### 409 Environmental Protection Agency § 131.20

water bodies where toxic pollutantsmay 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 oftoxic pollutants on water quality limited segments based on such narrativecriteria. 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 toprotect the existing uses shall be maintained and protected.

(2) Where the quality of the waters exceed levels necessary to supportpropagation of fish, shellfish, and wildlife and recreation in and on the water, that quality shall be maintained and protected unless the State finds, afterfull satisfaction of the intergovernmental coordination and public participation provisions of the State ’ s continuing planning process, that allowinglower water quality is necessary to accommodate important economic or social development in the area in which the waters are located. In allowingsuch degradation or lower water quality, the State shall assure water quality adequate to protect existing uses fully. Further, the State shall assurethat there shall be achieved the highest statutory and regulatory requirements for all new and existing pointsources 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 waterquality 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 applicablewater quality standards and, as appropriate, modifying and adopting standards. Any water body segment withwater quality standards that do not include the uses specified in section101(a)(2) of the Act shall be re-examined every three years to determine ifany new information has become available. If such new information indicates that the uses specified in section


### 410 40 CFR Ch. I (7

– 1

– 08 Edition) § 131.21

101(a)(2) of the Act are attainable, theState 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 Stateshall 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 (40CFR 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, anysupporting analysis for the use attainability analysis, the methodologiesused for site-specific criteria development, any general policies applicableto 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 toGreat Lakes States or Tribes (as defined in 40 CFR 132.2), 40 CFR part 132.

(c) How do I determine which waterquality standards are applicable for purposes of the Act? You may determinewhich 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, 200 0... . . . the State or Tribe ’ s waterquality 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 effec t... . . . 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, 200 0... . . . once EPA approves that water quality standard, it becomes the applicable water quality standard for purposes of the Ac t... . . . EPA has promulgated a more stringent water quality standard for the State or Tribe that is in effec t... . . . 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 waterquality 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


### 411 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 thatRegion, 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 thechanges 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 upondetermining such a standard is necessary to meet the requirements of the Act.

(c) In promulgating water quality standards, the Administrator is subjectto 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 theState, 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 Statewith the approval of EPA) shall implement a monitoring program to assessattainment 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. Thisantidegradation policy shall be applicable to all waters of the United Stateswithin the Commonwealth of Pennsylvania, including wetlands.

(1) Existing in-stream uses and thelevel 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 supportpropagation 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