STE CROIX_AUBERSON Wastewater Treatment Plant, Sainte-Croix, Vaud, Switzerland

STE CROIX_AUBERSON is an advanced wastewater treatment plant located in Sainte-Croix, in the canton of Vaud, Switzerland. The plant serves a small population of 898 residents and has a designed capacity of 1500 m³/day, with an average discharge volume of 407.62 m³/day. As an advanced treatment facility, it provides tertiary-level purification, which includes nutrient removal and disinfection, exceeding the minimum secondary treatment requirements under Swiss water protection law. Switzerland's Water Protection Act (Gewässerschutzgesetz) mandates stringent effluent standards for all wastewater treatment plants, particularly those discharging into sensitive water bodies. The plant discharges into the local watershed, which ultimately drains into the Rhone River basin via the Arnon River. The treated effluent contributes to the protection of downstream aquatic ecosystems, including Lake Geneva (Lac Léman), a large alpine lake that supports diverse fish populations and serves as a critical freshwater resource for the region.

The plant's treated effluent flows into the Arnon River, a tributary of the Rhone River, which eventually reaches Lake Geneva (Lac Léman). Lake Geneva is a large, deep alpine lake that supports diverse aquatic life, including several fish species and migratory birds. The advanced treatment ensures minimal nutrient loading, helping to prevent eutrophication and maintain water quality in this ecologically sensitive lake and its downstream river systems.