Waynesville Wastewater Treatment Plant, Illinois | Advanced Treatment Facility

The Waynesville wastewater treatment plant is located in Waynesville, Illinois, United States. It serves a small community of 438 residents, reflecting its role as a local municipal facility in DeWitt County. The plant provides advanced treatment, which goes beyond the secondary treatment standard required by the US Clean Water Act. With a designed capacity of 416.39 units and a discharge volume of 416.40 units, it operates near full capacity. As a US facility, it is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Illinois Environmental Protection Agency, ensuring compliance with water quality standards. The treated effluent is discharged into local waterways that ultimately drain into the Illinois River basin, a major tributary of the Mississippi River. The plant's advanced treatment helps protect downstream aquatic ecosystems and supports the ecological health of the region's freshwater resources.

The plant discharges into the Illinois River watershed, which flows into the Mississippi River and eventually the Gulf of Mexico. This region supports diverse aquatic life and is part of a major migratory corridor for waterfowl. Advanced treatment reduces nutrient loading, helping to mitigate downstream hypoxia in the Gulf.