GUIDELINES FOR STATE AND
AREAWIDE WATER QUALITY
MANAGEMENT PROGRAM
DEVELOPMENT
CHAPTER 5
WATER QUALITY STANDARDS
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
NOVEMBER, 1976
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Cover design adapted from
a report prepared for:
U.S. Fish and Wildlife Service
Office of Biological Services
Western Water Allocation
Illustrations and Graphics
by
Judith M. Ban
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FOREWORD
Chapter 5 - Water Quality Standards is part of "Guide-
lines for State and Areawide Water Quality Management Program
Development" which can be obtained upon request from this
office. This document was available for interim use and
public review and comment in November 1976. The Guide-
lines are intended to be used by State and areawide agencies
in developing implementable water quality management programs
consistent with Environmental Protection Agency regulations
40 CFR Parts 130 and 131. These regulations deal with the
State continuing planning process policies (40 CFR 130) and
the preparation of State and areawide water quality manage-
ment plans (40 CFR 131). In particular, 40 CFR 130.17 sets
forth the water quality standards policy, including anti-
degradation, which Chapter 5 addresses.
Due to the significant degree of interest in the water
quality standards policy and the ongoing activities to
review and revise standards, this office is republishing
Chapter 5 of that document. For further information on the
planning process and the relationship of standards to that
process, please refer to other Chapters of the Guidelines.
Requests for copies of Chapter 5 or the entire document
should be addressed to:
Environmental Protection Agency
401 M Street, S. W.
Washington, D. C. 20460
ATTN: Water Planning Division (WH-554)
Comments on these Guidelines are requested and should
also be addressed to this office. The Guidelines will be
revised on the basis of comments received and issued as
final in the Spring of 1977.
'i'-JZjL / (s-
Edmund Notzon
Acting Director
Water Planning Division
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TABLE OF CONTENTS
5. Water Quality Standards Revision
5.1 Introduction
5.2 Water Uses
5.3 Water Quality Criteria
5.4 Antidegradation
5.5 Mixing Zones
5.6 Thermal Water Quality Standards
5.7 Water Quality Related Effluent Limitations Under
Section 302 of the Act
5.8 Stream Flows
5.9 Discharge of Dredged or Fill Material
5.10 Groundwater
5.11 State Water Quality Standards Review
and Revision Procedures
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CHAPTER 5
WATER QUALITY STANDARDS
5.1 Introduction
Water quality standards are an essential part of the State water
quality management (WQM) system. The standards:
. Publicly define the State's water quality objectives, and hence
form the basis for its planning;
. Serve as the basis for determining National Pollution Discharge
Elimination System (NPDES) permit effluent limitations for
pollutants which are not specifically addressed in the effluent
guidelines or for pollutants for which the effluent guidelines
are not stringent enough to protect desired uses;
. Serve as a basis for evaluating and modifying Best Management
Practices (BMP) for control of nonpoint sources;
. Serve as a basis for judgment in other water quality related
programs, including water storage for regulation of stream flow,
water quality inventories, control of toxic substances, thermal
discharges, cooling lakes, aquaculture, and dredged and fill
activities.
. Contain the State's antidegradation policy.
A. Purpose and Applicability
The purposes of water quality standards are set forth in
Section 303 of the Act and in 40 CFR Part 130. Standards must be
reviewed and revised where appropriate at least once every three
years to assure that the standards are consistent with the Act
and regulations.
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Water quality standards must apply to all surface water of
the United States, including the territorial seas. In addition,
they must be applicable to all sources of pollutants. Provisions
in the standards which directly or indirectly exempt any class
of sources, such as nonpoint sources, are not allowable. These
guidelines, however, provide for methods to deal with exceptional
situations (e.g. extreme high or low flow conditions).
EPA strongly supports the establishment of water quality
standards which will support the protection and propagation of
fish, shellfish and wildlife and recreation in and on the water.
In furtherance of this objective, EPA believes that water quality
standards should be established at levels consistent with the
national water quality goal of section 101(a)(2) of the Act for
every stream segment wherever those levels are attainable.
B. Scope of State Review and Revision of Water Quality Standards
Portions of existing water quality standards may be adequate
and may require no revision. Hence, the State will only have to
concentrate on those standards that are inadequate. Revisions most
probably will be needed in three key areas:
1. Uses—must be upgraded wherever 1983 national water quality
goal uses are not designated and higher uses are attainable;
2. Criteria—new criteria should be added and existing criteria
modified as necessary to support the use, particularly in the
area of toxic pollutants; and
3. Antidegradation—revision of antidegradation policies is
likely to be required.
In addition, in its review and revision process, the State must
assure that its water quality standards provide for the attainment
of the water quality standards of downstream water (i!30.17(c)(4)).
C. General Content of State Mater Quality Standards
A centralized State water quality standards document must contain
at a minimum, the following components:
1. Certification that the standards are included within State
law;
2. Statement of general policy consistent with 40 CFR §130.17;
3. Statement of applicability of water quality standards,
including the State's mixing zone policy;
4. Definitions;
5. A listing of the use designations for all the waters of the
State, including any site specific water quality criteria for
specific segments.
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6. Water quality criteria that define the conditions necessary
to maintain the beneficial water use designations;
7. An antidegradation statement;
8. Specifications of statistical requirements and reference
to analytical testing and sampling procedures to determine if
standards are being met; and
9. A listing of outstanding national resource waters.
In addition, it is recommended that the standards document contain
maps delineating stream segments which can be clearly referenced
to the stream use designation list.
Where water quality standards are developed Statewide they must
be incorporated by reference into the individual State WQM plans.
Where water quality standards are developed for a planning area
through the State WQM process, any or all of the above components
can be incorporated by reference in the centralized State water
quality standards document. Identification of the State WQM plan
that contains the standards and the date of adoption and EPA
approval of the water quality standards contained within the plan
must be included.
D. Relationship to the State WQM Process
The State WQM process must contain mechanisms, including
public participation, to conduct water quality standards reviews
and revisions. By conducting standards reviews as a part of
the State WQM process, States can assure that standards are an
essential component of the overall State water quality planning
and management program. The State WQM process may itself result
in recommending revisions to water quality standards.
Water quality standards, once approved or promulgated, are to
be included as an element of the State WQM plan (5131.11(e)) and
are to be implemented through the State's WQM process. Water
quality standards play a key role in the State WQM process by
setting the goals for plan development and implementation and
providing information necessary to complete other outputs of the
State WQM program. In turn, the State WQM process is the vehicle
for "coordinating actions leading to water quality standards imple-
mentation. All aspects of the process are directed to achievement
of standards.
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The NPDES permits issued pursuant to Section 402 of the Act
and nonpoint source regulatory program controls (BMP) implemented
pursuant to Sections 208, 303(e) and 313 of the Act must be con-
sistent with the State WQM process. Together, point and nonpoint
source controls must result in the achievement and maintenance of
water quality standards.
If a violation of water quality standards can be shown to be
attributable to pollution from a particular point source or qroup
of sources then effluent limitations must be imposed. (S301(b)(l)(C)
of the Act.)
As no uniform or national BMP for nonpoint sources is mandated
under the Act, the level of BMP control may differ from area to area.
Water quality standards will serve as a basis for evaluating and
modifying BMP's for control of nonpoint sources. If water quality
standards violations attributable to nonpoint sources continue after
BMP's are implemented, the BMP's must be modified where practicable
to control specifically those pollutants responsible for the violations,
In some cases, even the reconsidered BMP's may not be sufficient to
stop the nonpoint source related water quality standards violations.
These violations may be continuous or rainfall related. If the 1983
goal uses and associated criteria are not being achieved, and cannot
be achieved through application of modified BMP's, then limited
spatial and temporal exceptions can be granted under certain condi-
tions (see the discussion on irretrievable man-induced conditions
on p. 5-7 and mixing zones on p. 5-16). All exceptions must be
reexamined every three years during the water quality standards
reviews to determine if new nonpoint source control technologies or
strategies that have been developed can restore the excepted waters.
5.2 Water Uses
A. Use Designation and Regulatory Requirements
The regulations (S130.17(c)(2)-(3)) provide the following:
"(2) The State shall maintain those water uses which are
currently being attained. Where existing water quality
standards specify designated water uses less than those
which are presently being achieved, the State shall upgrade
its standards to reflect the uses actually being attained.
"(3) At a minimum, the State shall maintain those water
uses which are currently designated in water quality stan-
dards, effective as of the date of these regulations or as
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subsequently modified in accordance with S130.17(c)(l) and
(2). The State may establish less restrictive uses than
those contained in existing water quality standards, however,
only where the State can demonstrate that:
(i) The existing designated use is not attainable
because of natural background;
(ii) The existing designated use is not attainable
because of irretrievable man-induced conditions; or
(iii) Application of effluent limitations for existing
sources more stringent than those required pursuant to
Section 301(b)(2)(A) and (B) of the Act in order to
attain the existing designated use would result in sub-
stantial and widespread adverse economic and social
impact."
The States must review their water quality standards and revise
them as appropriate. The review must include standards for all
waters and revisions must be consistent with the following:
1. Public health must be protected for all waters;
2. The national water quality goal uses of protection and
propagation of fish, shellfish and wildlife and recreation in
and on the water must be designated in the standards for all
waters, wherever attainable, including those segments where
they are not currently being attained instream. (The meaning
of the term "attainable" is discussed under Ch. 5.2(C)--Exceptions
to Designating National Goal Water Uses.)
3. Where current water quality conditions support a higher use
than that for which a segment is presently classified, standards
for that segment must be upgraded to include the higher use;
and
4. Water quality standards must provide for the attainment of
the water quality standards assigned to downstream waters.
In some cases it may be appropriate to provide for seasonal use
designations where uses are not attainable on a year round basis.
For example, intermittent streams that are dry in the summer might
qualify for seasonal designations. However, seasonal uses are
not appropriate where the effects of the discharge of pollutants
might preclude uses in other seasons.
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B. Maintenance of Existing Uses
Each beneficial water use which is currently being achieved
must be included in the use designations (S130.17(c)(2)). There
are no provisions for exceptions to this requirement. Beneficial
uses include such uses as protection and propagation of aquatic
life, recreation in and on the water, public water supplies, agri-
cultural and industrial water supplies, and navigational uses.
Waste assimilation and waste transport* are not approvable use
designations. The State's antidegradation policy and procedures
must assure maintenance of existing uses.
C. Exceptions to Designating National Goal Water Uses
Where a national water quality goal use, as specified by
Section 101(a)(2) of the Act, is determined to be unattainable, the
exception should be confined to a carefully limited geographic area.
The lowered use in that area must not result in the loss of an
existing or potential use elsewhere. In most cases, the unattaina-
bility of the use should be permitted to occur only in the near term,
and specific criteria should be adopted which will lead in the
direction of early future designation of the use. Where primary
water contact recreation is not attainable, but secondary contact
recreation is attainable, the latter use should be designated.
Exceptions must be reviewed as part of the three year water
quality standards review and removed if the previously designated
uses become attainable. National water quality goal uses must then
be designated.
The Regional Administrator has authority to approve any proposed
State water quality standards. He is also responsible for reviewing
existing and proposed standards which do not include designated uses
consistent with the national water quality goal. The Regional
Administrator, where appropriate, will request additional information
from the State to evaluate the basis for establishing uses at levels
less stringent than the national water quality goal.
The following guidance provides direction on EPA policy for
considering lesser uses than those associated with the national
water quality goal.
1. Determinations for Upgrading Existing Designated Uses
Waters that are currently designated for uses which require
water quality lower than that necessary to maintain the national
water quality goal uses must be upgraded wherever attainable.
The State should take into account environmental, technological
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social, economic and institutional factors, but it must jpcrade
standards in the following circumstances:
a. Where existing standards specify uses lower than those
actually being achieved instream;
b. Where existing water quality will improve as a result
of current technology-based control measures (BATEA and
BPWTT) being applied, and a higher use can be anticipated;
and
c. Where existing water quality standards specify uses or
criteria that will not provide protection for uses presently
achieved or to be achieved in downstream waters.
2. Determinations for Downgrading Existing Designated Uses
Waters that are currently designated for national water
quality goal uses may not be downgraded unless the State can
demonstrate in writing that one of the conditions set forth below
exist (il30.17(c)(3)). Any downgradings must also be consistent
with the antidegradation policy (Section 5.4). Any downgrading
is subject to the approval of the Regional Administrator.
a. The use cannot be attained because of natural background
conditions
This basis for an exception should have limited applica-
tion. It should be recognized that most water bodies have
some communities of fish, shellfish and wildlife. However,
examples of natural background conditions which may preclude
the aquatic life use include streams with leachate from
natural heavy metal deposits and streams with natural
ephemeral, intermittent or low flow conditions.
b. The use cannot be attained because of irretrievable
man-induced conditions
Man has changed his environment from that which occurred
historically. This basis for an exception applies only to
irretrievable losses of national water quality goal uses
that have occurred in the past.
The term "irretrievable" in the context of these guide-
lines means that the past loss of a national water quality
goal use, due to man's modification of his environment, is
considered permanent or incapable of being restored or
regained.
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Three primary situations may qualify a specific segment
for an exception:
(1) Where the national water quality goal use is not
being achieved due to nonpoint source pollution that
cannot be abated with application of BMP's or BMP's modified
to meet water quality standards and the activity or change
in land use is determined by the affected public to be
essential.
(2) Where the national water quality goal use is not
being achieved due to hydrological modifications that
cannot be removed or operated in such a manner as to
restore the use.
(3) Where the national water quality goal use is not
being achieved due to deposition of instream toxicants
due to man's past point or nonpoint source activities
and such deposits are not capable of being removed by
natural processes over an appropriate planning period
(usually 20 years) and are not capable of being removed
by man without a severe long-term environmental impact.
This basis for an exception must not be used to waive water
quality requirements with respect to individual point or nonpoint
sources where control methods or reasonable alternative control
strategies are available. It is important to remember that
natural processes may require many years to undo the damage that
man has caused. Since the water quality standards uses and
criteria provide a legal mechanism for imposition of controls,
downgrading national water quality goal uses may allow continued
abuse and natural recovery will be precluded.
c. The use cannot be attained because the imposition of
controls above or in addition to the technology-based require-
ments of BATEA* and BPWTT** would be required and would result
in a substantial and widespread adverse economic and social
impact
The Regional Administrator will carefully review the
State's determination of what constitutes a substantial and
widespread impact and warrants an exemption from designating
*Best Available Technology Economically Achievable (S301(b)(2)(A))
**Best Practicable Wastewater Treatment Technology (§301(b)(2)(B))
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the use. However, at a minimum, all three of the following
situations must be present:
(1) Imposition of controls above or in addition to
BATEA and BPWTT would be required even though BMP's
will be implemented;
(2) The adverse economic and social impacts resulting
specifically from imposition of the controls, and
reflected in primary and secondary unemployment impacts,
plant closures, changes in governmental fiscal base,
and other area economic indicators, are substantial
and widespread in comparison to other economic factors
affecting the area's economy, to national economic
conditions and fluctuations, and can be expected to
persist for periods longer than provided for by adjust-
ment payments such as unemployment compensation; and
they are detectable in an area appropriate for measure-
ment, at least as large as a county or SMSA and, if
appropriate, any larger economic areas such as defined
by the Bureau of Economic Analysis, U.S. Department of
Commerce. In making a determination of substantial
impact, the positive economic and social impact of
enhanced water quality must be evaluated.
5.3 Water Quality Criteria
State water quality standards must contain water quality criteria
which define the conditions necessary to maintain and protect the desig-
nated water uses. Narrative and numerical criteria should be adopted
that will provide the best management basis for control of water pollution
and maintenance of high quality waters. Numerical criteria are preferred
because they are more easily interpreted in defining specific control
requirements, but narrative criteria are useful also.
When a water use classification is changed, corresponding criteria
changes must also be made. Where waters are designated for multiple uses,
the standards must provide that the most stringent criterion for each
parameter will be applicable. Even when an existing use classification
is acceptable, criteria may require revision in the light of new know-
ledge concerning human health and aquatic life needs. Changes may also
be required in response to specific determinations made pursuant to
Section 316(a) of the Act.
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In keeping with established EPA policy:
. Numerical criteria should be stated wherever possible;
. Biological or bioassay criteria should be employed where
numerical values are not practicable provided that the criteria
are described with enough detail to be implementable. Bioassay
criteria, for example, should specify those species to be
used in particular waters and guidance should be given on how
to use the results to draft permit conditions or modify BMP's;
and
. Narrative criteria should be employed where other values cannot
be established or to supplement numerical values. Narrative
criteria should include detail sufficient to show clearly the
quality of the water intended, so that NPDES permit conditions
and nonpoint source control requirements (BMP's) can be
developed or modified based on the criteria.
Seasonal uses and criteria should be adopted wherever necessary
and appropriate. For example, where waters are used for propagation by
certain species only during certain periods of the year and such species
propagation requires higher levels of dissolved oxygen and/or lower
temperatures than otherwise necessary to protect the species, the
adopted criteria should include such higher dissolved oxygen levels
and/or lower temperatures for the periods when they are needed. Another
example might be an intermittent stream during periods when no water
is present in the stream bed. In this case special criteria or use
designations may be appropriate.
For any segment which provides habitat for any threatened or
endangered species identified pursuant to the Endangered Species Act
(P. L. 93-205), water quality standards must be adopted which will
protect such species and preclude the destruction or modification of
the critical habitat of those species identified as critical. Water
quality standards must also describe the water quality necessary to
assure the protection and propagation of protected species described
pursuant to the Marine Mammal Protection Act (P. L. 92-522), the
Migratory Bird Conservation Act (P. L. 70-257), and the Migratory
Bird Treaty Act (16 U.S.C. 701-711).
A. Numerical Water Quality Criteria
The Administrator's Quality Criteria for Water document
published under Section 304(a) of the Act will represent normally
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acceptable levels of water quality to support the related use.
While the Section 304(a) document will serve as the basic refer-
ence, other publications that define water quality criteria may
also be applicable.
Specific numerical criteria generally should be adopted for
those parameters which represent serious existing or potential water
quality problems in the State. The adoption of numerical values
for toxic substances is particularly important, to insure protection
of the highest uses and to provide a water quality basis for control
for these substances. Site specific circumstances may permit less
restrictive criteria or require stricter limits for specific para-
meters than those contained in the Section 304(a) document.
Establishment of a numerical value for a criterion at a less
stringent level than that recommended in the Section 304(a) docu-
ment should be accompanied by an adequate technical justification
to the Regional Administrator. Pursuant to the authority contained
in Section 510 of the Act, States may, of course, adopt more strin-
gent water quality criteria or water uses than that recommended by
EPA.
The Administrator will periodically modify or add to the criteria
developed under Section 304(a). Such changes should be considered
for adoption by the States during their next regularly scheduled
standards review following the change.
For numerical criteria, the statistical requirements for data
interpretation and sampling must be stated, for purposes of applying
and enforcing standards. Mean and maximum concentrations should be
stated where appropriate. The time, place, method and duration of
sampling should be identified or referenced as a part of the water
quality standards to assure comparable results. In general, sampling
locations and times should be based on critical conditions or alter-
natively should attempt to characterize the spatial or temporal
distribution of the pollutant or environmental parameter. All methods
of sample collection, preservation, and analysis used in applying
the standards should be in accord with those prescribed in 40 CFR
Part 136.
Revised water quality standards criteria will need to reflect the
conditions in individual areas. Some degree of instream biological
monitoring will often be necessary, both for establishing the standards
and in reviewing the effect of their implementation.
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Criteria also may be expressed in terms of biological parameters
such as bioassay or species diversity requirements provided that
such criteria are stated in a manner that will support specific
conforming control measures to be assigned on a case-by-case basis.
An example of a biological criterion might be the prohibition of
any deviation outside the range of normal variability for a given
species diversity index. Modeling techniques generally are not
sophisticated enough to relate a percent loss of diversity to a
percent reduction in pollutants so wasteload allocations will need
to be established based on best judgment as to cause and effect.
The State may elect to adopt 304(a) criteria by means of
incorporation by reference, if State law authorizes that device.
In that case, certain procedures should be followed to avoid con-
fusion. First, the State should carefully identify the criteria
being adopted (parameter and associated use) and the document
being referenced (i.e. citation of 304(a) criteria document and
date of publication). In addition, the State should explain what
criteria will apply in the event that the incorporated materials
are revised following adoption of the standards. Presumably, the
State will specify that the incorporated criteria will continue
to apply until the next State standards review, in order to assure
compliance with State requirements for due process, including
public hearings on revisions to standards. Finally, the State
should specify the location or locations within the State where
the criteria which have been incorporated by reference will be
reasonably available to the public for inspection and copying.
B. Narrative Water Quality Criteria
States should provide in the water quality standards that all
waters must meet the State's general narrative criteria. EPA
recommends language consistent with that below:
All waters shall be free from substances attributable to man-
caused point source or nonpoint source discharges in concentrations
that:
1. Settle to form objectionable deposits;
2. Float as debris, scum, oil or other matter to form nuisances;
3. Produce objectionable color, odor, taste, or turbidity;
4. Injure, are toxic to or produce adverse physiological or
behavior responses in humans, animals or plants; or
5. Produce undesirable aquatic life or result in the dominance
of nuisance species.
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These general narrative criteria can be used as a basis for
control activities. Ecological principles and biological monitoring
techniques can be used to quantitatively define violations of most
of these narrative criteria. If it can be shown that harm has
been caused to the balanced community of fish, shellfish and wild-
life in the vicinity of a discharge due to settleable solids, for
example, then those deposits can be termed objectionable and
measures can be taken to restrict the discharge of settleable
solids. Bioassays can be used to determine compliance with the
narrative prohibition on toxicity. Guidance for applying some of
these techniques can be found in the draft Section 316(a) guidance
manual dated September 30, 1974.
The aesthetic criteria are harder to quantify in terms of
violation. Photographic records or public complaints can provide
a good indication of problems. If the source of such violation
can be identified, control actions can be imposed by the regulatory
agency based on such observations.
5.4 Antidegradation
A. General
Each State must develop and adopt (or retain) a Statewide anti-
degradation policy in the water quality standards and identify
methods for its implementation through other components of the
State WQM process in accordance with S130.17(e). At a minimum the
policy should contain the following components:
1. In all cases, existing instream beneficial water uses must
be maintained and protected. Any actions that would intefere
with or become injurious to existing uses cannot be undertaken.
Waste assimilation and transport are not recognized beneficial
uses;
2. Existing high quality waters must be maintained at their
existing high quality unless the State decides to allov
limited degradation where economically or socially justified.
If limited degradation is allowed, it cannot result in viola-
tion of water quality criteria that describe the base levels
necessary to sustain the national water quality goal uses of
protection and propagation of fish, shellfish and wildlife and
recreation in and on the water;
3. In all cases, high quality waters which constitute an out-
standing national resource must be maintained and protected;
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4. Any determinations concerning thermal discharge limitations
under Section 316(a) of the Act will be considered to be in
compliance with the antidegradation policy.
High quality waters consist of those waters at or above the
minimum levels necessary to achieve the national water quality goal
uses.
Existing approved antidegradation statements consistent with
§130.17(e) may be retained, but procedures for implementation must
be established through the State WQM process. The process will
enable the State to determine on a case-by-case basis whether
and to what extent water quality may be lowered consistent with
§130.17.
B. Public and Intergovernmental Review
The State WQM process must provide that whenever an activity is
proposed which may degrade existing high quality waters, the State
will assure that there is adequate public and intergovernmental
participation in accordance with section 5.11.C. of this Chapter.
Where the public and intergovernmental response, taken as a
whole, clearly opposes a proposed degradation, the State must give
serious consideration to that response and may not allow the pro-
posed degradation activity unless a substantial and convincing
justification for the activity has been presented.
C. National Resource Waters
Waters which constitute an outstanding national resource may
not be degraded. At a minimum, waters in National and State
parks, wildlife refuges and waters of exceptional recreational
or ecological significance (for example, waters which provide a
unique habitat for an identified threatened or endangered species
or rivers designated under the National Wild and Scenic Rivers Act)
should be considered as outstanding national resource waters. The
State's intergovernmental review notice (see section 5.11.C) should
include notice to the Federal, State, or other agencies responsible
for administration of the waters or other resource involved. Such
notice should specifically call attention to the possible character-
ization of the waters in question as an outstanding national resource.
EPA recommends that each State include in its water quality
standards an initial listing of the outstanding national resource
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waters of the State. Such a list would provide a ready identification
of such waters. The possibility of additions or deletions from time
to time should be expected.
D. Antidegradation and Growth
National antidegradation requirements should not be viewed as
a "no growth" rule. Where the State intends to provide for further
development, the State WQM process should evaluate the alternative
measures which can be taken to preserve water quality at the levels
required by 5130.17. The evaluation must take into account the
physical, chemical, and biological characteristics of the water.
Examples of some techniques that can be used by the States
include:
1. Designing wasteload allocations to accommodate new sources,
via reduction in current source loadings;
2. Restricting any new discharge of pollutants from new and
existing sources;
3. Restricting any increase in pollutants discharged from
existing sources;
4. Adopting a no mixing zone policy, thus requiring safe
concentrations to be met at the end of the pipe;
5. Requiring land disposal for new projects; and
6. Requiring new nonpoint source activities to demonstrate no
permanent adverse impact on water quality.
E. Optional State Actions
The State's antidegradation policy is to be designed for the
protection of existing water quality. Use designations should not
be an issue, since the specific water quality standards should
always, at a minimum, designate existing beneficial uses. The
State's water quality standards for high quality waters may, within
the constraints and limitations of monitoring practicability, set
forth the existing water quality of a segment. Thus, the State may
adopt specific criteria at existing levels measured in the segment,
even though such levels may be more stringent than the Section 304(a)
criteria minimum levels for given uses. Documentation of existing
water quality may be useful in the State WQM process as a baseline
against which any future degradation could be measured.
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F. Federal Review of Antidegradation Policies and Actions
The State's antidegradation statement and implementing pro-
cedures, as a part of its water quality standards and WQM process,
are subject to the Regional Administrator's review and approval.
EPA encourages submittal of this statement and implementing pro-
cedures to the Regional Administrator for pre-adoption review so
that the State may take EPA comments into account prior to final
adoption.
5.5 Mixing Zones
A. General
A limited mixing zone, serving as a zone of initial dilution
in the immediate area of a point or nonpoint source of pollution,
may be allowed. Establishing a mixing zone policy is a matter of
State discretion. Such a policy, however, must be consistent with
the Act and is subject to the approval of the Regional Administrator.
Careful consideration must be given to the appropriateness of a
mixing zone where a substance discharged is bioaccummulative and
persistent or carcinogenic, mutagenic, or teratogenic. In such
cases the State must consider the ecological and human health effects
of assigning a mixing zone including such effects as bioconcentration
in sediments and aquatic biota, bioaccummulation in the food chains,
and the known or predicted safe exposure levels for the substance.
In some instances, the ecological and human health effects may be
so adverse that a mixing zone is not appropriate.
B. Definition of Allowable Mixing Zones
Water quality standards should describe the State's methodology
for determining the location, size, shape, outfall design and in-zone
quality of mixing zones, with sufficient precision to support such
regulatory actions as issuance of permits and determination of BMP's
for nonpoint sources. Specifications should relate to the individual
water body. EPA recommends the following:
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1. Location. Biologically important areas are to be identified
and protected. Where necessary to preserve the zone of passage
for migrating fish or other organisms in a water course, the
standards should specifically identify the portion of the waters
to be kept free from mixing zones.
2- Size. Various methods and techniques for defining the sur-
face area and the volume of mixing zones for various types of
waters have been formulated. Methods which result in quantita-
tive measures sufficient for permit actions and which protect
the designated uses of the water body as a whole are acceptable.
The area or volume of an individual zone or group of zones rust
be limited to an area or volume 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. The State WQM
process growth projections should be taken into account in settina
the total mixing zone size for the water course.
3. Shape. The shape of a mixing zone should be a simple con-
figuration that is easy to locate in the body of water and that
avoids impingement on biologically important areas. A circle
with a specified radius is generally preferable, but other
shapes may be specified in the case of unusual site require-
ments. "Shore-hugging" plumes should be avoided.
4. Outfall Design. Prior to designating any mixing zone, the
State should assure that the design and location of the existing
or proposed outfall provides maximum protection of aquatic
resources.
5. In-zone Quality. Water quality standards should provide
that all mixing zones conform with the following requirements.
Any mixing zone should be free of point or nonpoint source
related:
(a) Materials in concentrations that exceed the 96-hour
LC50 for biota significant to the indigenous aquatic community;
(b) Materials in concentrations that settle to form objec-
tionable deposits;
(c) Floating debris, oil, scum and other matter in con-
centrations that form nuisances;
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(d) Substances in concentrations that produce objec-
tionable color, odor, taste or turbidity; and
(e) Substances in concentrations which produce undesirable
aquatic life or result in a dominance of nuisance species.
C. Mixing Zones for the Discharge of Dredged or Fill Material
EPA, in conjunction with the Department of the Army, has dev-
eloped interim guidelines to be applied in evaluating the discharge
of dredged or fill material in navigable waters. (See 40 CFR
Part 230, Federal Register, September 5, 1975.) The interim
guidelines include provisions for determining the acceptability
of mixing discharge zones (§230.5(e)). The particular pollutants
involved should be evaluated carefully in establishing dredging
mixing zones. Dredged spoil discharges generally result in a
temporary short-term disruption and do not represent a continuous
discharge of materials that will affect beneficial uses over a
long period of time. A limited disposal operation whose primary
pollutant is inert suspended solids may qualify for a mixing zone
more readily than an operation discharging toxic pollutants. The
potential for long-term disruption of beneficial uses should be
the primary consideration in establishing mixing zones for dredged
and fill activities. State water quality standards should reflect
these principles if mixing zones for dredging activities are
referenced.
D. 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 Part 115, proposed June 7, 1974) provide in
part (5115.10(a)) that the aquaculture project must not result in
a violation of standards outside of the project area, and project
approval must not result in the enlargement of any previously
approved mixing zone. In addition, the aquaculture regulations
provide that designated projected 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 the conditions within the
designated project area (S115.10(e)). 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.
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5.6 Thermal Water Quality Standards
Water guality standards relating to heat are required by
Section 303(g) of the Act to be consistent with the requirements of
Section 316 of the Act. In keeping with the provisions of Section 303
and Section 316:
. Water quality standards relating to thermal criteria must
assure the protection and propagation of a balanced, indigenous
population consistent with Section 316.
. In areas in which a point source is entitled to the temporary
immunities of Section 316(c), water quality standards should be
established without regard to such immunity, but the standards
may not serve as a basis for imposing effluent limitations on
such source during the period of its immunity.
5.7 Water Quality Related Effluent Limitations Under Section 302
of the Act (RESERVED).
5.8 Stream Flows
A. Intermittent Streams
Water quality criteria should be adopted for intermittent
streams to the extent necessary to assure that conditions in the
streams or stream beds will not impair existing or designated uses
in the stream or in downstream waters.
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B. Low Flow
Water quality standards should protect water quality for
designated uses in critical low flow situations, and individual
sources or categories of sources should not be categorically exempted
from compliance with such standards during critical low flow periods.
Wasteload allocations for the achievement of water quality
standards may be based on a specified low flow which can be regarded
as the critical low flow. This critical low flow must be estab-
lished at a level which assures protection of beneficial uses desig-
nated in standards. In many cases, this will be the average seven-
day low flow which occurs once in ten years. In extreme situations
where flow falls below the critical low flow, the usually applicable
standards may be violated. As an alternative to a critical low
flow, States may adopt special low flow standards or policies to be
met seasonally or at all times regardless of low conditions. Examples
of situations where this may be appropriate include streams which are
of a natural ephemeral or intermittent nature or streams where an
endangered species is present and special standards are necessary to
protect the species and its habitat.
The State WQM process should be designed to minimize the effect
of conditions which may result from point source discharges or storm
related nonpoint source runoff during low flow periods. For example,
the WQM process may identify the need for NPDES permit conditions,
such as higher treatment levels or reduced discharge volumes necessary
to avoid or mitigate severe and long-lasting water quality impacts
during critical periods. Seasonal limitations may be included, such
as requiring seasonal control of certain pollutants during critical
months.
In addition, the State WQM process may identify special procedures
to be available to prevent major impacts as a result of low flow
periods. Responses may include release of impounded waters, effluent
or storm water storage or modification of industrial production
schedules.
C. High Flow
Water quality standards should protect water quality in critical
high flow situations, and individual sources or categories of sources,
such as nonpoint sources, should not be categorically exempted from
compliance with water quality standards.
The State WQM process should minimize the effects of conditions
which may result during high flow periods. For example, permit
conditions and BMP's for nonpoint sources should anticipate periods
of critical high flow. Many types of nonpoint source problems are
most intense during and after periods of precipitation, when flows
are higher than at other times.
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Extreme high flow, like extreme low flow, is not a required
design criterion for sources severely affected by the extreme con-
ditions. However, permits and nonpoint source controls should
assure that, in extreme high flow situations, man-induced incremental
pollution will not result in severe and long-lasting water quality
impacts. It may be appropriate for States to adopt specific stan-
dards to be met at all times, regardless of flow.
In addition, the State WQM process may identify special proce-
dures to be available to prevent major impacts as a result of high
flow periods. Responses may include curtailment of point source
discharges, if appropriate, or other feasible and useful measures.
D. Regulated Flow
Flow augmentation and regulation is not a substitute for
adequate treatment or control of pollutant sources, but may be an
important consideration in WQM. Minimum flow rates for regulated
waters should be specified in State water quality standards where
necessary to protect and attain the appropriate beneficial uses
of any waters.
5.9 Discharge of Dredged or Fill Material
As stated in section 5.5 of this Chapter, EPA has published
interim guidelines to be applied in evaluating activities involving
the discharge of dredged materials or fill material in navigable waters
(40 CFR Part 230). Appropriate water quality standards must be consid-
ered when discharging dredged or fill material. The interim guidelines
provide that:
"After application of the approaches presented in §230.4, the
District Engineer will compare the concentrations of appropriate
constitutents to applicable narrative and numerical guidance con-
tained in such water quality standards as are applicable by law.
In the event that such discharge would cause a violation of such
appropriate and legally applicable standards at the perimeter of
the disposal site after consideration of the mixing zone, dis-
charge shall be prohibited." (40 CFR S230.4-2.)
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In addition the interim guidelines provide that:
"In evaluating whether to permit a proposed discharge of dredged
or fill material into navigable waters, consideration shall be
given to the need for the proposed activity, the availability of
alternative sites and methods of disposal that are less damaging
to the environment, and such water quality standards as are
appropriate and applicable by law."
5.10 Groundwater
EPA recommends that States adopt water quality standards to protect
the underground waters of the State. Such standards are not a Federal
requirement; however, standards for groundwater are particularly desir-
able to protect waters which are a present or potential public drinking
water supply source or have particular ecological or hydrographic
significance.
5.11 State Water Quality Standards Review and Revision Procedures1
A general description of the relationship between the Standards
Review Process and State WQM Process is provided in Chapter 2.3.E
("Review/Revision of Water Quality Standards and Definition of Anti-
degradation Policy"). See also Chapter 3.6.C.2 ("Specify Water
Quality Standards and Anti degradation Policy"). The interdependency
of the State WQM process and standards review/revision process makes it
necessary to initiate both activities within the same time frame, com-
mencing with certain simplifying assumptions and proceeding later to
more appropriate refinement in both areas.
State water quality standards consist of water quality standards
which are approved or promulgated by the EPA pursuant to Section 303
of the Act and consist of designated beneficial uses, water quality
criteria to support those uses, anti degradation policy, and implementa-
tion plans established pursuant to Section 303(a) and (b).
A. Relationship to State WQM Process
40 CFR §130.10(c)(5) requires State water quality standards to
be reviewed and revised in time to impact 1977-1983 management and
regulatory decisions. This is imperative for State water quality
standards to be a meaningful tool in pollution abatement. In this
anticipates amending 40 CFR Part 120 to set forth the procedures
for State review and revision and EPA approval and promulgation of water
quality standards.
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next three-year period of statutory mandated review/revision
activities, revisions to standards which are adopted should be
submitted to the Regional Administrator by January 1, 1977, to
comply with 40 CFR S130.10(c)(5). The January 1 deadline will
assure that standards revisions will be approved or disapproved
and appropriate promulgation action taken in time to do the
following:
1. Set the objectives for the initial WQM plans which,
by court order, are due November 1, 1978.
2. Provide the necessary information for establishing water
quality related effluent limitations in the second round of
permits.
The State/EPA agreement on timing and level of detail for the
development of State WQM plans (40 CFR SI30.11) should provide
for the completion of standards revisions in time to meet
40 CFR S130.10(c)(5) requirements. The State's schedule and
milestones for reviewing and revising standards required pursuant
to 40 CFR S130.10(c) must contain:
1. An identification of each designated areawide planning
agency in the State which is involved in developing water quality
standards recommendations and the date by which such agency is
expected to make its recommendations to the State WQM agency.
2. The date when the State intends to submit its proposed
water quality standards revisions to the Regional Administrator.
3. A list of the public hearings which are expected to be held
on the existing and proposed standards and the tentative dates
for such hearings.
4. The projected dates when revisions to water quality standards
will be adopted and submitted to the Regional Administrator.
B. Proposed Revisions
States should work closely with their Regional Offices in dev-
eloping proposed revisions to standards. Such a relationship will
facilitate the development of proposed revisions which meet the
requirements of the Act and expedite the Agency review process.
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Each State should submit three copies of its proposed water
quality standards revisions to the Regional Administrator and
identify the proposed changes or additions in the submittal. The
Regional Administrator may submit comments to the State on the
proposed revisions if comments would be beneficial.
C. Public Participation and Intergovernmental Coordination
The States should provide for maximum public participation and
intergovernmental coordination in the standards review/revision
process. Public hearings are a mandatory requirement of the pro-
cess. All such activities should be conducted as a part of the
State WQM process. The guidelines on public participation in
Chapter 4 set forth the need and legal requirements for public
participation and contain the principles for structuring public
involvement.
The objective of the public participation and intergovernmental
coordination requirements is to involve the public and government
institutions in the review and revision of existing State water
quality standards in a meaningful way. They can make valuable
contributions toward establishing overall water quality goals and
expectations for the State. The public and government institutions
also can play a key role in developing the public support that
will ultimately lead to acceptance and implementation of the stan-
dards and achievement of the national water quality goal specified
in Section 101(a)(2) of the Act.
In providing for public participation and intergovernmental
response, the requirements in 40 CFR Part 105 are applicable. Such
requirements include but are not limited to the following:
1. A notice of the public hearing(s) must be published which
includes:
a. Time and location of hearing;
b. Hearing agenda;
c. Notification of the availability of a Fact Sheet as
required under Part 105.7(f). The sheet must outline the
major issues to be discussed, relevant tentative State staff
reports on standards, determinations on proposed revisions,
and any additional information the public should be aware
of prior to the hearing which is germane to the issues; and
d. The location where reports, documents, and data to be
discussed at the hearing are available for public inspection.
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2. Notice of the public hearing must be mailed to interested
and affected persons and organizations including private and
government organizations and individuals who have filed with
the State requesting such notices. Notice of hearings must
also be mailed to downstream States and Federal and State
agencies which are affected or potentially could be affected
by existing State water quality standards or proposed revisions
thereto.
The hearing notice(s) should solicit comments and provide oppor-
tunity for public comment. The State must prepare transcripts of
the hearing(s) or a summary which must be available for inspection
by the Regional Administrator and the public.
To facilitate EPA review of existing or revised State water
quality standards, States should supply the Agency with any docum-
entation or information on review/revision activities which is
requested. A central file containing information documenting
review/revision activities should be maintained. Such a file is
helpful in answering information requests by the Agency and public.
Documentation may be needed by EPA to assess whether existing
or revised State water quality standards meet the requirements of
the Act. Examples include the rationale for:
1. Why standards for a segment were not revised;
2. Why a particular criterion was not adopted; or
3. Why data or other information was or was not considered in
reviewing or revising State water quality standards.
D. Submittal of State Adopted Revisions
The Governor or his designee should submit to the Regional
Administrator three copies of revisions to State water quality
standards which are adopted. The submittal should also include
the following information which will be helpful in reviewing the
revisions and determining whether the revisions meet the require-
ments of the Act:
1. A statement by the State Attorney General or other appropriate
legal authority within the State that the revised water quality
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standards were duly adopted by the State and are included
within State law. (Note that standards are an element of the
State WQM plan and regulatory programs implementing the plan
must assure that water quality standards are met (see 40 CFR
Part 130). It is through these regulatory mechanisms that
standards are enforced under State law.)
2. The identification of specific water segments which have
water uses in the revised water quality standards which are at
the national water quality goal levels or which are less
restrictive than the national water quality goal uses.
A "less restrictive use" for the purpose of Part 120 is a
use which requires a lower level of water quality to be main-
tained and protected.
3. The identification of the specific water segments which have
water uses in the revised water quality standards that have
been upgraded.
4. The identification of the specific water segments which
have water uses in the revised water quality standards which
are more restrictive than the existing designated beneficial
water uses.
5. Identification of specific water segments with revised
standards which have less stringent water quality criteria than
those criteria contained in the Administrator's Quality Criteria
for Water document for the appropriate use or water conditions.
6. A summary of the intergovernmental coordination and public
participation which transpired in the development and adoption
of the revised water quality standards. The summary should
include a discussion of the important comments received. When
requested by the Regional Administrator, the State should also
submit its rationale for adopting the revised water quality
standards.
The rationale often may be an important factor in determining
whether to approve or disapprove a revision. The Regional
Administrator can request the rationale for the revisions
actually adopted as well as for the rejection of other alternatives
considered.
E. EPA Review, Approval, Disapproval and Promulgation
The Regional Administrator must review the revised water quality
standards and approve or disapprove the revision. A standard is
revised only where there has been a substantive change in that
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standard. Where the changes are not substantive (e.g. changing
the numbering system of a regulation or a document title but not
the content of the standards), 1t is not necessary to approve or
disapprove the change. Any change, however, should be submitted
to the EPA for a determination as to its substantive nature.
Depending on the nature of a non-substantive change, 40 CFR
Part 120 may have to be corrected to reflect the change.
1. Approval
Revisions to State water quality standards must be approved
by the Regional Administrator if they meet the requirements of
the Act and 40 CFR Parts 130 and 120. When only a portion of
the revisions submitted meet the requirements of the Act, the
Regional Administrator can only approve that portion. The
Regional Administrator should promptly notify the Governor by
letter of the approval and forward a copy of the letter to the
appropriate State agency with any additional information which
may be helpful in understanding the scope of the approval action
and in conducting future review/revision activities.
Where it is evident that the subsequent occurrence of
particular events could or will result in a failure of the
approved standards to continue to meet the requirements of the
Act, those events should be identified in the approval letter
to facilitate review/revision activities.
The Regional Offices are responsible for preparing the
Federal Register notice of approval amending 40 CFR Part 120
and the accompanying action memorandum. The notice should
contain a description of the State water quality standards as
they are affected by the approved revisions. The notice must
reference the documents containing the approved State water
quality standards, give the dates of adoption and approval, and
include the text of any previous promulgation actions.
The Regional Offices must forward the notice and memorandum
to the Deputy Assistant Administrator for Water Planning and
Standards (WH-551) for format review. The notice will then be
transmitted to the Federal Register by the Assistant Adminis-
trator for Water and Hazardous Materials. With the submittal,
the Regional Offices must also forward a copy of each of the
following:
. The letter from the appropriate State authority certifying
that the standards were duly adopted and are included within
State law;
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. The letter transmitting the revisions from the State to
EPA for approval;
. EPA approval letter; and
. Copy of the approved revisions.
2. Disapproval
If the Regional Administrator determines that the revisions
submitted or the existing water quality standards themselves are
not consistent with or do not meet the requirements of the Act,
the Regional Administrator must disapprove such standards by
notifying the Governor of the State by letter of that fact.
The letter must state the reason that the revision submitted
or the existing water quality standards are not consistent with
the Act and the specific revisions to State water quality stan-
dards which must be adopted to obtain full approval of the
revised standards. 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 the date of notification.
A revision whose subject matter is not an acceptable constit-
uent element of State water quality standards (e.g. Grandfather
clause or effluent guideline) and which is not consistent with
the applicable requirements of the Act must be disapproved.
The Regional Administrator must notify the State as required
above stating that such revisions must be deleted from water
quality standards in order to meet the requirements of the Act.
If the deletion is not made, the Administrator must proceed to
promulgate as necessary to supersede the inconsistent revision
(303(c)(4) of the Act).
3. Promulgation
Promulgation proceedings are initiated by the preparation
and publication of proposed regulations setting forth revised
State water quality standards. As soon as possible after the
expiration of the 90 days, proposed revisions should be published
in the Federal Register. A public hearing(s) must be held on
the proposed standards. Within 90 days of their proposal,
standards must be promulgated after giving due consideration
to comments received as a result of intergovernmental coordination
and public participation.
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The Regional Office has a major role in promulgating
standards. They should assist the Administrator by providing
the necessary background information and participating in
public hearings. They also have primary responsibility for
preparing the notices of proposed and final rulemaking and the
action memoranda. The documents should be forwarded to the
Deputy Assistant Administrator.
If a State remedies the deficiencies in State water quality
standards by adopting revised standards which the Regional
Administrator determines meet the requirements of the Act prior
to promulgation, the Administrator will promptly terminate
promulgation proceedings.
4. Withdrawal Notices
A. Proposed Rulemaking
Whenever promulgation proceedings are terminated a notice
of withdrawal of the proposed rulemaking must be published
in the Federal Register. The Regional Offices are respon-
sible for preparing the notice for the Administrator's
signature as well as the action memorandum. Both documents
should be forwarded to the Deputy Assistant Administrator.
B. Disapproval
Water quality standards submitted for approval must
either be approved or disapproved. Disapproval must be
followed by an EPA promulgation. Whenever a disapproval is
not followed by promulgation, the disapproval should be with-
drawn by the Agency. Where the withdrawal pertained to a
disapproval of revisions submitted for approval, the Regional
Administrator must promptly approve the revisions.
C. Promulgation
A promulgated standard should be withdrawn when it is
no longer necessary to assure that State water quality stan-
dards meet the requirements of the Act. Withdrawal may be
desirable for a variety of reasons. For example:
. The State complied fully with a promulgation which
required it to take a particular action; or
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. EPA approved revisions to State water quality standards
where the revisions included the substantive content of a
previous promulgation.
In such a situation, the Regional Offices should prepare the
notice of withdrawal for the Administrator's signature and the
action memorandum. The documents should be forwarded to the
Deputy Assistant Administrator.
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