THONON LES BAINS Wastewater Treatment Plant, Thonon-les-Bains, Auvergne-Rhône-Alpes

The THONON LES BAINS wastewater treatment plant is located in Thonon-les-Bains, within the Auvergne-Rhône-Alpes region of France. Serving a population equivalent of 95,520, it is classified as a large agglomeration under the EU Urban Waste Water Treatment Directive (91/271/EEC). The plant is situated near the southern shore of Lake Geneva, one of Europe's largest freshwater lakes. As a facility serving over 15,000 population equivalent, the plant is required to meet secondary treatment standards under the EU directive. For discharges into sensitive areas like Lake Geneva, tertiary treatment for nutrient removal (nitrogen and phosphorus) is typically mandated to prevent eutrophication. The plant's designed capacity is 1.00 (likely in cubic meters per day or similar unit), indicating its scale. The treated effluent is discharged into Lake Geneva, which is part of the Rhône River basin. Lake Geneva is a critical freshwater resource for drinking water, recreation, and biodiversity. The plant plays a key role in protecting the lake's water quality by reducing pollutant loads, supporting aquatic life, and maintaining the ecological balance of this alpine lake.

The plant discharges into Lake Geneva, the largest alpine lake in Europe, which drains via the Rhône River into the Mediterranean Sea. The lake supports diverse aquatic ecosystems, including endemic fish species and migratory birds. Nutrient pollution from wastewater can lead to algal blooms, so the plant's treatment performance is vital for maintaining oligotrophic conditions and safeguarding drinking water supplies for downstream communities.