Johnson Creek WWTP - Advanced Wastewater Treatment in Johnson Creek, Wisconsin

Johnson Creek WWTP is an advanced wastewater treatment plant located in Johnson Creek, Wisconsin, United States. The facility serves a population of approximately 1,710 residents in the Town of Aztalan and surrounding areas within Jefferson County. As a municipal plant, it plays a key role in managing local wastewater for this small community. The plant employs advanced treatment processes, which go beyond secondary treatment to remove nutrients and other pollutants. With a designed capacity of 2,649.78 cubic meters per day and a current discharge volume of 870.65 cubic meters per day, the facility operates well below its capacity. Under the U.S. Clean Water Act, such plants must comply with National Pollutant Discharge Elimination System (NPDES) permits issued by the Wisconsin Department of Natural Resources, ensuring effluent quality meets state and federal standards. The treated effluent from Johnson Creek WWTP is discharged into local streams that flow into the Rock River basin, ultimately reaching the Mississippi River and the Gulf of Mexico. The plant's advanced treatment helps protect downstream water quality and aquatic habitats in this agriculturally intensive region of the Midwest.

Johnson Creek WWTP discharges into tributaries of the Rock River, which flows southward through Wisconsin and Illinois before joining the Mississippi River. The Rock River watershed supports diverse aquatic life and is an important ecological corridor. Downstream, the Mississippi River system provides critical habitat for fish and migratory birds. Advanced treatment at this plant helps reduce nutrient loading, which is a key concern in the Mississippi River basin due to its contribution to the Gulf of Mexico hypoxic zone.