CAPRON STP - Secondary Wastewater Treatment Plant in Poplar Grove, Illinois

CAPRON STP is a municipal wastewater treatment plant located in Poplar Grove, Illinois, United States. The facility serves a population of 961 residents and operates under the regulatory framework of the U.S. Clean Water Act, which requires National Pollutant Discharge Elimination System (NPDES) permits for all discharges to surface waters. The plant provides secondary treatment, a standard level for small communities in the U.S., which typically involves biological processes to remove organic matter and suspended solids. The plant's designed capacity is 1,135.62 thousand cubic meters, and it currently discharges approximately 264.98 thousand cubic meters annually, indicating significant spare capacity. The treated effluent is discharged into local waterways that ultimately drain into the Rock River watershed, a tributary of the Mississippi River. The plant plays a key role in protecting downstream aquatic ecosystems and maintaining water quality in the region's surface waters.

The plant discharges into the Rock River watershed, which flows into the Mississippi River and eventually the Gulf of Mexico. The receiving waters support diverse aquatic life and are used for recreation and drinking water downstream. The plant's secondary treatment helps reduce nutrient and organic pollution, mitigating impacts on downstream ecosystems.