Charleston WWTP - Wastewater Treatment in Charleston, Illinois

Charleston WWTP is a municipal wastewater treatment facility located in Charleston, Coles County, Illinois. The plant serves a population of around 32,000 people, typical of a medium-sized agglomeration in the Midwestern United States. As a US facility, the plant operates under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Illinois Environmental Protection Agency. For a population of this scale, secondary treatment is the minimum standard, with potential for additional nutrient removal to protect downstream water quality. The plant's treated effluent flows into local streams that drain into the Embarras River, a tributary of the Wabash River, which ultimately joins the Ohio River and then the Mississippi River. This watershed supports diverse aquatic life and provides drinking water for downstream communities, making effective treatment critical for regional water quality.

The plant discharges into the Embarras River watershed, which flows through east-central Illinois before joining the Wabash River. The Wabash River drains into the Ohio River, a major tributary of the Mississippi River. This river system supports a variety of fish and wildlife, including several species of freshwater mussels and migratory birds. Nutrient loading from wastewater can contribute to algal blooms and hypoxia in the Gulf of Mexico, so effective treatment is important for downstream ecosystem health.