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Supplemental Information for

Water Quality Standards Regulatory Revisions Final Rule

Comparison of Final Rule Language and Proposed Rule Language

NOTE: THE FOLLOWING REGULATORY TEXT IS A COMPARISON OF THE 

PROPOSED RULE LANGUAGE AND THE FINAL RULE LANGUAGE. STRIKEOUTS 

INDICATE DELETION OF PROPOSED TEXT AND UNDERLINES INDICATE 

ADDITION OF FINAL RULE TEXT. 

THE TEXT BELOW SHOWS ONLY THE PROVISIONS AFFECTED BY THE 

REVISIONS IN THIS RULEMAKING. IT DOES NOT REPRESENT THE ENTIRETY 

OF THE PART 131 REGULATION.

PART 131—WATER QUALITY STANDARDS

§ 131.2 Purpose.

A water quality standard defines the water quality goals of a water body, or portion thereof, 

by designating the use or uses to be made of the water and by setting criteria that protect the 

designated uses. * * *

* * * * *

§ 131.3 Definitions.

* * * * *

(h) Water quality limited segment means any segment where it is known that water quality 

does not meet applicable water quality standards, and/or is not expected to meet applicable water 

quality standards, even after the application of the technology-based effluent limitations required 

by sections 301(b) and 306 of the Act.

* * * * *

(j) States include: The 50 States, the District of Columbia, Guam, the Commonwealth of 

Puerto Rico, Virgin Islands, American Samoa, the Commonwealth of the Northern Mariana 

Islands, and Indian Tribes that EPA determines to be eligible for purposes of water quality 

standards program.

* * * * *

(m) Highest attainable use is the modified aquatic life, wildlife, and/or recreation use that is both 

closest to the uses specified in section 101(a)(2) of the Act and attainable, as determined using 

best available data and information through a use attainability analysis defined in § 131.3(g)

based on the evaluation of the factor(s) in § 131.10(g) that preclude(s) attainment of the use and 

any other information or analyses that were used to evaluate attainability. There is no required 

highest attainable use where the State demonstrates the relevant use specified in section 

101(a)(2) of the Act and sub-categories of such a use are not attainable.
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(n) Practicable, in the context of § 131.12(a)(2)(ii), means technologically possible, able to be 

put into practice, and economically viable. 

(o) A water quality standards variance (WQS variance) is a time-limited designated use and 

criterion for a specific pollutant(s) or water quality parameter(s) that reflect the highest attainable 

condition during the term of the WQS variance. 

(p) Pollutant Minimization Program, in the context § 131.14, is a structured set of activities to 

improve processes and pollutant controls that will prevent and reduce pollutant loadings.

(q) Non-101(a)(2) use is any use unrelated to the protection and propagation of fish, shellfish, 

wildlife or recreation in or on the water. 

§ 131.5 EPA authority.

(a) * * *

(1) Whether the State has adopted designated water uses which that are consistent with the 

requirements of the Clean Water Act;

(2) Whether the State has adopted criteria that protect the designated water uses based on 

sound scientific rationale based on sound scientific rationale consistent with § 131.11;

(3) Whether the State has adopted an antidegradation policy consistent with § 131.12(a), and 

if the State has chosen to adopt implementation methods, whether those any State adopted 

antidegradation implementation methods are consistent with § 131.12;

(4) Whether any State adopted WQS variance is consistent with § 131.14;

(5) Whether any State adopted provision authorizing the use of schedules of compliance for 

water quality-based effluent limits in NPDES permits is consistent with § 131.15;

(46)Whether the State has followed its applicable legal procedures for revising or adopting 

standards; 

(57) Whether the State standards which do not include the uses specified in section 101(a)(2) 

of the Act are based upon appropriate technical and scientific data and analyses, and 

(68) Whether the State submission meets the requirements included in § 131.6 of this part 

and, for Great Lakes States or Great Lakes Tribes (as defined in 40 CFR 132.2) to conform to 

section 118 of the Act, the requirements of 40 CFR part 132. 

(b) If EPA determines that the State's or Tribe's water quality standards are consistent with the 

factors listed in paragraphs (a)(1) through (a)(68) of this section, EPA approves the standards. 

EPA must disapprove the State's or Tribe's water quality standards and promulgate Federal 

standards under section 303(c)(4), and for Great Lakes States or Great Lakes Tribes under 

section 118(c)(2)(C) of the Act, if State or Tribal adopted standards are not consistent with the 

factors listed in paragraphs (a)(1) through (a)(68) of this section. EPA may also promulgate a 

new or revised standard when necessary to meet the requirements of the Act.

* * * * *

§ 131.10 Designation of uses.
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(a) Each State must specify appropriate water uses to be achieved and protected. 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. If adopting 

new or revised designated uses other than the uses specified in section 101(a)(2) of the Act, or 

removing designated uses, States must submit documentation justifying how their consideration 

of the use and value of water for those uses listed in this paragraph appropriately supports the 

State’s action. A use attainability analysis may be used to satisfy this requirement. In no case 

shall a State adopt waste transport or waste assimilation as a designated use for any waters of the 

United States.

* * * * *

(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.

[Removed and Reserved]

* * * * *

(g) Pursuant to § 131.10(j), States may designate a use, or remove a use or a sub-category of a 

use as long as the action does not remove protection for that is not an existing use, and if the 

State can demonstrate conducts a use attainability analysis as specified in § 131.10(j) that 

demonstrates attaining the use is not feasible because of one of the six factors in this paragraph. 

If a State adopts a new or revised water quality standards standard based on a required use 

attainability analysis, the State shall also adopt the highest attainable use, as defined in § 

131.3(m). and the criteria to protect that use. To meet this requirement, States may, at their 

discretion, utilize their current use categories or subcategories, develop new use categories or 

subcategories, or adopt another use which may include a location-specific use.

* * * * *

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

131.10(g), whenever:

(1) The State designates for the first time, or has previously designated uses for a water 

body for the first time, 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 section 101(a)(2) of 

the Act, to remove a sub-category of such a use, or to designate a sub-category of such a use 

which that requires criteria less stringent than previously applicable.

(k) A State is not required to conduct a use attainability analysis whenever:

(1) The State designates for the first time, or has previously designated uses for a water 

body for the first time , uses that include the uses specified in section 101(a)(2) of the Act, or 

(2) The State wishes to remove a designated use that is not specified in section 101(a)(2) 

of the Act, or designate designates a sub-category of a use specified in section 101(a)(2) of the 

Act which that requires criteria at least as stringent as previously applicable., or
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(3) The State wishes to remove or revise a designated use that is a non-101(a)(2) use. In 

this instance, as required by § 131.10(a), the State must submit documentation justifying how its 

consideration of the use and value of water for those uses listed in § 131.10(a) appropriately 

supports the State’s action, which may be satisfied through a use attainability analysis.

§ 131.11 Criteria.

(a) * * *

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

identify specific 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 130).

(b) Form of criteria: In establishing criteria, States should:

* * * * *

§ 131.12 Antidegradation Policy policy and Implementation implementation Methods

methods.

(a) The State shall develop and adopt a statewide antidegradation policy. The 

antidegradation policy shall, at a minimum, be consistent with the following:

* * * * *

(2) Where the quality of the waters exceed exceeds levels necessary to support the protection 

and 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 ensure assure water quality adequate to protect 

existing uses fully. Further, the sState shall ensure 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.

(i) The State may identify waters for the protections describe in (a)(2) of this section on a 

parameter-by-parameter basis or on a water body-by-water body basis. Where the State identifies 

waters for antidegradation protection on a water body-by-water body basis, the State shall 

provide an opportunity for public involvement in any decisions about whether the protections 

described in (a)(2) of this section will be afforded to a water body, and the factors considered 

when making those decisions. Further, the State shall not exclude a water body from the 

protections described in (a)(2) of this section solely because water quality does not exceed levels 

necessary to support all of the uses specified in section 101(a)(2) of the Act.
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(ii) Before allowing any lowering of high water quality, pursuant to (a)(2) of this section, 

the State shall find, after an analysis of alternatives, that such a lowering is necessary to 

accommodate important economic or social development in the area in which the waters are 

located. The analysis of alternatives shall evaluate a range of practicable alternatives that would 

prevent or lessen the degradation associated with the proposed activity. When the analysis of 

alternatives identifies one or more practicable alternatives, the State shall only find that a 

lowering is necessary if one such alternative is selected for implementation.

* * * * *

(b) The State shall develop and make available to the public statewide methods for 

implementing the antidegradation policy that are, at a minimum, consistent with the State’s 

policy and with adopted pursuant to paragraph (a) of this section. The State shall provide an 

opportunity for public involvement during the development and any subsequent revisions of the 

implementation methods, and shall make the methods available to the public. A State’s 

antidegradation implementation methods shall be designed to achieve antidegradation protection 

consistent with paragraph (a) of this section. Such methods must ensure that:

(1) High quality waters are identified on a parameter-by-parameter basis or on a water bodyby-water body basis at the State’s discretion, but must not exclude any water body from high 

quality water protection solely because not all of the uses specified in CWA section 101(a)(2) are 

attained; and

(2) The State will only make a finding that lowering high water quality is necessary, pursuant 

to paragraph (a)(2) of this section, after conducting an alternatives analysis that evaluates a range 

of non-degrading and minimally degrading practicable alternatives that have the potential to 

prevent or minimize the degradation associated with the proposed activity. If the State can 

identify any practicable alternatives, the State must choose one of those alternatives to 

implement when authorizing a lowering of high water quality. 

§ 131.14 Water quality standards variances.

States may, at their discretion, grant adopt WQS variances as defined in § 131.3(o). Such a 

WQS variance is subject to the provisions of this section and public participation requirements at 

§ 131.20(b). A water quality standards variance (WQS variance) is a time-limited designated use 

and criterion for a specified pollutant(s), permittee(s), and/or water body or waterbody 

segment(s) that reflect the highest attainable condition during the specified time period. WQS 

variances are water quality standards standard subject to EPA review and approval or 

disapproval. and must be consistent with this section. Any such WQS variances adopted after 

[effective date of the final rule] must be consistent with this regulatory section.

(a) Applicability:

(1) All applicable WQS not specifically addressed by the WQS variance remain 

applicable. A WQS variance may be adopted for a permittee(s) or water 

body/waterbody segment(s) specified in the WQS variance. 

(2) (i) Where a state State adopts a WQS variance, the State regulations must 

continue to reflect retain, in its standards, the underlying designated use and 

criterion addressed by the WQS variance, unless the State adopts and EPA 

approves a revision to the underlying designated use and criterion consistent with 
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§ 131.10 or and § 131.11. All other applicable standards not specifically 

addressed by the WQS variance remain applicable.

(3) (ii) The interim requirements specified in the A WQS variance are in effect during 

the term of the WQS variance and apply for CWA section 402 permitting 

purposes and in, once adopted by the State and approved by EPA, shall be the 

applicable standard for purposes of the Act under 40 CFR 131.21(d)-(e), for the 

purposes of developing NPDES permit limits and requirements under 

301(b)(1)(C), where appropriate consistent with (a)(1) of this section. States and 

other certifying entities may also use an approved WQS variance when issuing 

certifications under section 401 of the Act. for the permittee(s), pollutant(s), 

and/or water body or waterbody segment(s) covered by the WQS variance. For 

these limited purposes,the interim requirements will be the standards applicable

for purposes of the CWA under 40 CFR 131.21(c)-(e).

(4)(3) A WQS variance shall State may not be granted adopt WQS variances if the 

designated use and criterion addressed by the proposed WQS variance can be 

achieved by implementing technology-based effluent limits required under 

sections 301(b) and 306 of the Act.

(b) Submission Requirements for Submission to EPA:

(1) A WQS variance must specify the following include:

(i) Identifying information: A WQS variance must identify Identification of 

the pollutant(s), permittee(s), and/or water quality parameter(s), and the 

water body or /waterbody segment(s) to which the WQS variance 

applies. Discharger(s)-specific WQS variances must also identify the 

permittee(s) subject to the WQS variance.

(ii) WQS that apply during a variance for CWA section 402 permitting 

purposes and in issuing certifications under section 401 of the Act: A 

WQS variance must specify: The requirements that apply throughout the 

term of the WQS variance. The requirements shall represent the highest 

attainable condition of the water body or waterbody segment applicable 

throughout the term of the WQS variance based on the documentation 

required in (b)(2) of this section. The requirements shall not result in any 

lowering of the currently attained ambient water quality, unless a WQS 

variance is necessary for restoration activities, consistent with paragraph 

(b)(2)(i)(A)(2) of this section. The State must specify the highest 

attainable condition of the water body or waterbody segment as a 

quantifiable expression that is one of the following: 

(A) The highest attainable interim use and interim numeric criterion, or

For discharger(s)-specific WQS variances:

(1) The highest attainable interim criterion, or

(2) The interim effluent condition that reflects the greatest

pollutant reduction achievable, or
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(3) If no additional feasible pollutant control technology can be 

identified, the interim criterion or interim effluent condition 

that reflects the greatest pollutant reduction achievable with the 

pollutant control technologies installed at the time the State 

adopts the WQS variance, and the adoption and 

implementation of a Pollutant Minimization Program.

(B) An interim numeric effluent condition that reflects the highest 

attainable condition for a specific permittee(s) during the term of the

variance. Neither (A) nor (B) of this paragraph shall result in any 

lowering of the currently attained water quality unless a time-limited 

lowering of water quality is necessary during the term of a variance for 

restoration activities, consistent with paragraph (b)(2)(ii) of this section.

For WQS variances applicable to a water body or waterbody segment:

(1) The highest attainable interim use and interim criterion, or

(2) If no additional feasible pollutant control technology can be 

identified, the interim use and interim criterion that reflects the 

greatest pollutant reduction achievable with the pollutant 

control technologies installed at the time the State adopts the 

WQS variance, and the adoption and implementation of a 

Pollutant Minimization Program.

(iii) A statement providing that the requirements of the WQS variance are 

either the highest attainable condition identified at the time of the 

adoption of the WQS variance, or the highest attainable condition later 

identified during any reevaluation consistent with (b)(1)(v) of this 

section, whichever is more stringent.

(iv) (iii) Date the WQS variance will expire: States must include an 

expiration date for all WQS variances, consistent with paragraph (b)(2) 

of this section. WQS variances The term of the WQS variance, 

expressed as an interval of time from the date of EPA approval or a 

specific date. The term of the WQS variance must only be as long as 

necessary to achieve the highest attainable condition short as possible 

but expire no later than 10 years after state adoption and consistent with 

the demonstration provided in paragraph (b)(2) of this section. The State 

may adopt a subsequent WQS variance consistent with this section.

(v) For a WQS variance with a term greater than five years, a specified 

frequency to reevaluate the highest attainable condition using all existing 

and readily available information and a provision specifying how the 

State intends to obtain public input on the reevaluation. Such 

reevaluations must occur no less frequently than every five years after

EPA approval of the WQS variance and the results of such reevaluation 

must be submitted to EPA within 30 days of completion of the 

reevaluation.
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(vi) A provision that the WQS variance will no longer be the applicable 

water quality standard for purposes of the Act if the State does not 

conduct a reevaluation consistent with the frequency specified in the 

WQS variance or the results are not submitted to EPA as required by 

(b)(1)(v) of this section.

(2) The supporting documentation must include:

(i) The State must submit a demonstration justifying Documentation 

demonstrating the need for a WQS variance. 

(2)(A) For a WQS variance to a use specified in section 101(a)(2) of the 

Act or a sub-category of such use, the State must submit a demonstration

demonstrate that attaining the designated use and criterion is not feasible 

during the term of the WQS variance because:

(i)(1) One of the factors listed in § 131.10(g) applies is met, or 

(ii)(2) Actions necessary to facilitate lake, wetland, or stream 

restoration through dam removal or other significant wetland or 

stream reconfiguration activities preclude attainment of the 

designated use and criterion while the actions are being 

implemented.

(3)(B) For a WQS variance to a non-101(a)(2) use, the State must submit 

documentation justifying how its consideration of the use and value of 

the water for those uses listed in § 131.10(a) appropriately supports the 

WQS variance and term. A demonstration consistent with (b)(2)(i)(A) of 

this section may be used to satisfy this requirement.

(ii) Documentation demonstrating that the term of the WQS variance is only as 

long as necessary to achieve the highest attainable condition. Such documentation 

must justify the term of the WQS variance by describing the pollutant control 

activities to achieve the highest attainable condition, including those activities 

identified through a Pollutant Minimization Program, which serve as milestones 

for the WQS variance.

(iii) In addition to (i) and (ii) of this section, for a WQS variance that applies to a 

water body or waterbody segment:

(3)(A) Identification and documentation of For a waterbody variance, 

the state must identify and document any cost-effective and reasonable 

best management practices for nonpoint source controls related to the 

pollutant(s) or water quality parameter(s) and location(s) water body or 

waterbody segment(s) specified in the WQS variance that could be 

implemented to make progress towards attaining the underlying 

designated use and criterion. A State must provide public notice and 

comment for any such documentation. 

(B) Any subsequent WQS variance for a water body or waterbody 

segment must include documentation of whether and to what extent best 

management practices for nonpoint source controls were implemented to 

address the pollutant(s) or water quality parameter(s) subject to the 

WQS variance and the water quality progress achieved.
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(c) Implementing WQS variances in NPDES permits: Consistent with paragraph (a)(2)(ii) of 

this section, a A WQS variance serves as the basis of a water quality-based effluent limit 

included in a applicable water quality standard for implementing NPDES permit 

permitting requirements pursuant to § 122.44(d) for the period term of the WQS variance

is in effect. Any limitations required and requirements necessary to implement the WQS 

variance shall be included as enforceable conditions of the NPDES permit for the 

permittee(s) subject to the WQS variance. 

(d) WQS variance renewals: EPA may approve a WQS variance renewal if the State meets 

the requirements of this section and provides documentation of the actions taken to meet 

the requirements of the previous WQS variance. For a waterbody WQS variance renewal, 

the state must also provide documentation of whether and to what extent BMPs have 

been implemented to address the pollutant(s) subject to the WQS variance and the water 

quality progress achieved during the WQS variance period. Renewal of a WQS variance 

may be disapproved if the applicant did not comply with the conditions of the original 

WQS variance, or otherwise does not meet the requirements of this section.

§ 131.15 Compliance schedule authorizing provisions. Authorizing the use of 

schedules of compliance for water quality-based effluent limits in NPDES permits.

A If a State may, at its discretion and consistent with state law, intends to authorize the use of 

schedules of compliance for water quality-based effluent limits (WQBELs) in NPDES permits, 

the State must adopt by including a permit compliance schedule authorizing provision. in its 

water quality standards or implementing regulations. Any s Such authorizing provision is a 

water quality standard subject to EPA review and approval under section 303 of the Act and 

must be consistent with sections 502(17) and 301(b)(1)(C) of the Act. Individual compliance 

schedules issued pursuant to such authorizing provisions are not themselves water quality 

standards. Individual compliance schedules must be consistent with CWA section 502(17), the 

state’s EPA-approved compliance schedule authorizing provision, and the requirements of §§ 

122.2 and 122.47.

§ 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 3 years, hold public 

hearings for the purpose of reviewing applicable water quality standards adopted pursuant to §§ 

131.10—131.15 and Federally promulgated water quality standards and, as appropriate, 

modifying and adopting standards; in particular,. The State shall also re-examine any water body

waterbody 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 3 years to determine if any new information has 

become available. If such new information indicates that the uses specified in section 101(a)(2) 

of the Act are attainable, the State shall revise its standards accordingly. Similarly, a State shall 

re-examine its water quality criteria to determine if any criteria should be revised in light of any 

new or updated CWA section 304(a) criteria recommendations to assure that designated uses 

continue to be protected. Procedures States establish for identifying and reviewing water bodies 

for review should be incorporated into their Continuing Planning Process. In addition, if a State 
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does not adopt new or revised criteria for parameters for which EPA has published new or 

updated CWA section 304(a) criteria recommendations, then the State shall provide an 

explanation when it submits the results of its triennial review to the Regional Administrator 

consistent with CWA section 303(c)(1) and the requirements of § 131.20(c). 

(b) Public participation. The State shall hold one or more public hearings for the purpose 

of reviewing or water quality standards as well as when revising water quality standards, in 

accordance with provisions of State law and EPA’s 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.

* * * * *

§ 131.22 EPA promulgation of water quality standards.

* * * * *

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

more States navigable waters, setting forth a new or revised standard upon determining such a 

standard is necessary to meet the requirements of the Act. To constitute an Administrator’s 

determination that a new or revised standard is necessary to meet the requirements of the Act, 

such determination must:

(1) Be signed by the Administrator or his or her duly authorized delegate, and 

(2) Contain a statement that the document constitutes an Administrator’s determination under 

section 303(c)(4)(B) of the Act.

* * * * *

§ 131.34 Kansas.

* * * * *

(c) Water quality standard variances. The Regional Administrator, EPA Region 7, is 

authorized to grant variances from the water quality standards in paragraphs (a) and (b) of this 

section where the requirements of § 131.14 are met. 

§ 131.40 Puerto Rico.

* * * * *

(c) Water quality standard variances. The Regional Administrator, EPA Region 2, is 

authorized to grant variances from the water quality standards in paragraphs (a) and (b) of this 

section where the requirements of § 131.14 are met.