Allegheny County, PA Environmental Rules: Erosion Control (2026)

DEP's Bureau of Clean Water administers the statewide Chapter 102 program for earth disturbance activities including erosion and sediment control (E&S) and post-construction stormwater management (PCSM). Chapter 102 requires a permit from DEP for the following activities: Construction activities with earth disturbances greater than or equal to one acre, not including agricultural plowing or tilling, animal heavy use areas, timber harvesting activities or road maintenance activities, which require National Pollutant Discharge Elimination System (NPDES) permit coverage. [...] Timber harvesting and road maintenance activities involving 25 or more acres of earth disturbance. An Erosion and Sediment Control (E&S) permit is required under Pennsylvania's Clean Streams Law for these activities, rather than a NPDES permit. Oil and gas activities (e.g., exploration, production, processing, treatment operations or transmission facilities) involving 5 or more acres of earth disturbance. An E&S permit is required under Pennsylvania's Clean Streams Law for these activities. [...] Other activities involving 5 or more acres of earth disturbance not identified above require an E&S permit.