Bellevaux Wastewater Treatment Plant, Haute-Savoie, France

Bellevaux wastewater treatment plant is located in the commune of Bellevaux, in the Haute-Savoie department of the Auvergne-Rhône-Alpes region, France. The plant serves a population of approximately 2,068 and is situated in a mountainous area near the Swiss border. It is part of the municipal infrastructure managed by the local authorities. The plant employs advanced treatment processes, which go beyond the secondary treatment required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. With a designed capacity of 5,000 cubic meters per day and an average discharge volume of about 369 cubic meters per day, the plant operates well within its capacity. The advanced treatment ensures high-quality effluent suitable for discharge into sensitive environments. The treated wastewater is discharged into local watercourses that eventually drain into the Dranse River and then into Lake Geneva (Lac Léman), a major alpine lake. The plant's proximity to the coast (within 10 km of Lake Geneva's shore) and its advanced treatment level help protect the lake's water quality and the downstream Rhône River ecosystem, which supports diverse aquatic life and is an important migratory corridor.

The plant discharges into the Dranse River watershed, which flows into Lake Geneva, one of the largest freshwater lakes in Europe. Lake Geneva is ecologically sensitive, supporting diverse aquatic species and serving as a critical water resource. The advanced treatment at Bellevaux helps minimize nutrient loading and protects the lake's water quality, which is vital for downstream ecosystems along the Rhône River to the Mediterranean Sea.