Eldorado WTF Wastewater Treatment Plant, Eldorado, Illinois

Eldorado WTF is a municipal wastewater treatment facility located in Eldorado, Illinois, serving a population of around 4,838 residents. The plant is situated in Saline County, a region characterized by its rural and small-town setting in the southern part of the state. As a facility serving a small population, Eldorado WTF operates under the regulatory framework of the United States Clean Water Act, which mandates that publicly owned treatment works meet secondary treatment standards. The plant's treatment processes and capacity are designed to comply with National Pollutant Discharge Elimination System (NPDES) permits issued by the Illinois Environmental Protection Agency, ensuring that effluent quality protects receiving waters. The plant discharges treated wastewater into the local watershed, which ultimately drains into the Saline River, a tributary of the Ohio River. The Ohio River flows into the Mississippi River, which empties into the Gulf of Mexico. This downstream connection highlights the plant's role in protecting water quality across a large regional basin, supporting aquatic ecosystems and downstream communities.

Eldorado WTF discharges into the Saline River watershed, which flows into the Ohio River and then the Mississippi River before reaching the Gulf of Mexico. The receiving waters support diverse aquatic life and are important for regional biodiversity. The plant's operations help maintain water quality in this interconnected river system, which is vital for both ecological health and human uses such as recreation and drinking water supply.