La Cavalerie Wastewater Treatment Plant: Advanced Treatment in Occitanie, France

The La Cavalerie wastewater treatment plant is located in the commune of La Cavalerie, in the Aveyron department of Occitanie, southern France. It serves a small population of approximately 2,228 residents, reflecting its role in a rural community. The plant is situated inland, far from the coast, and its operations are part of the regional water management infrastructure. The plant provides advanced treatment, which goes beyond the secondary treatment standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. Advanced treatment typically includes nutrient removal (nitrogen and phosphorus) to protect sensitive water bodies. The designed capacity is 2,917 cubic meters per day, with a reported discharge volume of 397.47 cubic meters per day, indicating ample capacity for current loads. The treated effluent is discharged into the local environment, ultimately draining into the Tarn River system, which flows into the Garonne River and then to the Atlantic Ocean. The plant's advanced treatment helps safeguard the ecological quality of the Tarn basin, which supports diverse aquatic life and is important for regional biodiversity.

The plant discharges into the Tarn River watershed, part of the larger Garonne basin that drains to the Atlantic Ocean. The Tarn River is known for its scenic gorges and supports a variety of fish species, including migratory trout. The advanced treatment at La Cavalerie reduces nutrient loading, helping to prevent eutrophication in downstream waters and protecting the ecological balance of this sensitive river system.