CULLYSIEL Wastewater Treatment Plant, Bourg-en-Lavaux, Vaud, Switzerland

CULLYSIEL is a wastewater treatment plant located in Bourg-en-Lavaux, within the canton of Vaud, Switzerland. The plant serves a population equivalent of 5,619, placing it in the small to medium agglomeration category under Swiss regulations. It is situated near the shores of Lake Geneva, a major freshwater body in the region. As a Swiss plant, CULLYSIEL operates under the Swiss Water Protection Act (Gewässerschutzgesetz), which mandates appropriate treatment levels based on the receiving water body's sensitivity. For plants discharging into Lake Geneva, advanced treatment with phosphorus removal is typically required to prevent eutrophication. The designed capacity of 1.00 (likely in thousands of cubic meters per day) indicates the plant's scale. The treated effluent from CULLYSIEL ultimately discharges into Lake Geneva (Lac Léman), which drains via the Rhône River into the Mediterranean Sea. Lake Geneva is a vital freshwater resource for drinking water, recreation, and aquatic biodiversity. The plant plays a key role in protecting the lake's water quality from nutrient loading and contaminants.

CULLYSIEL discharges into Lake Geneva, a large alpine lake that is part of the Rhône River basin. The lake supports diverse aquatic life, including endemic fish species, and is an important drinking water source for the region. Downstream, the Rhône flows through France to the Mediterranean Sea, making nutrient control critical to prevent eutrophication in both the lake and the coastal zone.