York City Sew Auth Wastewater Treatment Plant, Manchester Township, Pennsylvania

York City Sew Auth is a municipal wastewater treatment facility located in Manchester Township, York County, Pennsylvania. Serving an estimated population of 82,615, the plant is part of the region's critical water infrastructure, managing wastewater from residential and commercial sources in the greater York area. As a US-based facility, the plant operates under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Pennsylvania Department of Environmental Protection. For a plant serving a population of this scale, secondary treatment is the minimum standard, with potential requirements for nutrient removal depending on the receiving water body's sensitivity. The plant discharges into the Susquehanna River basin, which ultimately flows into the Chesapeake Bay. This makes the plant's operations significant for downstream water quality, as the Chesapeake Bay watershed is subject to strict nutrient and sediment reduction targets under the Chesapeake Bay Total Maximum Daily Load (TMDL) program.

The plant's treated effluent enters the Susquehanna River watershed, which drains into the Chesapeake Bay, the largest estuary in the United States. The Chesapeake Bay ecosystem supports diverse aquatic life, including blue crabs, oysters, and migratory fish, and is sensitive to nutrient pollution from wastewater discharges. The plant's location inland, over 50 km from the coast, reduces direct marine impact but contributes to the bay's overall nutrient load.