Scuol Sur En Wastewater Treatment Plant, Sur En, Graubünden, Switzerland

Scuol Sur En is a wastewater treatment plant located in Sur En, a village in the municipality of Scuol, in the Engadin region of Graubünden, Switzerland. The plant serves a small population of 176 people and is situated in the Swiss Alps, a mountainous area with sensitive alpine watersheds. The plant provides secondary treatment, which is the standard biological treatment required under Swiss water protection regulations. With a designed capacity of 413 m³/day and an average discharge volume of 79.89 m³/day, the plant operates well below its capacity, indicating sufficient headroom for current demand. Swiss wastewater treatment plants are regulated under the Federal Water Protection Act (Gewässerschutzgesetz), which mandates strict effluent standards to protect receiving waters. The treated effluent is discharged into the local watercourse, which flows into the Inn River (En in Romansh), a major tributary of the Danube. The Inn River eventually drains into the Black Sea via the Danube. The plant plays a key role in protecting the pristine alpine environment of the Engadin valley, which supports diverse aquatic life and is important for regional biodiversity.

The plant discharges into a local stream that feeds the Inn River, which flows through the Engadin valley and ultimately reaches the Black Sea via the Danube. The alpine watershed is ecologically sensitive, supporting cold-water fish species and clean-water invertebrates. The region's high-altitude environment requires careful wastewater management to prevent nutrient enrichment and protect downstream habitats.