E COLUMBIA SD 1 Wastewater Treatment Plant, Caldwell Parish, Louisiana

E COLUMBIA SD 1 is a municipal wastewater treatment plant located on Airport Road in Caldwell Parish, Louisiana, United States. The facility serves a small population of 650 residents, reflecting its role in a rural community within the state. The plant employs advanced treatment processes, which go beyond secondary treatment to remove nutrients and other pollutants. With a designed capacity of 227.12 megaliters and an annual discharge volume of 189.27 megaliters, the plant operates under the U.S. Clean Water Act, which requires National Pollutant Discharge Elimination System (NPDES) permits for all point source discharges. Advanced treatment is typical for facilities in sensitive watersheds or those with strict effluent limits. The treated effluent is discharged into local waterways that ultimately drain into the Ouachita River basin, contributing to the Mississippi River watershed and the Gulf of Mexico. The plant's advanced treatment helps protect downstream aquatic ecosystems and supports water quality in the region.

The plant discharges into local streams that flow into the Ouachita River, part of the larger Mississippi River basin. This watershed supports diverse aquatic life and provides habitat for fish and migratory birds. The advanced treatment reduces nutrient loading, which is critical for preventing hypoxia in the Gulf of Mexico, where excess nutrients from the Mississippi River contribute to a large dead zone each summer.