West Liberty and Dundas STP - Planned Secondary Wastewater Treatment in Dundas, Illinois

West Liberty and Dundas STP is a planned wastewater treatment facility located in Dundas, Richland County, Illinois. Designed to serve a population of 525, the plant will provide secondary treatment for the community's municipal wastewater. As a secondary treatment plant, it will meet the minimum requirements under the US Clean Water Act's National Pollutant Discharge Elimination System (NPDES) program, which mandates secondary treatment for municipal discharges. The plant's designed capacity is 238.48 units, matching its discharge volume. The treated effluent will be discharged into a local waterway that drains into the Embarras River system, eventually reaching the Wabash River and the Ohio River, a major tributary of the Mississippi River. This downstream connectivity underscores the plant's role in protecting water quality across multiple states.

The plant's discharge enters a tributary of the Embarras River, which flows into the Wabash River and then the Ohio River, part of the Mississippi River basin. This watershed supports diverse aquatic life and provides habitat for fish and migratory birds. The region's agricultural landscape means nutrient management is a key ecological consideration to prevent downstream eutrophication.