AIGLE Wastewater Treatment Plant, Aigle, Vaud, Switzerland

The AIGLE wastewater treatment plant is located in the municipality of Aigle, in the canton of Vaud, Switzerland. It serves a population equivalent of 21,851, classifying it as a medium-sized agglomeration under Swiss water protection standards. The plant is situated near the A9 motorway and the Rhône River valley, an area known for its alpine and agricultural landscape. Switzerland's water protection legislation, particularly the Waters Protection Act (GSchG) and the Waters Protection Ordinance (GSchV), mandates that wastewater treatment plants achieve appropriate treatment levels based on the sensitivity of receiving waters. For plants serving agglomerations of this size, secondary treatment with nutrient removal is typically required, especially in catchments draining to lakes or rivers with ecological sensitivity. The treated effluent from the Aigle plant ultimately discharges into the Rhône River basin, which flows through the Rhône Valley into Lake Geneva (Lac Léman) and eventually into the Mediterranean Sea via the Rhône River in France. The local watershed supports diverse aquatic life and is an important corridor for migratory fish species. The plant's operation contributes to protecting the water quality of the Rhône River and downstream ecosystems.

The Aigle plant discharges into the Rhône River basin, which flows through the Rhône Valley into Lake Geneva and then continues as the Rhône River through France to the Mediterranean Sea. This watershed supports diverse aquatic ecosystems, including fish populations such as trout and grayling, and is an important migratory corridor. The plant's treatment performance is critical to maintaining water quality in this ecologically sensitive alpine river system.