OKAWVILLE STP - Advanced Wastewater Treatment in Okawville, Illinois

OKAWVILLE STP is a municipal wastewater treatment facility located in Okawville, Washington County, Illinois. Serving a population of 1,057, the plant provides advanced treatment to protect public health and the environment. It is situated inland, away from coastal areas, and operates under the regulatory framework of the United States Clean Water Act. The plant employs advanced treatment processes, which go beyond secondary treatment to remove nutrients and other pollutants. With a designed capacity of 946.35 cubic meters per day and a current discharge volume of 227.13 cubic meters per day, the facility has ample capacity for future growth. As a US plant of this scale, it is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Illinois Environmental Protection Agency. The treated effluent is discharged into local streams that flow into the Kaskaskia River, a major tributary of the Mississippi River. The Kaskaskia River supports diverse aquatic life and provides recreational opportunities. The plant's advanced treatment helps maintain water quality in this important watershed, which ultimately drains into the Gulf of Mexico.

OKAWVILLE STP discharges into local waterways that feed the Kaskaskia River, a significant tributary of the Mississippi River. The Kaskaskia River basin supports a variety of fish and wildlife, including migratory birds and freshwater mussels. The plant's advanced treatment reduces nutrient loading, helping to mitigate downstream hypoxia in the Gulf of Mexico. The surrounding area is primarily agricultural, making nutrient removal critical for protecting water quality.