Caseyville Township East Wastewater Treatment Plant, Shiloh, Illinois

Caseyville Township East is a municipal wastewater treatment plant located in Shiloh, Illinois, serving a population of approximately 44,000. The facility is part of the region's wastewater infrastructure, managed by local authorities to meet community sanitation needs. As a medium-sized agglomeration, the plant plays a key role in protecting public health and the environment in Saint Clair County. The plant operates under the regulatory framework of the US Clean Water Act, which requires National Pollutant Discharge Elimination System (NPDES) permits for all discharges. For plants serving populations of this scale, secondary treatment is typically mandated, with additional nutrient removal requirements in sensitive watersheds. The facility's treatment processes are designed to meet state and federal effluent standards. The treated wastewater is discharged into local streams that drain into the Mississippi River basin, ultimately reaching the Gulf of Mexico. This downstream connection underscores the plant's role in regional water quality, as nutrients and pollutants from inland facilities can contribute to hypoxia in the Gulf. Proper treatment helps mitigate such impacts and supports aquatic life in the receiving waters.

The plant discharges into tributaries of the Mississippi River, which flows into the Gulf of Mexico. This watershed is ecologically significant, supporting diverse aquatic species and serving as a major migratory corridor for birds and fish. Nutrient loading from wastewater can contribute to algal blooms and hypoxic zones downstream, making effective treatment critical for the health of the Gulf ecosystem.