Fontenilles Wastewater Treatment Plant, Occitanie, France

The Fontenilles wastewater treatment plant is located in the commune of Fontenilles, in the Occitanie region of southern France. It serves a population of approximately 3,700 people, classifying it as a small agglomeration under French and EU regulations. The plant is situated inland, away from coastal areas, and treats municipal wastewater from the local community. The plant employs advanced treatment processes, which go beyond the secondary treatment required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. With a designed capacity of 3,000 m³/day and an average daily discharge of 666 m³/day, the plant operates well within its capacity, ensuring effective treatment. Advanced treatment typically includes nutrient removal (nitrogen and phosphorus) to protect sensitive receiving waters. The treated effluent is discharged into a local watercourse that eventually drains into the Garonne River basin. The Garonne flows northward through Toulouse and into the Gironde estuary, reaching the Atlantic Ocean. The plant's advanced treatment helps protect the ecological health of these downstream waters, supporting aquatic life and water quality in the region.

The plant discharges into a tributary of the Garonne River, which flows through the Occitanie region and into the Gironde estuary on the Atlantic coast. The Garonne basin supports diverse aquatic ecosystems, including migratory fish species such as salmon and eels. Advanced treatment at Fontenilles reduces nutrient loads, helping to prevent eutrophication in downstream waters and maintain the ecological balance of the river and estuary.