LE MANS Les Etangs Wastewater Treatment Plant, Allonnes, France

LE MANS Les Etangs is a wastewater treatment plant located in Allonnes, near Le Mans, in the Sarthe department of Pays de la Loire, France. The plant serves a population of approximately 21,216, classifying it as a medium-sized agglomeration under EU regulations. As a French facility, the plant operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for agglomerations of this size. The directive also mandates more advanced treatment if the receiving waters are designated as sensitive areas. Compliance with national and EU standards is expected. The treated effluent from the plant is discharged into the local watershed, which ultimately drains into the Sarthe River, a tributary of the Loire River. The Loire River flows into the Atlantic Ocean, supporting diverse aquatic ecosystems along its course. The plant plays a key role in protecting the water quality of the Sarthe and Loire rivers, which are important for biodiversity and regional water resources.

The plant discharges into the Sarthe River, which flows into the Loire River, one of France's longest rivers, before reaching the Atlantic Ocean. The Loire basin supports a rich variety of aquatic life, including migratory fish species such as Atlantic salmon and European eel. The watershed is ecologically sensitive, and the plant's treatment helps maintain water quality standards in this important river system.