TOLUCA STP - Advanced Wastewater Treatment in Toluca, Illinois

TOLUCA STP is an advanced wastewater treatment facility located in Toluca, Marshall County, Illinois, serving a population of 1,329. The plant operates under the U.S. Clean Water Act, which requires NPDES permits for discharges to surface waters. As an advanced treatment plant, it goes beyond secondary treatment to remove nutrients and other pollutants, ensuring high effluent quality. The plant treats an annual wastewater discharge volume of 529.96 thousand cubic meters, with a designed capacity of 757.08 thousand cubic meters. This capacity utilization of approximately 70% indicates room for future growth. The advanced treatment process typically includes biological nutrient removal, filtration, or disinfection, meeting stringent state and federal standards. The treated effluent is discharged to a local water body that ultimately drains into the Illinois River basin, part of the Mississippi River watershed. This region supports diverse aquatic life and is an important migratory corridor for birds. The plant's advanced treatment helps protect downstream water quality and ecosystem health.

The plant discharges into a tributary of the Illinois River, which flows into the Mississippi River and eventually the Gulf of Mexico. The watershed supports diverse aquatic species and is a critical habitat for migratory waterfowl. Advanced treatment reduces nutrient loading, helping to mitigate hypoxia in the Gulf of Mexico.