Sauget American Bottoms Regional STP - Cahokia, Illinois Wastewater Treatment

Sauget American Bottoms Regional STP is a wastewater treatment facility located in Cahokia, Illinois, within the St. Louis metropolitan area. It serves a population of around 72,467 residents, placing it in the medium-to-large agglomeration category for U. S. plants. As a facility operating under the U. S. Clean Water Act, it is subject to National Pollutant Discharge Elimination System (NPDES) permitting, which sets effluent limits to protect water quality. The plant discharges into the Mississippi River watershed, which drains into the Gulf of Mexico. The Mississippi River supports diverse aquatic life and is a critical migratory corridor for birds and fish. Downstream, the river contributes to the hypoxic zone in the Gulf, making nutrient management an important regional concern.

The plant discharges into the Mississippi River basin, which flows south to the Gulf of Mexico. This watershed supports a wide range of aquatic species and is an important migratory route. Downstream nutrient loading contributes to seasonal hypoxia in the Gulf, making effluent quality a key environmental consideration.