ROCHESIGE Wastewater Treatment Plant, Rennaz, Vaud, Switzerland

ROCHESIGE is an advanced wastewater treatment plant located in Rennaz, in the canton of Vaud, Switzerland. The facility serves a small population of 663 residents and has a designed capacity of 750 cubic meters per day, with an average discharge volume of 300.95 cubic meters per day. As an advanced treatment plant, ROCHESIGE likely employs tertiary processes such as nutrient removal or disinfection, exceeding the secondary treatment standards required under Swiss water protection law (Gewässerschutzgesetz). Switzerland's regulations align with the EU Urban Waste Water Treatment Directive, mandating advanced treatment for sensitive areas and larger agglomerations. The plant's discharge ultimately flows into the Rhône River basin, which drains into Lake Geneva (Lac Léman) and then the Mediterranean Sea via the Rhône. The facility's coastal proximity (within 10 km of Lake Geneva) underscores its role in protecting the lake's water quality, which supports tourism, drinking water, and aquatic ecosystems.

ROCHESIGE discharges into the Rhône River basin, which flows into Lake Geneva, a large alpine lake that serves as a critical freshwater resource and biodiversity hotspot. The lake supports diverse aquatic life, including endemic fish species, and is an important migratory corridor for birds. The plant's advanced treatment helps minimize nutrient loading and protect downstream water quality in the Rhône River and ultimately the Mediterranean Sea.