Williamsport Central STP | Municipal Wastewater Treatment in Williamsport, Pennsylvania

Williamsport Central STP is a municipal wastewater treatment facility located in Williamsport, Pennsylvania, serving a population of about 44,835. The plant is situated in Lycoming County and is part of the region's wastewater management system, discharging treated effluent into the West Branch Susquehanna River watershed. As a medium-sized agglomeration, the plant is expected to provide at least secondary treatment under the U.S. Clean Water Act, which requires secondary treatment for municipal wastewater plants. The facility is regulated under the National Pollutant Discharge Elimination System (NPDES) permit program, administered by the Pennsylvania Department of Environmental Protection. Typical treatment processes for plants of this scale include activated sludge or trickling filter systems. The plant's treated effluent ultimately drains into the West Branch Susquehanna River, which flows into the main stem Susquehanna River and then into the Chesapeake Bay. This makes the plant's performance important for downstream water quality, as the Chesapeake Bay is a large estuary with nutrient sensitivity. The plant's discharge contributes to the overall nutrient load management in the bay watershed.

The plant discharges into the West Branch Susquehanna River, a major tributary of the Susquehanna River, which flows into the Chesapeake Bay. The Chesapeake Bay is a large estuary that experiences seasonal hypoxia due to nutrient pollution, making nitrogen and phosphorus removal critical for downstream ecological health. The plant's location in the Susquehanna basin places it within a watershed that supports diverse aquatic life and is a key migratory corridor for fish species.