Castor STP - Secondary Wastewater Treatment Plant in Castor, Louisiana

Castor STP is a municipal wastewater treatment facility located in Castor, Louisiana, a small town in Bienville Parish. The plant serves a population of 258 and operates under the regulatory framework of the United States Clean Water Act, which requires secondary treatment for municipal wastewater discharges. The plant provides secondary treatment, a standard biological process that removes organic matter and suspended solids. With a designed capacity of 113.56 thousand cubic meters per year and an actual discharge volume of 75.71 thousand cubic meters per year, the facility operates below its capacity. As a small inland plant, it is subject to National Pollutant Discharge Elimination System (NPDES) permitting administered by the Louisiana Department of Environmental Quality. The treated effluent is discharged into a local water body, likely a tributary of the Red River basin, which flows into the Mississippi River and ultimately the Gulf of Mexico. The plant's operations help protect downstream water quality in this ecologically significant river system.

The plant discharges into a local watercourse within the Red River basin, which drains into the Mississippi River and then the Gulf of Mexico. This watershed supports diverse aquatic life and is an important migratory corridor for fish and birds. The secondary treatment process reduces organic pollutants and suspended solids, helping to maintain water quality in the downstream river system.