CITY OF SULFUR SOUTH REGIONAL STP - Calcasieu Parish, Louisiana Wastewater Treatment Plant

The CITY OF SULFUR SOUTH REGIONAL STP is a municipal wastewater treatment facility located on Bayou d'Inde Road in Calcasieu Parish, Louisiana. It serves an estimated population of 36,720, classifying it as a medium-sized agglomeration under US EPA guidelines. The plant is situated inland, more than 50 kilometers from the Gulf Coast, and operates within the regulatory framework of the Clean Water Act. As a facility of this scale in the United States, the plant is expected to provide at least secondary treatment under the National Pollutant Discharge Elimination System (NPDES) permit program. The plant's compliance with discharge limits is overseen by the Louisiana Department of Environmental Quality. The treated effluent is discharged into Bayou d'Inde, a waterway that flows into the Calcasieu River and eventually reaches the Gulf of Mexico. This watershed supports diverse aquatic life and is an important ecological corridor in southwestern Louisiana. The plant's operations contribute to protecting downstream water quality in the Calcasieu River basin and the Gulf coastal ecosystem.

The plant discharges into Bayou d'Inde, which flows into the Calcasieu River, a major waterway in southwestern Louisiana. The Calcasieu River drains into the Gulf of Mexico via the Calcasieu Ship Channel, supporting estuarine habitats and commercial fisheries. The watershed is ecologically sensitive, hosting diverse aquatic species and serving as a migratory corridor for birds and fish. Protecting water quality in this basin is critical for maintaining the health of the Gulf's coastal wetlands and marine ecosystems.