Sun Prairie STP - Wastewater Treatment Plant in Sun Prairie, Wisconsin

Sun Prairie STP is a municipal wastewater treatment plant located in Sun Prairie, Dane County, Wisconsin. It serves a population of about 29,849, placing it in the medium-agglomeration category for U.S. facilities. The plant is situated inland, approximately 50 km from the coast, and discharges into local waterways that ultimately drain to the Mississippi River basin. As a U.S. facility, Sun Prairie STP operates under the National Pollutant Discharge Elimination System (NPDES) permit program, as required by the Clean Water Act. For plants serving populations around 30,000, secondary treatment is the standard requirement, ensuring removal of organic matter and suspended solids. Regulatory compliance is expected. The treated effluent from Sun Prairie STP likely discharges into a tributary of the Yahara River, which flows into the Rock River and eventually the Mississippi River. This watershed supports diverse aquatic life and provides drinking water for downstream communities. The plant plays a key role in protecting water quality in the Yahara River chain and the larger Mississippi River basin.

Sun Prairie STP discharges into the Yahara River watershed, which flows into the Rock River and ultimately the Mississippi River. This chain of water bodies supports a variety of fish and wildlife, including migratory birds and aquatic species. The plant's operations help maintain water quality in a region characterized by agricultural runoff and urban development, reducing nutrient loading that could contribute to algal blooms in downstream lakes and the Gulf of Mexico hypoxic zone.