Fry, Benjamin, Clean Water Institute, Lycoming College, 1 College Place, Williamsport, PA 17701, frybenj@lycoming.edu; Terpak, Cheryl, Williamsport Municipal Water Authority, 253 W 4th St, Williamsport, PA 17701, CTerpak@wmwa-wsa.org; Rieck, Leslie O., Department of Biology, Lycoming College, 1 College Place, Williamsport PA 17701, rieck@lycoming.edu; Kaunert, Matthew, Clean Water Institute, Lycoming College, 1 College Place, Williamsport, PA 17701, kaunert@lycoming.edu.
The City of Williamsport owns a municipal separate storm sewer system (MS4) and has recently reached an agreement with the Williamsport Municipal Water Authority (WMWA) to have the WMWA assume responsibility for the inspection and maintenance of the MS4 system as required by United States Environmental Protection Agency (US EPA) regulations. The MS4 empties water into seven urbanized streams within city limits as well as directly into the Susquehanna River. As part of US EPA regulations, the WMWA must inspect and document the location and condition of stormwater outfalls. These stormwater outfalls penetrate the road to allow surface water to infiltrate streams, making them a possible entry point for illicit discharges (unauthorized dumping of materials into the MS4). Initial documentation of Williamsport’s MS4 recognized 32 outfalls. Further surveying discovered at least 360 outfalls, which now need to be documented and inspected. Throughout the summer of 2024 we inspected the stormwater outfalls within the Williamsport MS4 area with the goals of mapping the MS4, tracing and stopping illicit discharges and other pollution sources, producing an annual MS4 report, and developing a Standard Operating Procedure (SOP) for future work. Outfalls were characterized by their type, material, shape, size, and location, and inspected during low-flow (at least 48 hours after precipitation). Outfalls were photographed and inspection reports were electronically and physically filed. If outfalls had flow during dry weather, investigators attempted to find the source of the flow, whether that flow was illicit, and the nature of the flow. During summer 2024, 257 outfalls were inspected, with seven outfalls being newly discovered so added to the inventory and three outfalls containing dry-weather flow, so further investigated. The outfalls were added to the MS4 report and a SOP was developed for future work. 95% of outfalls within the MS4 area have now been inspected and documented, creating an accurate map of stormwater outfalls. This allows for efficient monitoring, effective remediation, and an enhanced ability to trace pollutants. Future work should focus on annual re-inspections to maintain the quality of the outfalls and to identify and ensure the termination of any illicit discharges.
MS4, Stormwater, Urban Streams, Infrastructure