ROLLE AIER Wastewater Treatment Plant, Rolle, Vaud, Switzerland

ROLLE AIER is a wastewater treatment plant located at 7 Rue Arthur Vittel in Rolle, a municipality in the district of Nyon, Vaud, Switzerland. The plant serves a population of approximately 13,022 people, placing it in the medium agglomeration category under Swiss and EU regulatory frameworks. As a Swiss plant, ROLLE AIER operates under the Swiss Water Protection Act (Gewässerschutzgesetz), which mandates appropriate treatment levels to protect water bodies. For agglomerations of this size, secondary treatment is typically required, with potential for nutrient removal if discharging into sensitive areas. The plant's treated effluent ultimately discharges into the Lake Geneva basin (Lac Léman), a major Alpine lake that drains via the Rhône River into the Mediterranean Sea. Lake Geneva is ecologically sensitive, supporting diverse aquatic life and serving as a critical freshwater resource for the region. The plant's proximity to the lake underscores the importance of effective treatment to prevent eutrophication and protect water quality.

ROLLE AIER discharges into the Lake Geneva watershed, which flows via the Rhône River to the Mediterranean Sea. Lake Geneva is a large, deep oligotrophic lake that supports diverse fish species and provides drinking water for millions. The plant's location within 50 km of the coast and near the lake requires advanced treatment to minimize nutrient loading and protect aquatic ecosystems.