### 407 Environmental Protection Agency § 131.10

which may include the administration of programs and services authorized by
the Indian Self-Determination and Education Assistance Act (25 U.S.C. 450 et seq. ), the Indian Mineral Development Act (25 U.S.C. 2101 et seq. ), or theIndian Sanitation Facility Construction Activity Act (42 U.S.C. 2004a);

(ii) A list of existing environmentalor public health programs administered by the Tribal governing body and copies of related Tribal laws, policies, and regulations;

(iii) A description of the entity (or entities) which exercise the executive, legislative, and judicial functions of the Tribal government;

(iv) A description of the existing, or proposed, agency of the Indian Tribewhich will assume primary responsibility for establishing, reviewing, implementing and revising water quality standards;

(v) A description of the technical and administrative capabilities of the staff to administer and manage an effective water quality standards program or a plan which proposes how the Tribe will acquire additional administrative andtechnical expertise. The plan must address how the Tribe will obtain the funds to acquire the administrative and technical expertise.

(5) Additional documentation required by the Regional Administrator which, in the judgment of the Regional Administrator, is necessary to support a Tribal application.

(6) Where the Tribe has previously qualified for eligibility or ‘‘ treatment
as a state ’’ under a Clean Water Act or Safe Drinking Water Act program, the Tribe need only provide the required
information which has not been submitted in a previous application.

(c) Procedure for processing an Indian Tribe ’ s application.

(1) The Regional Administrator shall process an application of an Indian Tribe submitted pursuant to § 131.8(b) in a timely manner. He shall promptly notify the Indian Tribe of receipt of the application.

(2) Within 30 days after receipt of the
Indian Tribe ’ s application the RegionalAdministrator shall provide appropriate notice. Notice shall:

(i) Include information on the substance and basis of the Tribe ’ s assertion of authority to regulate the quality of reservation waters; and

(ii) Be provided to all appropriate governmental entities.

(3) The Regional Administrator shall provide 30 days for comments to be submitted on the Tribal application.
Comments shall be limited to the
Tribe ’ s assertion of authority.

(4) If a Tribe ’ s asserted authority is subject to a competing or conflicting claim, the Regional Administrator,after due consideration, and in consideration of other comments received,
shall determine whether the Tribe has adequately demonstrated that it meets the requirements of § 131.8(a)(3).

(5) Where the Regional Administrator
determines that a Tribe meets the requirements of this section, he shall promptly provide written notification
to the Indian Tribe that the Tribe is
authorized to administer the Water Quality Standards program.

[56 FR 64895, Dec. 12, 1991, as amended at 59 FR 64344, Dec. 14, 1994]



### Subpart B

— Establishment of Water Quality Standards

§ 131.10 Designation of uses.

(a) Each State must specify appropriate water uses to be achieved andprotected. The classification of the waters of the State must take into consideration the use and value of water for public water supplies, protection and propagation of fish, shellfish and wildlife, recreation in and on the water, agricultural, industrial, and other purposes including navigation. In no case shall a State adopt waste transport or waste assimilation as a designated use for any waters of the
United States.

(b) In designating uses of a water body and the appropriate criteria for those uses, the State shall take intoconsideration the water quality standards of downstream waters and shall ensure that its water quality standardsprovide for the attainment and maintenance of the water quality standards of
downstream waters.

(c) States may adopt sub-categoriesof a use and set the appropriate criteria to reflect varying needs of such sub-categories of uses, for instance, to


### 408 40 CFR Ch. I (7

– 1

–08 Edition) § 131.11

differentiate between cold water and
warm water fisheries.

(d) At a minimum, uses are deemed attainable if they can be achieved bythe imposition of effluent limits required under sections 301(b) and 306 of
the Act and cost-effective and reasonable best management practices for nonpoint source control.

(e) Prior to adding or removing any use, or establishing sub-categories of a use, the State shall provide notice and an opportunity for a public hearing
under § 131.20(b) of this regulation.

(f) States may adopt seasonal uses as an alternative to reclassifying a waterbody or segment thereof to uses requiring less stringent water quality criteria. If seasonal uses are adopted,water quality criteria should be adjusted to reflect the seasonal uses,however, such criteria shall not preclude the attainment and maintenance of a more protective use in another

season.

(g) States may remove a designated
use which is not an existing use, as defined in § 131.3, or establish sub-categories of a use if the State can demonstrate that attaining the designated
use is not feasible because:

(1) Naturally occurring pollutant concentrations prevent the attainment of the use; or

(2) Natural, ephemeral, intermittent
or low flow conditions or water levelsprevent the attainment of the use, unless these conditions may be compensated for by the discharge of sufficient volume of effluent dischargeswithout violating State water conservation requirements to enable uses to be met; or

(3) Human caused conditions orsources of pollution prevent the attainment of the use and cannot be remedied or would cause more environmental damage to correct than to leave in place; or

(4) Dams, diversions or other types of hydrologic modifications preclude theattainment of the use, and it is not feasible to restore the water body to its original condition or to operate suchmodification in a way that would result in the attainment of the use; or

(5) Physical conditions related to the natural features of the water body, such as the lack of a proper substrate, cover, flow, depth, pools, riffles, and the like, unrelated to water quality, preclude attainment of aquatic life protection uses; or

(6) Controls more stringent than those required by sections 301(b) and
306 of the Act would result in substantial and widespread economic and social impact.

(h)States may not remove designated
uses if:

(1) They are existing uses, as defined
in § 131.3, unless a use requiring more stringent criteria is added; or

(2) Such uses will be attained by implementing effluent limits required under sections 301(b) and 306 of the Act and by implementing cost-effective and reasonable best management practices for nonpoint source control.

(i) Where existing water quality standards specify designated uses less than those which are presently being attained, the State shall revise its standards to reflect the uses actually being attained.

(j) A State must conduct a use attainability analysis as described in § 131.3(g) whenever:

(1) The State designates or has designated uses that do not include the uses specified in section 101(a)(2) of the Act, or

(2) The State wishes to remove a designated use that is specified in section101(a)(2) of the Act or to adopt subcategories of uses specified in section 101(a)(2) of the Act which require less stringent criteria.

(k) A State is not required to conduct a use attainability analysis under this regulation whenever designating uses which include those specified in section 101(a)(2) of the Act.

§ 131.11 Criteria.

(a) Inclusion of pollutants: (1) Statesmust adopt those water quality criteria that protect the designated use.
Such criteria must be based on sound
scientific rationale and must contain sufficient parameters or constituentsto protect the designated use. For waters with multiple use designations,the criteria shall support the most sensitive use.

(2) Toxic pollutants. States must review water quality data and information on discharges to identify specific


### 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 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 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