VAULION Wastewater Treatment Plant, Vaulion, Vaud, Switzerland

VAULION is a wastewater treatment plant located in Vaulion, within the District du Jura-Nord vaudois in the canton of Vaud, Switzerland. It serves a small population of 599 residents, reflecting its role in a rural or small community setting. The plant is situated inland, more than 10 km from the coast but within 50 km. The plant employs advanced treatment processes, which go beyond the secondary treatment standard required under Swiss regulations for smaller agglomerations. Switzerland's Water Protection Act mandates stringent treatment for discharges into sensitive water bodies, and advanced treatment typically includes nutrient removal (nitrogen and phosphorus) to protect water quality. The plant's designed capacity of 1,000 m³/day indicates it is sized to handle peak flows and future growth. The treated effluent from VAULION is discharged into local watercourses that ultimately drain into the Rhône River basin, which flows into Lake Geneva (Lac Léman) and then via the Rhône to the Mediterranean Sea. The plant's advanced treatment helps protect the ecological health of these downstream waters, which support diverse aquatic life and are important for recreation and drinking water supply.

The plant discharges into local streams that are part of the Rhône River basin. The Rhône flows into Lake Geneva, a large alpine lake with significant ecological and economic importance, and then continues to the Mediterranean Sea. Advanced treatment at VAULION reduces nutrient loads, helping to prevent eutrophication in Lake Geneva and downstream waters, which support fish populations and migratory birds.