Marlow Northwest WWT - Grady County, Oklahoma Wastewater Treatment Plant

Marlow Northwest WWT is a municipal wastewater treatment facility located in Grady County, Oklahoma, United States. The plant serves a small population of 1,378 residents and operates with a designed capacity of 567.81 m³/day, currently treating an average of 529.96 m³/day. The plant provides secondary treatment, which is the standard level required by the U.S. Clean Water Act for municipal wastewater facilities. Under the National Pollutant Discharge Elimination System (NPDES), plants of this scale must meet effluent limits for biochemical oxygen demand and total suspended solids to protect receiving water quality. The treated effluent is discharged into local streams that drain into the Washita River basin, ultimately flowing into the Red River and the Gulf of Mexico. The plant plays a key role in protecting downstream aquatic ecosystems and maintaining water quality in the region.

The plant discharges into tributaries of the Washita River, which flows through southern Oklahoma before joining the Red River. The Red River forms the border between Texas and Oklahoma and empties into the Gulf of Mexico. The watershed supports diverse aquatic life, including several fish species, and is an important resource for agriculture and recreation. Proper treatment helps prevent nutrient enrichment and pathogen contamination in downstream waters.