Forest SD 1 STP - Secondary Wastewater Treatment in Town of Forest, Wisconsin

Forest SD 1 STP is a municipal wastewater treatment facility located in the Town of Forest, Saint Croix County, Wisconsin. It serves a small population of 80 residents, reflecting its role in a rural community. The plant is situated in the Upper Midwest region of the United States, an area characterized by cold winters and a landscape of forests and farmland. The plant provides secondary treatment, a standard level required by the U.S. Clean Water Act for most municipal facilities. With a designed capacity of 30.28 megaliters per year and a current discharge volume of 22.71 megaliters per year, it operates below its full capacity. As a small facility, it is subject to state-level permitting under the National Pollutant Discharge Elimination System (NPDES), which sets effluent limits to protect water quality. The treated effluent is discharged into local streams that drain into the St. Croix River, a National Scenic Riverway. This river flows southward to join the Mississippi River, supporting diverse aquatic life and recreational activities. The plant's operations help maintain the ecological health of this sensitive watershed.

The plant discharges into tributaries of the St. Croix River, which flows into the Mississippi River and ultimately the Gulf of Mexico. The St. Croix River is a biologically rich waterway supporting fish species like walleye and smallmouth bass, and its riparian zones provide habitat for migratory birds. The plant's secondary treatment helps control nutrient loading, which is critical for preventing algal blooms in downstream waters.