409 

Environmental Protection Agency § 131.20 

water bodies where toxic pollutants 

may be adversely affecting water quality or the attainment of the designated 

water use or where the levels of toxic 

pollutants are at a level to warrant 

concern and must adopt criteria for 

such toxic pollutants applicable to the 

water body sufficient to protect the 

designated use. Where a State adopts 

narrative criteria for toxic pollutants 

to protect designated uses, the State 

must provide information identifying 

the method by which the State intends 

to regulate point source discharges of 

toxic pollutants on water quality limited segments based on such narrative 

criteria. Such information may be included as part of the standards or may 

be included in documents generated by 

the State in response to the Water 

Quality Planning and Management 

Regulations (40 CFR part 35). 

(b) Form of criteria: In establishing 

criteria, States should: 

(1) Establish numerical values based 

on: 

(i) 304(a) Guidance; or 

(ii) 304(a) Guidance modified to reflect site-specific conditions; or 

(iii) Other scientifically defensible 

methods; 

(2) Establish narrative criteria or criteria based upon biomonitoring methods where numerical criteria cannot be 

established or to supplement numerical 

criteria. 

§ 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, after 

full satisfaction of the intergovernmental coordination and public participation provisions of the State’s continuing planning process, that allowing 

lower water quality is necessary to accommodate important economic or social development in the area in which 

the waters are located. In allowing 

such degradation or lower water quality, the State shall assure water quality adequate to protect existing uses 

fully. Further, the State shall assure 

that there shall be achieved the highest statutory and 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 and 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. 

§ 131.13 General policies. 

States may, at their discretion, include in their State standards, policies 

generally affecting their application 

and implementation, such as mixing 

zones, low flows and variances. Such 

policies are subject to EPA review and 

approval. 

Subpart C—Procedures for Review 

and Revision of Water Quality 

Standards 

§ 131.20 State review and revision of 

water quality standards. 

(a) State review. The State shall from 

time to time, but at least once every 

three years, hold public hearings for 

the purpose of reviewing applicable 

water quality standards and, as appropriate, modifying and adopting standards. Any water body segment with 

water quality standards that do not include the uses specified in section 

101(a)(2) of the Act shall be re-examined every three years to determine if 

any new information has become available. If such new information indicates 

that the uses specified in section 


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§ 131.21 40 CFR Ch. I (7–1–08 Edition) 

101(a)(2) of the Act are attainable, the 

State shall revise its standards accordingly. Procedures States establish for 

identifying and reviewing water bodies 

for review should be incorporated into 

their Continuing Planning Process. 

(b) Public participation. The State 

shall hold a public hearing for the purpose of reviewing water quality standards, in accordance with provisions of 

State law, EPA’s water quality management regulation (40 CFR 130.3(b)(6)) 

and public participation regulation (40 

CFR part 25). The proposed water quality standards revision and supporting 

analyses shall be made available to the 

public prior to the hearing. 

(c) Submittal to EPA. The State shall 

submit the results of the review, any 

supporting analysis for the use attainability analysis, the methodologies 

used for site-specific criteria development, any general policies applicable 

to water quality standards and any revisions of the standards to the Regional Administrator for review and 

approval, within 30 days of the final 

State action to adopt and certify the 

revised standard, or if no revisions are 

made as a result of the review, within 

30 days of the completion of the review. 

§ 131.21 EPA review and approval of 

water quality standards. 

(a) After the State submits its officially adopted revisions, the Regional 

Administrator shall either: 

(1) Notify the State within 60 days 

that the revisions are approved, or 

(2) Notify the State within 90 days 

that the revisions are disapproved. 

Such notification of disapproval shall 

specify the changes needed to assure 

compliance with the requirements of 

the Act and this regulation, and shall 

explain why the State standard is not 

in compliance with such requirements. 

Any new or revised State standard 

must be accompanied by some type of 

supporting analysis. 

(b) The Regional Administrator’s approval or disapproval of a State water 

quality standard shall be based on the 

requirements of the Act as described in 

§§ 131.5 and 131.6, and, with respect to 

Great Lakes States or Tribes (as defined in 40 CFR 132.2), 40 CFR part 132. 

(c) How do I determine which water 

quality standards are applicable for purposes of the Act? You may determine 

which water quality standards are applicable water quality standards for 

purposes of the Act from the following 

table: 

If— Then— Unless or until— In which case—

(1) A State or authorized Tribe 

has adopted a water quality 

standard that is effective 

under State or Tribal law 

and has been submitted to 

EPA before May 30, 2000...

. . . the State or Tribe’s water 

quality standard is the applicable water quality standard for purposes of the 

Act . . .

. . . EPA has promulgated a 

more stringent water quality 

standard for the State or 

Tribe that is in effect...

. . . the EPA-promulgated 

water quality standard is 

the applicable water quality 

standard for purposes of 

the Act until EPA withdraws 

the Federal water quality 

standard. 

(2) A State or authorized Tribe 

adopts a water quality standard that goes into effect 

under State or Tribal law on 

or after May 30, 2000...

. . . once EPA approves that 

water quality standard, it 

becomes the applicable 

water quality standard for 

purposes of the Act...

. . . EPA has promulgated a 

more stringent water quality 

standard for the State or 

Tribe that is in effect...

. . . the EPA promulgated 

water quality standard is 

the applicable water quality 

standard for purposes of 

the Act until EPA withdraws 

the Federal water quality 

standard. 

(d) When do I use the applicable water 

quality standards identified in paragraph 

(c) above? Applicable water quality 

standards for purposes of the Act are 

the minimum standards which must be 

used when the CWA and regulations 

implementing the CWA refer to water 

quality standards, for example, in identifying impaired waters and calculating TMDLs under section 303(d), developing NPDES permit limitations 

under section 301(b)(1)(C), evaluating 

proposed discharges of dredged or fill 

material under section 404, and in 

issuing certifications under section 401 

of the Act. 

(e) For how long does an applicable 

water quality standard for purposes of the 

Act remain the applicable water quality 

standard for purposes of the Act? A State 


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Environmental Protection Agency § 131.32 

or authorized Tribe’s applicable water 

quality standard for purposes of the 

Act remains the applicable standard 

until EPA approves a change, deletion, 

or addition to that water quality 

standard, or until EPA promulgates a 

more stringent water quality standard. 

(f) How can I find out what the applicable standards are for purposes of the 

Act? In each Regional office, EPA 

maintains a docket system for the 

States and authorized Tribes in that 

Region, available to the public, identifying the applicable water quality 

standards for purposes of the Act. 

[48 FR 51405, Nov. 8, 1983, as amended at 60 

FR 15387, Mar. 23, 1995; 65 FR 24653, Apr. 27, 

2000] 

§ 131.22 EPA promulgation of water 

quality standards. 

(a) If the State does not adopt the 

changes specified by the Regional Administrator within 90 days after notification of the Regional Administrator’s 

disapproval, the Administrator shall 

promptly propose and promulgate such 

standard. 

(b) The Administrator may also propose and promulgate a regulation, applicable to one or more States, setting 

forth a new or revised standard upon 

determining such a standard is necessary to meet the requirements of the 

Act. 

(c) In promulgating water quality 

standards, the Administrator is subject 

to the same policies, procedures, analyses, and public participation requirements established for States in these 

regulations. 

Subpart D—Federally Promulgated 

Water Quality Standards 

§ 131.31 Arizona. 

(a) [Reserved] 

(b) The following waters have, in addition to the uses designated by the 

State, the designated use of fish consumption as defined in R18–11–101 

(which is available from the Arizona 

Department of Environmental Quality, 

Water Quality Division, 3033 North 

Central Ave., Phoenix, AZ 85012): 

COLORADO MAIN STEM RIVER 

BASIN: 

Hualapai Wash 

MIDDLE GILA RIVER BASIN: 

Agua Fria River (Camelback Road to 

Avondale WWTP) 

Galena Gulch 

Gila River (Felix Road to the Salt 

River) 

Queen Creek (Headwaters to the Superior WWTP) 

Queen Creek (Below Potts Canyon) 

SAN PEDRO RIVER BASIN: 

Copper Creek 

SANTA CRUZ RIVER BASIN: 

Agua Caliente Wash 

Nogales Wash 

Sonoita Creek (Above the town of 

Patagonia) 

Tanque Verde Creek 

Tinaja Wash 

Davidson Canyon 

UPPER GILA RIVER BASIN 

Chase Creek 

(c) To implement the requirements of 

R18–11–108.A.5 with respect to effects of 

mercury on wildlife, EPA (or the State 

with the approval of EPA) shall implement a monitoring program to assess 

attainment of the water quality standard. 

(Sec. 303, Federal Water Pollution Control 

Act, as amended, 33 U.S.C. 1313, 86 Stat. 816 

et seq., Pub. L. 92–500; Clean Water Act, Pub. 

L. 92–500, as amended; 33 U.S.C. 1251 et seq.) 

[41 FR 25000, June 22, 1976; 41 FR 48737, Nov. 

5, 1976. Redesignated and amended at 42 FR 

56740, Oct. 28, 1977. Further redesignated and 

amended at 48 FR 51408, Nov. 8, 1983; 61 FR 

20693, May 7, 1996; 68 FR 62744, Nov. 6, 2003] 

§ 131.32 Pennsylvania. 

(a) Antidegradation policy. This 

antidegradation policy shall be applicable to all waters of the United States 

within the Commonwealth of Pennsylvania, including wetlands. 

(1) Existing in-stream 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 

exceeds 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 Commonwealth 

finds, after full satisfaction of the 

inter-governmental coordination and 

public participation provisions of the 

Commonwealth’s continuing planning 

process, that allowing lower water 


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