Darlington WWTP - Advanced Wastewater Treatment in Town of Darlington, Wisconsin

Darlington WWTP is a municipal wastewater treatment facility located in Town of Darlington, Lafayette County, Wisconsin. The plant serves a population of approximately 2,442 residents, providing essential sanitation services for this rural community in the Driftless Area of southwestern Wisconsin. The facility employs advanced treatment processes, exceeding the secondary treatment standard required by the US Clean Water Act. With a designed capacity of 1,287.04 thousand cubic meters per year and an average discharge volume of 817.65 thousand cubic meters per year, the plant operates well within its capacity. As a US facility, it operates under a 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 from Darlington WWTP discharges into local streams that are part of the Mississippi River basin. The receiving waters eventually flow into the Mississippi River and ultimately to the Gulf of Mexico. The plant's advanced treatment helps reduce nutrient loading, contributing to the protection of downstream aquatic ecosystems and supporting regional water quality goals.

The plant discharges into tributaries of the Pecatonica River, which flows into the Rock River and then the Mississippi River. This watershed supports diverse aquatic life and is part of the Upper Mississippi River basin, an ecologically significant corridor for migratory fish and waterfowl. The advanced treatment helps minimize nutrient pollution, which is critical for preventing hypoxia in the Gulf of Mexico.