Marietta Donegal STP - Wastewater Treatment Plant in Marietta, Pennsylvania

Marietta Donegal STP is a municipal wastewater treatment plant located in Marietta, Lancaster County, Pennsylvania, along the Northwest Lancaster County River Trail. The facility serves a population of about 7,854 people, placing it in the small-to-medium agglomeration category for US wastewater systems. As a US plant, Marietta Donegal STP operates under the National Pollutant Discharge Elimination System (NPDES) permit program, which is part of the Clean Water Act. NPDES permits set limits on effluent quality to protect receiving waters. The plant discharges into the Susquehanna River basin, which flows south through Pennsylvania and into the Chesapeake Bay. The Chesapeake Bay is a major estuary of ecological and economic importance, supporting diverse aquatic life and fisheries. The plant's operations contribute to the overall nutrient management efforts in the bay watershed.

The plant discharges into the Susquehanna River basin, which drains into the Chesapeake Bay, the largest estuary in the United States. The bay supports critical habitats for blue crabs, oysters, and migratory birds. Nutrient loading from wastewater plants in the basin is a key concern, and the plant's discharge is regulated under the Chesapeake Bay Total Maximum Daily Load (TMDL) program to reduce nitrogen and phosphorus inputs.