Sterlington STP - Secondary Wastewater Treatment in Sterlington, Louisiana

Sterlington STP is a municipal wastewater treatment facility located in Sterlington, Ouachita Parish, Louisiana. The plant serves a population of about 2,794, classifying it as a small community system within the state's wastewater infrastructure. The plant provides secondary treatment, which is the standard level required by the U.S. Clean Water Act for municipal facilities. With a designed capacity of 1,419.53 volume units and an average discharge of 511.03 volume units, the plant operates well below its capacity, indicating room for future growth. The facility is regulated under the National Pollutant Discharge Elimination System (NPDES) permit program, administered by the Louisiana Department of Environmental Quality. The treated effluent from Sterlington STP is discharged into local streams that flow into the Ouachita River basin, ultimately reaching the Mississippi River and the Gulf of Mexico. This watershed supports diverse aquatic life and is important for regional water quality. The plant's performance helps protect downstream ecosystems and recreational uses.

The plant discharges into tributaries of the Ouachita River, which flows south to the Mississippi River and into the Gulf of Mexico. This watershed supports a variety of fish and wildlife, including species of recreational and ecological importance. The region's humid subtropical climate and flat terrain make water quality management critical to prevent nutrient enrichment and maintain healthy aquatic habitats.