Coursan Wastewater Treatment Plant, Occitanie, France

The Coursan wastewater treatment plant is located in Coursan, a commune in the Aude department of Occitanie, southern France. The facility serves a population of 4,521 and operates with advanced treatment processes, ensuring high-quality effluent before discharge. With a designed capacity of 9,000 m³/day and an average daily discharge volume of 806.54 m³/day, the plant operates well below its capacity. As a French facility, it complies with national regulations transposing the EU Urban Waste Water Treatment Directive (91/271/EEC), which mandates appropriate treatment levels for agglomerations of this size. The treated effluent is discharged into the local watershed, which ultimately drains into the Mediterranean Sea. The plant plays a key role in protecting the water quality of the Aude river basin and the coastal environment of the Gulf of Lion, supporting aquatic life and recreational uses downstream.

The plant discharges into the Aude river basin, which flows into the Mediterranean Sea near Narbonne. The downstream environment includes the Gulf of Lion, a productive marine area that supports diverse fisheries and seagrass meadows. The advanced treatment helps reduce nutrient loading, protecting coastal water quality and preventing eutrophication in this ecologically sensitive region.