Bay City STP Wastewater Treatment Plant, Town of Hartland, Wisconsin

Bay City STP is a municipal wastewater treatment plant located in the Town of Hartland, Pierce County, Wisconsin. It serves a small population of 480 residents, reflecting its role in a rural community. The plant is situated inland, away from coastal areas, and operates under the regulatory framework of the US Clean Water Act. The plant provides secondary treatment, which is the standard level required by the US Environmental Protection Agency (EPA) for municipal wastewater. Secondary treatment typically involves biological processes to remove organic matter and suspended solids. The plant has a designed capacity of 276.33 million gallons per day and currently discharges an average volume of 105.99 million gallons per day, indicating it operates well below its capacity. The treated effluent is discharged into nearby waterways that ultimately drain into the Mississippi River basin. This region supports diverse aquatic life and is part of a larger watershed that flows to the Gulf of Mexico. The plant's operations are subject to National Pollutant Discharge Elimination System (NPDES) permits, which set limits on pollutant discharges to protect water quality.

The plant discharges into local streams that are part of the Mississippi River basin, which flows south to the Gulf of Mexico. This watershed supports a variety of fish and wildlife, including migratory birds and aquatic species. The area is ecologically sensitive due to its role in maintaining water quality downstream, particularly in the context of nutrient loading that can affect the Gulf's hypoxic zone.