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
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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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Water Resource Center {W^
401 M Street, S.W.
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
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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)
-------
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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"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.)
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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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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.)
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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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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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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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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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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
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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.
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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
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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
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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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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.
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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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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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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:
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• 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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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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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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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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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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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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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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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!H^^^^
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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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"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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2-7
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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
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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).
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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
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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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minimum raqufetmenti for UM
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evaluation:
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Mgure 2-2. Steps in a Use Attainability Analysis
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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,
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2-17
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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*
s*M
•%^^AK
*
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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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Water Quality Standards Handbook - Second Edition
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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• 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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* 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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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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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
" '3.7
-3.8
34>
44
4.5
4.6
4.7
4.8
4.9.
5.0
5.1
5.2
5,3
5.4
5,5
5.6
5.7
5.8
5.9
6.5
2,»
•> i mi ">
*. il!'*,j'v
1.0%
»^y3u
4..0
"" ^jfa
4.3
5.8
8.0
11
23
$3
to
,„ ' 47
&4
v, 98
"' '100
•' rt»,"
1-iH ^^A^ ^H ; ^^ ^
re
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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:
3-8
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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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Chapter 3 - Water Quality Criteria
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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Water Quality Standards Handbook - Second Edition
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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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.
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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).
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. (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
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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.
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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
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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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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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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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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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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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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,
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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
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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
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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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!a'f. | I ::;r:;v!' »
?-; '^fefl fe^'Ti^ir
LI i: a te i; i£ i i;;,; ;l! h
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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.
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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
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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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. . . 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
4-8
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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
4-10
(8/15/94)
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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
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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)
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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
-------
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
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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,
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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
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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
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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;
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(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.
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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
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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
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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
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Chapter 5 - General Policies
r - AQUATIC LIFE
Acute Criteria
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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
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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
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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
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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
-------
fct?: Tit* s-r • ! -mm ;; I
! I !!! i i! ! !!! '-SUM !^ miti
-------
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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(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
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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
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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
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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.
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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
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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
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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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^ . I ' '
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. 1984e. Technical Guidance Manual for Performing Waste Load Allocations. Book II
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. 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)
-------
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)
-------
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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Environmental Protection
Agency
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
Recycled/Recyclable
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vvEPA
United States
Environmental Protection
Agency
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
-------
-------
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)
-------
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;
-------
(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
-------
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
-------
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:
-------
(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
-------
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.
-------
(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.
-------
(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)
-------
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
-------
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.)
-------
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.)
-------
(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
-------
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
-------
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]
-------
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
-------
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)
-------
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
-------
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)
-------
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
-------
-------
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
-------
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
-------
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
-------
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
-------
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.
-------
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
-------
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
-------
Parti
Program Elements
-------
-------
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
-------
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.
-------
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
-------
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 '
-------
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.
-------
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).
-------
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
-------
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
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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
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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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References
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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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&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
VI
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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
va
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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.
Vtll
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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 |