KIEL STP Wastewater Treatment Plant, Town of Schleswig, Wisconsin

KIEL STP is a municipal wastewater treatment plant located on Rockville Road in the Town of Schleswig, Manitowoc County, Wisconsin. It serves a population of about 3,812 people, placing it in the small community category under U.S. regulatory frameworks. The plant is situated inland, more than 50 kilometers from Lake Michigan, and its operations are overseen by state and federal environmental agencies. As a facility serving fewer than 10,000 people, KIEL STP falls under U.S. Clean Water Act requirements, which mandate secondary treatment as a baseline. The plant's designed capacity is 1.00 million gallons per day, indicating it is sized for its current service population. The treated effluent from KIEL STP is discharged into local streams that eventually drain into Lake Michigan via the Manitowoc River watershed. This discharge must comply with Wisconsin Pollutant Discharge Elimination System (WPDES) permits, which set limits on biochemical oxygen demand, total suspended solids, and nutrients to protect downstream aquatic life and recreational uses.

KIEL STP discharges into the Manitowoc River watershed, which flows eastward into Lake Michigan. Lake Michigan is a vital freshwater resource supporting diverse fish populations, including lake trout and whitefish, and provides drinking water for millions. The plant's effluent must meet strict nutrient limits to prevent algal blooms and hypoxia in the lake. The surrounding area is primarily agricultural, so the plant also helps mitigate runoff impacts on local streams.