Chapter 102: E&S Control & NPDES Permits for Construction Did you know that sediment is the #1 pollutant to waters of the Commonwealth? For that reason, earth disturbance activities are regulated under Pennsylvania DEP's Chapter 102 regulations. Chapter 102 requires persons proposing or conducting earth disturbance to develop, implement and maintain Erosion and Sediment (E&S) Control Best Management Practices (BMPs) to minimize erosion and the potential for pollution to water resources. In addition, the federal Clean Water Act requires that an earth mover disturbing 1 acre or more over the life of the project obtain a National Pollutant Discharge Elimination System (NPDES) Permit for Storm water Discharges from Construction Sites. The District strongly recommends pre-application meetings early on during a project's concept plan stage - before detailed plans are developed - in order to determine whether an NPDES permit is required and to expedite the permit and plan review process.