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Water: Designated Uses

Designating Attainable Uses for the Nation's Waters

out of date 

National Symposium

June 3-4, 2002; Washington, DC

40 CFR 131.10(g)

States may remove a designated use which is not an existing use, as defined in Sec. 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 levels prevent the attainment of the use, unless these conditions may be compensated for by the discharge of sufficient volume of effluent discharges without violating State water conservation requirements to enable uses to be met; or
  3. Human caused conditions or sources 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 the attainment of the use, and it is not feasible to restore the water body to its original condition or to operate such modification 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.



Many interested parties have expressed the need for additional guidance on establishing the protection levels or "designated uses" of waterbodies (e.g., aquatic life, recreation) and the process to follow when making designated uses more or less protective. In order to receive input from a broad set of stakeholders on these topics, we held a national symposium on designated uses June 3-4, 2002, in Washington, DC. Approximately 200 interested citizens, government officials, and regulated parties attended this open meeting.

We assembled an expert panel representing different viewpoints to share their perspectives, and invited stakeholders to submit abstracts on a variety of topics concerning designated uses. Based on these abstracts, the Agency selected speakers who gave brief presentations at the symposium.


The Clean Water Act (CWA) requires states to establish water quality standards to "protect the public health or welfare" and "enhance the quality of water" (Section 303(c)(2)(A)). Water quality standards are to be established for waterbodies "taking into consideration their use and value for public water supplies, propagation of fish and wildlife, recreational purposes, and agriculture, industrial, and other purposes, and also taking into consideration their use and value for navigation." (Section 303(c)(2)(A)). In addition, the CWA establishes the national goal that wherever attainable, "...water quality provides for the protection and propagation of fish, shellfish, and wildlife and provides for recreation in and on the water..." (Section 101(a)(2)).

Our water quality standards regulations at 40 CFR 131 include several key provisions concerning use designation of waterbodies. The regulations at 131.10(j) provide that a state must conduct a use attainability analysis (UAA) whenever:

  • The state designates or has designated uses that do not include those specified in CWA Section 101(a)(2), or
  • The state wishes to remove a CWA Section 101(a)(2) use, or to adopt subcategories of uses specified in CWA Section 101(a)(2) which require less stringent criteria.

Our regulations define a UAA as a "structured scientific assessment of the factors affecting the attainment of the use which may include physical, chemical, biological, and economic factors as described in 40 CFR 131.10(g).

Our water quality standards regulations at 40 CFR 131.20 provide that a state must periodically review and modify their water quality standards, including those for waterbody segments that do not include the uses specified in CWA Section 101(a)(2), to determine if any new information has become available. If such information indicates that the uses specified in CWA Section 101(a)(2) are attainable, water quality standards must be revised accordingly. Analyses supporting revisions to water quality standards, including UAAs, must be made available to the public so that the public can understand why the changes are proposed.

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