Table 2.

Symbol	Use
	Aquatic Life
WWF	Warm Water Fishes
	Water Supply
PWS	Potable Water Supply
IWS	Industrial Water Supply
LWS	Livestock Water Supply
AWS	Wildlife Water Supply
IRS	Irrigation
	Recreation
B	Boating
F	Fishing
WC	Water Contact Sports
E	Esthetics

(b) Less restrictive uses. Less restrictive uses than those currently designated for particular waters listed in § § 93.9a—93.9z may be adopted when it is demonstrated that the designated use is more restrictive than the existing use, the use cannot be attained by implementing effluent limits required under sections 301(b) and 306 of the Federal Clean Water Act (33 U.S.C.A. § § 1311(b) and 1316) or implementing cost-effective and reasonable BMPs for nonpoint source control, and one or more of the following conditions exist:

(1) Naturally occurring pollutant concentrations (natural quality) prevent the attainment of the use.

(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.

(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.

(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 the modification in a way that would result in the attainment of the use.

(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 uses.

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

(c) Redesignation of water. Waters considered for redesignation may not be redesignated to less restrictive uses than the existing uses.

Authority

The provisions of this § 93.4 amended under sections 5(b)(1) and 402 of The Clean Streams Law (35 P. S. § § 691.5(b)(1) and 691.402); and section 1920-A of The Administrative Code of 1929 (71 P. S. § 510-20).

Source

The provisions of this § 93.4 amended February 11, 1994, effective February 12, 1994, 24 Pa.B. 832; amended July 16, 1999, effective July 17, 1999, 29 Pa.B. 3720; amended November 17, 2000, effective November 18, 2000, 30 Pa.B. 6059. Immediately preceding text appears at serial pages (258050) to (258051).

Cross References

This section cited in 25 Pa. Code § 93.1 (relating to definitions); 25 Pa. Code § 93.7 (relating to specific water quality criteria); 25 Pa. Code § 250.309 (relating to MSCs for surface water); and 25 Pa. Code § 250.406 (relating to relationship to surface water quality requirements).