Valsot Martina Wastewater Treatment Plant, Valsot, Graubünden, Switzerland

The Valsot Martina wastewater treatment plant is located in the village of Martina, part of the municipality of Valsot in the Engiadina Bassa/Val Müstair region of Graubünden, Switzerland. This facility serves a population of approximately 968 residents, reflecting its role as a small-scale municipal treatment plant in a rural Alpine setting. The plant provides secondary treatment, which is the standard biological treatment required under Swiss water protection legislation (Gewässerschutzgesetz). With a designed capacity of 1,000 m³/day and an average discharge volume of 439.40 m³/day, the plant operates well within its capacity. Swiss regulations mandate that all wastewater treatment plants meet stringent effluent standards to protect sensitive Alpine water bodies. Treated effluent from the plant is discharged into the local hydrological network, which ultimately drains into the Inn River (En) and then into the Danube River basin, reaching the Black Sea. The plant plays a crucial role in protecting the pristine Alpine streams and rivers of the Engadin region, which support diverse aquatic life and are important for tourism and recreation.

The plant discharges into the Inn River catchment, which flows through the Engadin valley and eventually joins the Danube, reaching the Black Sea. The receiving waters are ecologically sensitive Alpine streams that support brown trout and other cold-water species. The region's water quality is vital for downstream ecosystems and for maintaining the natural beauty of the Swiss National Park area nearby.