RENWICK STL Wastewater Treatment Plant, Wright County, Iowa

RENWICK STL is a municipal wastewater treatment facility located in Wright County, Iowa, United States. The plant serves a small population of 242 residents, reflecting its role in a rural community. It operates under the regulatory framework of the U.S. Clean Water Act, which governs wastewater discharges through the National Pollutant Discharge Elimination System (NPDES) permit program. The plant provides secondary treatment, a standard level that removes biodegradable organic matter and suspended solids. With a designed capacity of 378.54 megaliters and an annual discharge volume of 151.42 megaliters, the facility operates well below its capacity, indicating room for future growth. Secondary treatment is typical for small communities in Iowa, meeting state and federal water quality standards. The treated effluent is discharged into local waterways that drain into the Mississippi River basin, ultimately reaching the Gulf of Mexico. The plant plays a key role in protecting downstream water quality and aquatic habitats in the region's agricultural landscape.

RENWICK STL discharges into tributaries of the Iowa River, which flows into the Mississippi River and eventually the Gulf of Mexico. The surrounding watershed is predominantly agricultural, with row crops and livestock operations. The plant's secondary treatment helps reduce nutrient loads that could contribute to hypoxia in the Gulf, supporting the health of downstream aquatic ecosystems.