---
kind: "section"
citation: "33 U.S.C. § 1313"
title: "33"
title_heading: "Navigation and Navigable Waters"
number: "1313"
heading: "Water quality standards and implementation plans"
release: "119-102"
date: "2026-07-12"
url: "https://uscodex.org/usc/33/1313"
units:
  - "Chapter 26 — Water Pollution Prevention and Control"
  - "Subchapter III — Standards and Enforcement"
---

# §1313. Water quality standards and implementation plans

- (a) **Existing water quality standards—**
  - (1) In order to carry out the purpose of this chapter, any water quality standard applicable to interstate waters which was adopted by any [State](/usc/33/1362.md?p=3) and submitted to, and approved by, or is awaiting approval by, the Administrator pursuant to this Act as in effect immediately prior to October 18, 1972, shall remain in effect unless the Administrator determined that such standard is not consistent with the applicable requirements of this Act as in effect immediately prior to October 18, 1972. If the Administrator makes such a determination he shall, within three months after October 18, 1972, notify the [State](/usc/33/1362.md?p=3) and specify the changes needed to meet such requirements. If such changes are not adopted by the [State](/usc/33/1362.md?p=3) within ninety days after the date of such notification, the Administrator shall promulgate such changes in accordance with [subsection (b)](#b) of this section.
  - (2) Any [State](/usc/33/1362.md?p=3) which, before October 18, 1972, has adopted, pursuant to its own law, water quality standards applicable to intrastate waters shall submit such standards to the Administrator within thirty days after October 18, 1972. Each such standard shall remain in effect, in the same manner and to the same extent as any other water quality standard established under this chapter unless the Administrator determines that such standard is inconsistent with the applicable requirements of this Act as in effect immediately prior to October 18, 1972. If the Administrator makes such a determination he shall not later than the one hundred and twentieth day after the date of submission of such standards, notify the [State](/usc/33/1362.md?p=3) and specify the changes needed to meet such requirements. If such changes are not adopted by the [State](/usc/33/1362.md?p=3) within ninety days after such notification, the Administrator shall promulgate such changes in accordance with [subsection (b)](#b) of this section.
  - (3)
    - (A) Any [State](/usc/33/1362.md?p=3) which prior to October 18, 1972, has not adopted pursuant to its own laws water quality standards applicable to intrastate waters shall, not later than one hundred and eighty days after October 18, 1972, adopt and submit such standards to the Administrator.
    - (B) If the Administrator determines that any such standards are consistent with the applicable requirements of this Act as in effect immediately prior to October 18, 1972, he shall approve such standards.
    - (C) If the Administrator determines that any such standards are not consistent with the applicable requirements of this Act as in effect immediately prior to October 18, 1972, he shall, not later than the ninetieth day after the date of submission of such standards, notify the [State](/usc/33/1362.md?p=3) and specify the changes to meet such requirements. If such changes are not adopted by the [State](/usc/33/1362.md?p=3) within ninety days after the date of notification, the Administrator shall promulgate such standards pursuant to [subsection (b)](#b) of this section.
- (b) **Proposed regulations—**
  - (1) The Administrator shall promptly prepare and publish proposed regulations setting forth water quality standards for a [State](/usc/33/1362.md?p=3) in accordance with the applicable requirements of this Act as in effect immediately prior to October 18, 1972, if—
    - (A) the [State](/usc/33/1362.md?p=3) fails to submit water quality standards within the times prescribed in [subsection (a)](#a) of this section.
    - (B) a water quality standard submitted by such [State](/usc/33/1362.md?p=3) under [subsection (a)](#a) of this section is determined by the Administrator not to be consistent with the applicable requirements of [subsection (a)](#a) of this section.
  - (2) The Administrator shall promulgate any water quality standard published in a proposed regulation not later than one hundred and ninety days after the date he publishes any such proposed standard, unless prior to such promulgation, such [State](/usc/33/1362.md?p=3) has adopted a water quality standard which the Administrator determines to be in accordance with [subsection (a)](#a) of this section.
- (c) **Review; revised standards; publication—**
  - (1) The Governor of a [State](/usc/33/1362.md?p=3) or the [State water pollution control agency](/usc/33/1362.md?p=1) of such [State](/usc/33/1362.md?p=3) shall from time to time (but at least once each three year period beginning with October 18, 1972) hold public hearings for the purpose of reviewing applicable water quality standards and, as appropriate, modifying and adopting standards. Results of such review shall be made available to the Administrator.
  - (2)
    - (A) Whenever the [State](/usc/33/1362.md?p=3) revises or adopts a new standard, such revised or new standard shall be submitted to the Administrator. Such revised or new water quality standard shall consist of the designated uses of the [navigable waters](/usc/33/1362.md?p=7) involved and the water quality criteria for such waters based upon such uses. Such standards shall be such as to protect the public health or welfare, enhance the quality of water and serve the purposes of this chapter. Such standards shall be established taking into consideration their use and value for public water supplies, propagation of fish and wildlife, recreational purposes, and agricultural, industrial, and other purposes, and also taking into consideration their use and value for navigation.
    - (B) Whenever a [State](/usc/33/1362.md?p=3) reviews water quality standards pursuant to paragraph (1) of this subsection, or revises or adopts new standards pursuant to this paragraph, such [State](/usc/33/1362.md?p=3) shall adopt criteria for all [toxic pollutants](/usc/33/1362.md?p=13) listed pursuant to [section 1317(a)(1) of this title](/usc/33/1317.md?p=a-1) for which criteria have been published under [section 1314(a) of this title](/usc/33/1314.md?p=a), the [discharge](/usc/33/1362.md?p=16) or presence of which in the affected waters could reasonably be expected to interfere with those designated uses adopted by the [State](/usc/33/1362.md?p=3), as necessary to support such designated uses. Such criteria shall be specific numerical criteria for such [toxic pollutants](/usc/33/1362.md?p=13). Where such numerical criteria are not available, whenever a [State](/usc/33/1362.md?p=3) reviews water quality standards pursuant to [paragraph (1)](#c-1), or revises or adopts new standards pursuant to this paragraph, such [State](/usc/33/1362.md?p=3) shall adopt criteria based on [biological monitoring](/usc/33/1362.md?p=15) or assessment methods consistent with information published pursuant to [section 1314(a)(8) of this title](/usc/33/1314.md?p=a-8). Nothing in this section shall be construed to limit or delay the use of [effluent limitations](/usc/33/1362.md?p=11) or other permit conditions based on or involving [biological monitoring](/usc/33/1362.md?p=15) or assessment methods or previously adopted numerical criteria.
  - (3) If the Administrator, within sixty days after the date of submission of the revised or new standard, determines that such standard meets the requirements of this chapter, such standard shall thereafter be the water quality standard for the applicable waters of that [State](/usc/33/1362.md?p=3). If the Administrator determines that any such revised or new standard is not consistent with the applicable requirements of this chapter, he shall not later than the ninetieth day after the date of submission of such standard notify the [State](/usc/33/1362.md?p=3) and specify the changes to meet such requirements. If such changes are not adopted by the [State](/usc/33/1362.md?p=3) within ninety days after the date of notification, the Administrator shall promulgate such standard pursuant to paragraph (4) of this subsection.
  - (4) The Administrator shall promptly prepare and publish proposed regulations setting forth a revised or new water quality standard for the [navigable waters](/usc/33/1362.md?p=7) involved—
    - (A) if a revised or new water quality standard submitted by such [State](/usc/33/1362.md?p=3) under paragraph (3) of this subsection for such waters is determined by the Administrator not to be consistent with the applicable requirements of this chapter, or
    - (B) in any case where the Administrator determines that a revised or new standard is necessary to meet the requirements of this chapter.

    The Administrator shall promulgate any revised or new standard under this paragraph not later than ninety days after he publishes such proposed standards, unless prior to such promulgation, such [State](/usc/33/1362.md?p=3) has adopted a revised or new water quality standard which the Administrator determines to be in accordance with this chapter.

- (d) **Identification of areas with insufficient controls; maximum daily load; certain effluent limitations revision—**
  - (1)
    - (A) Each [State](/usc/33/1362.md?p=3) shall identify those waters within its boundaries for which the [effluent limitations](/usc/33/1362.md?p=11) required by [section 1311(b)(1)(A)](/usc/33/1311.md?p=b-1-A) and [section 1311(b)(1)(B) of this title](/usc/33/1311.md?p=b-1-B) are not stringent enough to implement any water quality standard applicable to such waters. The [State](/usc/33/1362.md?p=3) shall establish a priority ranking for such waters, taking into account the severity of the [pollution](/usc/33/1362.md?p=19) and the uses to be made of such waters.
    - (B) Each [State](/usc/33/1362.md?p=3) shall identify those waters or parts thereof within its boundaries for which controls on thermal [discharges](/usc/33/1362.md?p=16) under [section 1311 of this title](/usc/33/1311.md) are not stringent enough to assure protection and propagation of a balanced indigenous population of shellfish, fish, and wildlife.
    - (C) Each [State](/usc/33/1362.md?p=3) shall establish for the waters identified in paragraph (1)(A) of this subsection, and in accordance with the priority ranking, the total maximum daily load, for those [pollutants](/usc/33/1362.md?p=6) which the Administrator identifies under [section 1314(a)(2) of this title](/usc/33/1314.md?p=a-2) as suitable for such calculation. Such load shall be established at a level necessary to implement the applicable water quality standards with seasonal variations and a margin of safety which takes into account any lack of knowledge concerning the relationship between [effluent limitations](/usc/33/1362.md?p=11) and water quality.
    - (D) Each [State](/usc/33/1362.md?p=3) shall estimate for the waters identified in paragraph (1)(B) of this subsection the total maximum daily thermal load required to assure protection and propagation of a balanced, indigenous population of shellfish, fish, and wildlife. Such estimates shall take into account the normal water temperatures, flow rates, seasonal variations, existing sources of heat input, and the dissipative capacity of the identified waters or parts thereof. Such estimates shall include a calculation of the maximum heat input that can be made into each such part and shall include a margin of safety which takes into account any lack of knowledge concerning the development of thermal water quality criteria for such protection and propagation in the identified waters or parts thereof.
  - (2) Each [State](/usc/33/1362.md?p=3) shall submit to the Administrator from time to time, with the first such submission not later than one hundred and eighty days after the date of publication of the first identification of [pollutants](/usc/33/1362.md?p=6) under [section 1314(a)(2)(D) of this title](/usc/33/1314.md), for his approval the waters identified and the loads established under paragraphs (1)(A), (1)(B), (1)(C), and (1)(D) of this subsection. The Administrator shall either approve or disapprove such identification and load not later than thirty days after the date of submission. If the Administrator approves such identification and load, such [State](/usc/33/1362.md?p=3) shall incorporate them into its current plan under [subsection (e)](#e) of this section. If the Administrator disapproves such identification and load, he shall not later than thirty days after the date of such disapproval identify such waters in such [State](/usc/33/1362.md?p=3) and establish such loads for such waters as he determines necessary to implement the water quality standards applicable to such waters and upon such identification and establishment the [State](/usc/33/1362.md?p=3) shall incorporate them into its current plan under [subsection (e)](#e) of this section.
  - (3) For the specific purpose of developing information, each [State](/usc/33/1362.md?p=3) shall identify all waters within its boundaries which it has not identified under paragraph (1)(A) and (1)(B) of this subsection and estimate for such waters the total maximum daily load with seasonal variations and margins of safety, for those [pollutants](/usc/33/1362.md?p=6) which the Administrator identifies under [section 1314(a)(2) of this title](/usc/33/1314.md?p=a-2) as suitable for such calculation and for thermal [discharges](/usc/33/1362.md?p=16), at a level that would assure protection and propagation of a balanced indigenous population of fish, shellfish, and wildlife.
  - (4) **Limitations on revision of certain effluent limitations.—**
    - (A) **Standard not attained.—** For waters identified under [paragraph (1)(A)](#d-1-A) where the applicable water quality standard has not yet been attained, any [effluent limitation](/usc/33/1362.md?p=11) based on a total maximum daily load or other waste load allocation established under this section may be revised only if (i) the cumulative effect of all such revised [effluent limitations](/usc/33/1362.md?p=11) based on such total maximum daily load or waste load allocation will assure the attainment of such water quality standard, or (ii) the designated use which is not being attained is removed in accordance with regulations established under this section.
    - (B) **Standard attained.—** For waters identified under [paragraph (1)(A)](#d-1-A) where the quality of such waters equals or exceeds levels necessary to protect the designated use for such waters or otherwise required by applicable water quality standards, any [effluent limitation](/usc/33/1362.md?p=11) based on a total maximum daily load or other waste load allocation established under this section, or any water quality standard established under this section, or any other permitting standard may be revised only if such revision is subject to and consistent with the antidegradation policy established under this section.
- (e) **Continuing planning process—**
  - (1) Each [State](/usc/33/1362.md?p=3) shall have a continuing planning process approved under paragraph (2) of this subsection which is consistent with this chapter.
  - (2) Each [State](/usc/33/1362.md?p=3) shall submit not later than 120 days after October 18, 1972, to the Administrator for his approval a proposed continuing planning process which is consistent with this chapter. Not later than thirty days after the date of submission of such a process the Administrator shall either approve or disapprove such process. The Administrator shall from time to time review each [State](/usc/33/1362.md?p=3)’s approved planning process for the purpose of insuring that such planning process is at all times consistent with this chapter. The Administrator shall not approve any [State](/usc/33/1362.md?p=3) permit program under subchapter IV of this chapter for any [State](/usc/33/1362.md?p=3) which does not have an approved continuing planning process under this section.
  - (3) The Administrator shall approve any continuing planning process submitted to him under this section which will result in plans for all [navigable waters](/usc/33/1362.md?p=7) within such [State](/usc/33/1362.md?p=3), which include, but are not limited to, the following:
    - (A) [effluent limitations](/usc/33/1362.md?p=11) and schedules of compliance at least as stringent as those required by [section 1311(b)(1)](/usc/33/1311.md?p=b-1), [section 1311(b)(2)](/usc/33/1311.md?p=b-2), [section 1316](/usc/33/1316.md), and [section 1317 of this title](/usc/33/1317.md), and at least as stringent as any requirements contained in any applicable water quality standard in effect under authority of this section;
    - (B) the incorporation of all elements of any applicable area-wide waste management plans under [section 1288 of this title](/usc/33/1288.md), and applicable basin plans under [section 1289 of this title](/usc/33/1289.md);
    - (C) total maximum daily load for [pollutants](/usc/33/1362.md?p=6) in accordance with [subsection (d)](#d) of this section;
    - (D) procedures for revision;
    - (E) adequate authority for intergovernmental cooperation;
    - (F) adequate implementation, including schedules of compliance, for revised or new water quality standards, under [subsection (c)](#c) of this section;
    - (G) controls over the disposition of all residual waste from any water treatment processing;
    - (H) an inventory and ranking, in order of priority, of needs for [construction](/usc/33/1292.md?p=1) of waste [treatment works](/usc/33/1292.md?p=2-A) required to meet the applicable requirements of sections [1311](/usc/33/1311.md) and [1312](/usc/33/1312.md) of this title.
- (f) **Earlier compliance—** Nothing in this section shall be construed to affect any [effluent limitation](/usc/33/1362.md?p=11), or [schedule of compliance](/usc/33/1362.md?p=17) required by any [State](/usc/33/1362.md?p=3) to be implemented prior to the dates set forth in sections [1311(b)(1)](/usc/33/1311.md?p=b-1) and [1311(b)(2)](/usc/33/1311.md?p=b-2) of this title nor to preclude any [State](/usc/33/1362.md?p=3) from requiring compliance with any [effluent limitation](/usc/33/1362.md?p=11) or [schedule of compliance](/usc/33/1362.md?p=17) at dates earlier than such dates.
- (g) **Heat standards—** Water quality standards relating to heat shall be consistent with the requirements of [section 1326 of this title](/usc/33/1326.md).
- (h) **Thermal water quality standards—** For the purposes of this chapter the term “water quality standards” includes thermal water quality standards.
- (i) **Coastal recreation water quality criteria—**
  - (1) **Adoption by States—**
    - (A) **Initial criteria and standards—** Not later than 42 months after October 10, 2000, each [State](/usc/33/1362.md?p=3) having [coastal recreation waters](/usc/33/1362.md?p=21-A) shall adopt and submit to the Administrator water quality criteria and standards for the [coastal recreation waters](/usc/33/1362.md?p=21-A) of the [State](/usc/33/1362.md?p=3) for those pathogens and [pathogen indicators](/usc/33/1362.md?p=23) for which the Administrator has published criteria under [section 1314(a) of this title](/usc/33/1314.md?p=a).
    - (B) **New or revised criteria and standards—** Not later than 36 months after the date of publication by the Administrator of new or revised water quality criteria under [section 1314(a)(9) of this title](/usc/33/1314.md?p=a-9), each [State](/usc/33/1362.md?p=3) having [coastal recreation waters](/usc/33/1362.md?p=21-A) shall adopt and submit to the Administrator new or revised water quality standards for the [coastal recreation waters](/usc/33/1362.md?p=21-A) of the [State](/usc/33/1362.md?p=3) for all pathogens and [pathogen indicators](/usc/33/1362.md?p=23) to which the new or revised water quality criteria are applicable.
  - (2) **Failure of States to adopt—**
    - (A) **In general—** If a [State](/usc/33/1362.md?p=3) fails to adopt water quality criteria and standards in accordance with [paragraph (1)(A)](#i-1-A) that are as protective of human health as the criteria for pathogens and [pathogen indicators](/usc/33/1362.md?p=23) for [coastal recreation waters](/usc/33/1362.md?p=21-A) published by the Administrator, the Administrator shall promptly propose regulations for the [State](/usc/33/1362.md?p=3) setting forth revised or new water quality standards for pathogens and [pathogen indicators](/usc/33/1362.md?p=23) described in [paragraph (1)(A)](#i-1-A) for [coastal recreation waters](/usc/33/1362.md?p=21-A) of the [State](/usc/33/1362.md?p=3).
    - (B) **Exception—** If the Administrator proposes regulations for a [State](/usc/33/1362.md?p=3) described in [subparagraph (A)](#i-2-A) under [subsection (c)(4)(B)](#c-4-B), the Administrator shall publish any revised or new standard under this subsection not later than 42 months after October 10, 2000.
  - (3) **Applicability—** Except as expressly provided by this subsection, the requirements and procedures of [subsection (c)](#c) apply to this subsection, including the requirement in [subsection (c)(2)(A)](#c-2-A) that the criteria protect public health and welfare.

## Source credit

(June 30, 1948, ch. 758, title III, § 303, as added Pub. L. 92–500, § 2, Oct. 18, 1972, 86 Stat. 846; amended Pub. L. 100–4, title III, § 308(d), title IV, § 404(b), Feb. 4, 1987, 101 Stat. 39, 68; Pub. L. 106–284, § 2, Oct. 10, 2000, 114 Stat. 870.)

## Notes

### Editorial Notes

### References in Text

This Act, referred to in subsecs. (a)(1), (2), (3)(B), (C) and (b)(1), means act June 30, 1948, ch. 758, 62 Stat. 1155, prior to the supersedure and reenactment of act June 30, 1948 by act Oct. 18, 1972, Pub. L. 92–500, 86 Stat. 816. Act June 30, 1948, ch. 758, as added by act Oct. 18, 1972, Pub. L. 92–500, 86 Stat. 816, enacted this chapter.

### Amendments

2000—Subsec. (i). Pub. L. 106–284 added subsec. (i).

1987—Subsec. (c)(2). Pub. L. 100–4, § 308(d), designated existing provision as subpar. (A) and added subpar. (B).

Subsec. (d)(4). Pub. L. 100–4, § 404(b), added par. (4).