PEKIN STP 1 - Pekin, Illinois Wastewater Treatment Plant

PEKIN STP 1 is a municipal wastewater treatment plant located in Pekin, Illinois, along the Illinois River. The plant serves a population of approximately 35,857 residents in the Pekin area, operating under the regulatory framework of the United States Clean Water Act. As a medium-sized facility, it is subject to National Pollutant Discharge Elimination System (NPDES) permitting requirements administered by the Illinois Environmental Protection Agency. Under the Clean Water Act, municipal treatment plants of this scale are typically required to provide at least secondary treatment, which involves biological processes to remove organic matter and suspended solids. The plant's treatment processes and capacity are designed to meet state and federal water quality standards, ensuring that effluent discharged does not impair the receiving water body. The plant's treated effluent is discharged into the Illinois River, a major tributary of the Mississippi River. The Illinois River basin supports diverse aquatic life and is an important migratory corridor for fish and waterfowl. Downstream, the Mississippi River carries the flow to the Gulf of Mexico, where nutrient loading from upstream sources can contribute to hypoxic zones. Proper treatment at plants like PEKIN STP 1 helps mitigate such impacts.

PEKIN STP 1 discharges into the Illinois River, which flows southwest to join the Mississippi River near Grafton, Illinois. The Mississippi River then empties into the Gulf of Mexico. The Illinois River watershed supports a variety of fish species and provides critical habitat for migratory birds along the Mississippi Flyway. Nutrient and pollutant loads from wastewater treatment plants in the basin can affect downstream water quality, including contributing to the seasonal hypoxic zone in the Gulf of Mexico.