Shawnee PWA WWT South Wastewater Treatment Plant, Shawnee, Oklahoma

Shawnee PWA WWT South is a municipal wastewater treatment facility located in Shawnee, Pottawatomie County, Oklahoma. The plant serves an estimated population of 21,519 people, placing it in the medium-sized agglomeration category for U.S. inland communities. As a U.S. facility, the plant operates under the National Pollutant Discharge Elimination System (NPDES) permit program established by the Clean Water Act. For communities of this scale, secondary treatment is typically required, and permits specify effluent limits for biochemical oxygen demand, total suspended solids, and other parameters to protect water quality. The plant's treated effluent is discharged into a local receiving water body, which ultimately drains into the Canadian River watershed and then into the Arkansas River system. This drainage basin supports diverse aquatic life and provides water for downstream communities and agriculture in central Oklahoma.

The plant discharges into a tributary of the Canadian River, which flows through central Oklahoma before joining the Arkansas River. This watershed supports a variety of fish species and provides habitat for migratory birds along the Central Flyway. The Arkansas River eventually drains into the Mississippi River, making water quality management at this plant important for downstream ecosystems in the Gulf of Mexico region.