STALDEN Wastewater Treatment Plant, Stalden (VS), Valais, Switzerland

STALDEN is a wastewater treatment plant located in Stalden (VS), within the Valais/Wallis canton of Switzerland. The facility serves a population of around 4,578 residents, placing it in the small-to-medium agglomeration category under Swiss water protection regulations. As a Swiss plant, STALDEN operates under the Swiss Water Protection Act (Gewässerschutzgesetz), which mandates appropriate treatment standards based on the size and sensitivity of the receiving environment. For agglomerations of this scale, secondary treatment is typically required, with additional nutrient removal if the discharge affects sensitive water bodies. The plant discharges into the local watershed, which ultimately drains into the Rhone River via the Vispa River. The Rhone flows through the Valais region and into Lake Geneva (Lac Léman), a major European lake with significant ecological and recreational value. The treatment plant plays a key role in protecting downstream water quality in this alpine environment.

The STALDEN plant is situated in the alpine Valais region, where the local watercourse feeds into the Vispa River, a tributary of the Rhone River. The Rhone flows through the Rhone Valley into Lake Geneva, one of the largest freshwater lakes in Europe. The watershed supports diverse aquatic life and is important for regional biodiversity. The plant's discharge must meet strict Swiss standards to protect the sensitive alpine streams and downstream lake ecosystem.