Otter Creek Lake Utility District Wastewater Treatment Plant, Winnebago County, Illinois

Otter Creek Lake Utility District is a wastewater treatment plant located in Winnebago County, Illinois, serving a population of approximately 2,400 residents. The facility operates under the regulatory framework of the United States Clean Water Act, which governs wastewater discharges through the National Pollutant Discharge Elimination System (NPDES) permit program. As a secondary treatment plant, it meets the standard level of treatment required for municipal wastewater in the US. The plant has a design capacity of 1,514.16 megaliters and currently treats an annual discharge volume of 832.79 megaliters. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The plant's capacity utilization suggests it operates below its designed capacity, indicating room for future growth. The treated effluent from the plant is discharged into local waterways that ultimately drain into the Mississippi River basin. This region is part of the Upper Mississippi River watershed, which supports diverse aquatic ecosystems and provides drinking water for millions downstream. The plant's operations contribute to protecting water quality in this ecologically significant basin.

The plant discharges into local streams that flow into the Rock River, a tributary of the Mississippi River. The Mississippi River basin is one of the largest watersheds in North America, supporting diverse aquatic life including fish, mussels, and migratory birds. The region's agricultural landscape means nutrient management is critical to prevent downstream eutrophication in the Gulf of Mexico.