Midwest City WWT | Oklahoma Wastewater Treatment Plant Serving 55,840

Midwest City WWT is a municipal wastewater treatment facility located in Midwest City, Oklahoma, within Oklahoma County. The plant serves a population of around 55,840, classifying it as a medium-sized agglomeration under US regulatory frameworks. As a US facility, the plant operates under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Oklahoma Department of Environmental Quality. These permits set effluent limits to protect water quality. For a plant of this scale, secondary treatment is typically required, with possible additional nutrient removal depending on the receiving water body. The plant's treated effluent is discharged into local waterways that ultimately drain into the Arkansas River basin, which flows into the Mississippi River and then the Gulf of Mexico. This downstream connection highlights the plant's role in protecting regional water quality and the ecologically significant Gulf Coast ecosystem.

The plant discharges into the Arkansas River watershed, which flows through Oklahoma and Arkansas before joining the Mississippi River. The Mississippi River delivers nutrients and pollutants to the Gulf of Mexico, where seasonal hypoxia affects marine life. The plant's treatment performance is critical for reducing nutrient loads that contribute to this dead zone. The local watershed supports diverse aquatic habitats and is important for regional biodiversity.