Collinsville STP Wastewater Treatment Plant, Illinois | USA

Collinsville STP is a municipal wastewater treatment facility located in Collinsville, Illinois, serving a population of around 34,578. Situated in Madison County, the plant is part of the region's infrastructure for managing domestic wastewater from this medium-sized agglomeration. As a U.S. facility, the plant operates under the Clean Water Act, with discharge regulated by an NPDES permit issued by the Illinois Environmental Protection Agency. For a population of this scale, secondary treatment is typically required, and the plant's design and operation must meet federal and state effluent guidelines to protect water quality. The treated effluent from Collinsville STP is discharged into a local water body that ultimately drains into the Mississippi River system. The Mississippi River basin supports diverse aquatic life and provides drinking water for millions downstream. Proper treatment at this plant helps reduce nutrient and pollutant loads entering this major river system.

Collinsville STP discharges into a tributary of the Mississippi River, which flows into the Gulf of Mexico. The Mississippi River basin is a critical ecological corridor, supporting diverse fish and wildlife. Nutrient pollution from wastewater can contribute to hypoxic zones in the Gulf, making effective treatment important for downstream environmental health.