Erie City STP - Major Wastewater Treatment Plant on Lake Erie, Pennsylvania

Erie City STP is a major wastewater treatment facility located in Erie, Pennsylvania, on the southern shore of Lake Erie. Serving a population of over 181,000, it is one of the largest treatment plants in the region, handling municipal wastewater from the city and surrounding areas. The plant's location on Port Access Road places it directly adjacent to the lake, making its discharge point critical for local water quality. As a large municipal facility in the United States, Erie City STP operates under the National Pollutant Discharge Elimination System (NPDES) permit program, as mandated by the Clean Water Act. Plants of this scale are typically required to provide at least secondary treatment, with additional nutrient removal standards applicable to Great Lakes discharges to address eutrophication concerns. The designed capacity of 1.00 million gallons per day indicates a substantial infrastructure investment. The treated effluent from Erie City STP is discharged into Lake Erie, the fourth-largest of the Great Lakes and a vital freshwater resource. Lake Erie drains via the Niagara River into Lake Ontario and eventually the St. Lawrence River to the Atlantic Ocean. The plant's discharge contributes to the lake's nutrient load, which has historically caused harmful algal blooms, making advanced treatment and monitoring essential for protecting the lake's ecosystem and drinking water supplies.

Erie City STP discharges into Lake Erie, part of the Great Lakes basin, which drains through the Niagara River and St. Lawrence River to the Atlantic Ocean. The lake supports diverse aquatic life, including walleye and perch fisheries, and provides drinking water for millions. Nutrient loading from wastewater and agricultural runoff has led to recurring harmful algal blooms, particularly in the western basin, making phosphorus removal a key environmental concern for the plant.