VETROZ Wastewater Treatment Plant, Vétroz, Valais, Switzerland

The VETROZ wastewater treatment plant is located in Vétroz, a municipality in the Valais/Wallis canton of Switzerland. The plant serves a population of approximately 14,094 people and has a designed capacity of 1.00, indicating it is a medium-sized facility for the region. Switzerland's wastewater treatment is regulated under the Swiss Water Protection Act (GSchG), which mandates advanced treatment for plants serving agglomerations over 10,000 people. For a plant of this scale, secondary treatment with nutrient removal is typically required to protect sensitive water bodies. The plant discharges into the local watershed, which drains into the Rhône River. The Rhône flows through the Valais valley and eventually into Lake Geneva (Lac Léman), a large alpine lake that supports diverse aquatic life and is an important ecological and recreational resource. The treatment plant plays a key role in maintaining water quality in this sensitive alpine environment.

The VETROZ plant discharges into the Rhône River basin, which flows through the Valais region and into Lake Geneva. Lake Geneva is a large, deep alpine lake that supports diverse aquatic ecosystems, including fish species such as Arctic char and whitefish. The plant's treatment performance is critical to preventing nutrient pollution that could lead to eutrophication in the lake.