SEILING WWT Wastewater Treatment Plant, Major County, Oklahoma

SEILING WWT is a municipal wastewater treatment facility located in Major County, Oklahoma, serving a population of 875. The plant provides secondary treatment, a standard level for small communities in the United States, ensuring compliance with the Clean Water Act's requirements for pollutant removal before discharge. The plant has a designed capacity of 454.25 thousand cubic meters and an annual discharge volume of 340.69 thousand cubic meters, indicating operational headroom. As a US facility, it operates under an EPA National Pollutant Discharge Elimination System (NPDES) permit, typically issued by the Oklahoma Department of Environmental Quality, which sets effluent limits to protect water quality. The treated effluent is discharged into a local water body within the Arkansas-White-Red River basin, ultimately draining into the Mississippi River and the Gulf of Mexico. The plant plays a key role in protecting local streams and groundwater from untreated sewage, supporting the ecological health of the region's prairie watersheds.

The plant discharges into a tributary of the North Canadian River, part of the Arkansas-White-Red River basin. This semi-arid region relies on surface water for agriculture and wildlife. Downstream, the river flows into the Arkansas River and eventually the Mississippi River, reaching the Gulf of Mexico. The plant helps prevent nutrient pollution that could contribute to hypoxic zones in the Gulf.