Colchester WWTP - Secondary Wastewater Treatment in Colchester, Illinois

Colchester WWTP is a municipal wastewater treatment facility located at 598 South Main Street in Colchester, Illinois, United States. The plant serves a population of approximately 1,763 residents in this small community within McDonough County. As a secondary treatment plant, Colchester WWTP provides biological treatment to remove organic matter and suspended solids. The facility has a designed capacity of 870.64 million gallons per year and currently discharges 643.52 million gallons annually. Under the U.S. Clean Water Act, such plants must comply with National Pollutant Discharge Elimination System (NPDES) permits issued by the Illinois Environmental Protection Agency. The treated effluent from Colchester WWTP is discharged into a local waterway that ultimately drains into the Mississippi River basin. This contributes to the overall water quality management of the region, supporting downstream aquatic ecosystems and recreational uses. The plant's operations help protect local streams from untreated wastewater pollution.

Colchester WWTP discharges into a tributary of the Mississippi River basin, which flows into the Gulf of Mexico. The plant's secondary treatment reduces organic pollutants and nutrients, helping to prevent eutrophication in downstream waters. The local watershed supports diverse aquatic life and is part of a larger network of rivers that sustain agriculture and communities in the Midwest.