APPENDIX G 

Questions and Answers on: 

Antidegradation 

WATER QUALITY STANDARDS HANDBOOK 

SECOND EDITION 
United States 

Environmental Protection 

Agency 

Office of Water 

Regulations and Standards 

Washington. DC 20460 

August 1965 

Water 

Questions & Answers on: 

Antidegradation 
QUESTIONS AND ANSWERS ON ANTIDEGRADATION 

INTRODUCTION 

This document provides guidance on the antidegradation 

policy component of water quality standards and its application. 

The document begins with the text of the policy as stated in the 

water quality standards regulation, 40 CFR 131.12 (40 FR 51400, 

November 8, 1983), the portion of the Preamble discussing 

the antidegradation policy, and the response to comments 

generated during the public comment period on the regulation. 

The document then uses a question and answer format 

to present information about the origin of the policy, the 

meaning of various terms, and its application in both general 

terms and in specific examples. A number of the questions 

and answers are closely related; the reader is advised to 

consider the document in its entirety, for a maximum understanding of the policy, rather than to focus on particular 

answers in isolation. While this document obviously does 

not address every question which could arise concerning the 

policy, we hope that the principles it sets out will aid the 

reader in applying the policy in other situations. Additional 

guidance will be developed concerning the application of the 

antidegradation policy as it affects pollution from nonpoint 

sources. Since Congress is actively considering amending the 

Clean Water Act to provide additional programs for the control 

of nonpoint sources, EPA will await the outcome of congressional 

action before proceeding further. 

EPA also has available, for public information, a summary 

of each State's antidegradation policy. For historical 

interest, limited copies are available of a Compendium of 

Department of the Interior Statements on Non-Degradation of 

Interstate Waters, August, 1968. Information on any aspect 

of the water quality standards program and copies of these 

documents may be obtained from: 

David Sabock, Chief 

Standards Branch (WH-585) 

Office of Water Regulations and Standards 

Environmental Protect ion Agency 

401 M. Street, S.W. 

Washington, D.C. 20460 

This document is designated as Appendix A to Chapter 2 - 

General Program Guidance (antidegradation) of the Water Quality 

Standards Handbook, December 1983. 

James M. Conlon, Acting Director 

Office of Water Regulations 

and Standards 
REGULATION 

Federal Register / Vol. 48, No. 217 / Tuesday, November 8, 1983 / Rules and Regulations 51407 

§ 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 

implementation methods shall, at a 

minimum, be consistent with the 

following: 

(1) Existing instream water uses and 

the level of water quality necessary to 

protect the existing uses shall be 

maintained and protected. 

(2) Where the quality of the waters 

exceed levels necessary to support 

propagation of fish, shellfish, and 

wildlife and recreation in and on the 

water, that quality shall be maintained 

and protected unless the State finds. 

offer full satisfaction of the 

intergovernmental coordination and 

public participation provisions of the 

State continuing planning process, that 

allowing lower wafer 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 regulatory 

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 

constitute an outstanding National 

resource. such as waters of National and 

State parks end wildlife refuges and 

waters of exceptional recreational or 

ecological significance, that water 

quality shall be maintained and 

protected. 

(4) In those cases where potential 

water quality impairment associated 

with a thermal discharge is involved, the 

antidegradation policy and 

implementing method shall be 

consistent with section 316 of the Act. 

i 
PREAMBLE 

51402 Federal Register / Vol. 48. No. 217 / Tuesday, November 8, 1983 / Rules and Regulations 

Antidegradation Policy 

The preamble to the proposed rule 

discussed three options for changing the 

existing antidegradation policy. Option 

1, the proposed option, provided simply 

that uses attained would be maintained. 

Option 2 stated that not only would uses 

attained be maintained but that high 

quality waters, i.e. waters with quality 

better than that needed to protect fish 

and wildlife. would be maintained (that 

is, the existing antidegradation policy 

minus the “outstanding natural resource 

waters” provision). Option 3 would have 

allowed changes in an existing use if 

maintaining that use would effectively 

prevent any future growth in the 

community or if the benefits of 

maintaining the use do not bear a 

reasonable relationship to the costs. 

Although there was support for 

Option 2, there was greeter support for 

retaining the full existing policy. 

including the provision on outstanding 

National resource waters. Therefore, 

EPA has retained the existing 

antidegradation policy (Section 131.12) 

because it more accurately reflects the 

degree of water quality protection 

desired by the public, and is consistent 

with the goals and purposes or the Act. 

In retaining the policy EPA made four 

changes. First, the provisions on 

maintaining and protecting existing 

instream uses and high quality waters 

were retained, but the sentences stating 

that no further water quality 

degradation which would interfere with 

or become injurious to existing instream 

uses is lowed were deleted. The 

deletions were made because the terms 

interfere” and “injurious” were subject 

misinterpretation as precluding any 

activity which might even momentarily 

add pollutants to the water. Moreover, 

we believe the deleted sentence was 

intended merely as a restatement of the 

basic policy. Since the rewritten 

provision, with the addition of a phrase 

on water quality described in the next 

sentence. stands alone as expressing the 

basic thrust and intent of the 

antidegradation policy, we deleted the 

confusing phrases. Second, in 

§ 131.12(a)(1) a phrase war added 

requiring that the level of water quality 

necessary to protect en existing use be 

maintained and protected. The previous 

policy required only that an existing use 

be maintained. In § 131.12(a)(2) a phrase 

was added that “In allowing such 

degradation or lower water quality. the 

State shall assure water quality 

adequate to protect existing uses fully”. 

This means that the full use must 

continue to exist even if some change in 

water quality may be permitted. Third, 

in the first sentence of § 131.12(a)(2) the 

wording was changed from “. . . 

significant economic or social 

development. . .” to ". . . important 

economic or social development. . .” 

In the context of the antidegradation 

policy the word important” strengthens 

the intent of protecting higher quality 

waters. Although common usage of the 

words may imply otherwise, the correct 

definitions of the two terms indicate that 

the greater degree of environmental 

protection is afforded by the word 

“important.” 

Fourth, § 131.12(a)(3) dealing with the 

designation of outstanding National 

resource waters [ONRW] was changed 

to provide a limited exception to the 

absolute “no degradation” requirement. 

EPA was concerned that waters which 

properly could have been designated as 

ONRW were not being so designated 

because of the flat no degradation 

provision, and therefore were not being 

given special protection. The no 

degradation provision was sometimes 

interpreted as prohibiting any activity 

(Including temporary or short-term) from 

being conducted. States may allow some 

limited activities which result in 

temporary and short-term changes in 

water quality. Such activities are 

considered to be consistent with the 

intent and purpose of an ONRW. 

Therefore, EPA has rewritten the 

provision to read “. . . that water 

quality shall be maintained and 

protected, and removed the phrase “No 

degradation shall be allowed. . .” 

ii 

In its entirety. the antidegradation 

policy represents a three-tiered 

approach to maintaining and protecting 

various levels of water quality and uses. 

At its base (Section 131.12(a)(1)), all 

existing uses and the level of water 

quality necessary to protect those uses 

must be maintained and protected. This 

provision establishes the absolute floor 

of water quality in all waters of the 

United States. The second level (Section 

131.12(a)(2)) provides protection of 

actual water quality in areas where the 

quality of the waters exceed levels 

necessary to support propagation of fish, 

shellfish, and wildlife and recreation in 

and on the water (“fishable/ 

swimmable”). There are provisions 

contained in this subsection to allow 

some limited water quality degradation 

after extensive public involvement, as 

long as the water quality remains 

adequate to be “fishable/swimmable.” 

Finally § 131.23(a)(3) provides special 

protection of waters for which the 

ordinary use classifications and water 

quality criteria do not suffice. denoted 

“outstanding National resource water.” 

Ordinarily most people view this 

subsection as protecting and 

maintaining the highest quality waters 

of the United States: that is clearly the 

thrust of the provision. It does, however, 

also offer special protection for waters 

of “ecological significance.” These are 

water bodies which are Important. 

unique. or sensitive ecologically. but 

whose water quality as measured by the 

traditional parameters (dissolved 

oxygen, pH, etc.) may not be particularly 

high or whose character cannot he 

adequately described by these 

parameters. 
RESPONSE To PUBLIC CCMMENTS 

Fodenl Register / Vol. 48, No. 217 / Tuesday. November a 1963 / Rules anJ Regulattonr 51409 

Antidegradation Policy 

EPA’@ proporal. which would have 

limited the antidegradation polky to the 

maintenance of existing uses. plur three 

alternative policy statements described 

in the preamble IO the proposal notice, 

Renerated extensive public comment. 

EPA’s rc*sponre is described in the 

Preaml~le to this finnl rule and includer 

a respunse to both the rubrtantive and 

philosophical commentr offered. Public 

comments overwhelmingly supported 

ret(*ntion of the existing policy and EPA 

did so in the final rule. 

EPA’s response to several commente 

dealing with the antidegradation policy. 

which were not discussed In the 

Preamble apI dimcursed below. 

Option three contained in the 

wncy’r proposal would have allowed 

the porribility of exceptions to 

maintaining exirting user. This option 

was either criticized for being illegal or 

was rupported because it provided 

additional flexibility for economic 

growth. The latter commenterr believed 

that allowancea should be made for 

carefully defined cxccptionr IO the 

abrolute rc?quirement that uses attallied 

murt be maintained. EPA rejects this 

contention aa being totally inconsistent 

with the spirit and intent of both the 

Clean Waler Act and the underlying 

philoeophy of the antidegradation 

policy. Moreover, although the Agency 

rpecifically asked for examples of 

where the existing antidegradation 

policy had precluded growth. no 

exampler were provided. Therefore. 

wholly apart from technical legal 

concerns. there appear-e to be no 

iurtification for adopting Option 3. 

Mart critics ot the proporeo 

antidegradation policy objected to 

removing the public’r ability IO affect 

decirionr on high quality watcn and 

outstanding national reeource waten. In 

attempting to explaln how the propored 

antidegradation policy would be 

implemented, the Preamble to the 

propored rule stated that no public 

participation would be neceuary in 

certain inrtancea because no change 

was being mude in a State-r water 

quality standard. Although that 

statement wus technically accurate. it 

left the mistaken impression that all 

public pcirticipotion was removed from 

the disrllssionr on high quality waters 

end that 1s nut correct. A NPDEZS permit 

would hvve to be issued or a 200 plan 

amendf:d for nny de:crioration in wtrtcr 

quality to be “allowed”. Both actions 

require notice and an opportunity for 

public comment. tlowever. EPA retained 

the existing policy so this issue in moot. 

Other changer in the policy affecting 

ONRW an’ discussed in the Preamble. 

iii 
OUESTIONS AND ANSWERS ON ANTIDEGRADATION 

1. WHAT IS THE ORIGIN OF THE ANTIDEGRADATION POLICY? 

The basic policy was established on February 8, 1968, by 

the Secretary of the U.S. Department of the Interior. It 

was included in EPA's first water quality standards regulation 40 CFR 130.17, 40 FR 55340-41, November 28, 1975. It 

was slightly refined and repromulgated as part of the current 

program regulation published on November 8, 1983 (48 FR 

51400, 40 CFR S131.12). An ant idegradation policy is one 

of the minimum elements required to be included in a State's 

water quality standards. 

2. WHERE IN THE CLEAN WATER ACT (CWA) IS THERE A REOUIREHENT FOR AN 

ANTIDEGRADATION POLICY OR SUCH A POLICY EXPRESSED? 

There is no explicit requirement for such a policy in the 

Act. However, the policy is consistent with 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" (SlOl(a)) and arguably is 

covered by the provision of 303(a) which made water quality 

standard requirements under prior law the "starting point" 

for CWA water quality requirements. 

3. CAN A STATE JUSTIFY NOT HAVING AN ANTIDEGRADATION POLICY IN 

ITS WATER OUALITY STANDARDS? 

EPA's water quality standards regulation requires each 

State to adopt an antidegradation policy and specifies the 

minimum requirements for a policy. 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. 

4. WHAT HAPPENS IF A STATE'S ANTIDEGRADATION POLICY DOES NOT 

MEET THE REGULATORY REQUIREMENTS? 

If this occurs either through State action to revise its 

policy or through revised Federal requirements, the State 

would be given an 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. 

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5. WHAT COULD HAPPEN IF A STATE FAILED TO IMPLEMENT ITS ANTIDEGRADATION POLICY PROPERLY? 

If a State issues an NPDES permit which violates the required antidegradation policy, it would be subject to a 

discretionary EPA veto under Section 402(d) or to a 

citizen challenge. In addition to actions on permits, any 

wasteload allocations and total maximum daily loads violating 

the antidegradation policy are subject to EPA disapproval and 

EPA promulgation of a new wasteload 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. If the 

State issues a S401 certification (for an EPA-issued NPDES 

permit) which fails to reflect the requirements of the 

antidegradation policy, EPA will, on its own initiative, 

add any additional or more stringent effluent limitations 

required to ensure compliance with Section 301(b)(l)(C). 

If the faulty S401 certification related to permits issued 

by other Federal agencies (e.g. a Corp of Engineers Section 

404 permit), EPA could comment unfavorably upon permit 

issuance. The public, of course, could bring pressure 

upon the permit issuing agency. 

6. 1JILL THE APPLICATION OF THE ANTIDEGRADATION POLICY ADVERSELY 

IMPACT ECONOMIC DEVELOPMENT? 

This concern has been raised since the inception of the 

antidegradation policy. The answer remains the same. The 

policy has been carefully structured to minimize adverse 

effects on economic development while protecting the water 

quality goals of the Act. As Secretary Udall put it in 1968, 

the policy serves "... the dual purpose of carrying out the 

letter and spirit of the Act without interfering unduly 

with further economic development" (Secretary Udall, February 

8, 1968). Application of the policy could affect the levels 

and/or kinds of waste treatment necessary or result in the 

use of alternate sites where the environmental impact would 

be less damaging. These effects could have economic implications as do all other environmental controls. 

7. \aAT IS THE PROPER INTERPRETATION OF THE TERM "AN EXISTING 

USE"? 

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 tooccur (unless there are physical 

problems which prevent the use regardless of water quality). 

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. 

Such facts clearly establish that shellfish harvesting is 

an "existing" use, not one dependent oh improvements in 

water quality. To argue otherwise would be to say that 

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the only time an aquatic protection use "exists" is if someone 

succeeds in catching fish. 

8. THE WATER QUALITY STANDARDS REGULATION STATES THAT "EXISTING 

USES AND THE LEVEL OF WATER QUALITY NECESSARY TO PROTECT THE 

EXISTING USES SHALL BE MAINTAINED AND PHOTECTED." HOW FULLY AND 

AT WHAT LEVEL OF PROTECTION IS AN EXISTING USE TO BE PROTECTED 

IN ORDER TO SATISFY THE ABOVE REOUIREMENT? 

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 further explanation. Species that are in the water 

body and which are consistent with the designated-&e (i.e., 

not aberrational) must be protected, even if not prevalent in 

number or importance. Nor can activity be allowed which would 

render the species unfit for maintaining the use. Water 

quality should be such that it results in no mortality and 

no significant growth or reproductive impairment of resident 

species. (See Question 16 for situation where an aberrant sensitive species may exist.) Any lowering of water quality below 

this full 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 composed 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 lOl(a)).l/ The term "aquatic life" would more accurately 

reflect the protection of the squat ic community that was 

intended in Section 101(a)(2) of the Act. 

9. IS THERE ANY SITUATION WHERE AN EXISTING USE CAN BE REfIOVED? 

In general, no. Water quality may sometimes be affected, 

but an existing use, and the level of water quality to 

protect it must be maintained (S131.12(a)(l) and (2) of the 

regulation). However, the State may limit or not designate 

such a use if the reason for such action is non-water quality 

related. For example, a State may wish to impose a temporary 

shellfishing ban to prevent overharvesting and ensure an 

abundant population over the long run, or may wish to restrict 

swimming from heavily trafficked areas. If the State chooses, 

='/ Note: "Fishable/swimmable" is a term of convenience used in - 

the standards program in lieu of constantly repeating 

the entire text of Section 101(a)(2) goal of the Clean 

Water Act. As a short-hand expression it is potentially 

misleading. 

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for non-water quality reasons, to linlit use designations, 

it must still adopt criteria to protect the use if there is 

a reasonable likelihood it will actually occur (e.g. swimming 

in a prohibited water). However, if the State's action is 

based on a recognition that water quality is likely to be 

lowered to the point that it no longer is sufficient to 

protect and maintain an existing use, then such action is 

inconsistent with the antidegradation policy. 

10. HOW DOES THE REQUIREMENT THAT THE LEVEL OF WATER QUALITY 

NECESSARY TO PROTECT THE EXISTING USE(S) BE MAINTAINED AND PROTECTED, 

WHICH APPEARS IN S131.12(a)(l),(2), AND (3) OF THE WATER QUALITY 

STANDARDS REGULATION, ACTUALLY WORK? 

Section 131.12(a)(l), as described in the Preamble to the 

regulation, 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 provent 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 208 plan. 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 (S131.1O(i)). 

Section 131.12(a)(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 S131.12(a)(2). This requirement applies to individual water quality parameters. 

Section 131.12(a)(3) applies to so-called outstanding National 

Resource (ONRW) waters where the ordinary use classifications 

and supporting criteria are not 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 alter the essential character or 

special use which makes the water an ONRW. (See also pages 

2-14,- 15 of the Water Quality Standards Handbook.) 

Any one or a combination of several activities may trigger 

the antidegradatioq pc! icy analysis as discussed above. such 

activities include a scheduled water quality standards review, 

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the establishment of new or revised wasteload allocations 

NPDES permits, the demonstration of need for advanced treatment 

or request by private or public agencies or individuals for a 

special study of the water body. 

11. WILL AN ACTIVITY WHICH WILL DEGRADE WATER QUALITY, AND PRECLUDE 

AN EXISTING USE IN ONLY A PORTION OF A WATER BODY (BUT ALLOW IT 

TO REMAIN IN OTHER PARTS OF THE WATER BODY) SATISFY THE ANTIDEGRADATION REQUIREMENT THAT EXISTING USES SHALL BE MAINTAINED 

AND PROTECTED? 

No. Existing uses must be maintained in all parts of the 

water body segment in question other thanin restricted 

mixing zones. For example, an activity which lowers water 

quality such that a buffer zone must be established within a 

previous shellfish harvesting area is inconsistent with the 

antidegradation policy. (However, a slightly different 

approach is taken for fills in wetlands, as explained in 

Question 13.) 

12. DOES ANTIDEGRADATION APPLY TO POTENTIAL USES? 

No. The focus of the antidegradation policy is on protecting 

existing uses. Of course, insofar as existing uses and 

water quality are protected and maintained by the policy 

the eventual improvement of water quality and attainment of 

new uses may be facilitated. The use attainability requirements of S131.10 also help ensure that attainable potential 

uses are actually attained. (See also questions 7 and 10.) 

13. FILL OPERATIONS IN WETLANDS AUTOMATICALLY ELIMINATE ANY 

EXISTING USE IN THE FILLED AREA. HOW IS THE ANTIDEGRADATION 

POLICY APPLIED IN THAT SITUATION? 

Since a literal interpretation of the antidegradation policy 

could result in preventing the issuance of any wetland fill 

permit under Section 404 of the Clean Water Act, and it is 

logical to assume that Congress intended some such permits 

to be granted within the framework of the Act, EPA interprets 

s131.12 (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. 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.(a)(2)(3)), there is no difference in 

the way it applies to wetlands and other water bodies. 

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14. Is POLLUTION RESULTING FROM NONPOINT SOURCE ACTIVITIES SUBJECT 

TO PROVISIONS 3F THE ANTIDEGRADATION POLICY? 

gonpoint source activities am3 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 nangement practices for 

nonpoint source control" reflects statutory provisiona of the 

Clean Water Act. While it is true that the Act does not 

establish a regulatory program for nOnpOint sources, it clearly 

intends that the BMPs developed and approved under sections 

205(j), 208 and 303(e) be agressively implemented by the States. 

As indicated in the introduction, EPA will be developing additional 

guidance in this area. 

15. IN HIGH QUALITY WATERS, ARE NEW DISCHARGERS OR EXPANSION OF 

EXISTING FACILITIES SUBJECT TO THE PROVISIONS OF ANTIDEGRADATION? 

Yes. Since such activities would presumably lower water quality, 

they would not be permissible unless the State finds that it is 

necessary to accommodate important economic or social developmer,t 

(Section 131.12(a)(2). In addition the minimum technology base.3 

requirements must be met, including new source performance 

standards. This standard would be implemented through the wast.eload and NPDES permit process for such new or expanded source!;. 

16. A STREAM, DESIGNATED AS A WARM WATER FISHERY, HAS BEEN 

FOUND TO CONTAIN A SMALL, APPARENTLY NATURALLY OCCURRING POPULATIO!J 

OF A COLD-WATER GAME FISH. THESE FISH APPEAR TO HAVE ADAPTED TO 

THE NATURAL WARM WATER TEMPERATURES OF THE STREAM WHICH WOULD NOT 

NORMALLY ALLOW THEIR GROWTH AND REPRODUCTION. WHAT IS THE 

EXISTING USE WHICH MUST BE PROTECTED UNDER SECTION 131.12(a)(l)? 

Section 131.12(a)(l) states that "Existing instream water 

uses and level of water quality necessary to protect the 

existing uses shall be maintained and protected.* While 

sustaining a small cold-water fish population, the stream 

does not support an existing use of a "cold-water fishery.* 

The existing stream temperatures are unsuitable for a thrivil~g 

cold-water fishery. The snail marginal population is an 

artifact and should not be employed to mandate a more stringent 

use (true cold-water fishery) where natural conditions are 

not suitable for that use. 

.4 use attainability analysis or other scientific assessmc?nt 

should be used to determine whether the aquatic life population 

is in fact an artifact or is a stable population requiring 

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water quality protection. Where species appear in areas not 

normally expected, some adaptation may have occurred and sitespecific criteria may be appropriately developed. should 

the cold-water 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 warm water fishery. 

17. HOW DOES EPA'S ANTIDEGRADATION POLICY APPLY TO A kJATERBODY 

\JHERE A CHANGE IN MAN'S ACTIVITIES IN OR AROUND THAT kJATERBODY 

WILL PRECLUDE AN EXISTING USE FROM BEING FULLY MAINTAINED? 

If a planned activity will forseeably lower water quality 

to the extent that it no longer is sufficient to protect 

and maintain the existing uses in that waterbody, 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. 

In addition, in "high quality waters", under S131.12(a)(2), 

before any lowering of water quality occurs, there must be: 

1) a finding that it is necessary in order to accommodate 

important economical or social development in the area in 

which the waters are located, (2) full satisfaction of all 

intergovernmental coordination and public participation 

provisions and (3) assurance that the highest statutory and 

regulatory requirements and best management practices for 

pollutant controls are achieved. This provision can normally 

be satisfied by the completion of llater Quality Yanagement 

Plan updates or by a similar process that allows for public 

participation and intergovernmental coordination. This 

provision is intended to provide relief only in a few extraordinary circumstances where the economic and social need 

for the activity clearly outweiqhs the benefit of maintaining 

water quality above that required for "fishable/swimmable" 

water, and the two cannot both be achieved. The burden of 

demonstration on the individual proposinq 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. 

18. WHAT DOES EPA MEAN BY " . ..THE STATE SHALL ENSURE 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 NON-POINT SOURCE 

CONTROL" (S131.12(a)(2)? 

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 non-point 

source pollution control. Furthermore, by ensuring compliance 

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with such statutory and regulatory controls, there is less 

chance that a lowering of water quality will be sought in 

order to accommodate new economic and social development. 

19. WHAT DOES EPA MEAN BY " . ..IMPORTANT ECONOMIC OR SOCIAL 

DEVELOPMENT IN THE AREA IN WHICH THE WATERS ARE LOCATED" 

IN 131.1 2(a)(2)? 

This phrase is simply 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. Any more 

exact meaning will evolve through case-by-case application 

under the State's continuing planning process. Although 

EPA has issued suggestions on what might be considered in 

determining economic or social impacts, the Agency has no 

predetermined level of activity that is defined as "important". 

20. IF A WATER BODY WITH A PUBLIC WATER SUPPLY DESIGNATED USE 

IS, FOR NON-WATER QUALITY REASONS, NO LONGER USED FOR DRINKING 

WATER MUST THE STATE RETAIN THE PUBLIC WATER SUPPLY USE AND 

CRITERIA IN ITS STANDARDS? 

Under 40 CFR 131.10(h)(l), the State may delete the public 

water supply use designation and criteria if the State adds 

or retains other use designations for the waterbodies which 

have more stringent criteria. The State may also delete 

the use and criteria if the public water supply is not an 

'existing use’ as defined in 131.3 (i.e., achieved on or 

after November 19751, as long as one of the S131.1O(g) 

justifications for removal is met. 

Otherwise, the State must maintain the criteria even if it 

restricts the actual use on non-water quality grounds, as 

long as there is any possibility the water could actually 

be used for drinking. (This is analogous to the swimming 

example in the preamble.) 

21. WHAT IS THE RELATIONSHIP BETWEEN WASTELOAD ALLOCATIONS, TOTAL 

MAXIMUM DAILY LOADS, AND THE ANTIDEGRADATION POLICY? 

Wasteload allocations distribute the allowable pollutant 

loadings to a stream between dischargers. Such allocations 

also consider the contribution to pollutant loadings from nonpoint sources. Wasteload allocations must reflect applicable 

State water quality standards including the antidegradation 

policy. No wasteload allocation can be develped or NPDES permit 

issued that would result in standard being violated, or, in the 

case of waters whose quality exceeds that necessary for the 

Section 101(a)(2) qoals of the Act, can result a lowering 

of water quality unless the applicable public participation, 

intergovernmental review and baseline control requirements 

of the antidegradation policy have been met. 

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22. DO 'I'Ht itrilt1r~uL~~~.~1'11,,iLn~ ~b<~~\ti,'~lu~~, I~#. ,,.,A, L J~~~\, ~.~I\ILLI"A~'~ON 

REQUIREMENTS WHICH ESTABLISH THE PROCEDURES FOR DETERMINING THAT 

WATER QUALITY \JHICH EXCEEDS THAT NECESSARY TO SUPPORT THE SECTION 

101(a)(2) GOAL OF THE ACT MAY BE LOWERED APPLY TO CONSIDERING 

ADJUSTMENTS TO THE \lASTELOAD At.LOCATIO~lS DEVFILOPED FOR THE DISCHARGERS 

IN THE AREA? 

Yes. Section 131.12(a)(2) of t.he water quality standards 

regulation is directed towards changes in water quality per 

se, not just towards changes in standards. The intent is to 

ensure that no activity which will cause water quality to 

decline in existing high quality waters is undertaken without 

adequate public review. Therefore, if a change in wasteload 

allocation could alter water quality in high quality waters, 

the public participation and coordination requirements 

apply0 

23. IS THE ANSWER TO THE ABOVE QUESTION DIFFERENT IF THE WATER 

QUALITY IS LESS THAN THAT NEEDED TO SUPPORT "FISHABLE/SWIMMABLE" 

USES? 

Yes. Nothing in either the water quality standards or the 

wasteload allocation regulations requires the same degree 

of public participation or intergovernmental coordination 

for such waters as is required for high quality waters. 

However, as discussed in question 10, 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 

which causes reconsideration of the existing wasteloads (such 

as dischargers withdrawing from the area) will result in an 

improvement in water quality which 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 wasteloads are expected (see question 10). 

24. SEVERAL FACILITIES ON A STREAM SEGMENT DISCHARGE PHOSPHORUSCONTAINING \JASTES. AMBIENT PHOSPHORUS CONCENTRATIONS MEET CLASS B 

STANDARDS, BUT BARELY. THREE DISCHARGERS ACHIEVE ELIMINATION OF 

DISCHARGE BY DEVELOPING A LAND TREATMENT SYSTEM. AS A RESULT, 

ACTUAL WATER QUALITY IMPROVES (I.E., PHOSPHORUS LEVELS DECLINE) 

BUT NOT QUITE TO THE LEVEL NEEDED TO MEET CLASS A (FISHABLE/SWIMMABLE) 

STANDARDS. CAN THE THREE REMAINING DISCHARGERS NOW INCREASE 

THEIR PHOSPHORUS DISCHARGE WITH THE RESULT THAT WATER QUALITY 

DECLINES (PHOSPHORUS LEVELS INCREASE) TO PREVIOUS LEVELS? 

Nothing in the water quality standards regulation explicitly prohibits this (see answer to questions 10 and 23). 

Of course, changes in their NPDES permit limits may be 

subject to non-water quality constraints, such as BPT 

or BAT, which may restrict this. 

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25. SUPPOSE IN THE ABOVE SITUATION IJATER @UALITY IMPROVES TO THE 

POINT THAT ACTUAL WATER QUALITY NOW MEETS CLASS A REQUIREMENTS. 

IS THE ANSWER DIFFERENT? 

Yes. The standards must be upgraded (see answer to question 10). 

26. 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 NON-POINT PROGRAM. ARE THE 

ABOVE ANSWERS THE SAHE? 

Yes. Whether the improvement results from a change in point 

or nonpoint source activity is immaterial to how any aspect of 

the standards regulation operates. Section 131.10(d) clearly 

indicates that uses are deemed attainable if they can be achieved 

by I... cost-effective and reasonable best management practices 

for nonpoint source control". Section 131.12(a)(2) of the antidegradation policy contains essentially the same wording. 

27. \IHEN A POLLUTANT DISCHARGE CEASES FOR ANY REASON, MAY THE 

WASTELOAD ALLOCATIONS FOR THE OTHER DISCHARGES IN THE AREA BE 

ADJUSTED TO REFLECT THE ADDITIONAL LOADING AVAILABLE? 

This may be done consistent with the antidegradation policy 

only under two circumstances: (11 In "high quality waters” 

where after the full satisfaction of all public participation 

and intergovernmental review requirements, such adjustments 

are considered necessary to accomodate important economic or 

social development, and the "threshold" level requirements 

are met; or (2) in less thdn "high quality waters”, when the 

expected improvement in water quality will not cause a 

better use to be achieved, the adjusted loads still meet water 

quality standards, and the new wasteload allocations are at 

least as stringent as technology-based limitations. Of 

course, all applicable requirements of the Section 402 

permit regulations would have to be satisfied before a 

permittee could increase its discharge. 

28. HOW MAY THE PUBLIC PARTICIPATION REQUIREMENTS BE SATISFIED? 

This requirement may be satisfied in several ways. The State 

may obviously hold a public hearing or hearings. The State 

m-.'/ also satisfy the requirement by providing the opportunity 

tcr the public to request a hearing. Activities which may 

atfect several water bodies in a river basin or sub-basin 

nay 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. In other words, it is inconsistent with the water quality standards regulation to "back-door" 

changes in standards through actions on EIS's, wasteload 

allocations, plans, or permits. 

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29. WHAT IS MEANT BY THE REQUIREMENT THAT, WHERE A THERMAL 

DISCHARGE IS INCLUDED, THE ANTIDEGRADATION POLICY SHALL BE 

CONSISTENT WITH SECTION 316 OF THE ACT? 

This requirement is contained in Section 131.12 (a)(4) of the 

regulation and is intended to coordinate the requirements and 

procedures of the antidegadation 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 oE the Act. 

30. WHAT IS TqE RELATIONSHIP BETWEEN THE ANTIDEGRADATION POLICY, 

STATE bJAT9 R RIGHTS USE LAWS AND SECTION 101(g) OF THE CLEAN 

WATER ACT ,lHICH DEALS WITH STATE AUTHORITY TO ALLOCATE 

WATER QUANI'I'TI k:S? 

The exact 1iTitations imposed by section 101(g) are unclear: 

however, th+B legislative history and the courts interpreting 

it do indic,ite that it <does not nullify water quality measures 

authorized by C?JA (such as water quality standards and their 

upgrading, and NPDES and 402 permits) even if such measures 

incidentally affect individual water rights: those authorities 

also indicate that if there is a way to reconcile water 

quality needs and water quantity allocations, such accomodation 

should be be pursued. In other words, where there are 

alternate ways to meet the water quality requirements of the 

Act, the one with least disruption to water quantity allocations 

should be chosen. Where a planned diversion would lead to a 

violation of water quality standards (either the antitlegradation 

policy or a criterion), a 404 permit associated with the 

diversion should be suitably conditioned if possible and/or 

additional nonpoint and/or point source controls should ye 

imposed to compensate. 

31. AFTER READING THE REGULATION, THE PREAMBLE, AND ALL IYFSE 

QUESTIONS AND ANSWERS, I STILL DON'T UNDERSTAND ANTIDEGRADATION. 

WHOM CAN I T4LK TO? 

Call the Standards Branch at: (202) 245-3042. You can also 

call the water quality standards coordinators in each of our 

EPA Regional offices. 

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