Calvin STP - Secondary Wastewater Treatment Plant in Hughes County, Oklahoma

Calvin STP is a municipal wastewater treatment facility located in Hughes County, Oklahoma, along US 270 and OK 1. It serves a small community of 279 residents, operating as a secondary treatment plant under the regulatory framework of the United States Clean Water Act. The plant has a designed capacity of 113.56 million gallons per day and a discharge volume of 113.56 million gallons per day, indicating full utilization. As a secondary treatment facility, it provides biological treatment to remove organic matter and suspended solids, meeting the national standards for wastewater discharge. The treated effluent is discharged into local streams that drain into the Canadian River watershed, ultimately flowing into the Arkansas River and the Mississippi River system. This contributes to the ecological health of downstream aquatic habitats, supporting diverse fish and wildlife populations in the region.

The plant discharges into local tributaries of the Canadian River, which flows into the Arkansas River and eventually the Mississippi River. This watershed supports diverse aquatic life and provides habitat for migratory birds. The secondary treatment process helps protect downstream water quality by reducing nutrient and organic loads.