CEPET_LABASTIDE SAINT SERNIN SITEC Wastewater Treatment Plant, Cépet, France

The CEPET_LABASTIDE SAINT SERNIN SITEC wastewater treatment plant is located in the commune of Cépet, within the Toulouse metropolitan area in the Occitanie region of southern France. The facility serves a population of around 2,106 residents and is designed to handle up to 5,000 cubic meters of wastewater per day, with a current discharge volume of approximately 376 m³/day. As an advanced treatment plant, it goes beyond secondary treatment to remove nutrients and other pollutants, meeting the stringent requirements of the EU Urban Waste Water Treatment Directive (91/271/EEC). For agglomerations of this size (under 10,000 population equivalent), the directive mandates secondary treatment, but the plant's advanced level indicates a higher standard, likely due to the sensitivity of the receiving environment. The plant discharges treated effluent into local watercourses that ultimately drain into the Garonne River, a major river in southwestern France that flows into the Gironde estuary and the Atlantic Ocean. The Garonne basin supports diverse aquatic ecosystems and is important for agriculture, drinking water, and recreation. The advanced treatment helps protect downstream water quality and ecological health.

The treated effluent from the plant enters local streams that feed into the Garonne River, which flows through Toulouse and eventually reaches the Gironde estuary on the Atlantic coast. The Garonne basin is ecologically significant, supporting species such as Atlantic salmon and European eel. Advanced treatment at this plant reduces nutrient loading, helping to prevent eutrophication in the estuary and coastal waters.