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Statewide Existing Use Classifications

What is an Existing Use?

An "existing use" is defined in 25 Pa. Code 93.1 as "Those uses actually attained in the water body on or after Nov. 28, 1975, whether or not they are included in the water quality standards." The same definition appears in the federal regulations at 40 CFR 131.3(e). An "existing use" is different than a "designated use." A "designated use" is defined in 93.1 as those uses specified in 93.9a-93.9z for each waterbody or segment whether or not the use is being attained. Designated uses are regulations promulgated by the Environmental Quality Board (EQB) through the rulemaking process.

What Uses are Protected as Existing Uses?

All of the water uses listed in 93.3 are protected as existing uses. These water uses include High Quality Waters (HQ) and Exceptional Value Waters (EV). Existing use protection is identical to designated use protection. The uses are protected on a waterbody segment when the department issues a permit or approval for an activity which may impact the use.

Existing Uses List:

The department maintains a publicly accessible list of surface water segments where data has been evaluated that indicates an existing use classification of a waterbody that is more protective than the designated use (including those segments which are HQ or EV). The list is maintained and updated by the Bureau of Clean Water and will be used by DEP and county conservation district staff with responsibility to protect surface water quality in reviewing requests for permits and approvals. Only an existing use that is more stringent than the designated use in 93.9a - 93.9z for a particular waterbody is placed on the existing use list.

Agencies or organizations outside the department and individuals have the option of providing sufficient data to substantiate their position that the existing use differs from the designated use or providing enough information to establish that the waterbody in question warrants an existing use evaluation.

Waterbodies on this list are periodically compiled into rulemaking actions taken before the EQB in order to change the designated uses as they appear in department regulations to match the existing use of the water. These rulemakings are subject to extensive public notice and input opportunities before finalization.

Additionally, a state summary table (PDF) is available, which lists county, stream code, water body, designated use, existing use, qualifier, location, date of evaluation and EQB proposed rule.