City of Pinckneyville STP 2 - Advanced Wastewater Treatment in Pinckneyville, Illinois

City of Pinckneyville STP 2 is an advanced wastewater treatment facility located in Pinckneyville, Illinois, serving a population of approximately 5,316. The plant is situated inland, away from coastal areas, and plays a key role in managing municipal wastewater for the community. The plant provides advanced treatment, which goes beyond secondary treatment to remove nutrients and other pollutants. With a designed capacity of 1,654.22 million gallons per year and an actual discharge volume of 810.08 million gallons per year, the facility operates well within its capacity. As a US plant, it is subject to the National Pollutant Discharge Elimination System (NPDES) permitting program under the Clean Water Act, which sets effluent limits to protect water quality. The treated effluent is discharged into local waterways that ultimately drain into the Mississippi River Basin. The plant's advanced treatment helps protect downstream aquatic ecosystems and supports the overall health of the Mississippi River watershed, which is ecologically significant for its diverse fish and wildlife habitats.

The plant discharges into local streams that flow into the Mississippi River Basin, a major watershed that drains much of the central United States. The Mississippi River supports diverse aquatic life, including over 260 fish species, and provides critical habitat for migratory birds. Advanced treatment at this plant helps reduce nutrient loading, which is important for preventing hypoxia in the Gulf of Mexico.