SULLIVAN SD 1 WWTP - Advanced Wastewater Treatment in Town of Sullivan, Wisconsin

SULLIVAN SD 1 WWTP is a municipal wastewater treatment facility located in the Town of Sullivan, Jefferson County, Wisconsin. It serves a population of approximately 895 residents, providing advanced treatment to ensure environmental protection. The plant is part of the state's wastewater infrastructure, operating under the regulatory framework of the US Clean Water Act. The facility employs advanced treatment processes, which go beyond secondary treatment to remove nutrients and other pollutants. With a designed capacity of 378.54 cubic meters per day and a discharge volume of 189.27 cubic meters per day, the plant operates at about half its capacity, indicating room for future growth. As a US facility, it is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Wisconsin Department of Natural Resources, ensuring compliance with water quality standards. The treated effluent is discharged into local streams that drain into the Rock River basin, ultimately reaching the Mississippi River and the Gulf of Mexico. This downstream connection highlights the plant's role in protecting both local aquatic life and the broader watershed. The advanced treatment helps reduce nutrient loading, which is critical for preventing algal blooms and maintaining ecosystem health.

The plant discharges into small streams within the Rock River watershed, which flows southward to the Mississippi River and eventually the Gulf of Mexico. This region supports diverse aquatic habitats, including wetlands and fish spawning areas. The advanced treatment reduces nutrient and pollutant loads, helping to mitigate hypoxia in the Gulf and protect local biodiversity.