Saint-Léger-sous-Cholet le Chiron Wastewater Treatment Plant, Pays de la Loire

The Saint-Léger-sous-Cholet le Chiron wastewater treatment plant is located in the commune of Saint-Léger-sous-Cholet, within the Maine-et-Loire department of Pays de la Loire, France. It serves a population of approximately 2,195 residents, classifying it as a small agglomeration under French and EU regulations. The plant employs advanced treatment processes, which go beyond the secondary treatment standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. Its designed capacity is 3,533 m³/day, and it currently discharges 391.58 m³/day of treated wastewater, indicating significant reserve capacity. Treated effluent from the plant is discharged into the local watershed, which ultimately drains into the Loire River basin. The Loire is France's longest river and a major ecological corridor, supporting diverse aquatic life and migratory fish species. The advanced treatment helps protect downstream water quality in this sensitive river system.

The plant discharges into the local watercourse within the Loire River basin. The Loire River flows westward through the Pays de la Loire region and into the Atlantic Ocean near Saint-Nazaire. This basin supports a rich diversity of fish, including Atlantic salmon and European eel, and is an important migratory corridor. Advanced treatment at this plant helps reduce nutrient loading and protect the ecological health of the downstream river and estuary.