CLARKS MILLS SD STP - Town of Cato, Wisconsin Wastewater Treatment Plant

CLARKS MILLS SD STP is a municipal wastewater treatment facility located in the Town of Cato, Manitowoc County, Wisconsin. Serving a small population of 200, the plant provides secondary treatment to meet state and federal water quality standards. The plant's designed capacity is 68.14 units, with an average daily discharge volume of 41.64 units, indicating operational headroom. As a secondary treatment plant, it employs biological processes to reduce organic matter and suspended solids before discharge. The facility operates under the US Clean Water Act, with National Pollutant Discharge Elimination System (NPDES) permits issued by the Wisconsin Department of Natural Resources. For small agglomerations like this, secondary treatment is the standard requirement to protect receiving water quality. The treated effluent is discharged into local streams that drain into Lake Michigan via the Manitowoc River watershed. Lake Michigan is a vital freshwater resource supporting diverse aquatic life, recreational activities, and municipal water supplies. The plant's inland location (more than 10 km from the coast) reduces direct marine impact, but its discharge contributes to the overall nutrient and pollutant load in the Great Lakes basin.

The plant's discharge enters the Manitowoc River watershed, which flows into Lake Michigan, one of the largest freshwater lakes in the world. Lake Michigan supports a complex ecosystem including native fish species, migratory birds, and aquatic plants. Nutrient loading from wastewater can contribute to eutrophication and algal blooms in nearshore areas, making effective treatment critical for maintaining water quality and ecological balance.