Marion Lagoon Wastewater Treatment Plant, Marion, Louisiana

Marion Lagoon is a wastewater treatment facility located at 112 Crow Street in Marion, Union Parish, Louisiana. It serves a small population of 893 residents, reflecting the rural character of the area. The plant is situated inland, far from coastal zones, and operates under the regulatory framework of the United States Clean Water Act. The plant provides advanced treatment, which goes beyond the secondary treatment standard typically required for municipal facilities under the National Pollutant Discharge Elimination System (NPDES). Advanced treatment often targets nutrient removal or other specific pollutants, ensuring high-quality effluent. The plant's designed capacity is 454.25 thousand cubic meters, with an actual discharge volume of 302.83 thousand cubic meters, indicating operational headroom. The treated effluent is discharged into a local water body that ultimately drains into the Ouachita River basin, part of the Mississippi River watershed. This system supports diverse aquatic life and provides water for downstream communities. The plant's advanced treatment helps protect water quality in this ecologically significant region.

The plant discharges into a receiving water body within the Ouachita River basin, which flows into the Mississippi River and eventually the Gulf of Mexico. This watershed supports a variety of fish and wildlife, including migratory birds and aquatic species. Advanced treatment at this plant helps reduce nutrient loading, which is critical for preventing hypoxia in the Gulf of Mexico.