Birnamwood STP - Secondary Wastewater Treatment Plant in Birnamwood, Wisconsin

Birnamwood STP is a municipal wastewater treatment plant located in Birnamwood, Wisconsin, a small community in Shawano County. The plant serves a population of 824 residents, classifying it as a small-scale facility within the state's wastewater infrastructure. The plant provides secondary treatment, which is the standard level required by the US Clean Water Act for municipal wastewater. It has a designed capacity of 552.67 million gallons per year and currently discharges 340.69 million gallons annually. As a US facility, it operates under an EPA National Pollutant Discharge Elimination System (NPDES) permit issued by the Wisconsin Department of Natural Resources, which sets effluent limits to protect water quality. The treated effluent is discharged into a local waterway that ultimately drains into the Wolf River basin and then to Lake Michigan via Green Bay. This watershed supports diverse aquatic life and is an important recreational and ecological resource in northeastern Wisconsin.

The plant discharges into a tributary of the Wolf River, which flows into Lake Michigan via Green Bay. The Wolf River basin is known for its diverse fish populations and serves as a critical habitat for migratory birds. The downstream environment includes wetlands and forested areas that benefit from maintained water quality through regulated wastewater treatment.