Sauk Prairie SC STP Wastewater Treatment Plant, Sauk City, Wisconsin

Sauk Prairie SC STP is a municipal wastewater treatment facility located in Sauk City, Wisconsin, serving a population of about 7,400. The plant is situated in Sauk County and operates under the regulatory framework of the United States Clean Water Act, which governs wastewater discharges through the National Pollutant Discharge Elimination System (NPDES) permit program. As a facility serving a small agglomeration, it is subject to secondary treatment standards to protect water quality. However, under the Clean Water Act, facilities of this scale typically employ secondary treatment, which includes biological processes to remove organic matter and suspended solids. The plant is likely permitted by the Wisconsin Department of Natural Resources, which enforces effluent limits to meet state water quality standards. The treated effluent from Sauk Prairie SC STP discharges to a receiving water body within the Wisconsin River watershed, which ultimately flows into the Mississippi River. This drainage basin supports diverse aquatic life and is an important ecological corridor in the Upper Midwest. The plant's operations contribute to protecting downstream water quality and recreational uses in the region.

The plant discharges into the Wisconsin River basin, a major tributary of the Mississippi River. The Wisconsin River supports a variety of fish species and provides habitat for migratory birds. Downstream, the Mississippi River is a critical waterway for commerce and ecology, including the Upper Mississippi River National Wildlife and Fish Refuge. The plant's treatment helps maintain water quality in this interconnected system.