Prairie City STL Wastewater Treatment Plant, Jasper County, Iowa

Prairie City STL is a municipal wastewater treatment facility located in Jasper County, Iowa, United States. The plant serves a population of about 1,681 residents in the Prairie City area, operating as part of the local infrastructure to manage domestic wastewater. The facility provides secondary treatment, which is the standard level required by the U.S. Clean Water Act for municipal plants of this scale. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The plant has a designed capacity of approximately 794.93 volume units and processes an average daily flow of 794.94 volume units, indicating near-full utilization. The treated effluent is discharged into local receiving waters that eventually drain into the Mississippi River basin. This contributes to the overall health of the watershed, supporting aquatic life and downstream water quality. The plant's operation is regulated under the National Pollutant Discharge Elimination System (NPDES) permit program, ensuring compliance with environmental standards.

The plant discharges into local streams that are part of the Mississippi River watershed, which ultimately flows into the Gulf of Mexico. The region's aquatic ecosystems support diverse fish and macroinvertebrate communities. Proper treatment helps reduce nutrient loading, which is critical for preventing downstream hypoxic zones in the Gulf.