25 Pa. Code § 93.4 : ENVIRONMENTAL PROTECTION — DEPARTMENT OF ENVIRONMENTAL PROTECTION — PROTECTION OF NATURAL RESOURCES — WATER RESOURCES — WATER QUALITY STANDARDS —GENERAL PROVISIONS — Statewide water uses

(a) Statewide water uses. Except when otherwise specified in law or regulation, the uses set forth in Table 2 apply to all surface waters. These uses shall be protected in accordance with this chapter, Chapter 96 (relating to water quality standards implementation) and other applicable State and Federal laws and regulations.

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.

25 Pa. Code § 93.4