15/94)

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                                                                                  References
(6)   U.S. General Accounting Office
     Post Office Box 6015
     Gaithersburg, MD 20877         ;,
     Telephone: 202-512-6000
     (First copy free)

(7)   U.S. Government Printing Office
     Superintendent of Documents
     North Capitol Street H Streets, NW
     Washington, DC 20401
     Ph:  (202) 783-3238

(8)   U. S. Environmental Protection Agency
     Nonpoint Source Control Branch
     401  M Street, S.W. (4305F)
     Washington, DC 20460
     Ph:  (202) 260-7100

(9)   U.S. Environmental Protection Agency
     Center for Environmental Research
     Office of Research and Development
     Room G72
     26 West Martin  Luther King Drive
     Cincinnati, OH 45268
     Ph:  (513) 569-7562

(10)  U. S. Environmental Protection Agency
     Office of Water Resource Center
     RC-4100
     401  M Street, S.W.
     Washington, DC 20460'
     Ph:  (202) 260-7786 (voice mail
     publication request line)
     (See Appendix V)
(11) U. S. Environmental Protection Agency
    Standards and Applied Science Division
  .., 401 M Street, S.W. (4305)
    Washington, DC 20460
    Fax: (202) 260-9830
    Ph:  (202)260-7301
    (See Appendix V)

(12) U. S. Environmental Protection Agency
    Wetlands Division
    401 M Street, S.W. (4502F)
    Washington, DC 20460
    Ph:  (202) 260-7719

(13) EPIC
    U. S. Environme'ntal Protection Agency
    11029 Kenwood Road
    Building 5
    Cincinnati, OH 45242
    Fax: (513) 569-7186
    Ph:  (513)569-7980

(14) U. S. Environmental Protection Agency
    Assessment and Watershed Protection
    Division
    401 M Street, S.W. (4503F)
    Washington, DC 20460
    Ph: (202) 260-7166
& U.S. GOVERNMENT PRINTING OFFICE: 1994-381-683
(8/15/94)
                                    REF-9

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                (4305)
EPA-823-B-94-005b
August 1994
Water Quality Standards
Handbook:  Second Edition
             Appendixes
    Contains update #1
    August 1994
                        "... to restore and maintain the chemical,
                        physical, and biological integrity of the Nation's
                        waters."

                               Section 101 (a) of the Clean Water Act
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            United States
            Environmental Protection
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               Office of Water
               (4305)
EPA-823-B-94-005b
August 1994
Water  Quality Standards
Handbook:  Second Edition
            Appendixes
    Contains update #1
    August 1994
                      "... to restore and maintain the chemical,
                      physical, and biological integrity of the Nation's
                      waters."

                             Section 101 (a) of the Clean Water Act

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     Water Quality Standards Regulation
         APPENDIX A

WATER QUALITY STANDARDS HANDBOOK
          SECOND EDITION

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                                                                     Appendix A - Water Quality Standards Regulation
                                    Water Quality Standards  Regulation
                 (40 CFR 131; 48 FR 51405, Nov. 8,1983; Revised through July 1,1991; amended at
            56 FR 64893, Dec. 12, 1991; 57 FR 60910,  Dec.  22, 1992)
      TITLE 40—PROTECTION
         OF ENVIRONMENT

   CHAPTER I—ENVIRONMENTAL
       PROTECTION AGENCY

      SUBCHAPTER D—WATER
             PROGRAMS

    PART 131—WATER QUALITY
             STANDARDS
  Authority:  33 U.S.C. 1251 *t seq.

[Amended at  56  FR 64893,  Dec.  12
1991; 57 FR  60910, Dec. 22, 1992]

Subpart A—General Provisions
Sec.
131.1     Scope
131.2     Purpose.
131.3     Definitions.
131.4     Slate authority.
131.5     EPA authority.
131.6     Minimum requirements for water
          quality standards submission.
131.7     Dispute resolution mechanism.
131.8     Requirements for Indian Tribes to be
          treated as States for purposes of
          water quality standards.

Subpart B—Establishment of Water Quality
  Standards
131.10    Designation of uses.
131.11    Criteria.
131.12    Antidegradation policy.
131.13    General policies.

Subpart C—Procedures for Review and Revision
  of Water Quality Standards
131.20    State review and revision of water
          quality standards.
131.21    EPA review and approval of water
          quality standards.
131.22    EPA promulgation of water quality
          standards.
 Subpart D—Federally Promulgated Water Quali-
  ty Standards
 131.31    Ari7x)na.
 131.33—131.34 [Reserved]
 131.35    Colville Confederated Tribes Indian
   Subpart A—General Provisions

 §131.1 Scope.
   This  part  describes the  requirements
 and procedures for developing, reviewing,
 revising and approving water quality stan-
 dards by the States as authorized by sec-
 tion 303(c) of the Clean Water Act. The
 reporting or  recordkeeping (information)
 provisions in this rule were approved by
 the Office of Management and Budget un-
 der 3504(b) of the Paperwork Reduction
 Act of 1980, U.S.C. 3501 et seq. (Approv-
 al number 2040-0049).

 §131.2 Purpose.
   A water quality  standard defines the
 water quality goals of a  water body, or
 portion thereof, by designating the use or
 uses to be made of the water and by set-
 ting criteria necessary to protect the uses.
 States adopt water quality  standards to
 protect public health or  welfare, enhance
 the quality of water and serve the pur-
 poses of the Clean Water Act (the Act).
 "Serve the purposes of the Act"  (as de-
 fined in sections  101(a)(2) and 303(c) of
 the Act) means  that water quality stan-
 dards should, wherever attainable, pro-
vide water quality for the protection  and
propagation of fish,  shellfish and wildlife
and for recreation in and on the water and
 take into consideration their use and value
of public water supplies,  propagation of
 fish, shellfish,  and wildlife, recreation in
and on the water, and agricultural, indus-
 trial, and other purposes including naviga-
 tion.
 Such standards serve the dual purposes of
 establishing the water quality goals for a
 specific water body and serve as the regu-
 latory basis for the establishment  of wa-
 ter-quality-based treatment controls and
 strategies  beyond the technology-based
 levels of treatment required by sections
 301(b) and 306 of the Act.

 §131.3 Definitions.

   (a) The  Act means the Clean  Water
 Act (Pub.  L. 92-500 , as  amended, (33
 U.S.C. 1251  etseq.)).
   (b) Criteria are elements of State water
 quality standards, expressed as constitu-
 ent  concentrations,  levels,  or  narrative
 statements, representing  a quality  of wa-
 ter that  supports a particular use.  When
 criteria are met, water quality will  gener-
 ally protect the designated use.
   (c) Section  304(a)  criteria are  devel-
 oped by  EPA under authority of section
 304(a) of the Act based on the  latest sci-
 entific information on  the relationship
 that the effect of a constituent concentra-
 tion has on  particular  aquatic species
 and/or human health. This information is
 issued periodically to  the States as guid-
 ance for  use in developing criteria.
   (d) Toxic pollutants are those  pollu-
 tants listed by the Administrator  under
section 307(a) of the Act.
   (e) Existing uses are those uses actual-
ly attained  in the water body on or after
November  28, 1975, whether or not they
are included  in  the  water quality stan-
dards.
   (0 Designated uses are those uses spec-
ified in water quality  standards for each
       (9/14/93)

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 water body or segment  whether or not
 they are being attained.
   (g) Use attainability analysis is a struc-
 tured scientific assessment of the factors
 affecting the attainment of the use which
 may include physical, chemical, biologi-
 cal, and economic factors as described in
 §13l.lO(g).
   (h) Water quality limited segment
 means any segment where it is known that
 water quality does  not meet  applicable
 water quality standards, and/or is not ex-
 pected  to meet applicable water quality
 standards,  even after the application of
 the technology-bases  effluent limitations
 required  by sections 301(b) and 306 of
 the Act.
   (i) Water quality standards are provi-
 sions of State or Federal law which con-
 sist of a designated  use  or  uses for the
 waters  of the United States and  water
 quality criteria for such waters based up-
 on such uses. Water quality standards are
 to protect  the public health or  welfare,
 enhance the quality  of water  and serve
 the purposes of the Act.
 [§131.30)—(1)  added at 56 FR 64893,
 Dec. 12. 1991]
   0) Slates include:  The 50 States, the
 District  of  Columbia, Guam,  the Com-
 monwealth of Puerto Rico, Virgin Islands,
 American Samoa, the Trust Territory of
 the Pacific Islands, the Commonwealth of
 the Northern Mariana Islands, and Indi-
 an Tribes that  EPA determines qualify
 for treatment as States for purposes of
 water quality standards.
   (k) Federal Indian Reservation, Indian
 Reservation,  or  Reservation means all
 land within  the limits of any Indian reser-
 vation under the jurisdiction of the United
 States Government, notwithstanding  the
 issuance of any patent, and  including
 rightsof-way running  through  the reser-
 vation."
   (I) Indian Tribe or Tribe means any In-
 dian Tribe, band, group, or community
 recognized by the Secretary of the Interi-
 or and exercising governmental authority
 over a Federal Indian reservation.

 §131.4 State authority.
   (a) States (as defined in §131.3) are re-
sponsible for reviewing, establishing, and
 revising water quality standards.  As rec-
ognized by section 510 of the Clean Wa-
ter Act, States may develop water quality
standards more stringent than required by
this  regulation.  Consistent with  section
 101(g) and  518(a) of the Clean Water
 Act, water quality standards shall not be
 construed to superseder or abrogate rights
 to quantities of water.
   (b) States (as defined  in §131.3) may
 issue certifications pursuant to the  re-
 quirements of Clean Water Act section
 401. Revisions adopted by States shall be
 applicable for use in issuing State certifi-
 cations consistent with the provisions of
 §131.21 (c).
   (c) Where EPA determines that  a
 Tribe qualifies  for treatment as a State
 for  purposes of water quality standards,
 the  Tribe likewise qualifies for treatment
 as a State for  purposes  of certifications
 conducted under Clean Water Act section
 401.

 [§131.4 revised at 56 FR 64893, Dec. 12,
 1991]

 §131.5 EPA  authority.

 [§131.5 former paragraphs (a)—(e) re-
 designated as new (a) and (a)(l)—(a)(5)
 at 56 FR 64893, Dec. 12, 1991]
   (a) Under section 303 (c)  of  the Act,
 EPA is to review and to approve or disap-
 prove State-adopted water quality stan-
 dards. The review  involves a determina-
 tion of:
   (1) Whether the State has adopted wa-
 ter uses which  are consistent with the re-
 quirements of the Clean Water Act;
   (2) Whether the  state has adopted cri-
 teria that protect  the designated water
 uses;
   (3) Whether the  State has followed its
 legal procedures for revising or  adopting
 standards;
   (4) Whether the State standards which
 do not include the uses specified in section
 101 (a) (2) of the Act are based upon ap-
 propriate  technical and scientific data and
 analyses,  and
   (5) Whether, the  State submission
 meets  the requirements  included  in
 §131.6  of this  part. If EPA determines
 that   State water quality  standards are
 consistent with the factors listed  in
 paragraphs (a) through (e) of this section,
 EPA approves  the standards. EPA  must
 disapprove the  State water quality  stan-
 dards under section 303 (c) (4) of the Act,
 if State adopted standards are not consis-
 tent  with  the factors listed in paragraphs
 (a) through (e) of this section. EPA may
also promulgate a new or revised standard
where necessary to meet the requirements
of the Act.
   (b) Section 401 of the Clean Water Act
 authorizes EPA to issue certifications pur-
 suant to the requirements of section 401
 in  any case where  a  State  or interstate
 agency has no authority for issuing such
 certifications.

 [§131.5(b)  added at 56 FR 64893, Dec.
 12, 1991]

 §131.6 Minimum  requirements for water
  quality standards submission.

   The following elements must be includ-
 ed in each State's water quality standards
 submitted to EPA for review:
   (a) Use designations consistent with the
 provisions  of sections 101(a)(2)  and
 303(c)(2) of the  Act.
   (b) Methods used and  analyses con-
 ducted to support water quality standards
 revisions.
   (c) Water quality criteria sufficient to
 protect the  designated uses.
   (d) An antidegradation  policy  consis-
 tent with §131.12.
   (e) Certification by the State Attorney
 General or other appropriate  legal author-
 ity within the State that the water quality
 standards were duly adopted pursuant to
 State law.
   (f) General information which will aid'
 the Agency in determining the adequacy
 of  the  scientific  basis  of  the standards
 which do not include the uses specified in
 section 101(a)(2) of the Act as well as
 information on general policies applicable
 to State standards which may affect their
 application and implementation.

 §131.7 Dispute resolution mechanism.

  (a) Where disputes between States and
 Indian Tribes arise as a result of differing
 water'quality standards on common bod-
 ies  of water, the lead EPA Regional Ad-
 ministrator,  as determined  based  upon
 OMB circular A-105, shall be responsible
 for acting in accordance with the  provi-
 sions of this section.
  (b) The Regional  Administrator shall
 attempt to resolve such disputes where:
  (l)The  difference  in  water quality
 standards results  in  unreasonable  conse-
 quences;
  (2) The dispute is  between a State (as
defined  in §131.30)  but exclusive  of all
 Indian Tribes) and a Tribe  which EPA
has determined qualifies to be treated as a
State for purposes of water quality stan-
dards;

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  (3) A reasonable effort to resolve the
dispute without  EPA  involvement has
been made;
  (4) The  requested  relief  is consistent
with the provisions of the Clean  Water
Act and other relevant law;
  (5) The differing State and Tribal wa-
ter quality standards have been adopted
pursuant to State and Tribal law and ap-
proved by EPA: and
  (6) A valid written request has been
submitted  by either the Tribe  or  the
State.
  (c) Either a State  or a Tribe may re-
quest EPA to resolve any dispute which
satisfies the criteria of  paragraph (b) of
this section. Written requests for EPA in-
volvement should be submitted to the lead
Regional  Administrator and must in-
clude:
  (1) A concise statement of the unrea-
sonable consequences that are alleged to
have arisen  because of  differing water
quality standards;
  (2) A concise description of the  actions
. which have been taken  to resolve  the dis-
pute without EPA involvement;
   (3) A  concise  indication  of the water
quality standards provision which  has re-
sulted in the alleged unreasonable conse-
quences;
   (4) Factual data to support the  alleged
unreasonable consequences; and
   (5) A statement  of  the  relief  sought
from  the  alleged unreasonable  conse-
quences.
   (d) Where, in the Regional Administra-
tor's judgment, EPA involvement is ap-
 propriate  based  on the factors of para-
graph (b) of this  section,  the Regional
 Administrator shall,  within  30 days, noti-
 fy  the parties in writing that  he/she  is
 initiating an EPA dispute  resolution ac-
 tion and solicit their written response. The
 Regional Administrator  shall also make
 reasonable efforts to  ensure that other in-
 terested individuals or groups have notice
 of  this action. Such efforts shall  include
 but not be limited to the following:
   (1) Written notice to responsible Tribal
 and  State Agencies, and other  affected
 Federal Agencies,
   (2) Notice to the specific individual  or
 entity that is alleging  that an unreason-
 able consequence is resulting from differ-
 ing standards  having been adopted on a
 common body of water,
   (3) Public notice  in  local  newspapers,
 radio, and television, as appropriate,
  (4) Publication in trade journal news-
letters, and
  (5) Other means as appropriate.
  (e) If  in  accordance  with  applicable
State and Tribal law an Indian Tribe and
State have entered into an agreement that
resolves the dispute or establishes a mech-
anism for resolving a dispute, EPA shall
defer to this agreement where it is consis-
tent with the Clean Water Act and where
it has been  approved by  EPA.
  (0 EPA dispute resolution actions shall
be consistent with one or a combination of
the following options:
  (1) Mediation. The Regional  Adminis-
trator may appoint a mediator to mediate
the dispute. Mediators shall be  EPA em-
ployees, employees  from other Federal
agencies, or other individuals with appro-
priate qualifications.
  (i) Where the State and Tribe agree to
participate  in the dispute resolution pro-
cess, mediation with  the intent to estab-
lish Tribal-State agreements, consistent
with Clean Water Act section 518(d)
shall normally be pursued as a first effort.
   (ii) Mediators  shall   act  as neutral
facilitators whose function is to encourage
communication and negotiation between
all parties to the dispute.
   (iii) Medfators may establish advisory
panels, to consist in part of representa-
tives from  the affected  parties, to study
the problem and recommend an appropri-
ate solution.
   (iv) The  procedure and schedule for
mediation of individual  disputes shall be
determined by the mediator  in consulta-
tion with the parties.
   (v) If formal public hearings are held in
connection  with the actions taken under
this  paragraph, Agency requirements  at
40 CFR 25.5 shall be followed.
   (2) Arbitration.  Where the  parties  to
the dispute agree to participate  in the dis-
 pute resolution process,  the Regional Ad-
 ministrator may appoint an arbitrator  or
arbitration panel to arbitrate the dispute.
 Arbitrators and panel members shall be
 EPA employees, employees  from other
 Federal  agencies, or  other  individuals
 with appropriate  qualifications. The Re-
 gional  administrator shall select as arbi-
 trators and arbitration panel members in-
 dividuals who are agreeable to all parties,
 are  knowledgeable  concerning the  re-
 quirements of the water quality standards
 program, have a basic  understanding  of
 the  political and  economic  interests  of
Tribes and States involved,, and are ex-
pected to fulfill the duties fairly and im-
partially.
  (i) The arbitrator or arbitration panel
shall conduct one or more private or pub-
lic meetings with the parties and actively
solicit  information  pertaining to the ef-
fects of differing water quality permit re-
quirements on upstream and downstream
dischargers, comparative risks  to public
health and the environment, economic im-
pacts,  present and  historical water  uses,
the quality of the .waters subject to such
standards, and other  factors  relevant to
the dispute such as whether proposed wa-
ter quality criteria are  more  stringent
than necessary to support designated uses,
more stringent than  natural background
water  quality or whether designated uses
are reasonable given natural background
water  quality.
   (ii) Following consideration of relevant
factors as defined in paragraph (f)(2)(i)
of this section, the arbitrator or arbitra-
tion panel shall  have the authority and
responsibility to  provide all  parties and
the Regional Administrator with a writ-
ten recommendation for resolution of the
dispute. Arbitration  panel recommenda-
tions shall, in general, be reached by ma-
jority  vote. However, where  the parties
agree  to binding..arbitration, or  where re-
quired by the Regional  Administrator,
recommendations of such  arbitration
panels  may  be  unanimous  decisions.
Where binding or non-binding arbitration
panels cannot reach a unanimous recom-
mendation after a  reasonable  period  of
time, the Regional Administrator may di-
 rect the panel to issue a non-binding deci-
sion by majority vote.
   (iii) The arbitrator or arbitration, panel
 members may consult with EPA's Office
of General Counsel on legal issues, but
otherwise shall have no ex pane commu-
 nications pertaining to the dispute. Feder-
 al employees who are arbitrators or arbi-
 tration panel members shall be neutral
 and shall not be predisposed for or against
 the position  of any disputing  party  based
 on any  Federal Trust responsibilities
 which their employers may have with re-
 spect  to the Tribe. In addition, arbitrators
 or arbitration panel members who are
 Federal employees shall act independent-
 ly from the normal hierarchy within their
 agency.
   (iv) The parlies  are  not obligated  to
 abide  by the arbitrator's  or arbitration

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 panel's recommendation unless they vol-
 untarily entered into a binding agreement
 to do so.
   (v) If a party to the dispute believes
 that the  arbitrator or arbitration panel
 has recommended an action contrary to or
 inconsistent with  the  Clean Water Act,
 the party may appeal the arbitrator's rec-
 ommendation to the Regional  Adminis-
 trator. The request for appeal must be in
 writing and must include a description of
 the statutory basis for altering the arbi-
 trator's recommendation.
   (vi) The procedure and schedule for ar-
 bitration  of individual disputes shall be
 determined by the arbitrator or arbitra-
 tion panel in consultation with parties.
   (vii) If formal public hearings are held
 in connection with the actions taken un-
 der this paragraph. Agency requirements
 at 40 CFR 25.5 shall be followed.
   (3) Dispute Resolution Default Proce-
 dure. Where one or more  parties (as de-
 fined in paragraph (g) of this section) re-
 fuse to participate in either the mediation
 or arbitration dispute  resolution process-
 es, the Regional Administrator may ap-
 point a single official or panel to review
 available  information  pertaining to the
 dispute and to issue a written recommen-
 dation for resolving the dispute. Review
 officials shall be EPA employees, employ-
 ees from other Federal agencies, or other
 individuals with  appropriate qualifica-
 tions. Review panels shall  include appro-
 priate members to be selected by the Re-
 gional Administrator in consultation with
 the participating  parties.  Recommenda-
 tions  of such review  officials or panels
 shall, to the extent possible given the lack
 of participation by one or more parties, be
 reached in a manner identical to that for
 arbitration  of disputes specified  in
 paragraphs (f)(2)(i) through (f)(2)(vii) of
 this section.
   (g) Definitions. For the purposes of this
 section:
   (1)  Dispute  Resolution  Mechanism
 means the EPA mechanism  established
 pursuant  to the  requirements of Clean
 Water Act section  518(e)  for  resolving
 unreasonable consequences that arise as a
 result of differing water quality standards
 that may  be set  by States  and  Indian
Tribes located on common bodies of wa-
 ter.
  (2) Parlies to a State-Tribal dispute in-
clude the State and the Tribe and may, at
the discretion of the Regional Administra-
 tor, include an NPDES permittee, citizen,
 citizen group, or other affected entity.
 [§131.7 added at 56  FR 64893, Dec.  12,
 1991]

 §131.8 Requirements  for Indian Tribes to
  be  treated as  States for  purposes of
  water quality standards.
   (a) The Regional Administrator, as de-
 termined  based  on OMB Circular  A105,
 may  treat an Indian  Tribe as a State  for
 purposes  of  the  water  quality standards
 program if the Tribe meets the following
 criteria:
   (l)The Indian Tribe is recognized  by
 the Secretary of the Interior and  meets
 the definitions in §131.3(k) and  (1),
   (2) The Indian Tribe has a governing
 body carrying out substantial governmen-
 tal duties and powers,
   (3) The water quality standards pro-
 gram to  be  administered  by the Indian
 Tribe pertains to the  management and
 protection of water resources which are
 within the borders of the Indian  reserva-
 tion and held by the  Indian Tribe, within
 the borders of the Indian reservation and
 held by the United States in trust for  In-
 dians, within the borders of the Indian
 reservation and  held  by a member  of the
 Indian Tribe if such property interest is
 subject to a trust restriction on alienation,
 or otherwise  within the borders of the  In-
 dian reservation, and
   (4) The Indian Tribe is  reasonably ex-
 pected to  be  capable, in the Regional Ad-
 ministrator's judgment, of carrying out
 the functions of an effective water quality
 standards program in a manner consistent
 with  the terms and purposes of  the Act
 and applicable regulations.
   (b) Requests by Indian Tribes for treat-
 ment as States for purposes of water qual-
 ity standards should  be submitted to the
 lead  EPA Regional  Administrator. The
 application shall  include the  following  in-
 formation:
   (1) A statement that the Tribe is recog-
 nized by the  Secretary of the Interior.
   (2) A  descriptive  statement  demon-
 strating that  the Tribal governing body is
 currently carrying out substantial govern-
 mental duties and powers over a defined
 area. The statement shall:
   (i)  Describe the form  of the Tribal gov-
 ernment;
   (ii) Describe the types of governmental
 functions  currently  performed  by the
Tribal governing body  such as,  but  not
limited to, the exercise  of police powers
affecting (or relating to) the health, safe-
ty, and welfare of the affected population,
taxation, and the exercise of the power of
eminent domain; and
   (iii) Identify the source of the Tribal
government's authority  to carry out the
governmental functions currently being
performed.
   (3) A descriptive statement of the Indi-
an Tribe's  authority  to regulate water
quality. The statement shall  include:
   (i) A map or  legal description of the
area over which  the Indian Tribe asserts
authority to regulate surface water quali-
ty:..
   (ii) A statement by the  Tribe's  legal
counsel (or  equivalent official) which de-
scribes the basis for the Tribes assertion
of authority;
   (iii) A copy of all documents  such as
Tribal constitutions, by-laws, charters, ex-
ecutive orders, codes,  ordinances, and/or
resolutions which support the Tribe's as-
sertion of authority; and
   (iv)  an identification of the surface wa-
ter for which the Tribe proposes to estab-
lish water quality standards.
   (4) A narrative  statement describing
the  capability of  the Indian Tribe  to
administer an effective water quality stan-
dards  program.  The narrative statement
shall include:
   (i) A description of the Indian Tribe's
previous management experience includ-
ing, but not limited to, the administration
of programs and services authorized by
the Indian Self-Determination and  Edu-
cation  Assistance Act (25 U.S.C. 450 et
seq.),  the Indian Mineral  Development
Act (25 U.S.C. 2101 et seq.), or the Indi-
an Sanitation Facility Construction Activ-
ity Act (42 U.S.C.  2004a);
   (ii) A list of existing environmental or
public  health programs  administered by
the Tribal governing body and copies of
related Tribal laws, policies, and regula-
tions;
   (iii)  A description of the entity  (or enti-
ties) which exercise the executive, legisla-
tive, and judicial functions of the Tribal
government;
  (iv) A description of the existing or pro-
posed,  agency of the Indian Tribe which
will assume  primary responsibility for es-
tablishing,  reviewing,  implementing and
revising water quality standards;
  (v) A description of the technical and
administrative capabilities of the staff to

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administer and manage an effective water
quality standards  program or  a  plan
which proposes how the Tribe will acquire
additional administrative and  technical
expertise. The plan must address how the
Tribe will obtain the funds to acquire the
administrative and technical expertise.
  (5) Additional documentation required
by the Regional Administrator which, in
the judgment of the Regional Administra-
tor, is necessary to support a Tribal re-
quest for treatment as a State.
  (6) Where  the  Tribe  has previously
qualified for treatment as a State under a
Clean Water Act or Safe Drinking Water
Act program, the Tribe  need only provide
the required information which  has not
been submitted in a previous treatment as
a State application.
  (c) Procedure for processing  an Indian
Tribe's application for treatment as a
State.
  (l)The Regional Administrator shall
process an application of an Indian  Tribe
for treatment as a State submitted pursu-
ant to 131.8(b) in a timely manner. He
shall  promptly notify the Indian Tribe of
receipt of the application.
  (2) Within 30 days after receipt of the
Indian Tribe's application for  treatment
as a  State,  the Regional Administrator
shall  provide appropriate notice. Notice
shall:
  (i) Include information  on  the  sub-
stance and basis of the Tribe's assertion of
authority to regulate the quality of reser-
vation waters; and
  (ii) Be provided to all appropriate gov-
ernmental entities.
  (3) The Regional Administrator  shall
provide 30 days for comments  to be sub-
mitted  on the Tribal application.  Com-
ments shall be limited to the Tribe's asser-
tion of authority.
  (4) If a Tribe's asserted authority is
subject  to  a  competing or conflicting
claim, the Regional Administrator,  after
consultation  with the Secretary of the In-
terior, or his designee, and in consider-
ation of  other comments received,  shall
determine whether the  Tribe  has ade-
quately  demonstrated  that it  meets the
requirements of 131.8(a)(3).
   (5) Where the Regional Administrator
determines  that  a Tribe meets the re-
quirements  of this section,  he  shall
promptly provide written notification to
the Indian Tribe that the Tribe has quali-
fied to be treated  as a State for purposes
of water quality standards and that  the
Tribe may initiate the formulation and
adoption of water quality standards  ap-
provable under this part.
[§131.8 added at 56 FR 64893, Dec. 12,
1991]

Subpart B—Establishment of Water
          Quality Standards

§131.10 Designation of uses.
   (a) Each State must specify appropri-
ate water uses to be achieved and protect-
ed. The classification of the waters of the
State must take into consideration the use
and value of water for public water sup-
plies, protection and propagation  of fish,
shellfish and wildlife, recreation in and on
the water, agricultural,  industrial, and
other purposes including navigation. In no
case shall a State adopt waste transport or
waste assimilation as a designated use for
any waters of the United States.
   (b) In designating uses of a water body
and the  appropriate  criteria for those
uses,  the State shall  take, into consider-
ation the water quality standards of down-
stream waters  and  shall ensure that  its
water quality standards  provide  for the
attainment and maintenance of the water
quality standards of downstream waters.
   (c) States may adopt sub-categories of
a use and set the appropriate criteria to
reflect  varying needs of such sub-catego-
ries of uses, for instance, to differentiate
between cold water  and warm water fish-
eries.
   (d) At a minimum, uses are deemed at-
tainable if they can be achieved by the
imposition of effluent  limits  required un-
der sections  301(b) and  306 of the  Act
and cost-effective  and  reasonable best
management  practices  for noripoirit
source  control.
   (e) Prior to  adding or removing  any
use, or establishing sub-categories of a
use, the State shall provide notice and an
opportunity for a  public hearing under
§131.20(b) of this regulation.
   (0 States may adopt  seasonal  uses as
an alternative to  reclassifyihg  a water
body or segment thereof to uses requiring
less stringent  water  quality criteria. If
seasonal  uses are adopted, water quality
criteria should be adjusted to reflect the
seasonal uses, however, such criteria shall
not preclude the attainment and  mainte-
nance of a more protective use in  another
season.
  (g) States may remove a designated use
which is not an existing use, as defined in
§131.3, or establish sub-categories  of  a
use if the State can demonstrate that at-
taining the designated use  is not feasible
because:
  (1) Naturally occurring  pollutant con-
centrations prevent the attainment of the
use; or
  (2) Natural, ephemeral, intermittent or
low flow conditions or water levels prevent
the  attainment of  the use, unless these
conditions may be compensated for by the
discharge of sufficient volume of effluent
discharges without violating State  water
conservation requirements  to enable uses
to be met; or
  (3) Human  caused conditions  or
sources of pollution prevent  the attain-
ment of the  use and cannot be  remedied
or would cause more environmental  dam-
age to correct than to  leave in place; or
  (4) Dams, diversions or  other types of
hydrologic modifications preclude the at-
tainment  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 attain-
ment of the use; or
  (5) Physical conditions  related to the
natural features of the water body, such
as  the lack of-a proper substrate,  cover,
flow, depth, pools, riffles, and the like, un-
related to water quality, preclude attain-
ment of aquatic life protection 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) States may not  remove designated
uses if:
   (1) They are existing uses, as defined  in
§131.3, unless a use requiring more strin-
gent criteria is added; or
   (2) Such uses will be attained by imple-
menting  effluent  limits required  under
sections 301(b) and 306 of the Act and by
implementing  cost-effective and reason-
able best  management  practices for
nonpoint  source control.
   (i) Where existing water quality stan-
dards specify  designated  uses  less than
those which are presently being attained,
the State shall revise  its standards to re-
flect the uses actually being attained.
   (j) A State must conduct a use attaina-
bility analysis as  described in  §131.3(g)
whenever:

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   (l)The State designates or has desig-
 nated  uses that do  not  include the uses
 specified in section 101 (a) (2) of the Act,
 or
   (2) The State wishes to remove a desig-
 nated  use  that  is  specified in  section
 101(a)(2) of the Act or to adopt subcate-
 gories of  uses  specified  in  section
 101(a)(2)  of the Act  which  require less
 stringent criteria.
   (k) A State is not  required to conduct a
 use attainability analysis under this regu-
 lation  whenever  designating  uses which
 include  those  specified  in  section
 101(a)(2)ofthe Act.

 §131.11 Criteria.
   (a) Inclusion of pollutants:
   (I) States must adopt those water qual-
 ity criteria that protect the designated
 use. Such criteria must be based on sound
 scientific rationale and must contain suffi-
 cient parameters or constituents  to pro-
 tect the designated  use.  For waters with
 multiple  use designations,  the criteria
 shall support the most sensitive use.
   (2) Toxic pollutants.  Slates  must  re-
 view water quality data  and  information
 on  discharges to  identify  specific water
 bodies where toxic pollutants  may be ad-
 versely affecting water quality or the  at-
 tainment  of the designated water use or
 where the levels of toxic pollutants are at
 a level to warrant concern and must adopt
 criteria for such toxic pollutants applica-
 ble to  the water body sufficient to protect
 the designated use. Where a State adopts
 narrative  criteria  for toxic pollutants to
 protect designated uses, the  State must
 provide information  identifying the meth-
 od by which the State intends to regulate
 point source discharges of toxic pollutants
 on water  quality limited segments based
 on such narrative criteria.  Such informa-
 tion may be included as  part of the stan-
 dards or may be included in documents
 generated by the State in response to the
 Water Quality  Planning  and Manage-
 ment Regulations (40 CFR part 35).
  (b) Form of criteria: In establishing cri-
 teria, States should:
  (I) Establish numerical values based
on;
  (j) 304(a) Guidance; or
  (ii) 304(a) Guidance modified to reflect
site-specific conditions; or
  (iii) Other scientifically  defensible
methods;
 _ (2) Establish narrative criteria or crite-
ria  based  upon  biomonitoring  methods
where numerical criteria cannot be estab-
lished or to supplement numerical crite-
ria.

§131.12 Antidegradation policy.

   (a) The'State shall develop and adopt a
statewide antidegradation policy and
identify the methods for implementing
such policy pursuant to this subpart. The
antidegradation policy and implementa-
tion methods shall, at a minimum, be con-
sistent with the following:
   (1) Existing  inslrcam water  uses and
the level of water quality necessary to pro-
tect the existing uses shall be maintained
and protected.
   (2) Where the quality of the waters ex-
ceed levels necessary to support propaga-
tion of fish, shellfish, and wildlife and rec-
reation in and  on the water, that  quality
shall  be maintained and protected unless
the State finds, after full  satisfaction of
the intergovernmental coordination and
public  participation  provisions  of  the
State's  continuing planning process, that
allowing lower  water quality is necessary
to accommodate important economic or
social development in the  area in  which
the waters are located. In allowing such
degradation or  lower water 'quality,  the
State shall assure water quality adequate
to protect existing uses fully. Further, the
State shall assure  that  there shall  be
achieved the highest statutory and  regula-
tory requirements for all new and existing
point  sources and all cost-effective and
reasonable best management practices for
nonpoint source control.
   (3) Where high quality  waters  consti-
tute an outstanding National  resource,
such  as waters  of  National and State
parks and wildlife refuges and waters of
exceptional recreational or ecological sig-
nificance,  that  water  quality  shall  be
maintained and protected.
   (4) In those cases where potential wa-
ter quality impairment associated  with a
thermal discharge is involved, the  an-
tidegradation  policy and  implementing
method shall be consistent, with section
316 of the Act.

§131.13 General policies.

  States may, at their discretion, include
in their State standards, policies generally
affecting their application and implemen-
tation, such as  mixing zones,  low flows
and variances. Such policies are subject to
EPA review and approval.
  Subpart C—Procedures for Review
    and Revision of Water Quality
              Standards

§131.20 State review and revision of water
  quality standards.
   (a) State review. The State shall  from
time to time, but at least once every three
years, hold public hearings  for the pur-
pose of reviewing applicable water quality
standards and, as appropriate, modifying
and adopting  standards. Any water  body
segment with water quality standards that
do not include the uses specified in section
101(a)(2) of the Act shall be re-examined
every three years to determine if any new
information has become available. If such
new information indicates that the uses
specified in section 101(a)(2) of the Act
are attainable, the State shall revise  its
standards accordingly.  Procedures States
establish  for  identifying and  reviewing
water bodies for review  should be incorpo-
rated into their Continuing Planning Pro-
cess.
   (b) Public  participation. The State
shall hold a public hearing for the purpose
of reviewing water quality  standards, in
accordance with  provisions of State law,
EPA's water quality management  regula-
tion (40  CFR  130.3(b)(6)) and public
participation  regulation (40 CFR  part
25). The proposed water quality stan-
dards  revision and supporting analyses
shall be made available  to the public prior
to the hearing.
   (c) Submittat to EPA. The State shall
submit the results of the review, any sup-
porting analysis for the use  attainability
analysis, the methodologies  used for site-
specific criteria development, any general
policies applicable to water quality stan-
dards and any revisions of the standards
to the  Regional Administrator for review
and approval, within 30 days of the  final
State action to adopt and certify  the re-
vised standard, or if no revisions are made
as a result of the review, within 30 days of
the completion of the review.

§131.21 EPA review and approval of water
  quality standards.
  (a) After  the State submits its officially
adopted revisions, the Regional Adminis-
trator shall either:
  (1) Notify the State within  60 days
that the revisions are approved, or
  (2) Notify the State within  90 days
that  the revisions  are disapproved. Such

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notification  of  disapproval  shall specify
the changes needed to assure compliance
with the requirements of the Act and this
regulation,  and shall explain  why the
State standard  is not in  compliance with
such  requirements. Any new or revised
State standard must be  accompanied  by
some type of supporting  analysis.
   (b) The  Regional Administrator's ap-
proval or disapproval of a State  water
quality standard shall be based on the re-
quirements of the Act  as described in
§§131.5, and 131.6.
   (c) A State water quality standard  re-
mains in effect, even though disapproved
by EPA, until the State revises it or EPA
promulgates a rule that supersedes the
State water quality standard.
   (d) EPA  shall,  at least  annually, pub-
lish in the  FEDERAL REGISTER a notice of
approvals under this section.

§131.22 EPA  promulgation of  water
  quality standards.
   (a) If the State  does  not adopt the
changes specified by the Regional Admin-
istrator within 90 days  after notification
of the Regional. Administrator's  disap-
proval, the Administrator shall promptly
propose and promulgate such standard.
   (b) The Administrator  may  also pro-
pose and promulgate  a  regulation, appli-
cable to one or more States, setting forth
a new or revised standard upon  determin-
 ing such a standard is necessary to meet
 the requirements of the Act.
   (c) In promulgating water quality stan-
 dards, the Administrator is subject to the
 same policies, procedures, analyses, and
 public participation  requirements  estab-
 lished  for  States in these regulations.

  Subpart D—Federally Promulgated
       Water Quality Standards

 §131.31 Arizona.
    (a) Article 6, Part 2 is amended as fol-
 lows:
    (l)Reg. 6-2-6.11 shall read:   .
   Reg. 6-2-6.11  Nutrient  Standards.  A.  The
 mean annual total phosphate and mean annual
 total nitrate concentrations of the following waters
 shall not exceed  the values given below  nor shall
 the total phosphate or total nitrate concentrations
 of more than 10 percent of the samples in any year
 exceed the 90 percent values given below. Unless
 otherwise specified, indicated values also apply to
 tributaries to the named waters.


1 . Colorado River from Utah
border to Willow Beach
2. Colorado River from Wil-
low Beach to Parker Dam
3. Colorado River from Par-
ker Dam to Imperial Dam
4. Colorado River from Im-
perial Dam to Morelos
5. Gila River from New Mex-
ico border to San Carlos
Reservoir (excluding San
6. Gila River from San Car-
los Reservoir to Ashurst
Hayden Dam (including
San Carlos Reservoir) 	
8. Verde River (except Gran-
ite Creek) 	
9. Salt River above Roose-
velt Lake 	
10. Santa Cruz River from
international boundary
near Nogales to Sahuarita
11. Little Colorado River
above Lyman Reservoir-
Mean 90 pet annual value
Total
phosphates
as PO4mg/l
0.04-0.06
0.06-0.10
0.08-0.12
0.10-0.10
0.50-0.80
0.30-0.50
0.30-0.50
0.20-0.30
0.20-0.30
0.50-0.80
0.30-0.50
Total ni-
trates as
NOjmg/l
4-7
5
5-7
5-7
  B. The above standards are intended to protect
the beneficial uses of the named waters. Because
regulation of nitrates and phosphates alone may
not be adequate to protect waters from eutrophica-
tion, .no substance shall be added  to any surface
water which produces aquatic growth to the extent
that such growths create a public  nuisance or in-
terference with beneficial uses of the water defined
and designated in Reg. 6-2-6.5..
  (2) Reg. 6-2-6.10 Subparts A and B are
amended to include Reg.  6-2-6.11 in se-
ries  with Regs.  6-2-6.6, 6-2-6.7 and 6-2-
6.8.

§131.33  [Reserved]

§131.34  [Reserved]

§131.35 Colville Confederated  Tribes
  Indian  Reservation.
  The water quality standards applicable
to the waters within the Colville Indian
Reservation, located  in the  State of
Washington.
   (a) Background.
   (1) It  is the purpose of these  Federal
water quality standards to prescribe mini-
mum water quality requirements for the
surface waters located within the exterior
boundaries of the Colville Indian Reserva-
tion to ensure compliance with  section
303 (c) of the Clean Water Act.
  (2) The  Colville Confederated Tribes
have a primary interest in the protection,
control, conservation, and utilization of
the water resources of the Colville Indian
Reservation.  Water  quality  standards
have been enacted into tribal law by the
Colville Business Council of the Confed-
erated Tribes of the Colville Reservation,
as  the Colville Water Quality Standards
Act, CTC Title 33 (Resolution No. 1984-
526 (August 6, 1984) as amended by Res-
olution No. 1985-20 (January 18,  1985)).
   (b) Territory Covered. The provisions
of these water quality standards shall ap-
ply to all surface waters within the exteri-
or  boundaries of the Colville Indian Res-
ervation.
   (c) Applicability,  Administration  and
Amendment.
   (1) The water  quality standards in this
section shall be used by the Regional Ad-
ministrator  for  establishing  any water
quality  based National Pollutant  Dis-
charge  Elimination System  Permit
(NPDES) for point sources  on the  Col-
ville Confederated Tribes Reservation.
   (2) In conjunction with the issuance of
section 402 or section 404 permits,  the
 Regional  Administrator may designate
 mixing zones -in  the waters of the United
States on the reservation on a  case-by-
case  basis. The size of such  mixing zones
 and the in-zone water quality in such mix-
 ing, zones shall be consistent with the ap-
 plicable  procedures and  guidelines  in
 EPA's Water Quality Standards Hand-
 book  and the Technical Support Docu-
 ment for Water  Quality  Based Toxics
 Control.
    (3) Amendments to the section at the
 request of the Tribe shall proceed in the
 following manner.
    (i) The requested amendment shall first
 be duly  approved  by the Confederated
 Tribes of the Colville Reservation (and so
 certified  by the Tribes  Legal  Counsel)
 and submitted to the Regional Adminis-
 trator.
    (ii) The requested amendment shall be
 reviewed  by EPA  (and  by the  State of
 Washington, if the action would affect a
 boundary water).
    (iii) If deemed in compliance  with the
 Clean Water  Act,  EPA  will propose and
 promulgate an appropriate change to this
 section.

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   (4) Amendment  of this section  at
 EPA's initiative will follow consultation
 with the Tribe and other appropriate enti-
 ties. Such amendments will then follow
 normal EPA rulcmaking procedures.
   (5) All other applicable  provisions of
 this part 131  shall apply  on the Colville
 Confederated Tribes Reservation. Special
 attention should be  paid to  §§131.6,
 131.10,131.11 and 131.20 for any amend-
 ment to  these standards to be initiated by
 the Tribe.
   (6) All numeric  criteria  contained in
 this section apply at'all  in-stream flow
 rales greater  than  or equal to the flow
 rate calculated as the minimum 7-consec-
 utivc day average flow  with a recurrence
 frequency of  once in ten years (7Q10);
 narrative criteria ( §131.35(e)(3)) apply
 regardless of flow. The 7Q10  low flow
 shall be  calculated using methods  recom-
 mended  by the U.S. Geological  Survey.
   (d) Definitions.
   (1) "Acute  toxicity"  means a deleteri-
 ous  response  (e.g.,  mortality, disorienta-
 tion,  immobilization) to a  stimulus ob-
 served in 96 hours or less.
   (2) "Background  conditions"  means
 the biological, chemical, and physical con-
 ditions of a water body,  upstream  from
 the point or  non-point  source  discharge
 under consideration. Background sam-
 pling location in an enforcement action
 will be upstream from the point  of dis-
 charge, but not upstream from  other in-
 flows. If several discharges  to any water
 body exist, and  an enforcement action is
 being taken for possible violations to the
 standards, background  sampling will be
 undertaken  immediately upstream from
 each discharge.
   (3) "Ceremonial and Religious water
 use" means activities involving traditional
 Native  American spiritual  practices
 which involve, among other things, prima-
 ry (direct) contact with water.
   (4) "Chronic Toxicity" means the low-
 est concentration of a constituent causing
 observable effects (i.e., considering lethal-
 ity, growth, reduced  reproduction, etc.)
over a relatively long period of time, usu-
ally a 28-day test period for small fish test
species.
   (5) "Council" or  "Tribal Council"
 means the Colville Business Council of
the Colville Confederated Tribes.
   (6) "Geometric  mean"  means  the
"nth" root of a product  of "n" factors.
   (7) "Mean  retention time" means the
 time obtained by  dividing a reservoir's
 mean  annual minimum total storage  by
 the  non-zero 30-day,  ten-year low-flow
 from the reservoir.
   (8) "Mixing Zone" or "dilution zone"
 means a limited area or volume of water
 where initial dilution of a discharge takes
 place; and where numeric water quality
 criteria can be exceeded but acutely toxic
 conditions are prevented from occurring.
   (9) "pH" means the negative logarithm
 of the hydrogen ion concentration.
   (10) "Primary  contact recreation"
 means  activities where a  person would
 have direct  contact with  water  to  the
 point of complete submergence, including
 but not limited to skin diving, swimming,
 and water skiing.
   (11) "Regional  Administrator"  means
 the Administrator of EPA's Region X.
   (12) "Reservation" means all land
 within  the limits  of the Colville  Indian
 Reservation, established on July 2, 1872
 by Executive  Order, presently containing
 1,389,000 acres more or less, and under
 the jurisdiction of the United States gov-
 ernment, notwithstanding the issuance of
 any  patent, and including  rights-of-way
 running through the reservation.
   (13) "Secondary  contact  recreation"
 means activities where a person's water
 contact would be limited  to the  extent
 that bacterial infections of eyes, ears, res-
 piratory, or digestive systems or urogeni-
 tal areas would'normally be avoided (such
 as wading or fishing).
   (14) "Surface water" means,all water
 above the surface of .the ground within the
 exterior boundaries of the Colville  Indian
 Reservation including but not limited to
 lakes, ponds,  reservoirs,  artificial im-
 poundments,  streams,  rivers,  springs,
 seeps and wetlands.
  (15) "Temperature" means water tem-
 perature expressed in Centigrade degrees
 (C).
  (16) "Total  dissolved solids"  (TDS)
 means  the total filterable  residue  that
 passes through a standard glass fiber filter
 disk and remains  after  evaporation  and
 drying to a constant weight at 180 degrees
 C. it is considered to be a measure of the
dissolved salt content of the water.
  (17) "Toxicity" means acute and/or
chronic toxicity.
  (18) "Tribe" or  "Tribes" means the
Colville Confederated Tribes.
   (19) "Turbidity" means the clarity of
 water expressed as nephelometric turbidi-
 ty units (NTU) and measured with a cali-
 brated turbidimeter.
   (20) "Wildlife habitat" means the wa-
 ters and  surrounding land areas of the
 Reservation  used by fish, other aquatic
 life and wildlife at any stage of their life
 history or activity.
   (e) General considerations. The follow-
 ing general guidelines shall apply to the
 water quality standards and classifications
 set forth  in the use designation Sections.
   (1)  Classification  Boundaries. At the
 boundary between  waters of  different
 classifications, the  water quality stan-
 dards  for the  higher classification  shall
 prevail.
   (2)  Antidegradation  Policy.  This an-
 tidegradation policy shall be applicable to
 all surface waters of the Reservation.
   (i) Existing  in-stream water  uses  and
 the level of water quality necessary to pro-
 tect the existing uses shall be maintained
 and protected.
   (ii)  Where the quality of the waters ex-
 ceeds levels necessary to support propaga-
 tion of fish, shellfish, and wildlife and rec-
 reation in and  on the water, that quality
 shall be maintained and protected unless
 the Regional Administrator finds, after
 full satisfaction of the inter-governmental
 coordination and public participation pro-
 visions of the Tribes' continuing planning
 process, that allowing lower water quality
 is necessary to accommodate important
 economic or social  development  in  the
 area in which  the waters are  located. In
 allowing such degradation or lower water
 quality, the Regional Administrator shall
 assure water quality adequate to protect
 existing uses fully. Further, the  Regional
 Administrator shall  assure that there
 shall  be   achieved the  highest statutory
 and regulatory requirements for all  new
 and existing point sources and  all cost-
 effective   and  reasonable best  manage-
 ment practices for nonpoint source  con-
 trol.
  (iii) Where  high  quality  waters are
 identified  as constituting an outstanding
 national or reservation  resource, such as
 waters within areas designated as unique
 water quality management areas and wa-
 ters otherwise of exceptional recreational
or ecological significance, and are desig-
nated as special resource waters, that wa-
ter  quality shall be maintained  and  pro-
tected.

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  (iv) In those cases where potential wa-
ter quality impairment associated with a
thermal  discharge  is involved,  this an-
tidegradation  policy's implementing
method shall be  consistent  with section
316 of the Clean  Water Act.
  (3) Aesthetic  Qualities. All  waters
within the Reservation, including  those
within mixing zones, shall be free from
substances, attributable to  wastewater
discharges or  other pollutant  sources,
that:
  (i) Settle to form objectionable depos-
its;
  (ii) Float as debris, scum, oil, or other
matter forming nuisances;
  (iii) Produce objectionable color, odor,
taste, or turbidity;
  (iv) Cause injury to, are toxic to,  or
produce adverse  physiological responses
in humans, animals, or  plants; or
  (v) Produce  undesirable or  nuisance
aquatic life.
  (4) Analytical  Methods.
   (i) The analytical testing methods used
to measure or otherwise evaluate compli-
ance with water quality standards shall to
the extent practicable,  be in  accordance
with  the "Guidelines Establishing Test
Procedures for the Analysis of Pollutants"
(40 CFR part 136). When a testing meth-
od is  not available for a particular sub-
stance, the most  recent edition of "Stan-
dard  Methods for the Examination of
Water and Wastewater"  (published  by
the American Public Health Association,
American Water Works Association, and
the  Water Pollution Control Federation)
and other or superseding methods pub-
lished and/or approved by  EPA shall be
 used.
   (f) General  Water Use  and  Criteria
 Classes. The following criteria shall apply
 to the various classes of surface waters on
 the Colville Indian Reservation:
   (1) Class I (Extraordinary)—
   (i) Designated uses. The designated
 uses include, but are not limited to, the
 following:
   (A) Water supply (domestic, industrial,
 agricultural).
   (B) Slock watering.
   (C) Fish and shellfish: Salmonid migra-
 tion,  rearing,  spawning,  and harvesting;
 other fish migration, rearing, spawning,
 and harvesting.
   (D) Wildlife habitat.
   (E) Ceremonial  and religious water
 use.
  (F) Recreation (primary contact recre-
ation, sport fishing, boating and aesthetic
enjoyment).
  (G) Commerce and navigation.
  (ii) Water quality criteria.
  (A) Bacteriological Criteria—The geo-
metric mean of the enterococci bacteria
densities in samples taken over a 30 day
period shall not exceed 8 per 100 millili-
ters, nor shall any single sample exceed an
enterococci density of 35 per 100 millili-
ters. These limits are calculated as  the
geometric mean of the collected  samples
approximately equally spaced over a thir-
ty day period.
  (B) Dissolved oxygen—The dissolved
oxygen shall exceed 9.5 mg/1.
  (C) Total                dissolved
gas—concentrations shall not exceed  110
percent of the saturation value for gases
at the existing atmospheric and hydrostat-
ic pressures at any point of sample collec-
tion.
   (D) Temperature—shall  not exceed
 16.0 degrees C due to human activities.
Temperature  increases shall not, at  any
time, exceed t=23/(T+5).
   (/) When natural  conditions  exceed
 16.0 degrees C, no temperature  increase
will be allowed which will raise the receiv-
ing  water by greater than 0.3 degrees C.
   (2) For purposes hereof, "t" represents
the  permissive temperature change across
the  dilution zone; and "T" represents the
 highest existing temperature in this water
 classification outside of any dilution zone.
   (3) Provided that temperature increase
 resulting from nonpoint source activities
 shall not exceed 2.8 degrees C, and the
 maximum water temperature shall not ex-
 ceed 10.3 degrees C.
   (E) pH shall be within the range of 6.5
 to 8.5 with a human-caused variation  of
 less than 0.2 units.
   (F) Turbidity shall not  exceed 5 NTU
 over background turbidity when the back-
 ground  turbidity  is 50 NTU or less,  or
 have more than a 10 percent increase in
 turbidity when the background  turbidity
 is more than  50 NTU.
   (G) Toxic, radioactive, nonconvention-
 al, or deleterious material concentrations
 shall be less  than those of public health
 significance, or which may cause acute or
 chronic toxic conditions to the aquatic  bi-
 ota, or which may adversely affect desig-
 nated water uses.
   (2) Class II (Excellent).—
   (i) Designated  uses.  The  designated
 uses  include but are not limited to, the
 following:
   (A) Water supply (domestic, industrial,
 agricultural).
   (B) Stock watering.
   (C) Fish and shellfish: Salmonid migra-
 tion, rearing,  spawning,  and harvesting;
 other fish migration,  rearing, spawning,
 and  harvesting; crayfish  rearing, spawn-
 ing, and harvesting.
   (D) Wildlife habitat.
   (E) Ceremonial and  religious water
 use.
   (F) Recreation  (primary contact recre-
 ation, sport fishing, boating and  aesthetic
 enjoyment).
   (G) Commerce and navigation.
   (ii) Water quality criteria.
   (A) Bacteriological Criteria—The geo-
 metric mean of the  enterococci bacteria
 densities in samples taken  over  a 30 day
 period shall not exceed  16/100 ml,  nor
 shall any single sample exceed an entero-
 cocci density  of  75 per 100 milliliters.
 These limits are calculated as the geomet-
 ric mean of the collected  samples approxi-
 mately equally spaced over a thirty day
 period.
   (B) Dissolved oxygen—The  dissolved
 oxygen shall exceed 8.0 mg/1.
   (C) Total dissolved gas—concentra-
 tions shall not exceed  110 percent of the
 saturation value for gases  at the existing
 atmospheric and  hydrostatic  pressures at
_ any point of sample collection.
   (D) Temperature—shall  not exceed
  18.0 degrees  C due to human  activities;
 Temperature  increases shall not, at  any
 time, exceed t=28/(T+7).
   (/) When natural conditions exceed 18
 degrees C no temperature increase will be
 allowed which will raise  the receiving wa-
 ter  temperature by greater than 0.3 de-
 grees C.
   (2) For purposes hereof, "t" represents
 the  permissive temperature change across
 the  dilution zone; and "T" represents the
 highest existing temperature  in this water
 classification outside of any dilution zone.
   (3) Provided that temperature increase
  resulting  from non-point source activities
 shall not exceed 2.8  degrees C, and the
  maximum water temperature shall not ex-
 ceed 18.3 degrees C.
    (E) pH shall be within the range of 6.5
  to 8.5 with a human-caused variation of
  less than.0.5 units.

-------
   (F) Turbidity shall not exceed 5 NTU
over background turbidity when the back-
ground turbidity is 50 NTU  or less, or
have more than a  10 percent  increase in
turbidity when the background  turbidity
is more than 50 NTU.
   (G) Toxic,  radioactive, nonconvention-
al, or deleterious material concentrations
shall be'less than  those of public health
significance, or which may cause acute or
chronic toxic conditions to the aquatic bi-
ota, or which may adversely affect desig-
nated water uses.
   (3) Class lit (Good).—
   (i) Designated uses. The  designated
uses  include but arc not limited  to, the
following:
   (A) Water  supply (industrial,  agricul-
tural).
   (B) Stock watering.
 __ (C) Fish and shellfish: Salmonid migra-
tion, rearing, spawning,  and  harvesting;
other fish migration,  rearing, spawning,
and harvesting; crayfish  rearing,  spawn-
ing, and harvesting.
   (D) Wildlife habitat.
   (E) Recreation (secondary contact rec-
reation, sport fishing, boating and aesthet-
ic enjoyment).
   (F) Commerce and navigation.
   (ii) Water quality criteria.
   (A) Bacteriological Criteria—The geo-
metric mean of the enterococci bacteria
densities  in samples taken over a 30 day
period shall not exceed 33/100  ml,  nor
shall any single sample exceed an entero-
cocci density  of 150 per 100 milliliters.
These limits are calculated as the geomet-
ric mean of the collected samples approxi-
mately equally spaced  over a  thirty day
period.
   (B) Dissolved oxygen.

7 diy mean »....,»„„..„..„.
1 
-------
  (F) Recreation (primary contact recre-
ation, sport fishing, boating and aesthetic
enjoyment).
  (G) Commerce and navigation.
  (ii) Water quality criteria.
  (A) Bacteriological  Criteria.  The geo-
metric  mean of the enterococci bacteria
densities in samples taken over a 30 day
period  shall not exceed  33/100 ml, nor
shall any single sample exceed an entero-
cocci density  of 150  per  100 milliliters.
These limits are calculated as the geomet-
ric mean of the collected samples approxi-
mately  equally spaced over  a thirty day
period.
   (B) Dissolved  oxygen—no measurable
decrease from natural conditions.
   (C) Total dissolved  gas concentrations
shall not exceed 110 percent  of the satura-
tion value for gases at the existing atmo-
spheric and hydrostatic pressures at amy
point of sample collection.
   (D) Temperature—no  measurable
change from natural conditions.
   (E) pH—no  measurable  change from
 natural conditions.
   (F) Turbidity shall not exceed 5  NTU
 over natural conditions.
   (G) Toxic,  radioactive, nonconvention-
 al,  or deleterious material concentrations
 shall be less than those which may affect
 public health, the natural aquatic environ-
 ment,  or the  desirability of  the water for
 any use.
    (6)  Special Resource  Water   Class
 (SRW)—
    (i) General characteristics.  These  are
 fresh or  saline waters which comprise a
 special and unique resource to the Reser-
 vation. Water quality of this class  will be
 varied and unique as determined  by the
 Regional Administrator in cooperation
 with the Tribes.
    (ii) Designated uses. The  designated
 uses include, but are not limited  to, the
 following:
    (A) Wildlife habitat.
    (B) Natural foodchain maintenance:.
    (iii) Water quality criteria.
    (A) Enterococci bacteria  densities shall
  not exceed natural conditions.
    (B)  Dissolved  oxygen—shall not show
  any  measurable  decrease  from  natural
  conditions.
     (C) Total  dissolved gas  shall not vary
  from  natural conditions.
     (D) Temperature—shall  not show any
  measurable  change  from  natural condi-
  tions.
  (E) pH shall not show any  measurable
change from natural conditions.
  (F) Settleable solids shall not show any
change from natural conditions.
  (G) Turbidity shall not exceed 5 NTU
over  natural conditions.
  (H) Toxic, radioactive,  or deleterious
material concentrations shall not exceed
those found under natural conditions.
  (g) General Classifications.  General
classifications applying to various surface
waterbodies not specifically classified un-
der §131.35(h) are  as follows:
   (1)A11 surface waters that are tribu-
taries  to Class  I  waters  are classified
Class I, unless otherwise classified.
   (2) Except for  those specifically classi-
fied otherwise, all lakes with existing aver-
age  concentrations  less than 2000 mg/L
TDS and their feeder streams on the Col-
ville Indian Reservation are classified  as
 Lake Class and Class I, respectively.
   (3) All  lakes  on the  Colville Indian
 Reservation with existing average concen-
 trations of  TDS equal to or exceeding
 2000 mg/L and their feeder streams are
 classified as Lake  Class and Class I re-
 spectively  unless  specifically  classified
 otherwise.
    (4) All  reservoirs with  a mean deten-
 tion time of greater than 15 days are clas-
 sified Lake Class.
    (5) All  reservoirs with a mean deten-
 tion time of 15 days or less are  classified
 the  same  as the river  section  in  which
 they are located.
    (6) All reservoirs established on pre-ex-
 isting lakes are classified as Lake Class.
    (7) AH  wetlands are  assigned  to  the
 Special Resource Water Class.
    (8) All  other waters not specifically  as-
 signed to a classification of the reservation
 are classified as Class II.
    (h) Specific  Classifications. Specific
 classifications for  surface waters of the
 Colville Indian Reservation are as follows:
  (1) Streams:
   Alice Creek	    Class III
   Anderson Creek	   Class III
   Armstrong Creek....	    Class III
   Barnaby Creek	    Class II
   Bear Creek	    Class III
   Beaver Dam Creek	    Class II
   Bridge Creek	    Class II
   Brush Creek	    Class III
   Buckhorn Creek	    Class III
   Cache Creek	    Class III
   Canteen Creek	    Class I
   Capoose Creek	Class III
   Cobbs Creek	    Class III
   Columbia  River (rom Chief Joseph
     Dam to Wells Dam
Columbia River from northern Res-
  ervation boundary to Grand Cou-
  lee Dam (Roosevelt Lake)
Columbia River from Grand Coulee
  Dam to Chief Joseph Dam
Cook Creek	    Class I
Cooper Creek	'.	    Class III
Cornstalk Creek	    Class III
Cougar Creek	    Class I
Coyote Creek	    Class II
Deerhorn Creek	    Class III
Dick Creek	    Class III
Dry Creek	    Class I
Empire Creek	    Class III
Faye Creek	    Class I
Forty Mile Creek	    Class III
Gibson Creek	    Class I
Gold Creek	    Class II
Granite Creek	    Class II
Grizzly Creek	    Class 111
Haley  Creek	    Class III
Hall Creek	    Class II
Hail Creek, West Fork	    Class I
Iron Creek	    Class III
Jack Creek	    Class III
Jerred Creek	    Class I
Joe Moses Creek	    Class III
John Tom Creek	    Class III
Jones Creek	    Class I
Kartar Creek	   Class III
Kincaid Creek	   Class 111
King Creek	   Class III
Klondyke Creek	   Class I
Lime Creek	   Class III
Little Jim Creek	   Class III
Little Nespelem	   Class H
 Louie Creek	   Class III
 Lynx Creek	:	   Class II
 Manila Creek	   Class III
 McAllister Creek	   Class III
 Meadow Creek	   Class III
 Mill Creek	   Class II
 Mission Creek	   Class III
 Nespelem River	   Class II
 Nez Perce Creek	    Class III
 Nine Mile Creek	    Class H
 Nineteen Mile Creek	    Class III
 No Name Creek	    Class II
 North Nanamkin Creek	    Class 111
 North Star Creek	    Class III
 Okanogan River from Reservation   Class II
   north boundary to Columbia River
 Olds  Creek	    Class I
 Omak Creek	    Class II
 Onion Creek	    Class II
 Parmenter Creek	    Class III
 Peel  Creek	    Class 111
  Peter Dan Creek	    Class III
  Rock Creek	    Class I
  San Poll River	    Class I
  Sanpoil, River West Fork	    Class II
  Seventeen Mile  Creek	    Class III
  Silver Creek	   Class III
  Sitdown Creek	   Class III
  Six Mile Creek	   Class 111
  South Nanamkin Creek	   Class III
  Spring Creek	   Class III
  Stapaloop Creek	   Class III
  Stepstone Creek	   Class III
  Stranger Creek	   Class II
  Strawberry Creek	   Class III
  Swimptkin Creek	   Class III
  Three Forks Creek	   Class I
  Three Mile Creek	   Class 111
  Thirteen Mile Creek	   Class II
  Thirty Mile Creek	   Class II
  Trail Creek	   Class III
  Twentyfive Mile Creek	   Class III
  Twentyone Mile Creek	   Class III
  Twentythree Mile Creek-	:;	   Class III
  Wannacot Creek	   Class III

-------
W«U Crt«k ---------- ..
Whl»»!»w Click,-...
WWntmt Ct«k,.,.,.,,
Dbow Uk«,,,,.,™,...
Fish Uk«.,,.,,,,,,,,,,,,,,.
Ook) Lak«..,:.„„,.,....
GttU Wif tarn Uk«..
Jonoion Uki.....».».
Class I
Class III
Class II

LC
LC
LC
LC
LC
LC
LC
LC
LC
LC
LC
LC
LaFleur Lake	
Little Goose Lake..
Little Owhl Lake....
McGinnisLake	
Nicholas Lake	
OmakLake	
Owhl Laks	
Panley Lake	
Rebecca Lake	
Round Lake	
Simpson Lake	
Soap Lake	
Sugar Lake	
Summit Lake	
Twin Lakes	
LC
LC
LC
LC
LC
SRW
SRW
SRW
LC
LC
LC
LC
LC
LC
SRW
 §131.36 Toxics  criteria  for those  states
  not  complying with  Clean Water Act
  section 303(cX2XB).

   (a) Scope. This section is not a general
 promulgation of the section 304(a)  crite-
 ria for priority toxic pollutants but  is re-
 stricted to  specific pollutants in specific
 States.

   (b)(l)EPA's Section  304(a)  Criteria
for Priority Toxic Pollutants.

-------
A B C
FRESHWATER SALTWATER
Criterion Criterion Criterion Criterion
Maximum Continuous Maximum Continuous
,#•> c o M p o U N 0 CAS Cone, d Cone, d Cone, d Cone, d
(#) c o M P u u (ug/L) (ug/L) (ug/L)
B1 B2 C1 C2
1 Antimony 7440360 ', ,
2 Arsenic 7440382 360 m 190 m 69 m 36 m
3 Beryllium 7440417
4 cadmium 7440439 | 3.9 e,m 1.1e,mj 43m 9.3m
5a Chromium (III) 16065831 | 1700 e,m 210 e,m j
b Chromium (VI) 18540299 j 16 m 11 m ! 1100 m 	 50 m
6 Copper 7440508 \ 18 e,m 12 e,m \ 2.9 m 2.9 m
7 Lead 7439921 [ 82 e.m 3.2 e.m | 220m 8.5m
8 Mercury ' 74395-76 j 2.4 m 0.012 1 j 2.1 m 0.025 i
9 nickel .7440CI20 | 1400 e,m 160 e,m j 75 m 8.3 m
in c i • 7782492 '20 5 ! 300 m 71 m
H sUver 7440224 j 4.1 e,m i 2.3 m
12 Thallium, 7440280 j
13 zinc 7440(S66 ! 120 e.m 110 e,m 95 m 86 m
14 Cyanide 57125 j 22 5.2 1 1
16 2,3,7,8-TCDD (Dioxin) 1746016 j !
17 Acrolein 107028 |
18 Acrylonitrile 107131 |
19 Benzene 71432 j i
nn n__m~f«^m 75252 ! ! 	
21 Carbon Tetrachloride 56235 j i
22 Chlorobenzene 108907 j !
23 Chlorodibromomethane 124481 i !
24 Chloroethane 715003 j i
25 2-Chl"r""»hy vinyl Ether 110758 | ! 	
26 Chloroform 67663 j i
D
HUMAN HEALTH
(10 risk for carcinogens)
For Consumption of:
Water & Organisms «.
Organisms Only
(ug/L) (ug/L)
01 D2
14 a 4300 a
0.018 a,b,c 0.14 a,b,c
n n
n n
n n
n n
n n
0.14 0.15
610 a 4600 a
n n
1.7 a 6.3 a
700 a 220000 a,j
7.000.000 fibers/L k
JO. 000000013 c 0.000000014 c
| *320 780
j 0.059 a,c 0.66 a,c
j 1.2 a,c 71 a,c
j 4.3 a.c 360 a,c
| 0.25 a.c 4.4 a,c
j 680 a 21000 a.j
j 0.41 a,c 34 a,c
i
i
i
— i 	 . — . 	
I 5.7 a,c 470 a,c
j 0.27 a.c 22 a.c

-------
28 1,1-Dichloroethane
29 1,2-Dichloroethane
30 1,1-Dichloroethylene
31 1,2-Dichloropropane
32 1,3-DichlorooroDVlene
33 Ethylbenzene
34 Methyl Bromide
35 Hethyl Chloride
36 Hethylene Chloride
37 1.1.2,2-Tetraehloroethane
38 Totrachtoroethylene
39 Toluene
40 1,2-Trans-Dichloroethylene
41 1,1,1-Trichloroethane
42 1.1,2-Trichloroethane
43 Trichloroethylene
44 Vinyl Chloride
45 2-Chlorophenol
46 2,4-Dichlorophenol
47 2.4-DimethvlDhenol
48 2-Hethyl-4,6-Dinitrophenol
49 2,4-Dinitrophenol
50 2-Mitrophenol
51 4-Hitrophenol
52 3-Hethvl-4-Chloroohenol
53 Pcntnchlorophenol
54 Phenol
55 2,4,6-Trichlorophenol
56 Acenaphthene
75343
107062
75354
78875
542756
100414
74839
74873
75092
79345
127184
108883
156605
71556
79005
79016
75014
95578
120832
105679
534521
51285
88755
100027
59507
87865
108952
88062
83329
: :
! | 0.38 a,c 99 a,c
! i 0.057 a,c 3.2 a,c
1 i
j 	 | 	 | 	 10 a 1700 a
• i ! 3100 a 29000 a
' | 48 a 4000 a
i |nn
! ! 4.7 a,c 1600 a,c
i 	 _j 	 j 	 Q.17 a.c 	 H a,c
! j 0.8 c 8.85 c
! j 6800 a 200000 a
i ,
l i
! Inn
	 1 	 	 	 j 	 0.60 a c 42 a c
i | 2.7 c 81 c
I i 2 c 525 c
i i
i !
! ! 93 a 790 a,j
j i
i i 13.4 765
! j 70 a 14000 a
j i
i 1
i ,
20 f 13 f j 13 7.9 j 0.28 a.c 8.2 a,c.
! j 21000 a 4600000 a, j
i I 2.1 a,c 6.5 a,c
i i
i

-------
A
(#) COMPOUND CAS
Number
B
FRESHWATER
Criterion Criterion
Maximum Continuous
Cone, d Cone, d
(ug/L) 
-------
(#> C 0 H P 0 U H D CAS
Number
— 	 — 	
b
FRESHWATER
Criterion Criterion
Maximum Continuous
Cone, d Cone, d
(ug/L) (ug/L)
B1 B2
C
SALTWATER
Criterion Criterion
Maximum Continuous
Cone, d Cone, d
(ug/L) (ug/L)
C1 C2
D
H U_M A N HEALTH
(10" risk for carcinogens)
For Consumption of:
Water & Organisms
Organisms Only
(ug/L) (ug/L)
D1 D2
86 Fluoranthene
87 Fluorene
88 Hexachlorobenzene
89 Hexachlorobutadiene
90 Hexachlorocvclooentadiene
91 Hexachloroethane
92 Indeno(1,2,3-cd)Pyrene
93 Isophorone
94 Naphthalene
95 Nitrobenzene
96 N-Hitrosodfmethylamine
97 N-Hitrosodi-n-Propylamine
98 H-Hitrosodiphenylaraine
99 Phenanthrene
100 Pvrene
101 1,2,4-Trichlorobenzene
102 Aldrin
103 alpha-BHC
104 beta-BHC
105 oawwi-BHC
106 delta-BHC

107 Chlordam
108 4-4' -DOT
109 4,4' -DOE
110 4.4'-000
111 OleldHn
112 alpha-Endosulfan
113 beta-Endosulfan
206440 j
86737 {
118741 |
87683 j
77474 !
67721 |
193395 |
78591 j
91203 j
98953 !
62759 j
621647 j
86306 j
85018 j
129000 !
120821 j
309002 j 3 g
319846 j
319857 j
58899 ! 2 a
319868 |

57749 | 2.4 g
50293 j 1.1 g
72559 j
72548 |
60571 j 2.5 g
959988 j 0.22 g
33213659 j 0.22 g
i j 300 a
1300 a
j 0.00075 a,c
! 0.44 a,c
	 . 	 j 	 240 a
1.9 a,c
0.0028 c
! 8.4 a,c

	 _i 	 , 	 17 a
! ! 0.00069 a,c
! j
5.0 a,c
! j
	 	 	 | 	 960 a
i
1.3 g | 0.00013 a,c
! | 0.0039 a,c
! | 0.014 a,c
0.08 g , 0.16 a 	 { 	 0.019 c
l
l
0.0043 g | 0.09 g 0.004 g | 0.00057 a,c
0.001 g j 0.13 g 0.001 g j 0.00059 a,c
! ! 0.00059 a,c
	 | 	 . 	 I 0.00083 a.c
0.0019 g | 0.71 g 0.0019 g | 0.00014 a,c
0.056 g j 0.034 g 0.0087 g | 0.93 a
0.056 g j 0.034 g 0.0087 g | 0.93 a
370 a
14000 a
0.00077 a.c
50 a,c
17000 a,j
8.9 a,c
0.031 c
600 a,c

1900 a,j
8.1 a,c

16 a,c

11000 a

0.00014 a,c
0.013 a,c
0.046 a,c
0.063 c


0.00059 a,c
0.00059 a,c
0.00059 a,c
0.00084 a,c
0.00014 a,c
2.0 a
2.0 a

-------
(#)  COMPOUND
 CAS
Number
                                            FRESHWATER
Criterion  Criterion
Max i mum    Cont i nuous
Cone, d    Cone, d
(ug/L)     (ug/L)
  B1         B2
                                                                     SALTWATER
Criterion  Criterion
Maximum    Continuous
Cone, d    Cone, d
(ug/L)     (ug/L)
  C1	C2
HUMAN     HEALTH
(10   risk for carcinogens)

   For Consumption of:
 Water &          Organisms
 Organisms        Only
 (ug/L)           (ug/L)
    D1	Si	
114 Endosulfan Sulfate
115 Endrin
116 Endrin Aldehyde
117 Heptachlor
118 Heptachlor Epoxide
119 PCB-1242
120 PCB-1254
121 PCB-1221
122 PCB-1232
123 PCB-1248
124 PCS- 1260
125 PCB-1016
126 Toxaphene
1031078
72?.08
7421934
76448
1024S73
53469219
11097(S91
11104282
11141165
12672296
/
11096825
12674112
8001352
l
i
0.18 g 0.0023 g j 0.037 g
!
0.52 g 0.0038 g j 0.053 g
0.52 g 0.0038 g j 0.053 g
0.014 g j
0.014 g |
0.014 g |
0.014 g I
0.014 a !
0.014 g I
0.014 g |
0.73 0.0002 | 0.21
!
0.0023 g

0.0036 g
0.0036 g
0.03 g
0.03 g
0.03 g
0.03 g
0.03 g
0.03 g
0.03 g
0.0002
0.93 a 2.0 a
0.76 a 0.81 a,j
0.76 a 0.81 a,j
0.00021 a,c 0.00021 a,c
G
0.00010 a.c 0.00011 a.c
0.000044 afc 0.000045 a,c
0.000044 a,c 0.000045 a,c
0.000044 a.c 0.000045 a.c
0.000044 a.c 0.000045 a.c
0.000044 a.c 0.000045 a.c
0.000044 a.c 0.000045 a.c
0.000044 a.c 0.000045 a,c
0.00073 a.c 0.00075 a.c
 Total No.  of Criteria  (h)  =
                                               24
                                                            29
                                                                        23
                                                                                      27
                                                                     91
                                                                                                                     90

-------
   Footnotes:
   a.  Criteria revised  to reflect current
 agency qi* or RfD, as contained in the
 Integrated Risk Information  System
 (IRIS).  The fish tissue  bioconcentration
 factor (BCF) from the 1980 criteria docu-
 ments was retained in all cases.
   b. The criteria refers  to  the inorganic
 form only.
   c. Criteria in the matrix based on carci-
 nogcnicily (10-* risk).  For a risk level of
 10*J, move the decimal point in the matrix
 value one place to the right.
   d.  Criteria Maximum Concentration
 (CMC)  — the highest concentration of a
 pollutant to which aquatic life can be ex-
 posed  for a short period of time (1-hour
 average) without deleterious effects. Cri-
 teria Continuous Concentration (CCC) =
 the highest concentration of a pollutant to
 which aquatic life can be exposed for an
 extended period of time (4 days) without
 deleterious effects, ug/L « micrograms
 per liter
   c. Freshwater aquatic life criteria for
 these metals are expressed as a function
 of total hardness (mg/L), and as a func-
 tion of the pollutant's  water effect ratio,
 WER, as  defined in §131.36(c).  The
 equations  are  provided in matrix at
 §131.36(b)(2). Values  displayed above in
 the matrix correspond  to a total hardness
 of 100 mg/L and a water effect  ratio of
 1.0.
   f.  Freshwater aquatic  life criteria for
 pcmachlorophcnol  are expressed  as  a
 function  of pH, and are calculated as fol-
 lows.  Values displayed above in the ma-
 trix correspond to a pH of 7.8.
 CMC -  cxp(1.005(pH) - 4.830) CCC =
    cxp(1.005(PH) - 5.290)
   g. Aquatic life criteria  for these com-
 pounds were issued in  1980 utilizing the
 1980 Guidelines for criteria development.
The acute  values shown  are final acute
values  (FAV)  which  by the  1980 Guide-
 lines are instantaneous values as  con-
 trasted with a CMC which is a one-hour
 average.
   h. These  totals simply sum the criteria
 in each column. For aquatic life, there are
 30 priority toxic pollutants with  some
 type of freshwater or saltwater, acute or
 chronic criteria. For human health, there
 are 91 priority toxic pollutants with either
 "water +  fish" or  "fish only" criteria.
 Note that these totals count chromium as
 one pollutant even though EPA has devel-
 oped criteria based on two valence states.
 In the matrix, EPA has assigned numbers
 5a and 5b to the criteria  for chromium to
 reflect the fact that the list of 126 priority
 toxic pollutants includes only a single list-
 ing for chromium.
  i. If the CCC for total mercury exceeds
 0.012  ug/L more than once in a 3-year
 period in the ambient water, the  edible
 portion of aquatic species of concern must
 be analyzed to determine  whether the
 concentration of methyl mercury exceeds
 the FDA action level (1.0 mg/kg). If the
 FDA action level is  exceeded,  the State
 must notify  the appropriate EPA Region-
 al Administrator, initiate a revision of its
 mercury criterion in its water quality
 standards so as to protect designated uses,
 and take other appropriate action such as
 issuance of  a fish consumption advisory
 for the affected area.
  j. No criteria for protection of human
 health from  consumption  of aquatic orga-
 nisms (excluding water) was presented in
 the 1980 criteria document or in the 1986
 Quality Criteria for Water. Nevertheless,
sufficient information was  presented in
the 1980 document to allow a calculation
of a criterion, even though  the  results of
such  a calculation were not shown in the
document.
  k.  The criterion for  asbestos is  the
MCL (56 FR 3526, January 30, 1991).
   1. This letter not used as a footnote.
   m. Criteria  for  these  metals  are ex-
 pressed as a function of the water effect
 ratio, WER,  as defined  in  40  CFR
 131.36(c).
 CMC = column Bl or Cl value X WER
 CCC = column B2 or C2 value X WER
   n.  EPA  is not promulgating  human
 health criteria for this contaminant. How-
 ever, permit authorities  should  address
 this contaminant in NPDES permit ac-
 tions using  the State's existing narrative
 criteria for toxics.
   General Notes:
   1. This chart lists all  of EPA's  priority
 toxic pollutants whether  or not  criteria
 recommendations are  available. Blank
 spaces indicate the absence of criteria rec-
 ommendations. Because of  variations in
 chemical nomenclature  systems, this list-
 ing of toxic pollutants does  not duplicate
 the listing in Appendix A of 40 CFR  Part
 423. EPA has  added the Chemical  Ab-
 stracts Service (CAS) registry numbers,
 which provide a unique identification for
 each chemical.
   2. The following chemicals have organ-
 oleptic  based criteria recommendations
 that are not included on  this chart  (for
 reasons which are discussed in the pream-
 ble): copper, zinc, chlorobenzene, 2-chlo-
 rbphenol, 2,4-dichlorophenol,  acenaph-
 thene, 2,4-dimethylphenol,  3-methyl-4-
chlorophenol, hexachlorocyclopentadiene,
pentachlorophenol, phenol
   3. For  purposes of this  rulemaking,
freshwater criteria and saltwater  criteria
apply as specified in 40 CFR 131.36(c).
   (2) Factors for  Calculating Metals
Criteria
CMC=WER exp|mA[ln(hardness)]+bA)
    CCC = WER
    exp(mc[ln(hardness)]+bc)

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                          CMC=WER exp|mA[ln(hardness)]+bA!- CCC=WER exp|mc[ln(hardness)]+bci





Nickel 	
Silver 	
niA
1.128
0.9422
0.8190
1.273
0.8460
1.72
0.8473
bA
-3.828
-1.464
3.688
-1.460
3.3612
-6.52
0.8604

0.7852
0.8545
0.8190
1.273
0.8460
0.8473
be
-3.490
-1 .465
1.561
-4.705
1.1645
0.7614
  Note: The term "exp" represents the base e exponential function.
  (c) Applicability.
  (1) The criteria in paragraph (b) of this
section  apply to the States'  designated
uses cited in paragraph (d) of this section
and supersede any criteria adopted by the
State, except when State regulations con-
tain criteria which are more stringent for
a particular use in which case the State's
criteria will continue to apply.
  (2) The criteria established  in this sec-
tion are  subject to the State's  general
rules of applicability in the same way and
to the same extent as are the other numer-
ic toxics criteria when applied to the same
use classifications  including mixing zones,
and low flow values below which numeric
standards can  be exceeded  in flowing
fresh waters.
  (i) For all waters with mixing zone reg-
ulations  or  implementation procedures,
the criteria apply  at the appropriate loca-
tions within or at the boundary  of the
mixing zones; otherwise the criteria apply
throughout  the waterbody including  at
the end of any discharge pipe, canal  or
other discharge point.
   (ii) A  State shall  not  use  a low flow
 value below which numeric standards ca.n
 be exceeded that is less stringent than the
 following for waters suitable for the estab-
 lishment of. low  flow return  frequencies
 (i.e., streams and rivers):
               Aquatic Life

 Acute criteria (CMC)    1 Q 10 or 1 B 3
 Chronic criteria (CCC)  7Q10or4B3
               Human Health
 Non-carcinogens
 Carcinogens
30 Q 5
Harmonic mean flow
  Where:
    CMC—criteria maximum concentra-
  tion—the water quality criteria to protect
  against acute effects in aquatic life and is
  theT highest  instream  concentration of a
  priority toxic  pollutant consisting of a
  one-hour average-not to be exceeded more
than once every three years on the aver-
age;
  CCC—criteria  continuous  concentra-
tion—the water quality criteria to protect
against chronic effects in  aquatic life is
the highest instream concentration  of a
priority toxic pollutant consisting of a 4-
day average not to be exceeded more than
once every three years on the average;
   1 Q 10 is the lowest one day flow with
an  average recurrence frequency of once
in 10 years determined hydrologically;
   1 B 3 is biologically based and indicates
an  allowable exceedence of once every 3
years. It is determined by  EPA's comput-
erized method (DFLOW model);
   7 Q 10 is the lowest average 7  consecu-
tive day low flow with an average recur^
rence frequency of once in 10 years deter-
mined hydrologically;
   4 B 3 is biologically based and indicates
an allowable exceedence for 4 consecutive
days once every 3 years. It is determined
by   EPA's   computerized   method
 (DFLOW model);
   30 Q 5 is the lowest average 30 consec-
 utive day low flow with an average recur-
 rence frequency of once in 5 years deter-
 mined hydrologically; and the harmonic
 mean flow is a long term mean flow value
 calculated by dividing the number of dai-
 ly flows analyzed  by  the sum of  the
 reciprocals of those daily  flows.
    (iii) If a State does not  have such a low
 flow value for numeric standards compli-
 ance, then none shall apply and  the crite-
 ria included in paragraph (d) of this sec-
 tion  herein apply at all flows.
    (3) The aquatic life criteria in the ma-
 trix in paragraph (b) of this section apply
 as follows:
    (i) For  waters  in  which the salinity  is
 equal to or less than 1 part per thousand
 95%  or more of  the time, the applicable
 criteria are the freshwater criteria in Col-
 umn B;
    (ii) For waters in which the salinity is
 equal to or greater than 10 parts per thou-
 sand 95% or more of the time,  the appli-
cable criteria are the saltwater criteria in
Column C; and
  (iii) For waters in which the salinity is
between  1 and 10 parts per thousand as
defined in paragraphs (c)(3) (i) and (ii) of
this section, the applicable criteria are the
more  stringent  of the  freshwater  or
saltwater criteria. However, the Regional
Administrator may approve the use of the
alternative freshwater or saltwater crite-
ria if scientifically defensible  information
and data demonstrate that on a site-spe-
cific basis the biology of the waterbody is
dominated by freshwater aquatic life and
that freshwater criteria are more appro-
priate; or conversely,  the biology of the
waterbody  is  dominated  by saltwater
aquatic life and that saltwater criteria are
more appropriate.
   (4) Application of metals criteria.
   (i) For purposes of calculating freshwa-
ter aquatic life  criteria for metals from
the equations in paragraph (b)(2) of this
section,  the minimum hardness  allowed
for use in those equations shall not be less
 than 25 mg/1, as calcium carbonate, even
 if the actual ambient hardness is less than
 25 mg/1 as calcium carbonate. The maxi-
 mum hardness  value for use  in  those
 equations shall  not exceed  400 mg/1  as
 calcium carbonate, even if the actual am-
 bient hardness  is greater than 400 mg/1
 as calcium carbonate.  The  same  provi-
 sions apply for calculating the metals cri-
 teria for the comparisons provided  for in
 paragraph  (c)(3)(iii) of this section,
   (ii)The  hardness values used shall  be
 consistent with the design discharge con-
 ditions established in paragraph (c)(2) of
 this  section for flows and mixing zones.
    (iii) The criteria for metals (compounds
 #1-#13 in  paragraph (b) of this section)
 are  expressed  as total  recoverable.  For
 purposes of calculating aquatic life crite-
 ria for metals from the equations in foot-
 note  M. in the criteria matrix  in para-
 graph (b)(l) of this section and the equa-
 tions in paragraph (b)(2) of this section,
 the  water-effect ratio is computed as a

-------
 Specific pollutant's acute or chronic toxici-
 ty values measured in water from the site
 covered  by the standard, divided by the
 respective acute or chronic toxicity value
 in laboratory dilution water. The water-
 efTcct ratio shall be assigned a value of
 1.0, except where the permitting authori-
 ty assigns a  different value that protects
 the  designated uses of the  water  body
 from the toxic effects of the pollutant, and
 is derived from suitable tests on sampled
 water representative of conditions in the
 affected  water body, consistent with the
 design discharge conditions established in
 paragraph (c)(2) of this section. For pur-
 poses of this paragraph, the term acute
 toxicity value is the  toxicity test results,
 such  as  the C6>ncitnl-ra.t/c.jitfjKj-fo one-
 half of the teSt organisms (i.e.,  LC50) af-
 ter 96 hours of exposure (e.g., fish toxicity
 tests) or the effect concentration to one-
 half of the test organisms, (i.e.,  EC50)
 after 48  hours of exposure (e.g., daphnia
 toxicity tests). For purposes of this para-
 graph, the term chronic value is the result
 from appropriate hypothesis testing or re-
 gression analysis of measurements  of
 growth, reproduction, or survival from life
 cycle, partial life cvcle, or early life stage
 tests. The determination of acute and
 chronic values shall  be according to cur-
 rent standard protocols  (e.g., those pub-
 lished by the American  Society for Test-
 ing  Materials (ASTM)) or other compa-
 rable methods. For calculation of criteria
 using site-specific values  for  both  the
 hardness and  the water effect  ratio,  the
 hardness used  in the equations in para-
 graph (b)(2) of this  section shall be as
 required  in paragraph  (c)(4)(ii) of this
 section. Water hardness shall be calculat-
 ed from the measured calcium and mag-
 nesium ions present, and the ratio of calci-
 um to magnesium shall be approximately
 the same in standard laboratory toxicity
 testing water as in the site water.
   (d) Criteria for  Specific  Jurisdic-
 tions—
   (1) Rhode Island. EPA Region I.
   (i) AH  waters assigned to the  following
 use classifications  in  the Water Quality
 Regulations for Water Pollution Control
 adopted under Chapters  46-12, 42-17 1
 and 42-35 of the General Laws of Rhode
 Island are subject to the criteria in para-
 graph (d)(l)(ii) of this  section, without
exception:
                         (ii) The following criteria from the ma-
                       trix in paragraph  (b)(l) of this section
                       apply to the use classifications identified
                       in paragraph (d)(l)(i) of this section:
                         Use classification
                       Class A
                       Class B waters where
                        water supply use is
                        designated

                       Class B waters where
                        water supply use is
                        not designated;
                       Class C;
                       Class SA;
                       Class SB;
                       Class SC
                         Applicable criteria

                       These classifications
                        are assigned the cri-
                        teria in:
                       Column D1—all
                                            Each of these classifi-
                                             cations is assigned
                                             the criteria in:
                                            Column D2—all
                         (iii) The human health criteria shall be
                      applied at the.10'5 risk level, consistent
                      with  the  State policy. To  determine ap-
                      propriate value for carcinogens, see foot-
                      note c in  the criteria matrix in paragraph
                      (b)(l) of this section.
                         (2) Vermont. EPA Region 1.
                         (i) All  waters assigned .to the following
                      use classifications in the Vermont Water
                      Quality Standards adopted under the au-
                      thority  of the Vermont Water Pollution
                      Control Act (10 V.S.A., Chapter 47) are
                      subject  to the  criteria  in  paragraph
                      (d)(2)(ii) of this section, without excep-
                      tion:
                         Class A
                         Class B
                         Class C
                         (ii) The following criteria from the ma-
                      trix in paragraph  (b)(l) of this section
                      apply to the use classifications identified
                      in paragraph (d)(2)(i) of this section:

                        Use classification
                      Class A
                      Class B waters where
                       water supply use is
                       designated
                      Class B waters where
                       water supply use is
                       not designated
                      Class C
  621 Freshwater

CUss A....................
Class B.,..,,...,,,	,
Class C.........	
  6.22 Saltwater:

Class SA
Class SB
Class SC
                                             Applicable criteria
                      This  classification  is
                       assigned the criteria
                       in:
                      Column B1—all
                      Column B2—all
                      Column 01—all
                                           These classifications
                                             are assigned the cri-
                                             teria in:
                                           Column B1—all
                                           Column B2—all
                                           Column D2—all
  (iii) The human health criteria shall be
applied at the State-proposed 10'6 risk lev-
el.
    (3) New Jersey, EPA Region 2.
    (i) All waters assigned to the following
 use classifications in the New Jersey Ad-
 ministrative Code (N.J.A.C.) 7:9-4.1 et
 seq., Surface Water  Quality Standards,
 are subject to the  criteria  in paragraph
 (d)(3)(ii) of this  section,  without excep-
 tion.
 N.J.A.C.  7:9-4.12(b): Class PL
 N.J.A.C.  7:9-4.12(c): Class FW2
 N.J.A.C.  7:9-4.12(d): Class SE1
 N.J.A.C.  7:9-4.12(e): Class SE2
 N.J.A.C.  7:9-4.12(0: Class SE3
 N.J.A.C.  7:9-4.12(g): Class SC
 N.J.A.C.  7:9-4.13(a):  Delaware River
     Zones 1C, ID, and IE
 N.J.A.C.  7:9-4.13(b):  Delaware River
     Zone 2
 N.J.A.C.  7:9-4.13(c):  Delaware River
     Zone 3
 N.J.A.C.  7:9-4.13(d):  Delaware River
     Zone 4
 N.J.A.C.  7:9-4.13(e):  Delaware River
     Zone 5
 N.J.A.C.  7:9-4.13(f):  Delaware River
     Zone 6
   (ii) The following criteria from the ma-
 trix in paragraph  (b)(l) of  this section
 apply to the use classifications identified
 in paragraph (d)(3)(i) of this section:

   Use classification       Applicable criteria

 PL (Freshwater Pine-   These  classifications
  lands), FW2            are assigned the cri-
                       teria in: Column
                      B1-all except #102,
                       105, 107,  108,  111,
                       112, 113,  115,  117,
                       118.
                      Column B2—all excep
                       #105, 107, 108, 111,
                       112, 113,  115,  117,
                       118, 119,  120,  121,
                       122, 123,  124, and
                       125.
                      Column  D1-all at a
                       10-8 risk level except •
                       #23, 30, 37, 38, 42,
                       68,  89, 91, 93,  104,
                       105; #23, 30, 37, 38,
                       42,  68, 89, 91,  93,
                       104,  105, at a  10-*
                       risk level.
                      Column D2—all at a
                       10-' risk level except
                       #23, 30, 37, 38, 42,
                       68, 89, 91, 93,  104,
                       105; 23, 30, 37,  38,
                       42,  68, 89, 91,  93,
                       104, 105, at a 10-»
                       risk level.
PL (Saline Water Pine-   These  classifications
 lands),  SE1, SE2,     are assigned the cri-
 SE3, SC               teria in:

-------
  Use classification
Delaware River zones
  1C, 1D, 1E, 2, 3, 4, 5
  and Delaware  Bay
  zone 6
  Applicable criteria

Column C1—all except
  #102, 105, 107, 106,
  111, 112, 113,  115,
  117, and 118.
Column C2—all except
  #105, 107, 108, 111,
  112, 113, 115,  117',
  118, 119, 120,  121,
  122, 123, 124, and
  125.
Column  D2—all  at a
  10-* risk level except
  #23, 30, 37, 38, 4!>,
  68, 89, 91, 93, 104,
  105; #23, 30, 37, 38,
  42,  68, 89,  91, 93,
  104, 105; at a 10-B
  risk level.
These classifications
  are assigned the cri-
  teria in:

Column B1—all
Column B2—all
Column D1—all at  a
  10-' risk level except
  #23, 30, 37, 38, 42,
  68, 89, 91, 93, 104,
  105; #23, 30, 37, 38,
  42, 68,  89, 91, 93,
  104, 105, at a 10-6
  risk level.
Column D2—all at  a
  10-$ risk level except
  #23, 30, 37, 38, 42,
  68, 89, 91, 93, 104.
  105; #23,30,37,38,
  42, 68, 89, 91, 93.
  104, 105, at a 10-5
  risk level.
 These  classifications
  are assigned the cri-
  teria in:
 Column C1—all
 Column C2—all
 Column D2—all at a
  10-' risk level except
  #23, 30, 37, 38, 42,
  68, 89,  91, 93, 104,
  105; #23, 30,  37, 38,
  42, 68, 89, 91, 93,
  104, 105, at a 10-6
  risk level.
   (iii) The human health criteria shall be
 applied at the State-proposed 10'6 risk lev-
 el  for EPA  rated Class  A, BI, and B2
 carcinogens;  EPA rated Class C carcino-
 gens shall be applied at 10'5 risk level. To
 determine  appropriate value for carcino-
 gens, see footnote c. in the matrix in para-
 graph (b)(l) of this section.
   (4) Puerto Rico, EPA Region 2.
   (i) All waters assigned to the following
 use classifications in the Puerto Rico Wa-
 ter Quality  Standards  (promulgated by
 Resolution Number  R-83-5-2)  are sub-
ject to the criteria in paragraph (d)(4)(ii)
of this section, without exception.
  Article 2.2.2—Class SB
  Article 2.2.3—Class SC
  Article 2.2.4—Class SD
  (ii) The following criteria from the ma-
trix in paragraph  (b)(l)  of this  section
apply to  the use classifications identified
in paragraph (d)(4)(i) of this section:

  Use classification        Applicable criteria
Delaware River zones
  3,4, and 5, and Dela-
  ware Bay zone 6
 Class SD               This Classification is
                        assigned the criteria
                        in:
                       Column  B1—all,  ex-
                        cept:  10, 102, 105,
                        107,  108, 111, 112,
                        113,  115,  117, and
                        126.
                       Column  B2—all,  ex-
                        cept: 105,  107, 108,
                        112, 113,  115, and
                        117.
                       Column  D1—all,  ex-
                        cept: 6, 14, 105, 112,
                        113, and 115.
                       Column  D2—all,  ex-
                        cept:  14, 105, 112,
                        113, and 115.
 Class SB, Class SC  ;    This. Classification  is
                        assigned the criteria
                        in:
                       Column C1—all, ex-
                        cept 4, 5b, 7, 8, 10,
                        11,13,102,105,107,
                        108, 111,  112, 113,
                        115, 117, and 126.
                       Column C2—all, ex-
                        cept:  4, 5b, 10, 13,
                        108, 112,  113, 115,
                        and 117.
                       Column D2—all, ex-
                        cept:  14,  105. 112,
                         113, and 115.
    (iii) The human health criteria shall be
 applied at the State-proposed 10"5 risk lev-
 el. To determine appropriate value  for
 carcinogens, see footnote c, in the criteria
 matrix in paragraph (b)(l) of this section.
    (5) District of Columbia, EPA Region
 3.                                ,
    (i) All waters assigned to the following
 use classifications in chapter  li  Title 21
 DCMR, Water Quality Standards  of the
 District of Columbia are subject  to  the
 criteria  in paragraph (d)(5)(ii) of this sec-
 tion, without exception:
    1101.2 Class C waters
    (ii) The following criteria from the ma-
 trix  in  paragraph  (b)(l) of  this section
 apply to the use classification identified in
 paragraph (d)(5)(i) of this section:
  Use classification       Applicable criteria

Class C                This classification  is
                        assigned  the  addi-
                        tional criteria in:
                      Colum  B2—#10, 118,
                        126.
                      Colum  D1—#15,  16,
                        44,-67, 68,79, 80,81,
                        88, 114, 116, 118.
                      Colum  D2—all.
   (iii) The human health criteria shall be
applied at the State-adopted 10"6 risk lev-
el.
   (6) Florida, EPA Region 4.
   (i) All waters assigned to the following
use classifications in Chapter  17-301  of
the Florida  Administrative Code  (i.e.,
identified in Section 17-302.600) are sub-
ject to the criteria in paragraph (d)(6)(ii)
of this section, without exception:
   Class I
   Class II
   Class III
   (ii) The following criteria from the ma-
trix paragraph (b)(l) of this section apply
to the  use  classifications identified  in
paragraph (d)(6)(i) of this section:
                                                                                          Use classification

                                                                                        Class I
                                                                                        Class II
 Class III (marine)
 Class III (freshwater).
                         Applicable criteria

                       This classification is
                         assigned the criteria
                         in:
                       Column D1— #16
                       This classification is
                         assigned the criteria
This classification  is
  assigned the criteria
  in:
Column D2— #16
    (iii) The human health criteria shall be
 applied at the State-adopted 10'6 risk lev-
 el.
   (7) Michigan, EPA  Region 5.
   (i) All  waters assigned to the  following
 use  classifications in  the Michigan  De-
 partment of Natural Resources  Commis-
 sion General  Rules,  R 323.1100 designat-
 ed uses, as defined at R 323.1043. Defini-
 tions;  A to N, (i.e., identified in Section
 (g) "Designated use") are subject  to the
 criteria in paragraph (d)(7)(ii) of this sec-
 tion, without exception:
   Agriculture
   Navigation
   Industrial  Water  Supply
   Public Water Supply at the Point  of
      Water Intake
   Warmwater Fish

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   Other  Indigenous  Aquatic Life and
     Wildlife
   Partial Body Contact Recreation
   (ii) The following criteria from the ma-
trix in paragraph  (b)(l)  of  this section
apply to the use classifications identified
in paragraph (d)(7)(i) of this section
   USB classification        Applicable criteria
Public Water supply
AH other designations
This  classification is
  assigned the criteria
  In:
   Column B1— all,
     Column B2—all,
     Column D1—all.
These classifications
  are assigned the cri-
  teria in:
   Column 81— all.
   Column B2—all,
     and
   Column D2—all.
   (iii) The human health criteria shall be
applied at the State-adopted 10'5 risk lev-
el. To determine appropriate  value for
carcinogens, see footnote c in the criteria
matrix in paragraph (b)(l) of this section.
   (8) Arkansas, EPA Region 6.
   (i) All waters assigned to the following
use  classification  in  section   4C
(Watcrbody uses) identified in Arkansas
Department  of Pollution Control  and
Ecology's Regulation No. 2 as amended
and entitled, "Regulation  Establishing
Water Quality Standards for Surface
Waters of the State of Arkansas" are sub-
ject to the criteria in paragraph (d)(8)(ii)
of this section, without exception:
Extraordinary Resource Waters
Ecologically Sensitive Walcrbody
Natural and Scenic Waterways
Rsheries:
(I) Trout
(2) Lakes and Reservoirs
(3) Streams
   (a) Ozark Highlands Ecoregion
   (b) Boston Mountains Ecoregion
   (c) Arkansas  River Valley Ecoregion
   (d) Ouachita  Mountains Ecoregion
   (e) Typical Gulf Coastal Ecoregion
   (f)  Spring  Water-influenced Gulf
     Coastal Ecoregion
   (g) Least-altered Delta Ecoregion
   (h) Channel-altered Delta Ecoregion
Domestic Water Supply
   (ii) The following criteria from the ma-
trix  in  paragraph (b)(l) of this section
apply to the use classification identified in
paragraph (d)(8)(i) of this section:
  Use classification

Extraordinary  Re-
 source Waters
Ecologically Sensitive
 Waterbody
Natural  and Scenic
 Waterways
Rsheries:
   (1) Trout
   (2) Lakes and Res-
    ervoirs
   (3) Streams
    (a) Ozark  High-
      lands Ecore-
      gion
    (b) Boston Moun-
      tains Ecoregion
    (c) Arkansas Riv-
      er     Valley
      Ecoregion
    (d)   Ouachita
      Mountains
      Ecoregion
    (e) Typical  Gulf
      Coastal Ecore-
      gion
    (f) Spring Water-
      influenced Gulf
      Coastal Ecore-
      gion
    (g) Least-altered
      Delta. Ecore-
      gion
    (h)  Channel-al-
      tered  Delta
      Ecoregion
                                            Applicable criteria
                                          These uses are each
                                            assigned the criteria
                                            in—
                                             Column B1— #4,
                                               5a, 5b, 6, 7, 8, 9,
                                               10, 11, 13, 14
                                             Column B2— #4,
                                               5a, 5b, 6, 7, 8, 9,
                                               10, 13, 14
                       (9) Kancas. EPA Region 7.  '
                       (i) All waters assigned to the following
                     use classification in the  Kansas Depart-
                     ment  of Health and Environment regula-
                     tions, K.A.R. 28-16-28b through K.A.R.
                     28-16-28f, are subject to the criteria  in
                     paragraph (d)(9)(ii) of this section, with-
                     out exception.
                     Section 28-16-28d
                       Section (2) (A)—Special Aquatic Life
                         Use Waters
                       Section (2)(B)—Expected Aquatic
                         Life Use Waters
                       Section  (2) (C)—Restricted Aquatic
                         Life Use Waters
                       Section (3)—Domestic Water Supply
                       Section (6)(c)—Consumptive  Recre-
                         ation Use.
                       (ii) The following criteria from the ma-
                     trix in  paragraph  (b)(l) of this section
                     apply to the  use classifications identified
                     in paragraph (d)(9)(i) of this section:
   Use classification       Applicable criteria

     Sections  (2)(A),   These classifactions
      (2)(B),  (2)(C),    are each assigned all
      (6)(C)            criteria in:
                          Column B1, all
                            except #9, 11,
                            13,  102,  105,
                            107,    108,
                            111-113,  115,
                            117, and 126;
                          Column B2, all
                            except #9, 13,
                            105, 107,  108,
                            111-113,  115,
                            117,  119-125,
                            and 126; and
                          Column D2, all
                            except   #9,
                            112,  113,  and
                            115.
 Section (3)             This classification is
                       assigned all criteria
                       in;
                          Column D1, all
                            except #9, 12,
                            112,  113,  and
                            115.
   (iii) The human health criteria shall be
applied at the State-proposed 10'6 risk lev-
el.
   (10) California, EPA Region 9.
   (i) All waters assigned any aquatic life
or human health use classifications in the
Water Quality Control Plans for the vari-
ous  Basins of the State ("Basin Plans"),
as amended,  adopted  by the California
State Water Resources Control  Board
("SWRCB"),  except  for  ocean waters
covered  by the  Water Quality Control
Plan for Ocean  Waters  of  California
("Ocean Plan") adopted by the SWRCB
with resolution Number 90-27 on March
22,  1990, are  subject  to the criteria in
paragraph  (d)(10)(ii)  of this  section,
without exception. These criteria amend
the  portions of the  existing State stan-
dards contained in the Basin Plans.  More
particularly these criteria  amend water
quality criteria contained  in the Basin
Plan Chapters  specifying  water quality
objectives (the State equivalent of federal
water quality criteria) for the toxic pollu-
tants identified  in paragraph  (d)(10)(ii)
of this section.  Although the State  has
adopted several  use designations for each
of these waters, for  purposes  of this ac-
tion, the specific standards to be applied
in paragraph  (d)(10)(ii) of this section
are based on the presence in all waters of
some aquatic life designation  and  the
presence or absence of the MUN use des-
ignation  (Municipal  and domestic  sup-
ply). (See Basin Plans  for  more detailed
use definitions.)

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  Other Indigenous Aquatic Life  and
    Wildlife
  Partial Body Contact Recreation
  (ii) The following criteria from the ma-
trix in  paragraph  (b)(l) of this  section
apply to the use classifications identified
in paragraph (d)(7)(i) of this section
  Use classification       Applicable criteria
Public Water supply
All other designations
This  classification is
  assigned the criteria
  in:
   Column  B1—all.
     Column B2—all,
     Column D1—all.
These classifications
  are assigned the cri-
  teria in:
   Column B1—all,
   Column  B2—all,
     and
   Column D2—all.
   (iii) The human health criteria shall be
applied at the State-adopted 10'5 risk lev-
el. To determine appropriate  value for
carcinogens, see footnote c in the criteria
matrix in paragraph (b)(l) of this section.
   (8) Arkansas, EPA Region 6.
   ([) All waters assigned to the  following
use  classification  in  section  4C
(Watcrbody us.cs) identified in Arkansas
Department  of Pollution Control  and
Ecology's Regulation No. 2 as  amended
and entitled,  "Regulation  Establishing
Water Quality Standards for Surface
Waters of the State of Arkansas" are sub-
ject to the criteria in paragraph  (d)(8)(ii)
of this section,  without exception:
Extraordinary Resource Waters
Ecologically Sensitive Waterbody
Natural and Scenic Waterways
 Fisheries:   "~
(1)  Trout
 (2)  Lakes and  Reservoirs
(3)  Streams
   (a)  Ozark Highlands Ecoregion
   (b)  Boston Mountains Ecoregion
   (c)  Arkansas River Valley Ecoregion
   (d)  Ouachita Mountains Ecoregion
   (e)  Typical Gulf Coastal Ecoregion
   (f)  Spring  Water-influenced  Gulf
     Coastal Ecoregion
   (g)  Least-altered Delta Ecoregion
   (h)  Channel-altered Delta  Ecoregion
 Domestic Water Supply
   (ii) The following criteria from the ma-
^trix in paragraph (b)(l) of this  section
'apply to the use classification identified in
 paragraph  (d)(8)(i) of this section:
  Use classification

Extraordinary  Re-
 source Waters
Ecologically Sensitive
 Waterbody
Natural  and Scenic
 Waterways
Fisheries:
   (1) Trout
   (2) Lakes and Res-
     ervoirs
   (3) Streams
     (a) Ozark High-
      lands Ecore-
      gion
     (b) Boston Moun-
      tains Ecoregion
     (c) Arkansas Riv-
      er    Valley
      Ecoregion
     (d)   Ouachita
      Mountains
      Ecoregion
     (e) Typical Gulf
      Coastal Ecore-
      gion
     (f) Spring Water-
      influenced  Gulf
      Coastal Ecore-
      gion
     (g) Least-altered
      Delta  Ecore-
      gion
     (h)  Channel-al-
      tered   Delta
       Ecoregion
                                            Applicable criteria
                                           These uses  are each
                                            assigned the criteria
                                            in—
                                              Column B1— #4,
                                                5a, 5b,  6, 7, 8, 9,
                                                10,11,13,14
                                              Column B2— #4,
                                                5a, 5b,  6, 7, 8, 9,
                                                10, 13,  14
                        (9) Kansas, EPA Region 7,
                        (i) All waters assigned to the following
                      use classification in the Kansas Depart-
                      ment of Health and Environment regula-
                      tions, K.A.R. 28-16-28b through K.A.R.
                      28-16-28f, are subject to the criteria  in
                      paragraph (d)(9)(ii) of this section, with-
                      out exception.
                      Section 28-16-28d
                        Section (2)(A)—Special Aquatic  Life
                           Use Waters
                        Section  (2)(B)—Expected  Aquatic
                           Life Use Waters
                        Section  (2)(C)—Restricted  Aquatic
                           Life Use Waters
                        Section (3)—Domestic Water Supply
                        Section  (6)(c)—Consumptive Recre-
                           ation Use.
                        (ii) The following criteria from the ma-
                      trix in  paragraph  (b)(l)  of  this section
                      apply to the use classifications identified
                      in paragraph (d)(9)(i) of this section:
  Use classification       Applicable criteria

    Sections  (2)(A),   These classifactions
      (2)(B),  (2)(C),     are each assigned all
      (6)(C)             criteria in:
                          Column B1, all
                           except #9, 11,
                           13,  102,  105,
                           107,    108,
                           111-113,  115,
                           117, and 126;
                          Column B2, all
                           except #9, 13,
                           105,  107,  108,
                           111-113,  115,
                           117,  119-125,
                           and 126; and
                          Column D2, all
                           except   #9,
                           112,  113, and
                           115.
Section (3)             This classification is
                       assigned all criteria
                       in;
                          Column D1, all
                           except #9, 12,
                           112,  113, and
                           115.
  (iii) The human health criteria shall be
applied at the State-proposed 1 Cr6 risk lev-
el.
  (10) California, EPA Region 9.
  (i) All waters assigned any aquatic life
or human health use classifications in the
Water Quality Control Plans for the vari-
ous  Basins of the State ("Basin Plans"),
as amended,  adopted  by the California
State  Water Resources Control  Board
("SWRCB"), except  for  ocean waters
covered by the  Water Quality Control
Plan  for Ocean Waters  of  California
("Ocean Plan")  adopted by the  SWRCB
with resolution Number 90-27 on March
22,  1990,  are subject to the criteria in
paragraph  (d)(10)(ii) of this section,
without exception. These criteria amend
the  portions  of  the  existing  State  stan-
dards  contained in the Basin Plans. More
particularly  these  criteria amend  water
quality criteria  contained in the  Basin
Plan Chapters  specifying  water quality
objectives (the State equivalent of federal
water quality criteria)  for the toxic pollu-
tants  identified in paragraph  (d)(10)(ii)
of this section.  Although  the State has
adopted several use designations for each
of these waters, for purposes of this  ac-
tion, the specific standards to be applied
in paragraph (d)(10)(ii) of  this section
are  based on the presence in all waters of
some  aquatic life  designation  and the
presence or absence of the MUN use des-
ignation (Municipal  and  domestic sup-
ply). (See Basin Plans for more detailed
use  definitions.)

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   (if) The following criteria from the ma-   defined  in paragraph  (d)(10)(i)  of this
 trix  in paragraph (b)(l)  of this section   section and identified below:
 apply  to the water and use classifications

                                   Water and use classification

 Waters ol the State defined as bays or estuaries except the Sacramento-San Joaquin Delta and San
  Francisco Bay
 Waters of the Sacramento—San Joaquin Delta and waters of the State defined as inland (i.e., all surface
  wators ol tha State not bays or estuaries or ocean) that include a MUN use designation
Waters o( tha State defined as inland without an MUN use designation
Waters ol tha San Joaquin River from the mouth of the Merced River to Vernahs
Waters of Salt Stough. Mud Slough (north) and the San Joaquin River, Sack Dam to the mouth of the
  Merced River
Wators ol San Francisco Bay upstream to and including Suisun Bay and the Sacramento San Joaquin Delta
AN Inland waters of the United States or enclosed bays and estuaries that are waters of the United States
  that Include an MUN use designation and that the State has either excluded or partially excluded from
  coverage under its Water Quality Control Plan for Inland Surface Waters of California, Tables 1 and 2, or
  Its Water Quality Control Plan for Enclosed Bays and Estuaries of California, Tables 1 and 2, or has
  deferred applicability of those tables. (Category (a), (b), and (c) waters described on page 6 of Water
  Quality Control Plan for Inland Surface Waters of California or page 6 of its Water Quality Control Plan for
  Enclosed Bays and Estuaries of California.)
AN Mind waters of the United States that do not include an MUN use designation and that the State has
  eniw excluded  or partially excluded from coverage  under its Water Quality Control Plan for Inland
  Surface Waters of California, Tables 1 and 2, or has deferred applicability of these tables. (Category (a),
  (b). and (c) waters described on page 6 of Water Quality Control Plan Inland Surface Waters of California)
             Applicable criteria
                                                                                                  These waters are assigned the criteria in:
                                                                                                       Column B1—pollutants 5a and 14
                                                                                                       Column B2—pollutants 5a and 14
                                                                                                       Column C1—pollutant 14
                                                                                                       Column C2—pollutant 14
                                                                                                       Column D2—pollutants 1, 12, 17, 18, 21,
                                                                                                        22, 29, 30,32, 33, 37, 38,42-44, 46, 48,
                                                                                                        49, 54, 59, 66, 67, 68, 78-82, 85, 89, 90,
                                                                                                        91.93,95,96, 98
These waters are assigned the criteria in:
     Column B1—pollutants 5a and 14
     Column B2—pollutants 5a and 14
     Column D1—pollutants, 1,12,15,17,18,
       21, 22,29,30,32,33, 37,38, 42-48,49,
       59, 66, 68, 78-82, 85, 89, 90, 91, 93, 95,
       96,98

These waters are assigned the criteria in:
     Column B1—pollutants 5a and 14
     Column B2—pollutants 5a and 14
     Column D2—pollutants 1, 12, 17, 18, 21,
       22, 29, 30, 32,33, 37, 38,42-44, 46,48,
       49, 54, 59, 66, 67, 68,78-82,85, 89,90,
       91,93,95,96,98

In addition to the criteria assigned to these wa-
  ters elsewhere in this rule, these waters  are
  assigned the criteria in:
     Column 82—pollutant 10
In addition to the criteria assigned to these wa-
  ters elsewhere in this rule, these waters are
  assigned the criteria in:
     Column  B1—pollutant 10
     Column  B2—pollutant 10

These waters are assigned the criteria in:
     Column  B1—pollutants 5a, 10' and 14
     Column  B2—pollutants 5a, 10' and 14
     Column  C1—pollutant 14
     Column  C2—pollutant 14
     Column  D2—pollutants 1, 12, 17, 18, 21,
      22, 29, 30,32,33, 37,38,42-44, 46, 48,
      49, 54; 59, 66, 67, 68,78-82, 85, 89, 90,
      91,93,95,96,98
                                                                                                 These waters are assigned the criteria for pol-
                                                                                                   lutants for which the State does not apply
                                                                                                   Table 1 or 2 standards. These criteria are: .
                                                                                                      Column B1—all pollutants
                                                                                                      Column B2—all pollutants
                                                                                                      Column D1—all pollutants except #Z

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                                Water and use classification
                                                                                                       Applicable criteria
                                                                                           These waters are assigned the criteria for pol-
                                                                               i  .            lutants for which the State does not apply
                                                                       L«S'V*fc  "*          Table 1 or 2 standards. These criteria are:
                                                                                                Column B1—all pollutants
                                                                                                Column B2—all pollutants
                                                                                                Column D2—all pollutants except #2
All enclosed bays and estuaries that are waters of the United States^nd that the State has either excluded
  or partially excluded from coverage under its Water Quality Control Plan for Inland Surface Waters of
  California, Tables 1 and 2, or its Water Quality Control Plan for Enclosed Bays and Estuaries of California,
  Tables 1 and 2, or has deferred applicability of those tables. (Category (a), (b), and (c) waters described
  on page 6 of Water Quality Control Plan for Inland Surface Waters of California or page 6 of its Water
  Quality Control Plan for Enclosed Bays and Estuaries of California.)                                ^^ ^^ m assigned ^ criteria for po,.

                                                                                             lutants for which  the State  does not apply
                                                                                             Table 1 or 2 standards. These criteria are:
                                                                                                Column  B1—all pollutants
                                                                                                Column  B2—all pollutants
                                                                                                Column  C1—all pollutants
                                                                                                Column  C2—all pollutants
                                                                                                Column  02—all pollutants except #2

   • The fresh water selenium criteria are included for the San Francisco Bay estuary because high levels of bioaccumulation of selenium in the estuary indicate
 that the salt water criteria are underprotective for San Francisco Bay.
   (iii) The human health criteria shall be
 applied at the State-adopted 10"6 risk lev-
 el.
   (11) Nevada, EPA Region 9.
   (I) All waters assigned the use classifi-
 cations in Chapter 445 of the Nevada Ad-
 ministrative Code (NAC),  Nevada Water
 Pollution Control Regulations, which are
                                 Water and
  referred  to in paragraph  (d)(ll)(ii)  of
  this section, are subject to the criteria in
  paragraph  (d)(ll)(ii)  of  this  section,
  without exception. These criteria amend
  the existing State standards contained in
  the Nevada Water Pollution Control Reg-
  ulations. More particularly, these criteria
  amend or supplement the table of numer-

use  classification
ic standards  in NAC  445.1339 for the
toxic pollutants identified  in paragraph
(d)(ll)(ii) of this  section.
  (ii) The following criteria from matrix
in paragraph (b)(l) of this section apply
to  the  waters defined  in  paragraph
(d)(ll)(i) of this section and  identified
below:
               Applicable criteria
 Waters that the State has included in NAC 445.13159 where Municipal or domestic supply is a designated
   use
 Waters that the State has included in NAC 445.1339 where Municipal or domestic supply is not a designat-
   ed use
                                                                                            These waters are assigned the criteria in:
                                                                                                 Column Bi—pollutant #118
                                                                                                 Column B2-^pollutant #118
                                                                                                 Column D1—pollutants  #15, 16, 18, 19,
                                                                                                   20,21, 23,26,27, 29,30,34,37,38,42.
                                                                                                   43, 55,58-62.64, 66,73,74,78.82, 85,
                                                                                                   87-89, 91, 92, 96, 98, 100,  103. 104.
                                                                                                   105,114.116,117, 118
    (iii) The human health criteria shall be
  applied at the  10'5 risk level, consistent
  with State policy. To determine appropri-
  ate value for carcinogens, see footnote c in
  the criteria matrix in paragraph (b)(l) of
  this section.
    (12) Alaska.  EPA Region 10.
    (i)  All waters assigned to the following
  use classifications in the Alaska Adminis-
  trative  Code (AAC),  Chapter  18  (i.e.,
  identified in 18 AAC 70.020) are subject
  to the criteria in paragraph (d)(12)(ii) of
  this section, without exception:
  70.020.(1) (A)  Fresh Water
  70.020.(1) (A)  Water Supply
      (i)  Drinking, culinary, and food  pro-
        cessing,
      (iii) Aquaculture;
   70.020.0)  (B) Water Recreation
      (i) Contact recreation,
      (ii) Secondary recreation;
   70.020.(1)  (C)  Growth and propagation
        of fish,  shellfish, other  aquatic life,
        and  wildlife
   70.020.(2)  (A) Marine Water
   70.020.(2)  (A) Water Supply
      (i) Aquaculture,
   70.020.(2)  (B) Water Recreation
      (i) contact recreation,
      (ii) secondary recreation;
   These waters are assigned the criteria in:
        Column B1—pollutant #118
        Column B2—pollutant #118
        Column D2—all pollutants except #2.


 70.020.(2) (C) Growth  and  propagation
      of fish,  shellfish,  other aquatic life,
      and wildlife;
 70.020.(2) (D) Harvesting for consump-
      tion  of  raw  mollusks  or other raw
      aquatic life.
   (ii) The following criteria from the ma-
 trix' in paragraph  (b)(l) of this  section
 apply  to  the use  classifications identified
 in paragraph (d)(12)(i)  of  this section:

   Use classification        Applicable criteria

 (1)(A) i                      Column B1—all
                            Column
                              B2—#10
                            Column D1

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  lisa classification
(1XA)W
(1KB) I, (1KB) li, (IRC)
(2XA)(. taXBJi. and
  (2XBJ8, (2XC), (2X0)
Applicable criteria
#'s2. 16. 18-21,
23, 26. 27. 29,
30. 32, 37. 38,
42-44. 53. 55,
CQ_CO CIA RC
99~O£, O*t, DO,
68. 73. 74, 78,
82. 85, 88. 89.
91-93, 96, 98,
102-105,
1 O7 — 1 1 1
1 U / — 1 1 1,
117-126
Column B1 — all
Column
B2— #10
Column DX
#'s 2. 14, 16.
18-21, 22, 23.
26. 27, 29, 30.
32, 37. 38.
42-44, 46, 53.
54, 55, 59-62,
64, 66. 68. 73,
74, 78. 82. 85,
88-93, 95, 96,
98, 102-105!
107-111.
115-126
Column B1 — all
Colum n
B2— #10
Column D2
#'s 2, 14. 16,
18-21, 22, 23,
26, 27. 29. 30,
32, 37, 38,
42-44, 46. 53.
54. 55. 59-62,
ex RC co 7«a
Q4| DO, DO, * O,
74, 78, 82. 85,
88-93, 95. 96,
98. 102-105.
107-111,
115-126
Column C1 — all
Colu m n
po attin
Wfc"~~rr IU
Column O2
#'s 2, 14, 16.
18-21 22 23
OR 07 OQ on
£O, £f . £a, Ou,
32, 37 38
42-44, 46. 53!
54, 55, 59-62

64, 66. 68. 73,
74. 78, 82. 85,
88-93. 95, 96.
98, 102-105,
107-111.
115-126
(iii) The human health criteria shall be
applied at the State-proposed risk level of
10'5. To determine appropriate value for
carcinogens, see footnote c in the criteria
matrix in paragraph (b)(l) of this section.
(13) Idaho. EPA Region 10.
(i) All waters assigned to the following
use classifications in the Idaho Adminis-
trative Procedures Act (IDAPA), Chap-
ter 16 (i.e., identified in IDAPA
16.01.2100,02-16.01.2100,07) are subject
to the criteria in paragraph (d)(13)(ii) of
this section, without exception:
16.01.2100.01.b. Domestic Water Sup-
plies
16.01.2100.02.3. Cold Water Biota
16.01.2100.02.b. Warm Water Biota
16.01.2100.02cc. Salmonid Spawning
16.01.2100.03.a. Primary Contact Recre-
cition

1 6.0 1.21 00.03. b Secondary Contact Rec-
reation
(ii) The following criteria from the ma-
trix in paragraph (b)(l) of this section
apply to the use classifications identified
in paragraph (d)(13)(i) of this section:

Use classification Applicable criteria
01 .b This classification is
assigned the criteria
in:
Column 01 — all
except #14
and 115
O2.a O2.b 02.cc These classifications
are assigned the cri-
tria in*
ina in.
Column B1 — all
Column B2 — all
Column D2 — all
03. a This classification is
assigned the criteria
in:
Column D2 — all
O3.b This classification is
assigned the criteria
in:
Column D2 — all


(iii) The human health criteria shall be
applied at the 10"6 risk level, consistent
with State policy.
  (14) Washington. EPA Region 10.

  (i) All waters assigned to the following
use classifications in the Washington Ad-
ministrative Code (WAC),  Chapter
173-201  (i.e.,  identified   in  WAC
173-201-045) are subject  to the criteria
in paragraph (d)(14)(ii) of this section,
without exception:

173-201-045

  Fish and Shellfish

  Fish

  Water Supply (domestic)

  Recreation

  (ii) The following criteria from the ma-
trix  in  paragraph (b)(l)  of this  section
apply to the use  classifications identified
in paragraph (d)(14)(i) of this section:
                                                                                         Use classification

                                                                                       Fish and Shellfish; Fish
                        Applicable criteria

                      These classifications
                       are assigned the cri-
                       teria in:
                           Column B1
                                                                                      Water Supply (domes-
                                                                                        tic)
                                                                                       Recreation
                          Column D2—all
                      These  classifictions
                       are assigned the cri-
                       teria in:
                          Column D1—all
                      This classification is
                       assigned the criteria
                       in:
                          Column  D2 —
                            Marine waters
                            and
                            freshwaters
                            not  protected
                            for  domestic
                            water supply
                                                                                         (iii) The human health criteria shall be
                                                                                       applied at the State proposed risk level of
                                                                                       io-6.

                                                                                       [§131.36 added at 57 FR 60910, Dec. 22,
                                                                                       1992]

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          APPENDIX B
        Chronological Summary of
      Federal Water Quality Standards
          Promulgation Actions
I
R
WATER QUALITY STANDARDS HANDBOOK
           SECOND EDITION

-------
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                                     Appendix B - Summary of Federal Promulgation Actions
     UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
              OF1B1CE OF SCIENCE AND TECHNOLOGY
           STANDARDS AND APPLIED SCIENCE DIVISION

                             JANUARY 1993

                   CHRONOLOGICAL SUMMARY OF
              FEDERAL WATER QUALITY STANDARDS
                       PROMULGATION ACTIONS

  STATE        DATE   STATUS REFERENCE      ACTION
1.  Kentucky       12/2/74   Final     39 FR 41709 Established statement in WQS
                                              giving EPA Administrator authority
                                              to grant a temporary exception to
                                              stream classification and/or criteria
                                              after case-by-case studies. Also,
                                              established statement that streams
                                              not listed in the WQS are
                                              understood to be classified as
                                              Aquatic Life and criteria for this
                                              use to be met.

2*.  Arizona       6/22/76   Final     41 FR 25000 Established nutrient standards for
                                              11 streams.

3.   Nebraska      6/6/78   Final     43 FR 24529 Redesignated eight stream segments
                                              for full body contact recreation and
                                              three for partial body contact
                                              recreation and the protection of fish
                                              and wildlife.

4.   Mississippi    4/30/79   Final     44 FR 25223 Established dissolved oxygen
                                              criterion for all water uses
                                              recognized by the State.
                                              Established criterion for a daily
                                              average of not less than 5.0 mg/1
                                              with a daily instantaneous minimum
                                              of not less than 4.0 mg/1.
(9/15/93)                                                                 B-l

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  Water Quality Standards Handbook - Second Edition
  5.  Alabama        11/26/79 Proposed   44 FR 67442 Proposal to reestablish previously
                                                       approved use classifications for
                                                       segments of four navigable
                                                       waterways, Five Mile Creek,
                                                       Opossum Creek, Valley Creek,
                                                       Village Creek, and upgrade the use
                                                       designation of a segment of Village
                                                       Creek from river mile 30 to its
                                                       source.

  6.   Alabama        2/14/80   Final     45 FR 9910   Established beneficial stream use
                                                       classification for 16 streams:  8
                                                       were designated for fish and
                                                       wildlife, 7 were upgraded to  a fish
                                                       and wildlife classification,  1 was
                                                       designated as agricultural and
                                                       industrial water supply.  Proposed
                                                       streams classification rulemaking
                                                       for 7 streams withdrawn.

 7.  North Carolina  4/1/80     Final    45 FR 21246  Nullified a zero dissolved oxygen
                                                       standard variance in a segment of
                                                       Welch Creek and reestablished the
                                                       State's previous standard of 5  mg/1
                                                       average, 4 mg/1 minimum,  except
                                                       for lower concentrations caused by
                                                      natural swamp conditions.

 8-   ohio            11/28/80   Final     45 FR 79053  (1) Established water use
                                                      designation, (2) establish a DO
                                                      criterion of 5 mg/1 for warmwater
                                                      use, (3) designated 17 streams as
                                                      warmwater habitat, (4) placed  111
                                                      streams downgraded by Ohio into
                                                      podified warmwater habitat, (5)
                                                      revised certain provisions relating
                                                      to mixing zones (principally on
                                                      Lake Erie), (6) revised low  flow
                                                      and other exceptions to standards,
                                                      (7) amended sampling and
                                                      analytical protocols, and  (8)
                                                      withdrew EPA proposal to establish
                                                      a new cyanide criterion.

9.  Kentucky       12/9/80    Final     45 FR 81042  Withdrew the Federal promulgation
                          (withdrawal)                action of 12/2/74 after adoption of
                                                      ppropriate water quality standards
                                                      by the State.


                                                                                (9/15/93)

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                                           Appendix B - Summary of Federal Promulgation Actions
 10.  North Carolina   11/10/81   Final     46 FR 55520 Withdrew the Federal promulgation
                          (withdrawal)               action of 4/1/80 following State
                                                     adoption of a dissolved oxygen
                                                     criterion consistent with the
                                                     Federally promulgated standard.

 11.  Ohio            2/16/82    Final     47 FR 29541 Withdrew Federal promulgation of
                          (withdrawal)               11/28/80 because it was based on a
                                                     portion of the water quality
                                                     standards regulation that has been
                                                     determined to be invalid.

 12.  Nebraska        7/26/82    Final     47 FR 32128 Withdrew Federal promulgation
                          (withdrawal)               action of 6/6/78 after adoption of
                                                     appropriate water quality standards
                                                     by the State.

 13.  Alabama        11/26/82   Final     47 FR 53372 Withdrew the Federal promulgation
                          (withdrawal)               action of 2/14/80 following State
                                                     adoption of requirements consistent
                                                     with the Federally promulgated
                                                     standard.

 14.  Idaho           8/20/85    Proposed 50 FR 33672 Proposal to replace DO criterion
                                                     downstream from dams, partially
                                                     replace Statewide ammonia
                                                     criterion, replace ammonia criterion
                                                     for Indian Creek, and delete
                                                     categorical exemption of dams from
                                                     Antidegradation Policy.

 15.  Mississippi      4/4/86     Final     51 FR 11581 Withdrew the Federal promulgation
                          (withdrawal)               of 4/30/79 following State adoption
                                                     of requirements consistent with the
                                                     Federally promulgated standard.

 16.  Idaho          7/14/86    Final     51 FR 25372 Withdrew portions of proposed rule
                          (withdrawal)               to replace DO criterion
                                                     downstream from dams and delete
                                                     categorical exemptions of darns
                                                     from antidegradation rule since
                                                     State adopted acceptable standards
                                                     in both instances.

 17.  Kentucky       3/20/87    Final     50 FR 9102   Established a chloride criterion of
                                                     600 mg/1 as a 30-day average, not
                                                     to exceed a maximum of 1,200
                                                     mg/1 at any time.


(9/15/93)                                                             "             B^3

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 Water Quality Standards Handbook - Second Edition
 18. Idaho
 19*.Coleville
     Indian
     Reservation

 20.  Kentucky
21'.12 States
    2 Territories
22.  Washington
7/25/88   Final    53 FR 27882 Withdrew portion of proposed rule
      (withdrawal)               which would have established a
                                Statewide ammonia criterion and a
                                site-specific ammonia criterion
                                applicable to lower Indian Creek
                                since State adopted acceptable
                                standards.
7/6/89    Final
54 FR 28622 Established designated uses and
             criteria for all surface waters
             on the Reservation.
4/3/91    Final    56 FR 13592 Withdrew the Federal promulgation
      (withdrawal)               of 3/20/87 after adoption of
                                appropriate WQS by the State.
12/22/92  Final
57 FR 60848  Established numeric water quality
             for toxic pollutants (aquatic life and
             human health).
7/6/93    Final    58 FR 36141  Withdrew, in part, the Federal
      (withdrawal)               Promulgation of 12/22/92 after
                                adoption of appropriate criteria by
                                the State.
* Final federal rule remains in force
          SUMMARY OF FEDERAL PROMULGATION ACTIONS
    Total Number of Proposed or Final Rules

    Final Standards Promulgated

    Withdrawal of Final Standards

    Federal Rules Remaining In Force

    No Action Taken on Proposals or Proposal Withdrawn
                                                   22

                                                   10

                                                   8

                                                   3

                                                   3
B-4
                                                                             (9/15/93)

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          APPENDIX C
           Biological Criteria:
       National Program Guidance
           for Surface Waters
I
WATER QUALITY STANDARDS HANDBOOK
           SECOND EDITION

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vvEPA
United States       Office of Water          EPA-440/5-90-004
Environmental Protection  Regulations and Standards (WH-585) April 1990
Agency	Washington, DC 20460	




Biological Criteria
                 National Program Guidance

                 For Surface Waters

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Biological Criteria
National Program Guidance for
         Surface Waters
          Criteria and Standards Division
        Office of Water Regulations and Standards
        U. S. Environmental Protection Agency
             401 M Street S.W.
           Washington D.C 20460

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                            Contents
Acknowledgments   	iv
Dedication	iv
Definitions	v
Executive Summary	vii
                                                                        *

Fart I: Program Elements
1.   Introduction	3
    Value of Biological Criteria   	4
    Process for Implementation	6
    Independent Application of Biological Criteria	7
    How to Use This Document	7
2.   Legal Authority  	9
    Section303    	9
    Section 304    	10
    Potential Applications Under the Act	•	10
    Potential Applications Under Other Legislation	10
3.   The Conceptual Framework	13
    Premise for Biological Criteria	13
    Biological Integrity	14
    Biological Criteria	 14
       Narrative Criteria %	.15
       Numeric Criteria  	16
    Refining Aquatic Life Use Classifications  	17
    Developing and Implementing Biological Criteria  	18
                                      ii

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4.   Integrating Biological Criteria in Surface Water Management	21
    Implementing Biological Criteria	21
    Biological Criteria in State Programs   	22
    Future Directions	24

Part II: The Implementation Process

5.   The Reference Condition	27
    Site-specific Reference Condition	28
        The Upstream-Downstream Reference Condition	28
        The Near Field-Far Field Reference Condition    	28
    The Regional Reference Condition  	29
        Paired Watershed Reference Condition   	29
        Ecoregional Reference Condition  .  .	29

6.   The Biological Survey   	33
    Selecting Aquatic Community Components	34
    Biological Survey Design   	35
        Selecting the Metric	35
        Sampling Design  	36
7.   Hypothesis Testing: Biological Criteria and the Scientific Method   	37
     Hypothesis Testing	37
     Diagnosis   	38


References	43
Appendix A: Common Questions and Their Answers	45
 Appendix B: Table of Contents; Biological Criteria—Technical Reference Guide	  49

 Appendix C: Table of Contents; Biological Criteria—Development By States	51
 Appendix D: Contributors and Reviewers	53
                                           Hi

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                               Acknowledgments
   Development of this document required the combined effort of ecologists, biologists, and policy makers from States, EPA
Regions, and EPA Headquarters. Initial efforts relied on the 1988 document Report of the National Workshop on Instream
Bidoyical Monitoring and Criteria that summarizes a 1987 workshop sponsored by the EPA Office of Water Regulations and
Standards,  EPA Region V, and EPA Environmental  Research Laboratory-Corvallis.-ln December 1988, contributing and
reviewing committees were established (see Appendix D). Members provided reference materials and commented on drafts.
Their assistance was most valuable.
   Special recognition goes to the Steering Committee who helped develop document goals and made a significant contribu-
tion toward the final guidance. Members of the Steering Committee include:
                       Robert Hughes, Ph.D.              Chris Yoder
                       Susan Davies                    Wayne Davis
                       John Maxted                     Jimmie Overton
                       James Plafkin, Ph.D.               Dave Courtemanch
                       PhilLarsen,Ph.D.
   Finally, our thanks go to States that recognized the importance of a biological approach in standards and pushed forward
independently to incorporate biological criteria into their programs. Their guidance made this effort possible. Development of
the program guidance document was sponsored by the U.S. EPA Office of Water Regulations and Standards and developed, in
part, through U.S. EPA Contract No. 68-03-3533 to Dynamac Corporation. Thanks to Dr. Mark Southerlandfor his technical
assistance.
                                      Suzanne K. Macy Marcy, Ph.D.
                                      Editor
                                       In Memory of

                         James  L.  Plafkin,  Ph.D.
                                                iv

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                              Definitions
       To effectively use biological criteria, a clear understanding of how these criteria are developed and ap-
       plied in a water quality standards framework is necessary. This requires, in part, that users of biological
       criteria start from the same frame of reference. To help form this frame of reference, the following defini-
tions are provided. Please consider them carefully to ensure a consistent interpretation of this document.
Definitions
a An AQUATIC COMMUNITY is an association of in-
  teracting populations of aquatic organisms in a given
  waterbody or habitat.

Q A BIOLOGICAL ASSESSMENT is an evaluation of
  the biological condition of a waterbody using biologi-
  cal surveys and other direct measurements of resi-
  dent biota in surface waters.

d BIOLOGICAL CRITERIA, or biocriteria, are numeri-
  cal values or narrative expressions that describe the
  reference biological integrity of aquatic communities
  inhabiting waters of a given designated aquatic life
  use.

Q BIOLOGICAL INTEGRITY is functionally defined as
  the condition .of the aquatic community inhabiting
  unimpaired waterbodies of a specified habitat as
  measured by community structure aind function.

Q BIOLOGICAL MONITORING is the use of a biologi-
  cal entity as a detector  and its response as a
  measure  to determine environmental conditions.
  Toxicity tests ..and biological surveys  are common
  biomonitoring methods.

Q A BIOLOGICAL SURVEY, or biosurvey, consists of
  collecting, processing and analyzing representative
   portions  of a resident aquatic community to deter-
   mine the community structure and function.

 Q A COMMUNITY COMPONENT is any portion of a
   biological community. The community component
   may  pertain to  the taxomonic group (fish, inver-
   tebrates, algae), the taxonomic  category  (phylum,
   order, family, genus,  species), the feeding strategy
  (herbivore, omnivore,  carnivore) or organizational
  level (individual, population, community association)
  of a biological entity within the aquatic community.

Q REGIONS OF ECOLOGICAL SIMILARITY describe
  a relatively homogeneous area defined by similarity
  of climate, landform, soil, potential natural vegeta-
  tion, hydrology, or other ecologically relevant vari-
  able. Regions of ecological similarity help define the
  potential  for designated  use  classifications of
  specific waterbodies.

G DESIGNATED USES are those uses specified in
  water quality standards for each waterbody or  seg-
  ment whether or not they are being attained.

a An IMPACT is a change in the chemical, physical or
  biological quality or condition of a waterbody caused
  by external sources.

Q An IMPAIRMENT is  a detrimental  effect on the
  biological integrity of a waterbody caused by an im-
  pact that prevents attainment of the designated .use.
  i A POPULATION is an aggregate of interbreeding in-
   dividuals of a biological species within a specified
   location.
 Q A WATER QUALITY ASSESSMENT is an evaluation
   of the condition of a waterbody using biological sur-
   veys, chemical-specific analyses of pollutants  in
   waterbodies, and toxicity tests.

 Q An ECOLOGICAL ASSESSMENT is an evaluation
   of the condition of a waterbody using water quality
   and physical habitat assessment methods.

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             Executive  Summary
       The Clean Water Act (Act) directs the U.S. Environmental Protection Agency (EPA) to develop
       programs that will evaluate, restore and maintain the chemical, physical, and biological in-
       tegrity of the Nation's waters. In response to this directive, States and EPA implemented
chemically based  water quality programs that successfully addressed significant water pollution
problems. However, these programs alone cannot identify or  address all surface water pollution
problems. To create a more comprehensive program, EPA is setting a new priority for the develop-
ment of biological water quality criteria. The initial phase of this program directs State adoption of
narrative biological criteria as part of State water quality standards. This effort will help States and
EPA achieve the objectives of the Clean Water Act set forth in Section 101 and comply with statutory
requirements under Sections 303 and 304. The Water Quality Standards Regulation provides additional
authority for biological criteria development.
   In accordance  with priorities established in the FY 2991 Agency Operating Guidance, States are to
adopt narrative biological criteria into State water quality standards during the FY 1991-1993 trien-
nium. To support this priority, EPA is developing a Policy on  the  Use of Biological Assessments and
Criteria in the Water Quality Program and is providing this program guidance document on biological
criteria.
   This document provides guidance for development and implementation of narrative biological
criteria. Future guidance documents will provide  additional technical information  to facilitate
development and implementation of narrative and numeric criteria for each of the surface water
types.
   When implemented, biological criteria will  expand  and improve water quality standards
programs, help identify impairment of beneficial uses, and help set program priorities. Biological
criteria are valuable because they directly measure  the condition of the resource  at risk, detect
problems that other methods may miss or underestimate, and provide a systematic process for
measuring progress resulting from the implementation of water quality programs.
                                         vii

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Biological Criteria: National Program Guidance

   Biological criteria require direct measurements of the structure and function of resident aquatic
communities to determine biological integrity and ecological function. They supplement, rather than
replace chemical and toxicological methods. It is EPA's policy that biological survey methods be fully
integrated with toxicity and chemical-specific assessment methods and that chemical-specific criteria,
whole-effluent toxicity evaluations and biological criteria be used as independent evaluations of non-
attainment of designated uses.
   Biological criteria are narrative expressions or numerical values that describe the biological in-
tegrity of aquatic communities inhabiting waters of a given aquatic life use. They are developed
under the assumptions that surface waters impacted by antnropogenic activities may contain im-
paired aquatic communities (this greater the impact the greater the expected impairment) and that
surface waters not impacted by anthropogenic activities are generally not impaired. Measures of
aquatic community structure and function in unimpaired surface waters functionally define biologi-
cal integrity and form the basis for establishing the biological criteria.
    Narrative biological criteria are definable statements of condition or attainable goals for a given
use  designation. They establish a positive statement about aquatic community characteristics ex-
pected to occur within a waterbody (e.g., "Aquatic life shall be as it naturally occurs" or "A natural
variety of aquatic life shall be present and all functional groups well represented"). These criteria can
be developed using existing information. Numeric criteria describe the expected attainable com-
 munity attributes and establish values based on measures such as species richness, presence or ab-
 sence of indicator taxa, and distribution of classes of organisms. To implement narrative criteria and
 develop numeric criteria, biota in reference waters must be carefully assessed. These are used as the
 reference values to determine if, and to what extent, an impacted surface waterbody is impaired.
     Biological criteria support designated aquatic life use classifications for application in standards.
 The designated use determines the benefit or purpose to be derived from the waterbody; the criteria
 provide a measure to determine.1 if the use is impaired. Refinement of State water quality standards to
 include more detailed language* about aquatic life is essential to fully implement a biological criteria
 program. Data collected from biosurveys can identify consistently distinct characteristics among
 aquatic communities inhabiting different waters with the same designated use. These biological and
 ecological characteristics  may be used to define separate categories within a designated use, or
 separate one designated use into two or more use classifications.
     To develop values for biological criteria, States should (1) identify unimpaired reference water-
 bodies to establish the reference condition and  (2) characterize the aquatic communities inhabiting
 reference surface waters. Currently, two principal approaches are used to establish reference sites: (1)
 the site-specific approach, which may require upstream-dpwnstream or near field-far field evalua-
 tions, and  (2) the regional approach, which identifies similarities in the physico-chemical charac-
 teristics of watersheds that influence aquatic ecology. The basis for choosing reference sites depends
 on classifying the habitat type and locating unimpaired (minimally impacted) waters.
                                             viii

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                                                                              Exacutiv* Summary
    Once reference sites are selected, their biological integrity must be evaluated using quantifiable
 biological surveys. The success of the survey will depend in part on the careful selection of aquatic
 community components (e.g., fish, macroinvertebrates, algae). These components should serve as ef-
 fective indicators of high biological integrity, represent a range of pollution tolerances, provide pre-
 dictable, repeatable results, and be readily identified by trained State personnel. Well-planned quality
 assurance protocols are required to reduce variability in data collection and to assess the natural
 variability inherent in aquatic communities. A quality survey will include multiple community com-
 ponents and may be measured using a variety of metrics. Since multiple approaches are available,
 factors to  consider  when choosing possible approaches for  assessing biological integrity are
 presented in this document and will be further developed in future technical guidance documents.
    To apply biological criteria in a water  quality standards program,  standardized sampling
 methods and statistical protocols must be used. These procedures must be sensitive enough to iden-
 tify significant differences between established criteria and tested communities. There are three pos-
 sible outcomes from hypothesis testing using these analyses: (1) the use is impaired, (2) the biological
 criteria are met, or (3) the outcome is indeterminate. If the use is impaired, efforts to diagnose the
 cause(s) will help determine appropriate action. If the use is not impaired, no action is required based
 on these analyses. The outcome will be indeterminate if the study design or evaluation was incom-
 plete. In this case, States would need to re-evaluate their protocols.
    If the designated use is impaired, diagnosis is the next step. During diagnostic evaluations three
 main impact categories must be considered: chemical, physical, and biological stress. Two questions
 are posed during initial diagnosis: (1) what are obvious potential causes of impairment, and (2) what
 possible causes do the biological data suggest? Obvious potential causes of impairment are often
 identified during normal field biological assessments. When an impaired use cannot be easily related
 to an obvious cause, the diagnostic process becomes investigative and iterative. Normally the diag-
 noses of biological impairments are relatively straightforward; States can use biological criteria to
 confirm impairment from a known source of impact.
    There is considerable State interest in integrating biological assessments and criteria in water
 quality management programs. A minimum of 20 States now use some form of standardized biologi-
 cal assessments to determine the status of biota in State waters.  Of these, 15 States are developing
biological assessments for future criteria development. Five States use biological criteria to define
 aquatic life use classifications and to enforce water quality standards. Several States have established
narrative biological criteria in their standards. One State has instituted numeric biological criteria.
    Whether a State is just beginning to establish narrative biological criteria or is developing a fully
 integrated biological  approach, the programmatic expansion  from source control  to  resource
management represents a natural progression in water quality programs. Implementation of biologi-
cal criteria will provide new options for expanding the scope and application of ecological perspec-
tives.
                                             IX

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           Parti
Program Elements

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                         Introduction
       The principal objectives of the Clean Water
       Act are "to restore and maintain the chemi-
       cal, physical and biological integrity of the
Nation's waters" (Section 101). To achieve these ob-
jectives, EPA, States, the regulated community, and
the pubjic need comprehensive information about
the ecological  integrity of  aquatic environments.
Such information will help us identify waters requir-
ing special protection and those that will benefit most
from regulatory efforts.
    To meet the objectives of the Act and to comply
with statutory requirements under Sections 303 and
304, States are to adopt biological criteria in  State
standards. The Water Quality Standards Regulation
provides  additional authority for this effort. In ac-
cordance with the FY 1991  Agency Operating
Guidance, States and qualified  Indian tribes are to
adopt  narrative biological criteria into  State  water
quality standards  during the FY  1991-1993  trien-
nium.  To support  this effort, EPA is developing a
 Policy on the  Use of Biological Assessments and
 Criteria in the Water Quality Program and providing
this program  guidance document on  biological
 criteria.
    Like  other water quality criteria, biological cri-
 teria  identify water quality impairments,  support
 regulatory controls  that  address water  quality
 problems,  and  assess improvements in  water
 quality from regulatory efforts. Biological criteria are
 numerical  values  or narrative  expressions that
 describe the reference biological integrity of aquatic
 communities inhabiting  waters of a given  desig-
 nated aquatic life use. They are developed through
Anthropogenic impacts, including point source
discharges, nonpoint runoff, and habitat degradation
continue to impair the nation's surface waters.
the direct measurement of aquatic community com-
ponents inhabiting unimpaired surface waters.
    Biological  criteria complement current pro-
grams. Of the three objectives identified in the Act
(chemical, physical, and biological integrity), current
water quality programs focus on direct measures of

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               Nttioml Prognm Guldanc*
 chemical integrity (chemical-specific and whole-ef-
 fluent toxicity) and, to some degree, physical in-
 tegrity through several  conventional criteria  (e.g.,
 pH, turbidity,, dissolved oxygen). Implementation of
 these programs has  significantly improved water
 quality. However, as we learn more about  aquatic
 ecosystems it is apparent that  other sources  of
 watarbody impairment exist. Biological impairments
 from diffuse sources and habitat degradation can be
 greater than those caused by point source dischar-
 ges (Judy et al. 1987; Miller et al. 1989). In Ohio,
 evaluation of Instream biota indicated that  36 per-
 cent of  impaired stream segments could  not be
 detected using chemical  criteria alone (see  Fig. 1).
 Although effective  for  their purpose,  chemical-
 specific  criteria and whole-effluent toxicity  provide
 only indirect evaluations and protection of biological
 integrity (see Table 1).
    To  effectively  address  our  remaining water
 quality  problems we need  to develop more in-
 tegrated and comprehensive evaluations. Chemical
 and physical integrity are necessary, but not  suffi-
 cient conditions to attain  biological integrity,  and
 only when  chemical, physical, and biological in-
 tegrity are achieved, is ecological integrity possible
 (see Fig. 2). Biological criteria provide an essential
 third element  for water  quality management  and
 serve  as   a  natural  progression  in  regulatory
 programs. Incorporating  biological criteria  into a
 fully Integrated program directly protects the  biologi-
 cal integrity of  surface waters and provides  indirect
 protection for chemical and physical integrity (see
 Table 2). Chemical-specific criteria, whole-effluent
 toxicity evaluations, and  biological criteria, when
 used together, complement the relative strengths
 and weaknesses of each approach.
 Figure 1.—Ohio Biosurvey Results Agree with
 Instream Chemistry or Reveal Unknown Problems

             Impairment identification
 Chemical Evaluation Indicate
 No Impairment: Biosurvey
 Show Impairment
Biosurvey Show No
Impairment; Chemical
Evaluation Indicates
Impairment
Chemical Prediction
& Biosurvey Agree
Fig. 1: In an intensive survey, 431 sites in Ohio were assessed
using instream chemistry and biological surveys. In 36% of
the cases, chemical evaluations implied no impairment but
biological survey evaluations showed impairment. In 58% of
the cases the chemical and biological assessments agreed.
Of these, 17% identified waters with no impairment, 41 %
identified waters which were considered impaired. (Modified
from Ohio EPA Water Quality Inventory, 1988.)

    Biological  assessments  have  been  used  in
biomonitoring programs by States for many years.
In this respect, biological  criteria  support earlier
work.  However, implementing biological criteria in
water  quality  standards  provides  a systematic,
structured,  and objective  process  for  making
decisions  about compliance with  water  quality
standards. This distinguishes biological criteria from
earlier use of biological information  and increases
the value of biological data in regulatory programs.
Table 1.—Currant Watw Quality Program Protection of the Three Elements of Ecological Integrity.
ELEMENTS OF ECOLOGICAL
INTEGRITY
Chemical Integrity
Physical Integrity
Biological Integrity
PROGRAM THAT DIRECTLY
PROTECTS
Chemical Specific Criteria (toxics)
Whole Effluent Toxicity (toxics)
Criteria for Conventionals
(pH, DO. turbidity)

PROGRAM THAT INDIRECTLY
PROTECTS


Chemical/Whole Effluent Toxicity
(biotic response in lab)
Table 1: Current programs focus on chemical specific and whole-effluent toxicity evaluations. Both are valuable approaches
tor the direct evaluation and protection of chemical integrity. Physical integrity is also directly protected to a limited degree
through criteria for conventional pollutants. Biological integrity is only indirectly protected under the assumption that by
evaluating toxicity to organisms in laboratory studies, estimates can be made about the toxicity to other organisms inhabiting
ambient waters.

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                                                                                   Chapter 1;
Table 2.—Water Quality Programs that Incorporate Biological Criteria to Protect Elements Of Ecological Integrity.
ELEMENTS OF
ECOLOGICAL INTEGRITY
Chemical Integrity
Physical Integrity
Biological Integrity
DIRECTLY PROTECTS
Chemical Specific Criteria (toxics)
Whole Effluent Toxicity (toxics)
Criteria for conventionals (pH, temp.,
DO)
Biocriteria (biotic response in surface
water)
INDIRECTLY PROTECTS
Biocriteria (identification of
impairment)
Biocriteria (habitat evaluation)
i
Chemical/Whole Effluent Testing
(biotic response in lab)
Table 2' When biological criteria are incorporated into water quality programs the biological integrity of surface waters may-
be directly evaluated and protected. Biological criteria also provide additional benefits by requiring an evaluation of physical
integrity and providing a monitoring tool to assess the effectiveness of current chemically based criteria.
 Figure 2.—The Elements of Ecological Integrity
 Fig. 2: Ecological Integrity is attainable when  chemical,
 physical, and biological integrity occur simultaneously.
  Value of Biological

  Criteria

      Biological criteria provide an  effective tool for
  addressing  remaining water quality problems by
  directing  regulatory efforts  toward  assessing  the
  biological resources at risk from chemical, physical
  or biological impacts. A primary strength of biologi-
  cal criteria is the detection of waiter quality problems
  that other  methods  may miss or  underestimate.
  Biological criteria can be used to determine to what
  extent current regulations are protecting the use.
    Biological  assessments   provide   integrated
evaluations of water quality. They can  identify im-
pairments from contamination of the water column
and sediments from unknown or unregulated chemi-
cals,  non-chemical impacts, and altered physical
habitat.  Resident  biota  function  as  continual
monitors of  environmental quality, increasing the
likelihood of detecting the effects of episodic events
(e.g., spills, dumping, treatment plant malfunctions,
nutrient enrichment), toxic nonpoint source pollution
(e.g., agricultural pesticides),  cumulative pollution
(i.e.,  multiple impacts over time or continuous low-
level  stress), or other impacts that periodic chemical
sampling is unlikely to detect. Impacts on the physi-
cal habitat such  as sedimentation from stormwater
runoff and  the  effects  of  physical or structural
habitat  alterations  (e.g., dredging, filling,  chan-
nelization) can also be detected.
    Biological criteria require the direct measure of
resident aquatic community structure and function
to determine biological integrity and ecological func-
tion. Using  these measures, impairment  can  be
 detected  and  evaluated without knowing  the im-
 pact^) that may cause tha impairment.
     Biological  criteria provide a regulatory frame-
 work for  addressing water  quality  problems and
 offer additional benefits, including providing:
     • the  basis for characterizing high quality
       waters and identifying habitats and
       community components requiring special
       protection under State anti-degradation
       policies;
      • a framework for deciding 319 actions for best
       control of  nonpoint source pollution;

      • an evaluation of surface water impairments
       predicted  by chemical analyses, toxicity

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 BtofogtaJ Critarta: National Program Guidance
      testing, and fate and transport modeling (e.g.,
      wasteload allocation);.
     • improvements In water quality standards
      (Including refinement of use classifications);
     • a process for demonstrating improvements in
      water quality after implementation of pollution
      controls;

     • additional diagnostic tools.

     Tha role of biological criteria as a regulatory tool
 is being realized in some States  (e.g., Arkansas,
 Maine, Ohio, North Carolina,  Vermont). Biological
 assessments and criteria have been useful for
 regulatory, resource protection, and monitoring and
 reporting  programs.  By  incorporating biological
 criteria in programs, States can improve standards
 setting and  enforcement, measure  impairments
 from permit violations, and refine wasteload alloca-
 tion models.  In addition, the location,  extent, and
 type of biological impairments measured in a water-
 body provide valuable information needed for iden-
 tifying  the cause of impairment and  determining
 actions required to improve water quality. Biological
 assessment and criteria programs provide a cost-
 effective method for evaluating water quality when a
 standardized, systematic approach to study design,
 field  methods,  and data  analysis  is  established
 (Ohio EPA 1988a).


 Process for

 Implementation

    The implementation of biological criteria will fol-
low the same process used for  current chemical-
                                  specific and whole-effluent toxicity applications: na-
                                  tional guidance produced by U.S. EPA will support
                                  States working to establish State standards for the
                                  implementation of regulatory programs (see Table
                                  3). Biological criteria differ, however, in the degree
                                  of State involvement  required. Because  surface
                                  waters vary significantly from region to region, EPA
                                  will provide guidance on acceptable approaches for
                                  biological criteria development rather than specific
                                  criteria with numerical limitations. States are to es-
                                  tablish  assessment  procedures,  conduct  field
                                  evaluations, and determine criteria values to imple-
                                  ment biological criteria in State standards and apply
                                  them in regulatory programs.
                                     The degree  of State involvement  required in-
                                  fluences how biological criteria will be implemented.
                                  It is  expected that  States  wiH implement these
                                  criteria in phases.

                                     •  Phase I  includes the development and adop-
                                        tion  of narrative biological criteria into  State
                                        standards  for  all  surface waters (streams,
                                        rivers, lakes, wetlands, estuaries). Definitions
                                        of terms and expressions in the narratives
                                        must be  included in these standards (see the
                                        Narrative Criteria Section, Chapter 3).  Adop-
                                        tion  of narrative biological criteria in State
                                        standards  provides  the legal and program-
                                        matic basis for using ambient biological sur-
                                       veys and assessments in regulatory actions.

                                     •  Phase II includes the development of an  im-
                                       plementation plan.  The plan should include
                                       program  objectives, study design, research
                                       protocols, criteria for selecting reference con-
                                       ditions and community components,  quality
                                       assurance  and  quality control  procedures,
Table 3.—Process for Implementation of Water Quality Standards.
CRITERIA

EPA GUIDANCE
Pollutant specific numeric criteria
STATE IMPLEMENTATION
State Standards
• use designation
• numeric criteria
• antidegradation
STATE APPLICATION
Permit limits Monitoring
Best Management Practices
Wasteload allocation
Narratlva Free Forms    Whole effluent toxicity guidance
Biological
Biosurvey minimum requirement
guidance
Water Quality Narrative
• no toxic amounts .translator

State Standards
• refined use
• narrative/numeric criteria
• antidegradation
Permit limits Monitoring
Wasteload allocation
Best Management Practices

Permit conditions Monitoring
Best Management Practices
Wasteload allocation
 ^L^LfiT1'3/^,^^1,03!,^.60!1'0 criteria and whole effluent toxicity evaluations. EPA is providing guidance to States for
the adoption of biological criteria into State standards to regulate sources of water quality impairment   '

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                                                                               Chapter 1: introduction
     and training for State personnel. In Phase II,
     States are to develop plans necessary to im-
     plement biological  criteria for each  surface
     water type.

   • Phase III requires full implementation and in-
     tegration of biological criteria in water quality
     standards. This requires using biological sur-
     veys to derive biological criteria for classes of
     surface waters and designated uses. These
     criteria  are then used  to  idemtify nonattain-
     ment of designated uses and make regulatory
     decisions.


    Narrative biological criteria cat be developed
for all five surface water classifications with little or
no data collection. Application of narrative criteria in
seriously degraded waters is possible  in the  short
term. However, because of the diversity of surface
waters and the biota that inhabit these waters, sig-
nificant planning, data collection, and evaluation will
be  needed to fully implement the program. Criteria
for each type of surface water are  likely to be
developed  at different rates.  The order and rate of
development will depend, in part, on the  develop-
ment of EPA guidance for specific types of surface
water.  Biological criteria technical guidance for
streams will be produced during Pf 1991. The ten-
tative order for future technical guidance documents
includes guidance for rivers (FY 1992), lakes (FY
 1993), wetlands (FY 1994) and estuaries (FY 1995).
This order and timeline for guidance does not reflect
the relative importance of these surface waters, but
 rather indicates the relative  availability of research
 and   the   anticipated   difficulty  of  developing
 guidance.
 Independent Application

 of Biological Criteria

     Biological  criteria  supplement,  but do not
 replace, chemical and toxicological methods. Water
 chemistry methods are necessary to predict risks
 (particularly to human health and wildlife), and  to
 diagnose,  model, and  regulate important  water
 quality problems. Because  biological criteria are
 able to detect different types of water quality impair-
 ments and, in particular, have different levels of sen-
 sitivity for detecting certain types  of  impairment
compared to toxicological methods, they are not
used in lieu of, or in conflict with, current regulatory
efforts.
    As with all criteria, certain limitations to biologi-
cal criteria make independent application essential.
Study  design and use influences how sensitive
biological criteria are for detecting community im-
pairment. Several factors  influence sensitivity:  (1)
State decisions about what is significantly different
between reference and test communities, (2)  study
design, which may include community components
that are not sensitive to the impact causing impair-
ment,  (3) high natural  variability that makes  it dif-
ficult  to detect real differences, and (4) types  of
impacts that may  be  detectable sooner by  other
methods (e.g., chemical criteria may provide earlier
indications of impairment from a bioaccumulative
chemical because aquatic communities require ex-
 posure over time to incur the full effect).
    Since each  type of criteria (biological criteria,
 chemical-specific criteria, or whole-effluent toxicity
 evaluations)  has  different  sensitivities and pur-
 poses, a criterion may fail to detect real impairments
 when used alone. As a result, these methods should
 be used together in an integrated water quality as-
 sessment, each providing an independent evalua-
 tion of nonattainment  of  a designated use.  If  any
 one type of criteria indicates impairment of the sur-
 face water,  regulatory action  can be taken  to im-
 prove water quality. However, no one type of criteria
 can  be used to  confirm attainment of  a  use if
 another form of  criteria indicates  nonattainment
 (see Hypothesis Testing:  Biological Criteria and the
 Scientific Method, Chapter 7).  When  these three
 methods are used together, they provide a powerful,
 integrated, and effective foundation for waterbody
 management and regulations.
  How to Use  this

  Document

      The purpose of this document is to provide EPA
  Regions, States and  others with the conceptual
  framework  and assistance necessary to develop
  and implement narrative  and numeric  biological
  criteria and to promote national consistency in ap-
  plication. There are two main parts of the document.
  Part One (Chapters 1, 2, 3, and 4) includes the es-
  sential concepts about what biological criteria are
                                                  7

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 Sfcfcgfca/Crfterfi: Ntltawi Pmgnm Guidanc*


 and how they are used in regulatory programs. Part
 Two (Chapters 5, 6, and 7) provides an overview of
 the process  that is essential for implementing a
 State biological criteria program. Specific chapters
 include the following:

 Parti: PROGRAM ELEMENTS

  Q Chapter 2, Legal Authority, reviews the legal
    basis for biological criteria under the Clean
    Water Act and includes possible applications
    under the Act and other legislation.

  Q Chapters, Conceptual Framework,
    discusses the essential program elements for
    biological criteria, including what they are and
    how they are developed and used within a
    regulatory program. The development of
    narrative biological criteria is discussed in this
    chapter.

  Q Chapter 4, Integration, discusses the use of
    biological criteria in regulatory programs.

Part II: THE IMPLEMENTATION PROCESS

  Q Chapter 5, The  Reference Condition,
    provides a discussion on alternative forms of
    reference conditions that may be developed by
    a State based on circumstances and needs.

  Q Chapter 6, The Biological Survey, provides
    some detail on the elements of a quality
    biological survey.

  Q Chapter 7, Hypothesis Testing: Biological
    Criteria and the Scientific Method, discusses
    how biological surveys are used to make
    regulatory and diagnostic decisions.

  Q Appendix A Includes commonly asked
    questions and their answers about biological
    criteria.
    Two additional  documents are planned in the
 near term to supplement  this  program guidance
 document.

    1. "Biological   Criteria  Technical  Reference
       Guide* will contain a cross reference of tech-
       nical papers on  available  approaches and
       methods  for  developing  biological criteria
       (see tentative table of contents in Appendix
       B),

    2. "Biological Criteria Development by State?
       will  provide a summary of different  mecha-
       nisms several States have used to implement
       and apply biological  criteria in water quality
       programs (see tentative outline in Appendix
       C).

    Both documents are planned for FY 1991. As
previously discussed, over the next triennium tech-
nical guidance for specific systems (e.g., streams,
wetlands) will be developed to provide guidance on
acceptable biological assessment procedures to fur-
ther support State implementation of comprehen-
sive programs.
    This biological criteria program guidance docu-
ment supports development and implementation of
biological criteria by providing guidance to States
working to comply  with requirements under  the
Clean Water Act and the Water  Quality Standards
Regulation. This guidance is not regulatory.

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                                Chapter  2
                    Legal  Authority
      The Clean Water Act (Federal Water Pollution
      Control  Act of 1972, Clean Water Act of
      1977, and the Water Quaility Act of 1987)
mandates State development of criteria based on
biological assessments of natural ecosystems.
   The  general  authority for biological  criteria
comes from Section 101 (a) of the Act which estab-
lishes as the objective of the Act the restoration and
maintenance of the chemical, physical, and biologi-
cal integrity of the Nation's waters. To meet this ob-
jective, water quality criteria must include criteria to
protect  biological integrity. Section 101 (a) (2) in-
cludes the interim water quality goal for the protec-
tion and propagation of fish, shellfish, and wildlife.
Propagation includes the full  range of biological
conditions  necessary  to  support  reproducing
populations of all forms of aquatic life and other life
that depend on aquatic systems.  Sections  303 and
304 provide specific directives foir the development
of biological criteria.
 Section 303

    Under Section 303(c) of the Act, States are re-
 quired to adopt protective water quality standards
 that consist of uses, criteria, and antidegradation.
 States are to review these standards every three
 years and to revise them as needed.
    Section 303 (c) (2) (A) requires the adoption of
 water quality standards that"... serve the purposes
 of the Act," as  given  in Section  101.  Section
 303(c)(2)(B), enacted in 1987, requires States to
Balancing the legal authority for biological criteria.


adopt numeric criteria for toxic pollutants for which
EPA has published 304(a)(1) criteria. The section
further requires that, where numeric 304(a) criteria
are not available, States should adopt criteria based
on biological  assessment and monitoring methods,
consistent with information oublished by EPA under
304(a)(8).
    These specific directives do not serve to restrict
the use of biological criteria in other settings where
they may be helpful. Accordingly, this  guidance
document provides  assistance  in  implementing
various sections of the Act, not just 303 (c) (2) (B).

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              Uttioncl Prognm Quidanc*
 Section  304

    Section  304(a)  directs  EPA  to  develop  and
 publish water quafity  criteria  and information on
 methods for measuring  water quality and estab-
 lishing water quality criteria for toxic pollutants on
 bases other than pollutant-by-pollutant, including
 biological monitoring  and  assessment methods
 which assess:

    • the effects of pollutants on aquatic community
      components ("... plankton, fish, shellfish,
      wildlife, plant life...") and community
      attributes ("... biological community diversity,
      productivity, and stability..."); in any body of
      water and;

    * factors necessary"... to restore and
      maintain the chemical, physical, and
      biological integrity of all navigable waters..."
      for"... the protection of shellfish, fish, and
      wildlife for classes and categories of receiving
      waters.. ."
Potential Applications

Under the Act

   Development and use of biological criteria will
help States to meet other requirements of the Act,
including:

  Q setting planning and management priorities for
    waterbodies most in need of controls
    [Sec. 303(d)J;

  Q determining impacts from nonpoint sources
    P.O., Section 304(f) '(1) guidelines for
    identifying and evaluating the nature and
    extent of nonpoint sources of pollutants, and
    (2) processes, procedures, and methods to
    control pollution..."].

  Q biennial reports on the extent to which waters
   support balanced biological communities
    [Sec. 305(b)J;

  Q assessment of lake trophic status and trends
   [Sec. 314];
   Q lists of waters that cannot attain designated
     uses without nonpoint source controls
     [Sec. 319];

   a development of management plans and
     conducting monitoring in estuaries of national
     significance [Sec. 320];

   Q issuing permits for ocean discharges and
     monitoring ecological effects [Sec. 403(c) and
     301(h)(3)];

   Q determination of acceptable sites for disposal
     of dredge and fill material [Sec. 404];
Potential Applications

Under Other Legislation

    Several legislative acts require an assessment
of risk to the environment (including resident aquatic
communities) to determine the need for regulatory
action. Biological criteria can be used in this context
to support EPA assessments under:

  a Toxic Substances Control Act (TSCA) of 1976

  a Resource Conservation and Recovery Act
    (RCRA),

  a Comprehensive Environmental Response,
    Compensation and Liability Act of 1980
    (CERCLA),

  a Superfund Amendments and Reauthorization
    Act Of 1986 (SARA),

  a Federal Insecticide, Fungicide, and
    RodenticideAct (FIFRA);

  a National Environmental Policy Act (NEPA);

  a Federal Lands Policy and Management Act
    (FLPMA).

  a The Fish and Wildlife Conservation Act of 1980

  a Marine Protection, Research, and Sanctuaries
    Act

  a Coastal Zone Management Act
                                             10

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                                                                              Chapters: Legal Authority
  3 Wild and Scenic Rivers Act

  3 Fish and Wildlife Coordination Act, as
    Amended in 1965

   A summary of the applicability of these Acts for
assessing ecological impairments may be found in
Risk Assessment Guidance for Superfund-Environ-
mental Evaluation Manual (Interim Final) 1989.
   Other  federal  and State  agencies  can also
benefit from using biological criteria to evaluate the
biological  integrity of surface waters  within their
jurisdiction and to the effects of specific practices on
surface water quality. Agencies that could benefit in-
clude:

  3  Department of the Interior (U.S. Fish and
     Wildlife Service, U.S. Geological Survey,
     Bureau of Mines, and Bureau of Reclamation,
     Bureau of Indian Affairs, Bureau of Land
     Management, and National Park Service),

  a Department of Commerce (National Oceanic
     and Atmospheric Administration, National
     Marine Fisheries Service),

  3 Department of Transportation (Federal
     Highway Administration)

   3 Department of Agriculture (U.S. Forest
     Service, Soil Conservation Service)

   3 Department of Defense,

   G Department of Energy,

   3 Army Corps of Engineers,

   3 Tennessee Valley Authority.
                                                 11

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                              Chapter  3
   The   Conceptual Framework
      Biological integrity and the determination of
      use impairment through assessment of am-
      bient biological communities form the foun-
dation  for biological  criteria development. The
effectiveness  of a biological critefia program will
depend on the development of quality criteria, the
refinement of use  classes  to support narrative
criteria, and careful application of scientific prin-
ciples.
Premise for Biological

Criteria

   Biological criteria are based on the premise that
the structure and function of an aquatic biological
community within a specific habitat provide critical
information about the quality of surface waters. Ex-
isting aquatic communities in pristine environments
not subject  to anthropogenic  impact  exemplify
biological integrity and serve as the best possible
goal  for water quality. Although pristine environ-
ments  are  virtually  non-existent (even  remote
waters are impacted by air pollution), minimally im-
pacted waters exist. Measures of the structure and
function of aquatic communities inhabiting unim-
paired  (minimally impacted)  waters provide the
basis for establishing a reference condition that may
be compared to the condition of impacted surface
waters to determine impairment.
   Based on this premise, biological  criteria are
developed under the assumptions that: (1) surface
waters  subject to anthropogenic disturbance may
contain impaired populations or communities  of
aquatic organisms—the greater the anthropogenic
Aquatic communities assessed in unimpaired
waterbodies (top) provide a reference for evaluating
impairments in the same or similar waterbodies suffering
from increasing anthropogenic impacts (bottom).
                                         13

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               Mttiofml Progam Grtfenc*
 disturbance, the greater the  likelihood and mag-
 nitude of impairment; and (2) surface waters not
 subject to anthropogenic disturbance generally con-
 tain unimpaired  (natural) populations  and com-
 munities of aquatic organisms exhibiting biological
 integrity.
the basis for establishing water quality goals for
those  waters. When tied  to  the  development  of
biological criteria,  the  realities of  limitations on
biological integrity  can be considered  and incor-
porated  into a  progressive  program  to improve
water quality.
Biological  Integrity

    The expression "biological integrity" is used in
the Clean Water Act to define the Nation's objec-
tives for water quality. According to Webster's New
World Dictionary (1966), integrity is, "the quality or
state  of being complete; unimpaired." Biological in-
tegrity has been defined as "the ability of an aquatic
ecosystem to support and maintain a balanced, in-
tegrated, adaptive community of organisms having
a species composition, diversity, and functional or-
ganization comparable to that of the natural habitats
within a region" (Karr and Dudley 1981). For the pur-
poses of biological criteria, these concepts are com-
bined   to  develop  a   functional  definition  for
evaluating biological integrity  in  water quality
programs. Thus, biological integrity is functionally
defined as:

      the condition of the aquatic community
      inhabiting the unimpaired waterbodies
      of a specified habitat as measured by
      community structure and function.

    It wilt often be difficult to find unimpaired waters
to define biological integrity and establish the refer-
ence condition. However, the structure and function
of aquatic communities of high quality waters can be
approximated in  several ways. One is to charac-
terize  aquatic communities in the most  protected
waters  representative of the regions where such
sites  exist. In areas where few or no unimpaired
sites  are  available," characterization of  least im-
paired systems approximates unimpaired systems.
Concurrent analysis  of historical  records should
supplement descriptions of the condition of least im-
paired systems. For some systems, such as lakes,
evaluating paleoecotogical  information (the record
stored in sediment profiles) can provide a measure
of less disturbed conditions.
    Surface waters, when inhabited by aquatic com-
munities, are exhibiting  a degree  of biological in-
tegrity.  However,  the   best  representation  of
biological integrity for a surface water should form
Biological Criteria

    Biological criteria are narrative expressions or
numerical values that describe the biological in-
tegrity of aquatic communities inhabiting waters of a
given designated aquatic life use. While biological
integrity  describes  the  ultimate  goal for water
quality, biological criteria are based on aquatic com-
munity structure and function for waters within a
variety of designated uses. Designated aquatic life
uses serve as general statements of attained or at-
tainable uses of State waters. Once established for
a designated use, biological criteria are quantifiable
values used to determine whether a use is impaired,
and if so, the level of impairment. This is done by
specifying what aquatic  community structure  and
function should exist in waters of a given designated
use, and then comparing this condition with the con-
dition of a  site under evaluation. If the existing
aquatic  community  measures  fail  to meet  the
criteria, the use is considered impaired.
    Since biological  surveys  used for  biological
criteria  are capable of  detecting water quality
problems  (use  impairments)   that  may not  be
detected by chemical or toxicity testing, violation of
biological criteria is sufficient cause for States to in-
itiate regulatory action. Corroborating chemical and
toxicity testing data are not required (though they
may be desirable) as  supporting evidence to sustain
a determination of use impairment. However, a find-
ing that biological criteria fail to indicate use impair:
ment  does  not mean  the  use is automatically
attained. Other evidence, such as violation of physi-
cal or chemical criteria, or results from toxicity tests,
can also be  used to identify impairment. Alternative
forms of criteria provide independent assessments
of nonattainment.
    As stated above,  biological criteria may be nar-
rative statements or  numerical  values. States  can
establish general narrative biological criteria early in
program development without conducting biological
assessments. Once established in State standards,
narrative biological  criteria form the  legal   and
                                                 14

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                                                                        ChaptorS: Th« Conceptual Framework
programmatic basis for expanding biological as-
sessment and biosurvey programs needed to imple-
ment  narrative  criteria   and  develop  numeric
biological  criteria  Narrative  biological   criteria
should become part of State regulations and stand-
ards.
Narrative Criteria

    Narrative biological  criteria are general state-
ments of attainable or attained conditions of biologi-
cal integrity and water quality for a  given  use
designation. Although  similar to the  "free from"
chemical  water quality criteria,  narrative biological
criteria establish a positive  statement about what
should occur within a water body. Narrative criteria
can take  a number of forms but they must contain
several attributes to support the goals of the Clean
Water Act to provide for the protection and propaga-
tion of fish, shellfish, and wildlife. Thus, narrative
criteria should  include  specific language about
aquatic community  characteristics that (1)  must
exist in a waterbody to meet a particular designated
aquatic life use, and  (2) are quantifiable. They must
be written to protect the use. Supporting statements
for the criteria  should promote v/ater  quality to
protect the most natural community possible for the
designated use. Mechanisms should be established
 in  the standard to  address potentially  conflicting
 multiple  uses.  Narratives  should  be written to
                                     protect  the most sensitive use and support an-
                                     tidegradation.
                                         Several States currently use narrative criteria.
                                     In Maine, for example, narrative criteria were estab-
                                     lished for four classes of water quality for streams
                                     and rivers (see Table 4). The classifications were
                                     based on the range of goals in the Act from "no dis-
                                     charge"  to  "protection  and  propagation of fish,
                                     shellfish, and wildlife"  (Courtemanch and Davies
                                     1987). Maine separated its "high quality water" into
                                     two categories, one that reflects the highest goal of
                                     the  Act (no discharge, Class  AA)  and one that
                                     reflects high integrity but is minimally impacted  by
                                     human   activity  (Class A).  The  statement "The
                                     aquatic life ... shall be as naturally occurs" is a nar-
                                     rative biological  criterion for both Class AA and A
                                     waters. Waters  in Class B meet the use when the
                                     life stages of all indigenous aquatic species are sup-
                                     ported  and no detrimental changes occur in com-
                                     munity   composition  (Maine DEP  1986).  These
                                     criteria directly  support refined designated aquatic
                                     life uses (see Section D, Refining Aquatic Life Use
                                     Classifications).
                                         These narrative criteria are effective only if, as
                                      Maine  has  done, simple  phrases  such as   "as
                                      naturally occurs" and  "nondetrimental" are clearly
                                      operationally defined.  Rules for  sampling  proce-
                                      dures and data analysis and interpretation should
                                      become  part  of the regulation  or  supporting
                                      documentation.  Maine was able to develop these
                                      criteria and  their supporting statements using avail-.
 Table 4.—Aquatic Life Classification Scheme for Maine's Rivers and Streams.
 RIVERS AND
 STREAMS
MANAGEMENT PERSPECTIVE
LEVEL OF BIOLOGICAL INTEGRITY
 Class AA       High quality water for preservation of
                recreational and ecological interests. No
                discharges of any kind permitted. No
                impoundment permitted.
 Class A        High quality water with limited human
                interference. Discharges restricted to noncontact
                process water or highly treated wastewater of
                quality equal to or belter than the receiving
                water. Impoundment permitted.
 Class B        Good  quality water. Discharges of well treated
                effluents with ample dilution permitted.
  Class C        Lowest quality water. Requirements consistent
                with interim goals of the federal Water Quality
                Law (fishable and swimmabie).
                                              Aquatic life shall be as naturally occurs.
                                              Aquatic life shall be as naturally occurs.
                                              Ambient water quality sufficient to support life
                                              stages of all indigenous aquatic species. Only
                                              nondetrimental changes in community
                                              composition may occur.
                                              Ambient water quality sufficient to support the
                                              life stages of all indigenous fish species.
                                              Changes in species composition may occur but
                                              structure and function of the aquatic community
                                              must be maintained.	
                                                    15

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               Ntttormi Progam Guidance
 able data from water quality programs. To imple-
 ment the criteria, aquatic life inhabiting unimpaired
 waters must be measured to quantify the  criteria
 statement.
     Narrative criteria can take more specific forms
 than illustrated in  the Maine  example. Narrative
 criteria may Include specific classes and species of
 organisms that will occur in waters for a given desig-
 nated use. To develop these narratives, field evalua-
 tions of  reference conditions  are necessary  to
 Identify biological community attributes that differ
 significantly between designated uses. For example
 in the  Arkansas use class Typical Gulf  Coastal
 Ecoreghn (i.e., South Central Plains) the narrative
 criterion reads:

      "Streams supporting diverse
      communities of indigenous or adapted
      species offish and other forms of
      aquatic life. Fish communities are
      characterized by a limited proportion of
      sensitive species; sunfishes are
      distinctly dominant, followed by darters
      and minnows. The community may be
      generally characterized by the following
      fishes: Key Species—Redfin shiner,
      Spotted sucker, Yellow bullhead, Flier,
      Slough darter, Grass pickerel; Indicator
      Species—Pirate perch, Warmouth,
      Spotted sunfish, Dusky darter,  Creek
      chubsucker, Banded pygmy sunfish
      (Arkansas DPCE1988).

    In Connecticut,  current designated uses are
supported  by narratives in the  standard.  For ex-
ample, under Surface Water Classifications,  Inland
Surface Waters Class AA,  the Designated Use is:
"Existing or proposed drinking water supply;  fish
and wildlife habitat; recreational use; agricultural, in-
dustrial supply, and other purposes (recreation uses
may be restricted)*"
   The supporting narratives include:

     Benthic invertebrates which inhabit lotic
     waters: A wide variety of
     macrotnvertebrate taxa should normally
     be present and all functional groups
     should normally be well represented...
     Water quality shall be sufficient to
     sustain a diverse macroinvertebrate
     community of indigenous species. Taxa
     within the Orders Plecoptera
      (stoneflies), Ephemeroptera (mayflies),
      Coleoptera (beetles), Tricoptera
      (caddisflies) should be well represented
      (Connecticut DEP 1987).

     For these narratives to be effective in a biologi-
 cal  criteria program expressions such as  "a wide
 variety" and "functional groups should normally be
 well  represented"  require  quantifiable  definitions
 that  become part  of  the  standard or supporting
 docum'  -tion. Many  States may find such narra-
 tives in .. .dir standards already. If so, States should
 evaluate current language to determine  if it meets
 the  requirements of quantifiable narrative criteria
 that support refined aquatic life uses.
    Narrative biological  criteria are similar to  the
 traditional  narrative "free froms" by providing  the
 legal basis for standards applications. A  sixth "free
 from" could be incorporated into standards to help
 support narrative biological criteria such as "free
 from activities that  would impair the aquatic com-
 munity  as  it naturally  occurs."  Narrative biological
 criteria  can be used immediately to address obvious
 existing problems.
Numeric Criteria

    Numerical  indices  that  serve  as  biological
criteria should  describe expected attainable com-
munity attributes for different  designated uses. It is
important to note that full  implementation of narra-
tive criteria will require similar data as that needed
for developing numeric criteria. At this time,  States
may or may not choose to  establish numeric criteria
but may find it an effective  tool for regulatory use.
   To derive a numeric criterion, an aquatic com-
munity's structure and function is  measured at refer-
ence  sites  and  set as  a  reference condition..
Examples of relative measures include similarity in-
dices,  coefficients of community  loss, and  com-
parisons of lists  of dominant taxa. Measures of
existing community structure  such as species rich-
ness, presence or absence of indicator taxa,  and
distribution of trophic feeding  groups are useful for
establishing the normal range of community com-
ponents to be expected in  unimpaired systems. For
example,  Ohio uses criteria for  the  warmwater
habitat use class based on multiple measures in dif-
ferent  reference sites within  the same ecoregion.
Criteria are set as the 25th percentile of all biologi-
cal index scores recorded  at  established reference
                                                16

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                                                                     Chapter 3:
sites within the ecoregion. Exceptional warmwater
habitat index criteria are set at the 75th percentile
(Ohio EPA 1988a). Applications such as this require
an extensive data base and multiple reference sites
for each criteria value.
    To develop numeric biological criteria, careful
assessments of biota in  reference!  sites  must be
conducted  (Hughes  et   al.  1986).  There  are
numerous ways to assess community structure and
function  in  surface  waters.  No  single  index  or
measure is universally recognized as free from bias.
It is important to evaluate the strengths and weak-
nesses of different assessment approaches. A multi-
metric approach  that incorporates information on
species richness, trophic composition, abundance
or  biomass,  and organism  condition  is recom-
mended. Evaluations that measure multiple com-
ponents  of  communities  are  also  recommended
because they  tend  to  be  more  reliable  (e.g.,
measures of fish and macroinvertebrates combined
will provide more information than measures of fish
communities  alone). The  weaknesses  of  one
measure or index can often be  compensated  by
combining it with the strengths of other community
measurements.
    The particular indices used to develop numeric
criteria depend  on  the  type of surface  waters
(streams, rivers, lakes, Great Lakes, estuaries, wet-
lands, and nearshore marine) to which they must be
applied.  In general,  community-level indices  such
as the Index of Biotic Integrity developed for mid-
western  streams (Karr et al. 1986) are more easily
interpreted and less variable than fluctuating num-
bers  such as population size. Future EPA technical
guidance documents will include evaluations of the
effectiveness of different biological  survey and as-
sessment approaches for measuring the biological
integrity  of  surface water  types and provide
guidance on acceptable approaches for biological
criteria development.
 Refining  Aquatic Life  Use

 Classifications

     State  standards  consist  of (1) designated
 aquatic life uses, (2) criteria sufficient to protect the
 designated  and  existing use,  and  (3)  an  an-
 tidegradation clause.  Biological  criteria  support
 designated aquatic life use  classifications for ap-
 plication in State standards. Each State develops its
own designated use classification system based on
the generic uses cited in the Act (e.g., protection
and propagation of fish,  shellfish, and  wildlife).
Designated uses are intentionally general.  How-
ever, States may develop subcategories within use
designations  to  refine and clarify the use class.
Clarification of the use class is particularly helpful
when a variety of surface waters with distinct char-
acteristics fit within the same use class, or do not fit
well into  any  category. Determination of nonattain-
ment in these waters may be difficult and open to al-
ternative interpretations. If a  determination is in
dispute,  regulatory actions will be difficult to  ac-
complish. Emphasizing aquatic community structure
within the designated use focuses the evaluation of
attainment/nonattainment on the resource of con-
cern under the Act.
    Flexibility inherent  in the  State  process  for
designating uses allows the development of sub-
categories  of   uses   within   the Act's  general
categories. For example, subcategories of aquatic ,
life uses may be on the basis of attainable habitat
(e.g., cold versus warmwater habitat); innate  dif-
ferences in community structure and function, (e.g.,
high versus low species richness or productivity); or
fundamental  differences in important community
components  (e.g., warmwater fish  communities
dominated by bass versus catfish).  Special uses
may also be  designated to protect particularly  uni-
que,  sensitive, or valuable aquatic species, com-
munities, or habitats.
    Refinement   of  use  classes can   be  ac-
complished within current State use  classification
structures. Data collected from biosurveys as part of
a developing biocriteria program may reveal unique
and consistent  differences among  aquatic com-
munities inhabiting different waters with the same
designated use. Measurable  biological  attributes
could then be used to separate one class into two or
 more  classes.  The result is  a refined aquatic life
 use.  For example, in Arkansas the beneficial use
 Fisheries "provides for the protection and  propaga-
 tion of fish, shellfish, and other forms of aquatic life"
 (Arkansas DPCE 1988). This use is subdivided into
 Trout, Lakes and Reservoirs, and Streams. Recog-
 nizing that stream characteristics across regions of
 the State differed ecologically, the State further sub-
 divided the stream designated uses into eight addi-
 tional uses based on regional characteristics (e.g.
 Springwater-influenced  Gulf  Coastal  Ecoregion,
 Ouachita Mountains Ecoregion). Within this clas-
 sification system, it was relatively straightforward for
                                                 17

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Oologta! Crmrt*: NMitoatl Prognm Guktonca
Arkansas to establish detailed narrative biological
criteria that list aquatic community components ex-
pected in each  ecoregion (see Narrative  Criteria
section).  These narrative criteria can then be used
to establish whether the use is impaired.
    States can refine very general designated uses
such as  high, medium, and low quality to  specific
categories that Include measurable ecological char-
acteristics. In Maine, for example, Class AA waters
are defined as "the highest classification and shall
be applied to waters which are outstanding natural
resources and which should be preserved because
of their ecological, social, scenic, or recreational im-
portance." The designated use includes "Class AA
waters shall be of such quality that they are suitable
... as habitat for fish and other aquatic life. The
habitat shall  be  characterized as free flowing and
natural."  This use supports development of narra-
tive criteria based on  biological characteristics  of
aquatic communities (Maine  DEP  1986; see the
Narrative Criteria section).
    Biological criteria that include lists of dominant
or typical species expected  to live in the  surface
water are particularly effective. Descriptions of im-
paired conditions are more  difficult to interpret.
However, biological criteria may contain statements
concerning which species dominate disturbed sites,
as well as those species expected at minimally im-
pacted sites.
    Most States  collect  biological data  in current
programs. Refining aquatic life use classifications
and Incorporating biological criteria into standards
will enable States to evaluate these data more ef-
fectively.
Developing and

Implementing  Biological

Criteria

    Biological criteria development and implemen-
tation In standards require an understanding of the
selection and evaluation of reference sites, meas-
urement of aquatic community structure and func-
tion, and  hypothesis testing under the  scientific
method. The developmental process is important for
State water quality managers and their staff to un-
derstand to promote effective planning for resource
and staff needs. This major program element deser-
ves careful consideration and has been separated
out in Part II by chapter for each developmental step
as noted below. Additional guidance will be provided
in future technical guidance documents.
   The developmental process is illustrated in Fig-
ure 3. The first step is establishing narrative criteria
in standards.  However, to support these narratives,
standardized  protocols  need  to be developed to
quanitify the  narratives for  criteria implementation.
They should include data collection procedures,
selection of reference sites, quality assurance and
quality control procedures,  hypothesis testing, and
statistical  protocols. Pilot studies should be con-
ducted  using these standard protocols to ensure
they  meet the  needs  of  the program,  test the
hypotheses, and provide effective  measures of the
biological integrity of surface waters in the State.

Figure 3.—Process for the Development and
Implementation of Biological Criteria
            Develop Standard Protocols
             (Test protocol sensitivity)
        Identify and Conduct Biosurveys at
            Unimpaired Reference Sites
            Establish Biological Criteria
       Conduct Biosurveys at Impacted Sites
             (Determine impairment)
                                                        Impaired Condition
                              Not Impaired
    Diagnose Cause of
       Impairment
 No Action Required
Continued Monitoring
   Recommended
    Implement Control
Fig. 3: Implementation of biological criteria requires the in-
itial selection of reference sites and characterization of resi-
dent aquatic communities inhabiting those sites to establish
the reference condition and biological criteria. After criteria
development, impacted sites are evaluated using the same
biosurvey procedures to assess resident biota. If impairment
is found, diagnosis of cause will lead to the implementation
of  a control. Continued monitoring should accompany con-
trol implementation to determine the effectiveness of in-
tervention. Monitoring is also recommended where no im-
pairment is found to ensure that the surface water maintains
or  improves in quality.
                                                 18

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                                                                      Chapters: The Conceptual Framework
    The next step is establishing the reference con-
dition for the surface water being tested. This refer-
ence  may be site specific  or regional  but must
establish the unimpaired  baseline for comparison
(see Chapter 5, The  Reference Condition). Once
reference sites are selected, the biological integrity
of the site must be evaluated using carefully chosen
biological surveys. A quality biological survey will in-
clude multiple community  components and may be
measured using a variety of metrics (see Chapter 6,
The Biological Survey). Establishing the reference
condition and conducting  biological surveys at the
reference locations provide the necessary informa-
tion for establishing the biological criteria.
    To apply biological criteria, impacted surface
waters with comparable habitat characteristics are
evaluated using the same  procedures as those used
to establish the criteria. The biological survey must
support standardized  sampling methods and statis-
tical protocols that are sensitive enough to identify
biologically relevant  differences between  estab-
lished criteria and the community under evaluation.
Resulting data are compared through hypothesis
testing to determine impairment (see Chapter 7,
Hypothesis Testing).
    When water quality impairments are detected
using biological criteria, they can only be applied in
a regulatory setting if the  cause for impairment can
 be identified. Diagnosis is iterative and investigative
 (see Chapter 7, Diagnosis). States must then deter-
 mine  appropriate  actions to  implement controls.
 Monitoring  should remain a part of  the  biological
 criteria program  whether  impairments are found or
 not. If an impairment exists, monitoring provides a
 mechanism to determine if the control effort (inter-
 vention)  is resulting in improved water  quality. If
 there is no impairment, monitoring ensures  the
 water quality is maintained and documents any  im-
 provements. When improvements  in water quality
 are detected through monitoring programs two  ac-
 tions are recommended.  When reference condition
 waters improve, biological criteria values should be
 recalculated to reflect this  higher level of integrity.
 When impaired  surface waters  improve,  states
 should  reclassify those waters to  reflect a refined
 designated use  with a higher level of biological in-
 tegrity.  This provides a mechanism for progressive
 water quality improvement.
                                                  19

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                           Chapter  4
         Integrating Biological
   Criteria  Into  Surface  Water
                     Management
   Integrating biological criteria into existing water
   quality programs will help to assess use attain-
   ment/nonattainment,  improve problem dis-
covery in specific waterbodies, and  characterize
overall water resource condition  within a region.
Ideally, biological criteria function in atn iterative man-
ner. New biosurvey information can be used to refine
use classes.  Refined use  classes will help support
criteria development and improve the value of data
collected in biosurveys.
Implementing Biological

Criteria

   As biological survey data are collected, these
data  will increasingly  support current use  of
biomonitoring data  to  identify  water  quality
problems, assess their severity, and set planning
and management priorities for remediation. Monitor-
ing data and biological criteria should be used at the
outset to help make regulatory decisions, develop
appropriate controls, and evaluate the effectiveness
of controls once they are implemented.
   The value of incorporating biological survey in-
formation in  regulatory programs is  illustrated  by
evaluations  conducted  by North  Carolina.  In
To integrate biological criteria into water quality
programs, states must carefully determine where and
how data are collected to assess the biological integrity
of surface waters.

response to amendments of the Federal Water Pol-
lution Control Act requiring secondary effluent limits
for all wastewater treatment plants, North Carolina
became embroiled in a debate over whether meet-
ing secondary effluent limits (at considerable cost)
would result in better water quality. North Carolina
chose to test the effectiveness of additional treat-
ment by conducting seven chemical and biological
surveys before  and  after facility upgrades (North
                                    21

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              NtHorml Program Gutdam*
Carolina DNRCD1984). Study results indicated that
moderate to substantial in-stream improvements
were observed at six of seven facilities. Biological
surveys were used  as an efficient, cost-effective
monitoring tool for assessing in-stream improve-
ments after facility modification. North Carolina has
also conducted comparative studies of benthic mac-
roinvertebratp surveys  and chemical-specific and
whole-effluent evaluations to assess sensitivities of
these   measures   for  detecting   impairments
(Eagleson etal. 1990).
    Narrative biological criteria provide a scientific
framework for evaluating biosurvey, bioassessment,
and biomonitoring data collected in most States. Ini-
tial application of narrative biological criteria may re-
quire only an evaluation of current work. States can
use available data to define variables for choosing
reference sites, selecting appropriate biological sur-
veys, and assessing the response of local biota to a
variety of impacts. States should also consider the
decision criteria that will be used for determining ap-
propriate State action when  impairment is found.
    Recent efforts by several  States  to  develop
biological criteria for freshwater streams provide ex-
cellent examples for how biological criteria can be
Integrated into water quality programs. Some of this
work Is described in the National Workshop on In-
stream Biological Monitoring and Criteria proceed-
ings which recommended  that  "the  concept of
biological sampling should be integrated into the full
spectrum  of  State  and  Federal  surface  water
programs*  (U.S. EPA  1987b). States are actively
developing  biological  assessment and  criteria
programs; several have programs in place.
Biological Criteria in  State

Programs

    Biological   criteria  are  used  within  water
programs to  refine use designations,  establish
criteria for determining use  attainment/nonattain-
ment,  evaluate  effectiveness  of  current  water
programs, and detect and  characterize previously
unknown impairments. Twenty States are currently
using some form of standardized ambient biological
assessments to determine the status of biota within
State waters: Levels of effort vary from bioassess-
ment studies to fully developed biological criteria
programs.
    Fifteen  States  are  developing  aspects  of
biological assessments  that  will support  future
development Of biological criteria. Colorado, Illinois,
Iowa, Kentucky, Massachusetts, Tennessee, and
Virginia conduct biological monitoring to evaluate
biological conditions, but are not developing biologi-
cal criteria.  Kansas is  considering using a com-
munity  metric  for water  resource assessment.
Arizona is planning to  refine ecoregions  for the
State. Delaware, Minnesota, Texas, and Wisconsin
are developing sampling and evaluation methods to
apply to future biological criteria  programs. New
York is proposing to use biological criteria for site-
specific evaluations of  water quality impairment.
Nebraska and  Vermont  use informal  biological
criteria to support existing aquatic life narratives in
their water quality standards and other regulations.
Vermont  recently  passed  a  law  requiring that
biological criteria be used to regulate through per-
mitting the indirect discharge of sanitary effluents.
    Florida  incorporated,  a  specific  biological
criterion  into  State  standards  for  invertebrate
species diversity. Species diversity within a water-
body, as measured by a Shannon diversity index,
may not fall below 75 percent of reference values.
This criterion has been used in enforcement cases
to obtain injunctions and monetary settlements.
Florida's approach is very specific and  limits alter-
native applications.
    Four States—Arkansas,  North Carolina, Maine,
and Ohio—are currently using biological criteria to
define aquatic life  use classifications and enforce
water quality standards. These states have made
biological criteria an integral part of comprehensive
water quality programs.

  • Arkansas rewrote its aquatic life use classifica-
tions for each of the State's ecoregions. This has al-
lowed many cities  to design wastewater treatment
plants to meet realistic attainable dissolved oxygen
conditions as determined by the new criteria.

  • North Carolina developed biological criteria to
assess impairment to aquatic life uses written as nar-
ratives in the State water quality standards. Biologi-
cal data and criteria are used extensively to identify
waters of special concern or those with exceptional
water quality. In addition to the High Quality Waters
(HQW) and  Outstanding Resource Waters (ORW)
designations, Nutrient Sensitive  Waters (NSW) at
risk for eutrophication are assessed using biological
                                                22

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criteria. Although specific biologicatl  measures are
not in the regulations, strengthened use of biological
monitoring data to assess  water quality  is  being
proposed for incorporation in North Carolina's water
quality standards.

  •  Maine  has enacted  a revised  Water Quality
Classification Law specifically designed to facilitate
the use of  biological  assessments. Each of four
water classes contains descriptive aquatic life condi-
tions necessary to attain that class. Based on  a
statewide database  of macroinveriebrate samples
collected above and below outfalls, Maine is now
developing a set of dichotomous keys that serve as
the biological  criteria.  Maine's program is not ex-
pected to have a significant roie in permitting, but will
be used to assess the  degree of protection afforded
by effluent limitations.

  • Ohio has instituted the most extensive use of
biological criteria for defining use classifications and
assessing  water  quality. Biological  criteria  were
developed for Ohio rivers  and streams  using an
ecoregional reference site approach. Within each of
the State's five ecoregions, criteria for three biologi-
cal indices  (two for fish communities  and one for
macroinvertebrates) were derived. Ohio successfully
uses biological criteria to demonstrate attainment of
aquatic life uses and discover previously unknown or
unidentified environmental degradation (e.g.,  twice
as  many impaired waters  were discovered using
biological criteria and water chemistry together than
were found using chemistry alone). The  upgraded
use designations  based on biological  criteria were
upheld in Ohio courts and the Ohio EPA successfully
proposed their biological criteria for inclusion in the
State water quality standards regulations.

     States and EPA have learned a great deal about
the  effectiveness of integrated  biological assess-
ments through the development of biological criteria
for  freshwater  streams.  This information  is  par-
ticularly valuable in providing guidance on develop-
ing biological criteria for other surface water types.
As previously discussed, EPA plans to produce sup-
 porting technical guidance for biological  criteria
development  in streams and other surface waters.
 Production  of these  guidance documents will be
 contingent on technical progress made on each sur-
                  Chapter 4: Integrating Biological Criteria


face water type by researchers in EPA, States and
the academic community.
    EPA will also be developing outreach  work-
shops to  provide technical assistance  to Regions
and States working  toward the implementation of
biological criteria programs in State water quality
management  programs.   In  the  interim,  States
should use the technical guidance currently avail-
able in the Technical Support Manualfs): Waterbody
Surveys and Assessments for Conducting Use At-
tainability Analysis (U.S. EPA 1983D, 1984a,b).
    During the next triennium, State effort will  be
focused on developing narrative biological criteria.
Full implementation  and  integration of biological
criteria will require several years. Using available
guidance,  States can complement the  adoption of
narrative  criteria  by developing  implementation
plans that include:

    1. Defining program objectives, developing
       research protocols, and setting priorities;

    2. Determining the process for establishing
       reference conditions, which includes
       developing a process to evaluate habitat
       characteristics;

    3. Establishing biological survey protocols that
       include justifications for surface water
       classifications and selected aquatic
       community components to be evaluated;
       and

    4. Developing a formal document describing
       the research design, quality assurance and
       quality control protocols, and required
       training for staff.

    Whether a State begins with narrative biological
 criteria or moves to fully implement numeric criteria,
 the shift of the. water quality program focus from
 source control to resource management represents
 a natural progression in the evolution from the tech-
 nology-based to water quality-based approaches in
 water  quality management.  The  addition  of  a
 biological perspective allows water quality programs
 to more directly address the objectives of the Clean
 Water Act and to place their efforts in a context that
 is more meaningful to the public.
                                                  23

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 Bido&etl CtttKix Ntioail Program Guidanca
 Future  Directions

    Biological criteria now focus on resident aquatic
 communities in surface waters.  They  have the
 potential to expand in scope toward greater ecologi-
 cal integration. Ecological criteria may encompass
 the ambient aquatic communities in surface waters,
 wildlife species that use the same aquatic resour-
 ces,  and the  aquatic  community inhabiting the
 gravel and sediments underlying the surface waters
 and adjacent land (hyporheic zone); specific criteria
 may apply to physical habitat. These areas may rep-
 resent only a few possible options for  biological
 criteria in the future.
    Many wildlife species depend on aquatic resour-
 ces. If aquatic population levels decrease or if the
 distribution of species changes, food sources may
 be sufficiently altered to cause problems for wildlife
 species using aquatic resources.  Habitat degrada-
 tion  that impairs aquatic species  will  often impact
 important wildlife habitat as well. These kinds of im-
 pairments are likely to be detected using  biological
 criteria as currently formulated.  In  some cases,
 however, uptake  of  contaminants  by  resident
 aquatic organisms may not result  in altered struc-
 ture and function of the aquatic community. These
 Impacts  may go undetected by biological  criteria,
 but could result in wildlife impairments because of
 bioaccumulation.  Future expansion  of-  biological
 criteria to include  wildlife species  that depend on
 aquatic resources could provide a more integrative
 ecosystem approach.
    Rivers may have a subsurface flood plain ex-
tending as far as two kilometers from the river chan-
 nel. Preliminary mass transport calculations made
 in the Rathead River basin in Montana indicate that
 nutrients discharged from this subsurface  flood
 plain may be crucial to biotic productivity in the river
channel (Stanford and Ward 1988). This is an unex-
plored dimension in the ecology of gravel river beds
and potentially in other surface waters.
    As discussed in Chapter 1, physical integrity is a
necessary condition  for biological  integrity. Estab-
lishing the reference condition for biological criteria
requires evaluation of habitat. The rapid bioassess-
ment protocol provides a good example of the im-
portance  of habitat  for  interpreting   biological
assessments (Plafkin et al.  1989). However, it may
be useful to more fully  integrate  habitat charac-
teristics into the regulatory process by establishing
criteria based on the necessary physical structure of
habitats to support ecological integrity.
                                                24

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            Part II
The Implementation
           Process

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        N*ttonal Prognm Guidtnca
The implementation of biological criteria requires: (1) selection of unimpaired
(minimal impact) surface waters to use as the reference condition for each desig-
nated use, (2) measurement of the structure and function of aquatic communities in
reference surface waters to establish biological criteria, and (3) establishment of a
protocol to compare the biological criteria to biota in impacted waters to determine
whether impairment has occurred. These elements serve as an interactive network
that  is particularly important during early development of biological  criteria
where rapid accumulation of information is effective for refining both designated
uses and developing biological criteria values. The following chapters describe
these three essential elements.
                                    26

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                                 Chapter 5
        The  Reference  Condition
A        key step in developing values for support-
        ing narrative and creating numeric biologi-
        cal  criteria  is  to  establish  reference
conditions; it is an essential feature of environmental
impact evaluations (Green  1979).  Fleference condi-
tions are critical for environmental assessments be-
cause standard experimental controls are  rarely
available. For most surface waters, baseline data
were not collected prior to an impact, thus impair-
ment must be inferred from differences between the
impact site and established references. Reference
conditions describe the characteristics of waterbody
segments least impaired by human activities and are
used to define attainable biological or habitat condi-
tions.
    Wide variability among natural! surface waters
across the country resulting from cliimatic, landform,
and other  geographic differences  prevents the
development of nationwide reference conditions.
Most States are also too heterogeneous for single
reference conditions. Thus, each State, and when
appropriate, groups of States, will be responsible for
selecting and evaluating reference waters within the
State to establish biological criteria for a given sur-
face water type or category of designated use. At
least seven methods for estimating attainable condi-
tions for streams have been identified (Hughes et al.
1986).  Many of these can apply to other surface
waters.  References may be established by defining
models  of attainable conditions based on historical
data or unimpaired habitat (e.g., streams  in old
growth forest). The reference condition established
as before-after comparisons or concurrent  mea-
Referenca conditions should tie established by
measuring resident biota in unimpaired surface waters.
sures of the reference water and impact sites can be
based on empirical data (Hall et al. 1989).
   Currently, two principal approaches are used for
establishing the reference condition. A State may
opt to (1)  identify site-specific reference sites for
each evaluation of impact or (2) select ecologically
similar regional reference sites for comparison with
impacted sites within the same region. Both ap-
proaches depend on evaluations of habitats to en-
sure that waters with similar habitats are compared.
The designation  of discrete habitat types is more
fully developed for streams and rivers. Development
of habitat types for lakes, wetlands, and estuaries is
ongoing.
                                            27

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 Sfefcgfca/ Gntete Niitoimt Program Guidance
 Site-Specific Reference

 Condition.

    A site-specific reference condition, frequently
 used to evaluate the impacts from a point discharge,
 is best for surface waters with  a strong directional
 flow such as in streams and rivers (the upstream-
 downstream approach). However,  it  can also  be
 used for other  surface waters  where gradients in
 contaminant  concentration   occur   based   on
 proximity to a source (the  near field-far field ap-
 proach). Establishment of a site-specific reference
 condition requires the availability  of  comparable
 habitat within the same waterbody in both the refer-
 ence location and the impacted  area.
    A site-specific reference condition is difficult to
 establish if (1) diffuse nonpoint source pollution con-
 taminates most  of the water body; (2) modifications
 to the channel,  shoreline, or bottom substrate are
 extensive; (3) point sources occur at multiple loca-
 tions on the waterbody; or (4) habitat characteristics
 differ significantly between possible reference loca-
 tions and the impact site (Hughes et al. 1986; Plaf-
 kin  et al.  1989).  In  these  cases,  site-specific
 reference conditions could result in underestimates
 of impairment. Despite limitations, the use of site-
 specific reference conditions is  often the method of
 choice for  point  source discharges  and  certain
 waterbodies, particularly when  the  relative impair-
 ments from different local impacts need to be deter-
 mined.
The Upstream-Downstream
Reference Condition

    The upstream-downstream reference condition
is  best  applied to streams and  rivers where the
habitat characteristics of the waterbody above the
point of discharge are similar to the habitat charac-
teristics of the stream below the point of discharge.
One standard procedure is to characterize the biotic
condition just above the discharge point (accounting
for possible upstream circulation) to establish the
reference condition. The  condition below the  dis-
charge  is  also  measured at several sites. If  sig-
nificant  differences  are found   between  these
measures,  impairment  of the biota  from the  dis-
charge is indicated. Since measurements of resi-
dent biota taken in any two sites are expected to
differ because of natural variation, more than  one
biological assessment  for  both upstream and
downstream sites is often needed to be confident in
conclusions  drawn from these data (Green, 1979).
However, as more data are collected by a State, and
particularly if regional characteristics of the water-
bodies are incorporated, the basis for determining
impairment from site-specific upstream-downstream
assessments may require fewer individual samples.
The same measures made below the "recovery
zone"  downstream from  the discharge will help
define where recovery occurs.
    The upstream-downstream reference condition
should be used with discretion since the reference
condition may be impaired from impacts upstream
from the point source of interest. In these cases it is
important to discriminate between individual point
source impact versus overall impairment of the sys-
tem. When overall impairment occurs, the resident
biota may be sufficiently impaired to make it impos-
sible to detect the effect of the target point source
discharger.
    The approach can be cost effective when one
biological assessment of the upstream reference
condition adequately reflects the attainable condi-
tion of the impacted site.  However, routine com-
parisons   may require  assessments  of  several
upstream sites to adequately describe the natural
variability of reference biota. Even so, measuring a
series of  site-specific references will likely continue
to be the method of choice for certain point source
discharges,  especially where the relative impair-
ments from different local impacts need to be deter-
mined.
The Near Field-Far Field Reference
Condition

    The near field-far field reference condition is ef-
fective for establishing a reference condition in sur-
face waters other than rivers and streams and is
particularly  applicable for unique waterbodies (e.g.,
estuaries such as Puget Sound may not have com-
parable  estuaries for  comparison). To apply this
method, two  variables are measured (1)  habitat
characteristics, and (2) gradient of impairment. For
reference waters to be identified within the same
waterbody,  sufficient size is necessary to separate
the  reference  from the  impact area so  that a
gradient of  impact exists. At the same time, habitat
characteristics must be comparable.
                                               28

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                                                                       ChapttrS: Tht Roffrarica Condition
    Although not fully developed, this approach may
provide an effective way to establish  biological
criteria for estuaries, large lakes, or wetlands. For
example, estuarine habitats could be defined and
possible reference waters identified using physical
and chemical variables like those selected by the
Chesapeake Bay Program (U.S. EPA 1987a, e.g.,
substrate type, salinity, pH) to establish comparable
subhabitats in an estuary. To determine those areas
least impaired, a "mussel watch" program like that
used in Narragansett Bay (i.e., captive mussels are
used as indicators of contamination, (Phelps 1988))
could establish impairment gradients. These two
measures, when combined, could form the basis for
selecting specific habitat types in areas of least im-
pairment to establish the reference condition.
Regional Reference

Conditions

    Some of the limitations of site-specific reference
conditions can be overcome by using regional refer-
ence conditions that are based on the assumption
that surface waters integrate the character of the
land they drain. Waterbodies within the same water-
shed in the same region should be more similar to
each other than to those within watersheds  in dif-
ferent regions. Based on these assumptions, a dis-
tribution of aquatic regions can be developed based
on ecological features that directly or indirectly re-
late to water quality and quantity, such as soil type,
vegetation (land cover), land-surface form, climate,
and  land use. Maps  that incorporate  several of
these features will provide a general purpose broad
scale ecoregional framework (Gallant et al. 1989).
     Regions of ecological similarity  are based on
 hydrologic, climatic,  geologic, or  other  relevant
 geographic variables that influence the nature of
 biota in surface waters. To establish a regional refer-
 ence condition, surface waters of similar habitat
 type are identified in definable ecological regions.
 The biological integrity of these reference waters is
 determined to establish the reference condition and
 develop biological criteria. These criteria are then
 used to assess impacted surface)  waters  in the
 same watershed or region. There are two forms of
 regional reference conditions:  (1)  paired  water-
 sheds and (2) ecoregions.
Paired Watershed Reference
Conditions

    Paired watershed,reference conditions are es-
tablished to evaluate impaired waterbodies, often
impacted by multiple sources. When the majority of
a waterbody is impaired, the upstream-downstream
or near field-far field reference condition does not
provide an adequate representation of the unim-
paired condition of  aquatic communities  for  the
waterbody. Paired  watershed reference conditions
are established by identifying unimpaired  surface
waters within the same or very similar local water-
shed  that is of comparable type and habitat. Vari-
ables to consider when selecting the watershed
reference condition include absence of human  dis-
turbance, waterbody size and other physical charac-
teristics, surrounding vegetation,  and others  as
described in the "Regional Reference Site Selec-
tion" feature.
    This method   has been  successfully  applied
(e.g., Hughes 1985) and  is an approach  used in
Rapid Bioassessment  Protocols  (Plafkin et  al.
1989). State use of this approach results  in good
reference conditions that can be used immediately
in current programs. This  approach has the added
benefit of promoting the development of a database
on high quality waters in the State that could form
the foundation for establishing larger regional refer-
ences (e.g., ecoregions.)
 Ecoregional Reference Conditions

     Reference conditions can also be developed on
 a larger scale. For these references, waterbodies of
 similar type are identified in regions of ecological
 similarity. To  establish a regional reference condi-
 tion, a set of  surface waters of similar habitat type
 are. identified  in each ecological region. These sites
 must represent similar habitat type and be repre-
 sentative of the region. As with other reference con-
 ditions, the biological integrity of selected reference
 waters is determined to establish the reference.
 Biological criteria can then be developed and used
 to assess impacted surface  waters in the same
 region. Before reference conditions may be estab-
 lished, regions of  ecological similarity must be
 defined.
                                                 29

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BiologicalCrHfrix NtSonti Prognm Guidtnct
       Regional Reference Site

                 Selection

       To determine specific regional reference sites
    for streams, candidate watersheds are selected
    from the  appropriate maps and evaluated to
    determine if they are typical for the region. An
    evaluation of level of human disturbance is made
    and a number of relatively undisturbed reference
    sites are selected from  the  candidate sites.
    Generally, watersheds are chosen as regional ref-
    erence sites when they fall entirely within typical
    areas of the region.  Candidate sites  are  then
    selected by aerial and ground surveys. Identifica-
    tion of candidate sites is based on: (1)  absence
    of human  disturbance, (2) stream size, (3)  type
    of stream channel, (4) location within a natural or
    political refuge,  and (5) historical records of resi-
    dent btota and possible migration barriers.
       Final selection of reference sites depends on
    & determination of minimal disturbance derived
    from habitat evaluation made during site visits.
    For example, indicators of good quality streams in
    forested ecoregions include: (1) extensive,  old,
    natural riparian vegetation; (2) relatively high het-
    erogeneity in channel width and depth; (3) abun-
    dant large woody  debris,  coarse bottom sub-
    strate, or extensive aquatic or overhanging vege-
    tation; (4) relatively high or constant discharge;
    (5) relatively clear waters with natural color and
    odor; (6) abundant diatom, insect, and fish as-
    semblages; and (7) the presence of piscivorous
    birds and mammals.
    One frequently used method is described by
Omernik (1987) who combined maps of land-sur-
face form, soil, potential  natural vegetation,  and
land use within the conterminous United States to
generate  a  map  of aquatic  ecoregions for the
country. He also developed more detailed regional
maps. The ecoregions defined by  Omernik  have
been evaluated for streams and small rivers in
Arkansas (Rohm et al. 1987), Ohio (Larsen et al.
1986; Whittier et al. 1987), Oregon (Whittier et al.
1988), Colorado (Gallant et al. 1989), and Wiscon-
sin (Lyons 1989) and for lakes in Minnesota (Heis-
kary  et  al.  1987).  State ecoregion  maps  were
developed for Colorado (Gallant et al. 1989) and
Oregon (Clarke et al. mss).  Maps for the national
ecoregions  and six mufti-state  maps  of more
detailed ecoregions are  available from the U.S. EPA
Environmental   Research   Laboratory,   Corvallis,
Oregon.
    Ecoregions such as those defined by Omernik
(1987) provide  only a first step  in  establishing
regional reference sites for development of the ref-
erence condition. Reid site evaluation is required to
account  for  the inherent variability  within each
ecoregion. A general method for selecting  reference
sites for streams has been described (Hughes et al.
1986). These are the same variables used for com-
parable   watershed  reference  site  selection.
Regional and on-site evaluations of biological fac-
tors help determine specific sites that best  represent
typical but unimpaired surface water habitats within
the region. Details on this approach for streams is
described in the "Regional Reference Site Selec-
tion" feature. To date,  the regional approach has
been  tested on  streams,  rivers,  and lakes. The
method appears applicable for assessing other in-
land ecosystems. To apply this approach to wet-
lands  and  estuaries  will   require  additional
evaluation based on the relevant ecological features
of these  ecosystems  (e.g.  Brooks and Hughes,
1988).
    Ideally, ecoregional reference sites should be
as little disturbed as possible, yet represent water-
oodies for which they  are  to serve as reference
waters. These sites may serve as references for a
large  number of similar waterbodies (e.g., several
reference streams may  be used to define  the refer-
ence  condition  for numerous physically  separate
streams if the reference streams contain the same
range of stream morphology, substrate, and flow of
the other  streams  within  the  same ecological
region).
    An important benefit of a regional reference sys-
tem is the establishment of a baseline  condition for
the least  impacted  surface  waters  within  the
dominant  land  use pattern of the region. In many
areas a return  to pristine, or presettlement, condi-
tions is impossible, and  goals for waterbodies in ex-
tensively  developed  regions  could  reflect  this.
Regional  reference sites  based on the  least im-
pacted sites within a region will help water quality
programs restore and protect the environment in a
way that is ecologically feasible.
                                                 30

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                                                                        Chapter S: The Reference Condition
    This approach must be used with caution for two
reasons. First, in many urban, industrial, or heavily
developed agricultural regions, even the least im-
pacted sites are seriously degraded. Basing stand-
ards or criteria on such sites will set standards too
low if these high levels of environmental degrada-
tion are considered acceptable or adequate. In such
degraded  regions,  alternative  sources  for the
regional reference may be needed (e.g., measures
taken from  the same region  in a less developed
neighboring State or historical records from the
region before serious impact occurred). Second, in
some regions  the minimally-impacted sites are not
typical of most sites in the region and may have
remained unimpaired precisely bejcause they are
unique. These two considerations emphasize the
need to select reference  sites very carefully, based
on solid quantitative data  interpreted by profes-
sionals familiar with the biota of the region.
    Each State, or groups of States, can select a
series of regional reference sites that represent the
attainable conditions  for  each region. Once biologi-
cal criteria are established using this approach, the
cost for evaluating local  impairments is often lower
than a series of measures of site-specific reference
sites. Using paired watershed reference conditions
immediately in regulatory programs will provide the
added  benefit  of  building a  database  for  the
development of regions of ecological similarity.
                                                  31

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                                Chapter
            The  Biological  Survey
A        critical element of biological criteria is the
        characterization of biological communities
        inhabiting surface waters. Use of biological
data is not new; biological information has been used
to  assess impacts from pollution  since  the 1890s
(Forbes  1928),  and most States  currently incor-
porate biological information in their decisions about
the quality of surface waters. However, biological in-
formation can be obtained  through a variety  of
methods, some of which are more effective  than
others for characterizing  resident  aquatic biota.
Biological criteria are developed using biological sur-
veys;  these  provide  the  only direct  method for
measuring the structure and  function of an aquatic
community.
 Different subhabitat within the same surface water will
 contain unique aquatic community components. In
 fast-flowing stream segments species such as (1) black
 fly larva; (2) brook trout; (3) water penny; (4) crane fly
 larva; and (5) water moss occur.
                                               However, In slow-flowing stream segments, species
                                               like (1) water strider, (2) smallmouth bass; (3) crayfish;
                                               and (4) fingernail dams are abundant.
   Biological survey study design is of critical im-
portance to criteria development. The design must
be scientifically rigorous to provide the  basis for
legal action, and be biologically relevant to detect
problems of regulatory concern. Since it is not finan-
cially or technically feasible to evaluate  all or-
ganisms in an entire ecosystem at all times, careful
selection of community components, the time and
place chosen for assessments, data  gathering
methods used, and the consistency with which
these variables are applied will determine the suc-
cess of the biological criteria program.  Biological
surveys must therefore be carefully planned to meet
scientific and legal requirements, maximize informa-
tion, and minimize cost.
                                            33

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 Btotog&l CrtMi: Nriorml Prognm Guidinc*
    Biological surveys can range  from collecting
samples of  a single species to  comprehensive
evaluations of an entire  ecosystem. The first ap-
proach Is difficult to Interpret for community assess-
ment;  the second  approach is  expensive  and
impractical. A balance between these extremes can
meet program needs. Current approaches range
between detailed ecological surveys, biosurveys of
targeted community components, and biological in-
dicators (e.g., keystone  species).  Each  of these
bfosurveys has advantages and limitations. Addi-
tional  discussion will be  provided  in technical
guidance under development.
    No single type of approach to biological surveys
Is always best Many factors affect the value of the
approach, Including seasonal variation, waterbody
size, physical boundaries, and other natural charac-
teristics. Pilot  testing alternative  approaches in
State waters may be the best way to determine the
sensitivity of specific methods for evaluating biologi-
cal integrity of local waters. Due to the number of al-
ternatives available  and the diversity of ecological
systems,  individuals   responsible for  research
design should be experienced  biologists with exper-
tise in the local and regional ecology of target  sur-
face  waters.  States  should  develop  a  data
management program that includes data analysis
and evaluation and standard operating procedures
as part of a Quality Assurance  Program Plan.
   When  developing  study designs for biological
criteria, two key elements to  consider include (1)
selecting aquatic community components that will
best represent the biological integrity of State sur-
face waters  and  (2)  designing data  collection
protocols to ensure  the best representation of the
aquatic community.  Technical guidance currently
available to aid the development of study design in-
clude:  Water  Quality Standards Handbook (U.S.
EPA1983a), Technical Support Manual: Waterbody
Surveys and Assessments for Conducting Use At-
tainability  Analyses  (U.S.  EPA 1983b);  Technical
Support Manual: Waterbody Surveys and Assess-
ments  for Conducting Use Attainability Analyses,
Volume II: Estuarine Systems (U.S. EPA 1984a);
and Technical Support Manual: Waterbody Surveys
and Assessments for Conducting Use Attainability
Analyses,  Volume  III:  Lake  Systems (U.S.  EPA
1984b). Future technical  guidance will build on
these documents and provide specific guidance for
biological criteria development.
 Selecting  Aquatic

 Community Components

    Aquatic communities contain  a  variety  of
 species  that  represent  different  trophic levels,
 taxonomic  groups, functional characteristics, and
 tolerance  ranges.  Careful  selection  of  target
 taxonomic groups can provide a balanced assess-
 ment that is sufficiently broad to describe the struc-
 tural  and  functional  condition  of an  aquatic
 ecosystem, yet be sufficiently practical to use on a
 daily basis (Plafkin et at. 1989; Lenat 1988). When
 selecting community components to include in a
 biological assessment, primary emphasis should go
 toward including species or taxa that (1) serve as ef-
 fective indicators  of  high  biological integrity (i.e.,
 those likely to live in unimpaired waters), (2) repre-
 sent a range of pollution tolerances, (3) provide pre-
 dictable,  repeatable results, and (4) can be readily
 identified by trained State personnel.
    Fish, macroinvertebrates, algae, and zooplank-
 ton are most commonly used in current bioassess-
 ment programs. The taxonomic groups chosen will
 vary depending on the type of aquatic ecosystem
 being assessed and  the type of expected impair-
 ment. For example, benthic macroinvertebrate and
 fish  communities  are taxonomic  groups  often
 chosen for flowing fresh water.  Macroinvertebrates
 and  fish both provide valuable  ecological  informa-
 tion  while fish  correspond to the regulatory and
 public  perceptions of water quality and reflect
 cumulative environmental stress over longer time
frames. Plants  are  often  used In wetlands, and
 algae are useful in lakes  and estuaries to assess
 eutrophication. In marine systems, benthic macroin-
 vertebrates and submerged aquatic vegetation may
 provide key community components. Amphipods,
for example, dominate many aquatic communities
 and  are  more sensitive than other invertebrates
 such as polychaetes and molluscs to a wide variety
 of pollutants including hydrocarbons and  heavy me-
tals  (Reich and Hart 1979; J.D. Thomas, pers.
comm.).
    It is beneficial to supplement standard groups
with additional  community components to meet
specific goals, objectives,  and resources of the as-
sessment program. Biological surveys that use two
or three taxonomic groups (e.g., fish, macroinver-
tebrates, algae) and, where appropriate, include dif-
ferent  trophic  levels within  each  group  (e.g.,
 primary, secondary, and  tertiary consumers)  will
                                               34

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                                                                          Chapter & The Biological Survey
provide a  more realistic  evaluation  of system
biological  integrity.  This  is  analogous  to  using
species from  two or more taxonomic  groups in
bioassays.  Impairments that are difficult to detect
because of the temporal or spatial habits or the pol-
lution tolerances of  one group  may be revealed
through impairments in differenl:  species or as-
semblages (Ohio EPA 1988a).
    Selection  of aquatic  community components
that show  different  sensitivities  and responses to
the same perturbation will aid in identifying the na-
ture of a problem. Available data on the ecological
function, distribution, and abundance of species in a
given  habitat will help determine  the  most ap-
propriate target  species or taxa For  biological sur-
veys in the  habitat.  The selection  of community
components should also depend on the ability of the
organisms  to be accurately identified  by trained
State  personnel.  Attendent  with  the  biological
criteria program  should be the development of iden-
tification keys for the organisms selected for  study
in the biological survey.


Biological Survey  Design

     Biological surveys  that measure the structure
and function of aquatic communities will provide the
information needed  for biological criteria develop-
ment. Elements  of community structure and function
may be evaluated using a series of metrics. Struc-
tural metrics describe  the composition  of a  com-
munity, such as the number of different species,
relative abundance of specific species, and number
and relative abundance of tolerant and intolerant
 species. Functional  metrics describe the ecological
 processes of the community.  These may include
 measures such as community photosynthesis or
 respiration. Function may also be estimated from
 the proportions  of various feeding groups (e.g., om-
 nivores, herbivores, and insectivores, or shredders,
 collectors,  and  grazers). Biological surveys can
 offer variety and flexibility in application. Indices cur-
 rently available  are primarily for freshwater streams.
 However, the approach has been used for lakes and
 can be developed for estuaries and wetlands.
 Selecting the metric

     Several  methods  are currently  available for
 measuring the relative structural and functional well-
 being  of fish assemblages in freshwater streams,
such as the Index of Biotic Integrity (IBI); Karr 1981;
Karr et al. 1986; Miller et al. 1988) and the Index of
Well-being (IWB; Gammon 1976,  Gammon et al.
1981). the IBI  is one of the more widely used  as-
sessment methods. For additional detail, see  the
"Index of Biotic  Integrity" feature.
      Index of Biotic Integrity

       The Index of Biotic Integrity (IBI) is commonly
    used for fish community analysis (Karr 1981). The
    original IBI was comprised of 12 metrics:

     • six metrics evaluate species richness and
       composition

         ' number of species
         • number of darter species
         * number of sucker species
         • number of sunfish species
         • number of intolerant species
         * proportion of green sunfish

     • three metrics quantify trophic composition

         ' proportion ofomnivores
         • proportion of insectivorous cyprinids
         • proportion ofpiscivores

     • three metrics summarize fish abundance and
       condition information

          • number of individuals in sample

          ' proportion of hybrids
          • proportion of individuals with disease

        Each metric is scored 1 (worst). 3, or 5 (best),
     depending on how the field data compare with an
     expected value obtained from reference sites. All
     12 metric values are then summed to provide an
     overall index value that represents relative  in-
     tegrity. The IBI was designed for midwestern
     streams; substitute  metrics  reflecting the same
     structural and functional characteristics  have
     been created to accommodate regional variations
     in fish assemblages (Miller et al. 1988).
                                                  35

-------
 Sfotogfci/Crflfrtr Niton*] Program Gutdm*
    Several Indices that evaluate  more than one
 community characteristic are also available for as-
 sessing  stream  macroinvertebrate  populations.
 Taxa richness, EPT taxa (number of taxa of the in-
 sect orders Ephemeroptera, Plecoptera, and Tricop-
 tera), and species pollution tolerance values are a
 few of several components of these macroinver-
 tebrate assessments. Example indices include the
 Invertebrate  Community  Index  (ICI;  Ohio  EPA,
 1988) and Hilsenhoff Biotic Index (HBI; Hilsenhoff,
 1987).
    Within these metrics specific information on the
 pollution tolerances of different species within a sys-
 tem will help define the type of impacts occurring in
 a waterbody. Biological indicator groups (intolerant
 species, tolerant species, percent  of diseased or-
 ganisms) can be used for  evaluating community
 biological integrity if sufficient data have been col-
 lected to support conclusions  drawn  from the in-
 dicator  data.  In  marine systems, for example,
 amphipods have  been used by a number of re-
 searchers  as  environmental  indicators  (McCa'll
 1977; Botton 1979; Meams and Word 1982).
Sampling design

    Sampling design and statistical protocols are re-
quired to reduce sampling error and evaluate the
natural variability of biological responses that are
found  in  both laboratory and  field data.  High
variability reduces the power of a statistical test to
detect real impairments (Sokal and  Rohlf, 1981).
States may reduce  variability by refining sampling
techniques and protocol to decrease variability in-
troduced during data  collection, and increase the
power of the evaluation by  increasing the number of
replications. Sampling techniques  are refined,  in
part, by collecting a representative sample of resi-
dent biota from the same component of the aquatic
community from the same  habitat type in the same
way at sites being  compared. Data  collection
protocols  should  incorporate  (1)  spatial  scales
(where and how samples are collected) and (2) tem-
poral scales (when data  are  collected)  (Green,
1979):

  • Spatial Scales refer to the wide variety of sub-
     habitats  that exist within  any surface  water
     habitat. To account for subhabitats, adequate
     sampling  protocols require  selecting  (1) the
     location within  a  habitat where target groups
     reside and (2) the method for collecting data on
     target groups. For example, if fish are sampled
     only from fast flowing riffles within stream A, but
     are sampled from slow flowing pools in stream
     B, the data will not be comparable.

     Temporal  Scales refer to aquatic community
     changes that occur over time because of diurnal
     and life-cycle changes in organism behavior or
     development, and seasonal or annual changes
     in the environment. Many organisms go through
     seasonal life-cycle  changes that dramatically
     affect  their presence and abundance in  the
     aquatic community. For example, macroinver-
     tebrate data collected from stream A in March
     and stream B in May, would not be comparable
     because the emergence of insect adults after
     March would significantly alter the abundance
     of subadults found in stream B in May.  Similar
     problems would occur if algae were collected in
     lake A during the dry season and lake B during
     the wet season.
    Field sampling protocols that produce  quality
assessments from a limited number of site visits
greatly enhance the utility of the sampling  techni-
que.  Rapid  bioassessment  protocols,  recently
developed for assessing streams, use standardized
techniques to quickly gather physical, chemical, and
biological quantitative data that can assess changes
in biological integrity (Plafkin et al. 1989). Rapid
bioassessment   methods  can  be  cost-effective
biological assessment approaches when they have
been verified with more comprehensive evaluations
for the habitats and region where they are to be ap-
plied.
    Biological survey methods such as the  IBI for
fish and ICI for macroinvertebrates were developed
in streams and rivers and have yet to be applied to
many ecological  regions. In addition,  further re-
search is needed to adapt  the approach to lakes,
wetlands, and estuaries, including the development
of alternative structural  or functional endpoints. For
example,  assessment  methods for algae (e.g.
measures of biomass,  nuisance bloom frequency,
community structure) have been used for lakes. As-
sessment   metrics  appropriate  for  developing
biological criteria for lakes, large rivers, wetlands,
and  estuaries are being developed and tested so
that a multi-metric approach can be effectively used
for all surface waters.
                                                36

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                           Chapter 7
            Hypothesis  Testing:
   Biological  Criteria  and  the
              Scientific  Method
     Biological criteria are applied in the standards
     program by testing hypotheses about the
     biological integrity of  impacted surface
waters.  These  hypotheses  include  the  null
  lothesis—the designated use of the waterbody is
   impaired—and alternative hypotheses such as
   designated use of the waterbody is impaired
(more specific hypotheses can also be generated
that predict the type(s) of impairment). Under these
hypotheses specific predictions are generated con-
cerning the kinds and numbers of organisms repre-
senting community structure and function expected
or found in unimpaired habitats. The kinds and num-
bers of organisms surveyed in unimpaired waters
are used to establish the biological criteria. To test
the alternative hypotheses,  data collection and
analysis procedures are used to compare the criteria
to comparable measures of community structure and
function in impacted waters.
Hypothesis Testing

   To detect differences of biological and regula-
tory concern between biological criteria and ambient
biological integrity at a test site, it is important to es-
tablish the sensitivity of the evaluation. A10 percent
difference in condition is more difficult to detect than
  50 percent difference. For the experimental/sur-
  y design to be effective, the level of  detection
should be predetermined to establish sample size
                                        Multiple impacts in the same surface water such as
                                        discharges of effluent from point sources, leachate from
                                        landfills or dumps, and erosion from habitat degradation
                                        each contribute to impairment of the surface water. AH
                                        impacts should be considered during the diagnosis
                                        process.
                                        for data  collection  (Sokal  and  Rohlf  1981).
                                        Knowledge of expected natural variation,  experi-
                                        mental error, and the kinds of detectable differences
                                        that can be expected will help determine  sample
                                     37

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               N*fon»l Progam Quid***
 size and location. This forms the basis for defining
 data quality objectives, standardizing data collection
 procedures,  and  developing  quality  assurance/
 quality control standards.
     Once data are collected and analyzed, they are
 used to test the hypotheses to determine if charac-
 teristics of the resident biota at a test site are sig-
 nificantly different from  established criteria values
 for a comparable habitat. There are three possible
 outcomes:

     1. The use is impaired when survey design and
       data analyses are sensitive enough to detect
       differences of regulatory importance, and
       significant differences were detected. The
       next step is to diagnose the cause(s)  and
       source(s)  of impairment.

    2. The biological criteria are met when survey
       design and data analyses are sensitive
       enough  to detect differences of regulatory
       significance, but no differences were found.
       In this case,  no action is required by States
       based on these measures. However, other
       evidence may indicate impairment (e.g.,
       chemical criteria are violated; see below).

    3.  The outcome is indeterminate when survey
       design and data analyses are not sensitive
       enough to detect differences of regulatory
       significance, and no differences were
       detected. If a State or Region determines
       that this is occurring, the development of
       study design and evaluation for biological
       criteria was incomplete. States must then
       determine whether they will accept the
       sensitivity of the survey or conduct
       additional surveys to increase the power of
       their analyses. If the sensitivity of the
       original survey is accepted, the State should
       determine what magnitude of difference the
       survey is capable of detecting. This will aid
       In re-evaluating research design and desired
       detection limits. An indeterminate outcome
       may also occur if the test site and the
       reference conditions were not comparable.
       This variable may also require re-evaluation.

   As with all scientific studies, when implementing
biological criteria, the purpose of hypothesis testing
is to determine if the data support the conclusion
that the null hypothesis is false (i.e., the designated
 use  is not  impaired  in  a particular waterbody).
 Biological criteria cannot prove attainment.  This
 reasoning provides the basis for emphasizing inde-
 pendent   application   of  different   assessment
 methods  (e.g., chemical verses biological criteria).
 No type of criteria can "prove" attainment; each type
 of criteria can disprove attainment.
    Although this discussion is limited to the null
 and one  alternative hypothesis, it is possible  to
 generate   multiple  working  hypotheses  (Popper,
 1968) that promote the diagnosis of  water quality
 problems when they exist. For example, if physical
 habitat limitations are believed to be causing impair-
 ment   (e.g.,  sedimentation)    one   alternative
 hypothesis could specify  the  loss of community
 components  sensitive to this impact. Using multiple
 hypotheses can  maximize the information gained
 from each study. See the Diagnosis section for addi-
 tional discussion.
 Diagnosis
    When  impairment of the  designated use  is
found using biological criteria, a diagnosis of prob-
able cause of impairment is the next step for im-
plementation. Since biological criteria are primarily
designed  to  detect  water  quality impairment,
problems are likely to be identified without a known
cause. Fortunately the  process of evaluating test
sites for biological impairment  provides significant
information to aid in determining cause.
    During diagnostic evaluations, three main im-
pact categories should be  considered:  chemical,
physical, and biological. To begin the  diagnostic
process two questions are posed:

    • What are the obvious causes of impairment?

    • If no obvious causes are apparent, what
     possible causes do the biological data
     suggest?

    Obvious causes such as habitat degradation,
point source discharges, or introduced species are
often identified during the course of a normal field
biological assessment. Biomonitoring programs nor-
mally provide knowledge of potential sources of im-
pact and characteristics of  the habitat.  As  such,
diagnosis is partly incorporated into many existing
State  field-oriented  bioassessment  programs.   If
more than one impact source is obvious,  diagnosis
                                                38

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                                                                             Chapter 7: Hypothesis Tasting
will require determining which impact(s) is the cause
of impairment or the extent to which each impact
contributes to impairment. The nature of the biologi-
cal impairment can guide evaluation (e.g., chemical
contamination may  lead  to  the  loss  of sensitive
species, habitat degradation may result in loss of
breeding habitat for certain species).
    Case studies  illustrate  the  effectiveness  of
biological criteria in identifying  impairments and
possible sources. For  example,  in  Kansas  three
sites on Little Mill Creek were assessed using Rapid
Bioassessment  Protocols (Plafkin et al.  1989; see
Fig. 4). Based  on  the results of a  comparative
analysis,  habitats at the three  sites were  com-
parable and of high quality. Biological impairment,
however, was identified at two of the three sites and
directly related to proximity to a point source dis-
charge from a sewage treatment plant. The severely
impaired  Site (STA 2)  was located  approximately
100 meters downstream from the plant. The slightly
impaired Site (STA 3) was located between one and
two miles downstream from the plant. However, the
unimpaired Site (STA 1(R)) was approximately 150
meters upstream from the plant (Plafkin et al. 1989).
This simple example illustrates the basic principles
of  diagnosis. In  this case the treatment plant ap-
pears responsible for  impairment of  the resident
biota  and the discharge needs  to  be  evaluated.
Based on the biological survey the results are clear.
However, impairment  in  resident populations of
macrpinvertebrates probably would not have been
recognized using more traditional methods.
    In Maine, a more complex problem arose when
effluents from a textile plant met chemical-specific
and effluent toxicity criteria, yet a biological survey
of downstream biota revealed up to 80 percent
reduction in invertebrate richness below  plant out-
falls. Although the source of impairment seemed
clear, the cause of impairment was more  difficult to
determine.  By engaging in a diagnostic evaluation,
Maine was able to determine that the discharge con-
tained  chemicals   not  regulated  under  current
programs and that  part of the toxicity effect was due
to the  sequential   discharge of unique  effluents
(tested  individually these effluents were  not toxic;
when exposure was  in a  particular  sequence,
toxicity occurred). Use'of biological criteria resulted
in the detection and diagnosis of this toxicity prob-
lem, which allowed Maine to develop workable alter-
native operating procedures for the textile industry
to correct  the problem  (Courtemanch  1989, and
pers. comm.).
    During  diagnosis it is important to consider and
discriminate among multiple sources of impairment.
In a North Carolina stream (see Figure 5) four sites
were evaluated using rapid bioasseissment techni-
Figure 4.—Kansas: Benthic Bioassossment of Little Mill Creek (Little Mill Creek
Relationship of Habitat and Bioassessment
                     Site-Specific Reference)
    100
                                                                                              100
                                     Habitat Quality (% of Reference)
Fig. 4: Three stream segments sampled in a stream in Kansas using Rapid Bioassessment Protocols (Plafkin et al 1989) reveaied
significant impairments at sites below a: sewage treatment plant.
                                                  39

-------
 Stofcfffca/CWfrrfr Naitorml Program Guidance
 Figure 5—The Relationship Between Habitat Quality and Benthic Community Condition at the North Carolina
 Pilot Study Site.
                                     Habitat Quality (% of Reference)
Fig. 5: Distinguishing between point and nonpoint sources of impairment requires an evaluation of the nature and magnitude
of different sites in a surface water. (Plafkin, et al. 1989)
ques. An ecoregional reference site (R) established
the  highest  level of  biological  integrity for that
stream  type. Site (1), well upstream from a local
town, was used as the upstream reference condi-
tion. Degraded conditions at Site (2) suggested non-
point source  problems  and  habitat degradation
because of proximity  to residential  areas on the
upstream edge of town.  At Site (3)  habitat altera-
tions, nonpoint runoff, and point source discharges
combined to severely degrade resident biota. At this
site, sedimentation  and  toxicity  from  municipal
sewage treatment effluent appeared responsible for
a  major portion of this degradation. Site (4),  al-
though several mites downstream from  town, was
still  Impaired  despite significant improvement  in
habitat  quality.  Thfc  suggests that toxicity from
upstream discharges may still be occurring (Bar-
fa our, 1990 pers. comm.). Using these kinds of com-
parisons, through a diagnostic procedure and by
using available chemical and biological assessment
tools, the relative effects of impacts  can be deter-
mined so that solutions can  be formulated to im-
prove water quality.
   When point and nonpoint impact and physical
habitat degradation occur simultaneously, diagnosis
may require the combined use of biological, physi-
cal, and chemical evaluations to discriminate be-
tween these impacts. For example, sedimentation of
a stream caused by  logging practices is likely  to
result in a decrease in species that require loose
gravel for spawning but increase species naturally
adapted to fine sediments. This shift in community
components correlates well with the observed im-
pact.  However, if the  impact is a point source dis-
charge or nonpoint runoff of toxicants, both species
types are likely to be impaired whether sedimenta-
tion occurs or not (although gravel breeding species
can  be  expected to  show greater  impairment if
sedimentation  occurs).  Part  of  the  diagnostic
process  is derived from an understanding  of or-
ganism sensitivities to djfferent kinds of impacts and
their habitat requirements. When habitat is good but
water  quality  is  poor,  aquatic community com-
ponents sensitive to toxicity will  be impaired. How-
ever, if both habitat and water quality degrade, the
resident  community is  likely to be  composed  of
tolerant and opportunistic species.
   When an impaired use cannot be easily related
to  an obvious cause, the  diagnostic process be-
comes investigative and iterative. The iterative diag-
nostic process as shown in Figure 6 may require
additional time and resources to verify cause  and
source.  Initially,  potential sources  of impact are
identified and mapped to determine location relative
                                                40

-------
                                                                             Chapter 7: Hypothesis Tasting
Figure 6.—Diagnostic Process


           Establish Biological Criteria
Conduct Field Assessment to Determine Impairment

                  X    V
               Yes            No «^> No Further
                                        Action
     Evaluate Data to Determine
          Probable Cause
   Generate Testable Hypotheses
         for Probable Cause
          Collect Data and
          Evaluate Results
                 *
No Apparent Cause
                               Obvious Cause
  ( Propose New Alternative
  ' Hypotheses and Collect
          New Data
                       Formulate Remedial m
                             Action
 Fig. 6: The diagnostic process is a stepwise process for
 determining the cause of impaired biological integrity in sur-
 face waters. It may require multiple hypotheses testing and
 more than one remedial plan.
                                               to the area suffering from biological impairment. An
                                               analysis of the physical, chemical, and biological
                                               characteristics of the study area will help identify the
                                               most likely sources and determine which data will
                                               be most valuable. Hypotheses that distinguish be-
                                               tween  possible causes of impairment should be
                                               generated. Study design and appropriate data col-
                                               lection procedures need to be developed to test the
                                               hypotheses. The severity of the impairment, the dif-
                                               ficulty  of  diagnosis,  and the  costs  involved will
                                               determine  how many iterative loops will be  com-
                                               pleted in the diagnostic process.
                                                   Normally,  diagnoses  of  biological  impairment
                                               are  relatively  straightforward. States  may  use
                                               biological criteria as a method to confirm impairment
                                               from a known source of impact. However, the diag-
                                               nostic process provides an effective way to identify
                                               unknown  impacts and diagnose their cause so that
                                               corrective action can  be devised and implemented.
                                                   41

-------

-------
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                                                          44

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                             Appendix  A
            Common  Questions  and
                        Their  Answers
   Q. How will implementing biological criteria
benefit State water quality programs?

   A. State water quality programs will benefit from
biological criteria because they:
   a) directly assess impairments in ambient
      biota from adverse impacts on the
      environment;

   b) are defensible and quantifiable;

   c) document improvements in water quality
      resulting from agency action;

   d) reduce the likelihood of false positives (i.e.,
      a conclusion that attainment is achieved
      when it is not);

   e) provide information on the integrity of
      biological systems that is compelling to the
      public.


   Q. How will biological criteria be used in a
 permit program?

   A. When permits are renewed, records from
 chemical analyses and biological assessments are
 used to determine if the permit  has  effectively
 prevented degradation and led to improvement. The
 purpose for this evaluation is to determine whether
 applicable water quality standards were achieved
 under the expiring permit and to decide if changes
 are needed. Biological surveys and criteria are par-
 ticularly effective for determining the quality  of
 waters  subject to permitted  discharges.  Since
 biosurveys provide ongoing integrative evaluations
 of the biological integrity of resident biota, permit
writers can make informed decisions on whether to
maintain or restrict permit limits.

   Q. What expertise and staff will be needed to
implement a biological criteria program?

   A. Staff with sound knowledge of State aquatic
biology and scientific protocol are needed to coor-
dinate a  biological criteria program.  Actual  field
monitoring could be accomplished by summer-hire
biologists led by permanent staff aquatic biologists.
Most States employ aquatic biologists for monitor-
ing trends or issuing site-specific permits.

    Q. Which management personnel should be
involved in a biologically-based approach?

    A. Management  personnel  from each  area
within  the  standards  and monitoring  programs
should be involved in this approach, including per-
mit engineers, resource managers, and field per-
sonnel.

    Q. How much will this approach cost?

    A. The cost of developing biological criteria is a
 State-specific question depending upon many vari-
 ables. However, States thai have  implemented a
 biological criteria program have found it to be cost
 effective (e.g., Ohio). Biological criteria provide an
 integrative assessment over time. Biota reflect mul-
 tiple  impacts. Testing for impairment of resident
 aquatic  communities  can actually  require less
 monitoring than would be required to detect many
 impacts using  more traditional  methods  (e.g.,
 chemical testing for episodic events).
                                           45

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Btotogictl CrHarit: National Prognm Guidance
    Q. What are some concerns of dischargers?

    A. Dischargers are concerned that  biological
criteria will  identity impairments that may be er-
roneously attributed to a  discharger who is  not
responsible. This is a legitimate concern that the
discharger and  State  must  address with careful
evaluations and diagnosis of cause of impairment.
However, it is particularly important to ensure that
waters used for the reference condition are not al-
ready  impaired as  may occur  when conducting
site-specific upstream-downstream evaluations. Al-
though a discharger may be contributing to surface
water degradation, it may be hard to detect using
biosurvey methods if the waterbody is also impaired
from other sources. This can be evaluated by test-
ing the possible toxicity of  effluent-free  reference
waters on sensitive organisms.
    Dischargers are also concerned that  current
permit limits may become  more stringent if  it is
determined that meeting chemical and  whole-ef-
fluent permit  limits  are not sufficient to  protect
aquatic life  from discharger activities. Alternative
forms of regulation  may be  needed; these are not
necessarily financially  burdensome but  could in-
volve additional expense.
    Burdensome monitoring requirements are addi-
tional concerns. With  new  rapid bioassessment
protocols available for streams, and under develop-
ment for other surface waters, monitoring resident
biota is becoming more straightforward. Since resi-
dent biota provide an integrative measure of en-
vironmental  impacts  over   time, the  need   for
continual  biomonitoring  is  actually  lower  than
chemical analyses and  generally less expensive.
Guidance is being developed to establish accept-
able research protocols, quality assurance/quality
control programs and training opportunities to en-
sure that adequate guidance is available.


    Q. What are the concerns of
environmentalists?

    A. Environmentalists are concerned that biologi-
cal criteria could be used to alter restrictions on dis-
chargers if biosurvey data indicate attainment  of a
designated  use  even  though  chemical  criteria
and/or whole-effluent toxicity evaluations predict im-
pairment. Evidence suggests that this occurs infre-
quently  (e.g.,  in Ohio,  6   percent of 431 sites
evaluated using  chemical-specific  criteria   and
bfosurveys resulted in this disagreement). In those
cases where evidence suggests more than one con-
clusion, independent application applies. If biologi-
cal  criteria  suggest  impairment  but  chemical-
specific and/or whole-effluent toxicity implies attain-
ment of the use, the cause for impairment of the
biota is to be evaluated  and,  where appropriate,
regulated. If whole effluent and/or chemical-specific
criteria imply impairment but no impairment is found
in resident biota, the whole-effluent and/or chemi-
cal-specific criteria provide the basis for regulation.


    Q. Do biological criteria have to be codified
in State regulations?

    A. State water quality standards require  three
components:  (1) designated uses, (2)  protective
criteria, and  (3) an antidegradation  clause. For
criteria to be enforceable  they must be codified  in
regulations.  Codification could involve general nar-
rative  statements of biological  criteria,  numeric
criteria, and/or criteria accompanied by specific test-
ing  procedures.  Codifying   general  narratives
provides the most flexibility—specific methods for
data collection the least flexibility—for incorporating
new data and  improving data gathering methods as
the  biological criteria  program develops. States
should  carefully consider how  to  codify  these
criteria.
    Q. How will biocriteria fit into the agency's
method of implementing standards?

    A. Resident biota integrate multiple impacts
over time and can detect impairment from known
and unknown causes. Biocriteria can be used to
verify improvement in water quality in response to
regulatory efforts and detect continuing degradation
of waters. They provide a framework for developing
improved best management practices for nonpoint
source impacts. Numeric criteria can provide effec-"
live monitoring criteria for inclusion in permits.


    Q. Who determines the values for biological
criteria and decides whether a waterbody meets
the criteria?

    The process of developing biological criteria, in-
cluding refined use classes, narrative criteria,  and
numeric criteria, must include agency managers,
staff biologists, and the public through public hear-
ings and comment.  Once criteria are established,
determining attainment\nonattainment of a use re-
                                                46

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                                                            Appendix A Common Questions and Their Answers
quires biological and statistical evaluation based on
established protocol. Changes in the criteria would
require the same steps as the initial criteria: techni-
cal modifications by biologists, goal clarification by
agency managers, and public hearings. The key to
criteria development and revision is  a clear state-
ment of measurable objectives.
    Q. What additional information Is available
on developing and using biological criteria?

    A. This program guidance  document will be
supplemented by the document Biological Criteria
Development by States that includes case histories
of State implementation of biological criteria as nar-
ratives, numerics, and some data procedures. The
purpose for the document is to expand on material
presented in Part I. The document will be available
in October 1990.
    A general Biological Criteria Technical Refer-
ence  Guide will also  be available for  distribution
during FY 1991. This document outlines basic ap-
proaches for developing biological criteria in all sur-
face   waters  (streams,  rivers,  lakes,  wetlands,
estuaries). The primary focus of the document is to
provide a reference guide to scientific literature that
describes approaches and methods used to deter-
mine  biological  integrity of specific surface  water
types.
    Over the next triennium more detailed guidance
will be produced that focuses on each surface water
type  (e.g.,  technical guidance for streams will be
 produced during FY 91). Comparisons of different
 biosurvey approaches will be included for accuracy,
 efficacy, and cost effectiveness.
                                                  47

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                      Appendix B
    Biological Criteria  Technical
                Reference  Guide
Table of Contents (tentative)

SECTION 1. INTRODUCTION
   o Purpose of the Technical Support Document
   a Organization of the Support Document

SECTION 2. CONCEPTUAL FRAMEWORK FOR BIOLOGICAL CRITERIA
   Q Definitions
   a Biocriteria and the Scientific Method
   Q Hypothesis Formulation and Testing
   a Predictions
   a Data Collection and Evaluation

SECTION 3. QUALITY ASSURANCE/QUALITY CONTROL
   a Data Quality Objectives
   a Quality Assurance Program Plans and Project Plans
   a Importance of QA/QC for Bioassessment
   a Training
   a Standard Procedures
   a Documentation
   a Calibration of Instruments

 SECTION 4. PROCESS FOR THE DEVELOPMENT OF BIOCRITERIA
    a Designated Uses
    a Reference Site or Condition
    a Biosurvey
    Q Biological Criteria
                                49

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           : National Program Guidance
SECTION 5. BIOASSESSMENT STRATEGIES TO DETERMINE BIOLOGICAL INTEGRITY
    o Detailed Ecological Reconnaissance
    a Blosurveys of Targeted Community Segments
    Q Rapid Bloassessment Protocols
    o Bloindicators

SECTION 6. ESTABLISHING THE REFERENCE CONDITION
    a Reference Conditions Based on Site-Specific Comparisons
    a Reference Conditions Based on Regions of Ecological Similarity
    o Reference Conditions Based on Habitat Assessment

SECTION 7. THE REFERENCE CATALOG

SECTION 8. THE INFLUENCE OF HABITAT ON BIOLOGICAL INTEGRITY
    a Habitat Assessment for Streams and Rivers
    Q Habitat Assessment for Lakes and Reservoirs
    Q Habitat Assessment for Estuaries and Near-Coastal Areas
    Q Habitat Assessment for Wetlands

SECTION 9. BIOSURVEY METHODS TO ASSESS BIOLOGICAL INTEGRITY
    a Biotic Assessment in Freshwater
    Q Biotic Assessment hi Estuaries and Near-Coastal Areas
    o Biotic Assessment in Wetlands

SECTION 1 0. DATA ANALYSIS
    a Sampling Strategy and Statistical Approaches
    a Diversity Indices
    a Biological Indices
    D Composite Community Indices

APPENDIX A. Freshwater Environments
APPENDIX B. Estuarine and Near-Coastal Environments
APPENDIX C. Wetlands Environments
APPENDIX D. Alphabetical Author/Reference Cross Number Index for the Reference Catalog
APPENDIX E. Reference Catalog Entries
LIST OF FIGURES
    Q Figure 1 Bioassessment decision matrix
    a Figure 2 Specimen of a reference citation in the Reference Catalog
                                          50

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                             Appendix C
                 Biological  Criteria
            Development  by  States
Table of Contents (tentative)

I.   Introduction

II.   Key Concepts
III.  Biological Criteria Across the 50 States

IV.  Case Study of Ohio
    A. Introduction
       1.  Derivation of Biological Criteria
       2.  Application of Biological Criteria
    B. History
       1.  Development of Biological Criteria
       2.  Current Status of Biological Criteria
    C. Discussion
       1.  Program Resources
       2.  Comparative Cost Calculations
       3.  Program Evaluation

V.   Case Study of Maine
    A. Introduction
       1.  Derivation of Biological Criteria
       2. Application of Biological Criteria
    B. History
       1. Development of BiologicaJ Criteria
       2. Program Rationale
    C. Discussion
       1. Program Resources
       2. Program Evaluation

VI.  Case Study of North Carolina
    A. Introduction
       1. Derivation of  Biological Criteria
       2. Application of Biological.Griteria
    B. History
       1.  Development of Biological Criteria
       2.  Current Status of Biological Criteria
    C. Discussion
       1.  Program Resources
       2.  Program Evaluation

VII.  Case Study of Arkansas
    A. Introduction
       1.  Derivation of Biological Criteria
       2.  Application of Biological Criteria
    B. History
       1.  Development of Biological Criteria
       2.  Current Status of Biological Criteria
    C. Discussion
       1.  Program Resources
       2.  Program Evaluation

VIII. Case Study of Florida
    A. Introduction
       1.  Derivation of Biological Criteria
       2.  Application of Biological Criteria
    B. History
    C. Discussion

IX.  Case Summaries of Six States
    A. Connecticut
    B. Delaware
    C. Minnesota
    D. Nebraska
    E. New York
    F. Vermont
                                         51

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                              Appendix  D
      Contributors  and Reviewers
Contributors
Gerald Ankley
USEPA Environmental Research
  Lab
6201 Congdon Blvd.
Ouluth, MN 55804

John Arthur
USEPA
ERL-Duluth
6201 Congdon Blvd.
Duluth. MN 55804

Patricia Bailey
Division of Water Quality
Minnesota Pollution Control Agency
520 Lafayette Road
St. Paul, MN 55155

Joe Ball
Wisconsin DNR
Water Resource Management
  (WR/2)
P.O. Box 7291
Madison, Wl 53707

Michael Barbour
EA Engineering, Science, and
  Technology Inc.
Hunt Valley/Loveton Center
15 Loveton Circle
Sparks, MD 21152

Raymond Beaumler
Ohio EPA
Water Quality Laboratory
1030 King Avenue
Columbus, OH 43212
John Bender
Nebraska Department of
  Environmental Control
P.O. Box 94877
State House Station
Lincoln, NE 69509

Mark Blosser
Delaware Department of Natural
Resources - Water Quality Mgmt.
  Branch
P.O. Box 1401, 89 Kings Way
Dover, DE 19903

Robert Bode
New York State Department of
Environmental Conservation
Box 1397
Albany, NY 12201

Lee Bridges
Indiana Department of Environment
  Management
5500 W.Bradbury
Indianapolis, IN 46241

Claire Buchanan
Interstate Commission on Potomac
  River Basin
6110 Executive Boulevard Suite 300
Rockville, MD 20852-3903

David Courtemanch
Maine Department of
  Environmental Protection
Director, Division of Environmental
Evaluation and Lake Studies
State House No. 17
Augusta, ME 04333
Norm Crisp
Environmental Services Division
USEPA Region 7
25 Funston Road
Kansas City, KS 66115

Susan Davies
Maine Department of
  Environmental Protection
State House No. 17
Augusta, ME 04333

Wayne Davis
Environmental Scientist
Ambient Monitoring Section
USEPA Region 5
536 S. Clark St. (5-SMQA)
Chicago, IL 60605

Kenneth Duke
Battelle
505 King Avenue
Columbus, OH 43201-2693

Gary Pandrel
Minnesota Pollution Control Agency
Division of Water Quality
520 La Fayette Road North
St. Paul, MN 55155

Steve Fiske
Vermont Department of
  Environmental Conservation
6 Baldwin St
Montpelier, VT 05602
                                           53

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               Nattontl Program Guidance
John GI*M
Arkansas Department Of Pollution
 , Control and Ecology
P.O. Box 9583
8001 National Drive
Little Rock, AR 72209

St»v«n Glomb
Office of Marine and Estuarine
  Protection
USEPA (WH-556F)
401 M Street SW
Washington, DC 20460

Sttv* Goodbrcd
Division of Ecological Services
U. S. Fish and Wildlife Service
1825 B. Virginia Street
Annapolis, MD 21401

Jim Hirrlaon
USEPA Region 4
345 Courtland St. (4WM-MEB)
Allan ta.G A 30365

Margaret* H«b»r
Office of Water Enforcements and
  Permits
USEPA (EN-336)
401 M Street SW
Washington, DC 20460

Slav* Hedtka
US EPA Environmental Research
  Lab
6201 Congdon Blvd.
Duluth, MN 55804

RobertHitt
Illinois EPA
2209 West Main
Marion, IL 62959

Linda Hoist
USEPA Region 3
841 Chestnut Street
Philadelphia, PA 19107

Evan Hornig
USEPA Region 6
First Interstate Bank at Fountain
  Place
1445 Ross Avenue, Suite 1200
Dallas, TX 75202
William B. Horning II
Aquatic Biologist. Project
  Management Branch
USEPA/ORD Env. Monitoring
  Systems
3411 Church St.
Cincinnati, OH 45244

Robert Hughes
NSI Technology Services
200 SW 35th Street
Corvallis, OR 97333

Jim Hulbert
Rorida Department of
  Environmental Regulation
Suite 232
3319Maguire Blvd.
Orlando, FL 32803

James Kennedy
Institute of Applied Sciences
North Texas State University
Denton, TX 76203

Richard Langdon
Vermont Department of
  Environmental
  Conservation—10 North
10SS. Main Street
Waterbury. VT 05676

John Lyons
Special Projects  Leader
Wisconsin Fish Research Section
Wisconsin Department of Natural
  Resources
3911 Rsh Hatchery Rd.
Fitchburg, Wl 53711

Anthony Maclorowskl
Battelle
505 King Avenue
Columbus, OH 43201-2693

Suzanne Marcy
Office of Water Regulations and
  Standards
USEPA (WH 585)
401 M St. SW
Washington, DC 20460

Scott Mattee
Geological Survey of Alabama
PO Drawer O
Tuscaloosa, AL 35486
John Maxted
Delaware Department of Natural
  Resources and Environmental
  Control
39 Kings Highway, P.O. Box 1401
Dover, DE 19903

Jlmmie Overton
NC Dept of Natural Resources and
Community Development
P.O. BOX27687
512 N.Salisbury
Raleigh, NC 27611-7687

Steva Paulsen
Enviromental Research Center
University of Nevada - Las Vegas
4505 Maryland Parkey
Las Vegas, NV 89154

Loys Parrlsh
USEPA Region 8
P.O. Box25366
Denver Federal Center
Denver, CO 80225

David Penros*
Environmental Biologist
North Carolina Department of
  Natural Resources and
Community Development
512 N.Salisbury Street
Raleigh, NC 27611

Don Phelps
USEPA
Environmental Research Lab
South Ferry Road
Narragansett, Rl 02882

Ernest Plzzuto
Connecticut Department
  Environmental Protection
122 Washington Street
Hartford, CT 06115

James Plafkin
Office of Water Regulations and
  Standards
USEPA (WH 553)
401 M Street, SW
Washington. DC 20460

Ronald Preston
Biological Science Coordinator
USEPA Region 3
Wheeling Office (3ES12)
303 Methodist Building
Wheeling, WV 26003
                                                  54

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                                                                      Appendix D: Contributors and Reviewers
Ronald Raschke
Ecological Support Branch
Environmental Services Division
USEPA Region 4
Athens, GA 30613

Mark Southerland
Dynamac Corporation
The Dynamac Building
11140RickvillePike
Rockviile, MD 20852

James Thomas
Newfound .Harbor Marine Institute
Rt. 3.BOX170
Big Pine Key, FL 33043

Nelson Thomas
USEPA, ERL-Duluth
Senior Advisor for National Program
6201 Congdon Blvd.
Duluth, MN 55804
Randall Waite
USEPA Region 3
Program Support Branch (3WMIO)
841 Chesnut Bldg.
Philadelphia, PA 19107

JohnWegrzyn
Manager, Water Quality Standards
  Unit
Arizona Department of
  Environmental Quality
2005 North Central Avenue
Phoenix, AZ 95004

Thorn Whittier
NSI Technology Services
200 SW 35th Street
Corvallis, OR 97333

BUI Wuerthele
Water Management Division
USEPA Region 8 (WM-SP)
999 18th Street Suite 500
Denver, CO 80202
Chris Yoder
Asst. Manager, Surface Water
  Section
Water Quality Monitoring and
  Assessment
Ohio EPA-Water Quality Lab
1030 King Ave.
Columbus, OH 43212

David Yount
US EPA Environmental Research
  Lab
6201 Congdon Blvd.
Duluth, MN 55804

Lee Zeni
Interstate Commission on Potomac
   River Basin
6110 Executive Boulevard Suite 300
Rockviile, MD 20852-3903
Reviewers
 Paul Adamus
 Wetlands Program
 NSI Technology Services
 200 S.W. 35th Street
 Corvailis, OR 97333

 Rick Albright
 USEPA Region 10 (WD-139)
 1200 6th Avenue NW
 Seattle, WA 98101

 Max Anderson
 USEPA Region 5
 536 S. Clark St. (5SCRL)
 Chicago, IL 60605

 Michael D. Bilgtr
 USEPA Region 1.
 John F. Kennedy Building
 Boston, MA 02203

 Susan Boldt
 University of Wisconsin Extension
 Madison, Wl

 Paul Campanella
 Office of Policy, Planning and
   Evaluation
 USEPA (PM 222-A)
 401 M St. S.W.
 Washington, DC 20460
Cindy Carusone
New York Department of
   Environmental Conservation
Box 1397
Albany. NY 12201

Brian Choy
Hawaii Department of Health
645 Halekauwila St.
Honolulu, HI 96813

Bill Creal
Michigan DNR
Surface Water Quality Division
P.O. Box 30028
Lansing, Ml 48909

Phil Crocker
Water Quality Management Branch
USEPA Region 6 /1445 Ross Ave.
Dallas, TX 75202-2733

 Kenneth Cummins
Appalachian Environmental Lab
 University of Maryland
 Frostburg,MD21532

 Jeff DeShon
 Ohio EPA, Surface Water Section
 1030 King Ave.
 Columbus, OH 43212
 Peter Farrington
 Biomonitoring Assessments Officer
 Water Quality Branch
 Inland Waters Directorate
 Environment Canada
 Ottawa, Ontario K1AOH3

 Kenneth Fenner
 USEPA Region 5
 Water Quality Branch
 230 S. Dearborn
 Chicago. IL 60604

 Jack Freda
 Ohio EPA
 Surface Water Section
 1030 King Avenue
 Columbus. OH 43212

 Toby Frevert
 Illinois EPA
 Division of Water Pollution Control
 2200 Churchill Road
 Springfield. IL 62706

 Cynthia Fuller
 USEPA QLNPO
 230 S. Dearborn
 Chicago. IL 60604
                                                  55

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               Nitiontl Program Guidanco
Jiff Gagler
USEPA Region 5
230 S. Dearborn (5WQS)
Chicago, IL 60604

Miry Jo Garrel*
Maryland Department of the
  Environment
2500 Broening Highway
Building 30
Baltimore, MD 21224

Jim Glattlna
USEPA Region 5
230 S. Dearborn (5WQP)
Chicago, IL 60604

Jim Green
Environmental Services Division
USEPA Region 3
303 Methodist Bldg.
11th and Chapline
Wheeling, WV 26003

Larindo Gronner
USEPA Region 4
345 Courtland St.
Atlanta, GA 30365

Martin Gurtz
U.S. Geological Survey, WRD
P.O. Box 2857
Raleigh, NO 27602-2857

Rick Hafele
Oregon Department Environmental
  Quality
1712 S.W.  11th Street
Portland, OR 97201

Stevt Helskary
MN Pollution Control Agency
520 Lafayette Road
SLPaul. MN55155

Rollle Hemmett
USEPA Region 2
Environmental Services
Woodridge Avenue
Edison, NJ 08837

Charles Hocutt
Horn Point Environmental
  Laboratory
Box 775 University of Maryland
Cambridge, MD 21613
Hoke Howard
USEPA Region 4
College Station Road
Athens, G A 30605

Peter Husby
USEPA Region 9
215 FreemontSt
San Francisco, CA94105

Gerald JacobI
Environmental Sciences
School of Science and Technology
New Mexico Highlands University
Las Vegas, NM 87701

James Karr
Department of Biology
Virginia Polytechnic Institute and
  State University
Blacksburg, VA 24061-0406

Roy Kleinsasser
Texas Parks and Wildlife
P.O. Box 947
San Marcos, TX 78667

Don Klemm
USEPA Environmental Monitoring
  and Systems Laboratory
Cincinnati, OH 45268

Robin Knox
Louisiana Department of
  Environment Quality
P.O. Box 44091
Baton Rouge, LA 70726

Robert Koroncai
Water Management Division
USEPA Region 3
847 Chestnut Bldg.
Philadelphia, PA 19107

Jim Kurztenbach
USEPA Region 2
WoodbridgeAve.
Rariton Depot Bldg. 10
Edison, NJ 08837

Roy Kwlatkowski
Water Quality Objectives Division
Water Quality Branch
Environment Canada
Ottawa, Ontario Canada
K1AOH3
Jim Lajorchak
EMSL-Cincinnati
U.S. Environmental Protection
  Agency
Cincinnati, OH

David Lenat
NC Dept of Natural Resources and
Community Development
512 N.Salisbury St.
Raleigh, NC 27611

James Luey
USEPA Region 5
230 S. Dearborn (5WQS)
Chicago, IL 60604

Terry Maret
Nebraska Department of
  Environmental Control
Box 94877
State House Station
Lincoln, NE 69509

Wally Matsunaga
Illinois EPA
1701 First Ave., #600
Maywood, IL60153

Robert Mosher
Illinois EPA
2200 Churchill Rd. #15
P.O. Box19276
Springfield, IL 62794

Phillip Oshlda
USEPA Region 9
215 Fremont Street
San Francisco, CA94105

Bill Painter
USEPA, OPPE
401 M Street, SW (W435B)
Washington, DC 20460

Rob Pepln
USEPA Region 5
230 S. Dearborn
Chicago, IL 60604

Wayne Poppe
Tennessee Valley Authority
270 Haney Bldg.
Chattanooga, TN 37401

Walter Redmon
USEPA Region 5
230 S. Dearborn
Chicago, IL 60604
                                                 56

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                                                                       Appendix O: Contributors and Reviewers
LandonRoss
Florida Department of
  Environmental Regulation
2600 Blair Stone Road
Tallahassee, FL 32399

Jean Roberts
Arizona Department of
  Environmental Quality
2655 East Magnolia
Phoenix, AZ 85034

Charles Saylor
Tennessee Valley Authority
Reid Operations Eastern Area
Division of Services and Field
Operations
Norn's, TN 37828

Robert Schacht
Illinois EPA
1701 First Avenue
Maywood,IL60153

Duane Schuettpelz
Chief, Surface Water Standards and
Monitoring Section-Wisconsin
  Department of Natural
  Resources
Box 7921
Madison, Wl 53707
Bruce Shackleford
Arkansas Department of Pollution
  Control and Ecology
8001 National Drive
Little Rock, AR 72209

Larry Shepard
USEPA Region 5
230 S. Dearborn (5WQP)
Chicago, IL 60604

Jerry Shulte
Ohio River Sanitation Commission
49 E. 4th St., Suite 851
Cincinnati, OH 45202

Thomas Simon
USEPA Region 5
536 S. Clark St. (5SCRL)
Chicago, IL 60605

J. Singh
USEPA Region 5
536 Clark St. (5SCDO)
Chicago, IL 60605
Marc Smith
Biomonitoring Section
Ohio EPA
1030 King Avenue
Columbus, OH 43212

Denise Steurer
USEPA Region 5
230 S. Dearborn
Chicago, IL 60604

William Tucker
Supervisor, Water Quality
  Monitoring
Illinois EPA
Division of Water Pollution Control
4500 S. Sixth Street
Springfield, IL 62706

Stephen Twldwell
Texas Water Commission
P.O. Box13087
Capital Station
Austin, TX 78711-3087

Barbara Williams
USEPA Region 5
230 S. Dearborn
Chicago, IL 60604
                                                   57

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         APPENDIX D
          National Guidance:
         Water Quality Standards
             for Wetlands
WATER QUALITY STANDARDS HANDBOOK

           SECOND EDITION

-------
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                                 11!!"!!	Ill  I'I1  IIII'I I'll	II	I	(•Illli'i
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&EPA
           United States
           Environmental Protection
           Agency
              Office of Water
              Regulations and Standards (WH-585)
              Washinton, DC 20460
EPA44Q/S-9Q-Q1t
July 1990
Water  Quality  Standards
for Wetlands

National Guidance

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WATER QUALITY STANDARDS FOR
                 WETLANDS
                National Guidance
                      July 1990
                     Prepared by:

          U.S. Environmental Protection Agency
         Office of Water Regulations and Standards
              Office of Wetlands Protection

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  This document is designated as Appendix B to Chapter 2 - General Program Guidance of the Water Quality
Standards Handbook, December 1983.
             Table   of  Contents
 Transmittal Memo	•	 v

 Executive Summary	•	vii

 1.0 INTRODUCTION	-	1

    1.1 Objectives	2

    1.2 Organization	2

    1.3 Legal Authority	•	-.	3

 2.0 INCLUSION OF WETLANDS IN THE DEFINITION OF STATE WATERS	5

 3.0 USE CLASSIFICATION	7

    3.1 Wetland Types	8

    3.2 Wetland Functions and Values	10

    3.3 Designating Wetland Uses	11

 4.0 CRITERIA	15

    4.1 Narrative Criteria	15

       4.1.1 General Narrative Criteria	16

       4.1.2 Narrative Biological Criteria	•	16

    4.2 Numeric Criteria	•	17

       4.2.1 Numeric Criteria - Human Health	17

       4.2.2 Numeric Criteria - Aquatic Life	17

 5.0 ANTIDEGRADATION	,	19

    5.1 Protection of Existing Uses	19
                                      in

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     5.2  Protection of High-Quality Wetlands	20
     5.3  Protection of Outstanding Wetlands	20
 6.0  IMPLEMENTATION	23
     6.1  Section 401 Certification	23
     6.2  Discharges to Wetlands	„	24
        6.2.1 Municipal Wastewater Treatment	24
        6.2.2 Stormwater Treatment	24
        6.2.3 Fills	25
        6.2.4 Nonpoint Source Assessment and Control	25
     6.3 Monitoring	   25
     6.4 Mixing Zones and Variances	26
7.0  FUTURE DIRECTIONS	29
     7.1 Numeric Biological Criteria for Wetlands	29
     7.2 Wildlife Criteria	30
     7.3 Wetlands Monitoring	30
References	31
Appendices
    A -Glossary	A_-l
    B - Definition of "Waters of the U.S."	B-1
    C - Information on the Assessment of Wetland Functions and Values	C-1
    D - Regional Wetlands Coordinators
          U.S. Environmental Protection Agency
          U.S. Fish and Wildlife Service	D-1
    E - Example of State Certification Action Involving Wetlands under CWA Section 401	E-1
                                              IV

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          UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                         WASHINGTON. D.C. 20460
                                                        OFFICE OF

                               ML 30 1990

MEMORANDUM

SUBJECT:  Final Document: National Guidance on Water Quality
          Standards for Wetlands
FROM:     Martha G. Prothro, Director
          Office of Water Regul
                                   ' \
          David G. Davis, Dirlacttar 1.1
          Office of Wetlands Protectr6ri

TO:       Regional Water Division Directors
          Regional Environmental Services Division Directors
          Assistant Regional Administrator for Policy
           and Management, Region VII
          OW Office; Directors
          State Water Quality Program Managers
          State Wetland Program Managers


     The following document entitled "National Guidance: Water
Quality Standards for Wetlands" provides guidance for meeting the
priority established in the FY 1991 Agency Operating Guidance to
develop water quality standards for wetlands during the FY 1991-
1993 triennium.  This document was  developed jointly by the
Office of Water Regulations and Standards (OWRS) and the Office
of Wetlands Protection  (OWP), and reflects the comments we
received on the February 1990 draft from EPA Headquarters and
Regional offices, EPA laboratories, and the States.

     By the end of FY 1993, the minimum requirements for States
are to include wetlands in the definition of "State waters",
establish beneficial uses for wetlands, adopt existing narrative
and numeric criteria for wetlands,  adopt narrative biological
criteria for wetlands, and apply antidegradation policies to
wetlands.  Information in this document related to the
development of biological criteria  has been coordinated with
recent guidance issued by OWRS; "Biological Criteria: National
Program Guidance for Surface Waters", dated April 1990.

     We are focusing on water quality standards for wetlands to
ensure that provisions of the Clean Water Act currently applied
to other surface waters are also being applied to wetlands.  The
document focuses on those elements  of water quality standards

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that can be developed now using the overall structure of the
water quality standards program and existing information and data
sources related to wetlands.  Periodically, our offices will
provide additional information and support to the Regions and
States through workshops and additional documents.  We encourage
you to let us know your needs as you begin developing wetlands
standards.  If you have any questions concerning this document,
please contact us or have your staff contact Bob Shippen in OWRS
(FTS-475-7329) or Doreen Robb in OWP (FTS-245-3906).


Attachment


cc:  LaJuana Wilcher
     Robert Wayland
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     EXECUTIVE  SUMMARY
 Background
  This document provides program guidance to States on how to ensure effective application of water
quality standards (WQS) to wetlands. This guidance reflects the level of achievement EPA expects the States
to accomplish by the end of FY1993, as defined in the Agency Operating Guidance, FY1991, Office of Water.
The basic requirements for applying State water quality standards to wetlands include the following:


   • Include wetlands in the definition of "State waters."
   • Designate uses for all wetlands.
   • Adopt aesthetic narrative criteria (the "free froms") and appropriate numeric criteria for wetlands.
   • Adopt narrative biological criteria for wetlands.
   • Apply the State's antidegradatton policy and implementation methods to wetlands.


  Water quality standards for wetlands are necessary to ensure that the provisions of the Clean Water Act
(CWA) applied to other  surface waters  are also applied to wetlands.   Although Federal regulations im-
plementing the CWA include wetlands in the definition of "waters of the U.S." and therefore require water
quality standards, a number of States have not developed WQS for wetlands and have not included wetlands
in their definitions of "State waters." Applying water quality standards to wetlands is part of an overall effort
to protect and enhance the Nation's wetland  resources and  provides  a regulatory basis for a variety  of
programs to meet this goal. Standards provide the foundation for a broad range of water quality manage-
ment activities including, but not limited to,  monitoring under Section 305(b), permitting under Sections 402
and 404, water quality certification under Section 401, and the control of NPS pollution under Section 319.

  With the issuance of this guidance, EPA proposes a two- phased approach for the development of WQS
for wetlands.  Phase 1 activities  presented in  this guidance include the development of WQS elements for
wetlands based  upon existing  information and science to be implemented within the next triennium. Phase
2 involves the further refinement of these basic elements using new science and program developments. The
development of WQS for all surface waters is an iterative process.

  Definition
  The first and most important step in applying water quality standards to wetlands is ensuring that wetlands
are legally included in the scope of States' water quality standards programs. States may accomplish this  by
adopting a regulatory definition  of "State waters" at least as inclusive as the Federal definition of "waters of
the U.S." and by adopting an appropriate definition for "wetlands." States may also need to remove or modify
regulatory language that explicitly or implicitly limits the authority of water quality standards over wetlands.

  Use  Designation
  At a minimum, all wetlands must have uses designated that meet the goals of Section 101 (a) (2) of the CWA
by providing for the protection and propagation offish, shellfish, and wildlife and for recreation in and on the
water, unless the results of a use  attainability analysis (UAA) show that the CWA Section  101 (a) (2) goals
cannot be achieved. When designating  uses for wetlands, States may choose to use their existing general
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  and water-specific classification systems, or they may set up an entirely different system for wetlands
  reflecting their unique functions. Two basic pieces of information are useful in classifying wetland uses: (1)
  the structural types of wetlands and (2) the functions and values associated with such types of wetlands.
  Generally, wetland functions directly relate to the physical, chemical,  and biological integrity of wetlands.
  The protection of these functions through water quality standards also may be needed to attain the uses of
  waters adjacent to, or downstream of, wetlands.

   Criteria
   The Water Quality Standards Regulation (40 CFR I31.l1(a)(1)) requires States to adopt criteria sufficient
  to protect designated uses that may include general statements (narrative) and specific numerical values
  (I.e., concentrations of contaminants and water quality characteristics). Most State water quality standards
  already contain many criteria for various water types and designated use classes that may be applicable to
  wetlands.

   Narrative criteria are particularly important in  wetlands, since many wetland impacts cannot be fully
  addressed by numeric criteria. Such impacts may result from the discharge of chemicals for which there are
  no numeric criteria in State standards, nonpoint sources, and activities that may affect the physical  and/or
  biological, rather than the chemical, aspects of water quality (e.g.,  discharge of dredged and fill material).
  Narratives should be written to protect the most sensitive designated use and to support existing uses under
  State  antldegradatlon policies.  In addition to other narrative criteria, narrative biological criteria provide a
 further basis for managing a broad range of activities that impact the  biological integrity of wetlands and
 other  surface waters, particularly physical and hydrologic modifications.   Narrative biological  criteria are
 general statements of attainable or attained conditions of biological integrity and water quality for a given use
 designation.  EPA has published national guidance on developing biological criteria for all surface waters.

   Numeric criteria are specific numeric values for chemical constituents, physical parameters, or biological
 conditions that are adopted in State standards. Human health water quality criteria are based on the toxicity
 of a contaminant and the amount of the contaminant consumed through  ingestion  of water and fish
 regardless of the type of water.  Therefore, EPA's chemical-specific human  health criteria  are directly
 applicable to wetlands.   EPA also develops chemical-specific numeric criteria recommendations for the
 protection of freshwater and  saltwater aquatic life. The numeric aquatic life criteria, although not designed
 specifically for wetlands, were designed to be protective of aquatic life and are generally applicable to most
 wetland types. An exception to this are  pH-dependent criteria, such as ammonia and pentachlorophenol,
 since wetland pH  may be outside the normal  range of 6.5-9.0. As in  other waters, natural water quality
 characteristics in some wetlands may be outside the range established  for uses designated in State stand-
 ards.  These water quality characteristics may require the development of criteria that  reflect the natural
 background conditions in a specific wetland or wetland type.  Examples  of some of the wetland charac-
 teristics that may fall into this category are dissolved oxygen, pH, turbidity, color, and hydrogen sulfide.

  Antidegradation
   The antldegradation policies contained in all State standards provide a powerful tool for the protection of
 wetlands and can  be used by States to regulate point and  nonpoint source discharges to wetlands  in the
 same way as other surface waters. In conjunction with beneficial uses and narrative criteria, antidegradation
 can be used to address  impacts to wetlands that cannot be fully addressed by chemical criteria, such as
 physical and  hydroiogic modifications.  With  the inclusion of wetlands  as "waters of the  State,"  State
 antidegradation policies and their implementation  methods will apply to wetlands in the same way as other
 surface waters. State antidegradation policies should provide for the protection of existing uses in wetlands
 and the level of water quality necessary to  protect those uses  in the same manner as provided for other
 surface waters; see Section 131.12(a)(1) of the WQS regulation.  In the case of fills, EPA interprets protection
 of existing uses to be met if there is no significant degradation as defined according to the Section 404(b)(1)
 guidelines.  State antidegradation policies also provide special protection for outstanding natural resource
waters.
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 Implementation
  Implementing water quality standards for wetlands will require a coordinated effort between related
Federal and State agencies and programs.  Many States have begun to make more use of CWA Section 401
certification to manage certain activities that impact their wetland resources on a physical and/or biological
basis rather than just chemical impacts.   Section 401 gives the States the authority to grant, deny,- or
condition certification of Federal permits or licenses that may result in a discharge to "waters of the U.S."
Such action is taken by the State to ensure compliance with various provisions of the CWA, including the
State's water quality standards.  Violation of water quality standards  is often the basis for  denials or
conditioning through Section 401 certification.

  Natural wetlands are nearly alv/ays "waters of the U.S." and are afforded the same level of protection as
other surface waters with regard to standards and  minimum wastewater treatment requirements.  Water
quality standards for wetlands can prevent the misuse and overuse of natural wetlands for treatment through
adoption of proper uses and criteria and application of State antidegradation policies.  The Water Quality
Standards Regulation (40 CFR 131.10(a)) states that, "in no case shall a State adopt waste transport or waste
assimilation as a designated use for any 'waters of the U.S.'."  Certain activities involving the discharge of
pollutants to wetlands may be permitted;  however,  as with other surface waters, the State must ensure,
through ambient monitoring, that permitted discharges to wetlands preserve and protect wetland functions
and values as defined in State v/ater quality standards.  For municipal  discharges to natural wetlands, a
minimum of secondary treatment  is required, and applicable water quality standards for the wetland and
adjacent waters must be met.  EPA anticipates that the policy for stormwater discharges to wetlands will
have some similarities to the policies for municipal wastewater discharges to wetlands.

   Many wetlands, through their assimilative capacity for nutrients and sediment, also serve an important
water quality control function for nonpoint source pollution effects on waters adjacent to, or downstream of,
the wetlands.  Section 319 of the CWA requires the States to complete assessments of nonpoint  source
(NP'S) impacts to State waters,  including wetlands, and to prepare management programs to control NFS
impacts. Water quality standards for wetlands can form the basis for these assessments and management
programs for wetlands.

   In addition,  States can address physical  and hydrological impacts on wetland quality through the applica-
tion of narrative criteria to protect existing uses and through application of their antidegradation policies.
The States should  provide a linkage in their water quality standards to the determination of  "significant
degradation" as required under EPA guidelines (40 CFR 230.10(c)) and other applicable State laws affecting
the disposal of dredged or fill materials in wetlands.

   Finally,  water  quality  management  activities,  including the  permitting of wastewater and  stormwater
discharges, the assessmen