Key Concepts

Changing a Designated Use: Feasibility Factors

In developing a use attainability analysis, a State/Tribe must demonstrate that attaining a CWA 101(a)(2) goal use is infeasible due to one of the factors listed below (40 CFR 131.10(g)). The State/Tribe should also identify the highest attainable use in its UAA.

Factor #1

Naturally occurring pollutant concentrations prevent the attainment of the use; or

Factor #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

Factor #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

Factor #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

Factor #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

Factor #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.

Key Point. The process of developing a use attainability analysis works best when States/Tribes, Federal agencies, and other stakeholders agree beforehand on key factors that will be presented, what information will be needed, and how data will be interpreted.

Learn More. Additional detail on aspects of the use attainability analysis that should be agreed on up front. Proceed to the Learn More Topic. »