Mutten Wastewater Treatment Plant, Vaz/Obervaz, Graubünden, Switzerland

Mutten is a wastewater treatment plant located in the municipality of Vaz/Obervaz, within the canton of Graubünden (Grischun/Grigioni), Switzerland. The plant serves a small population of 139 people, reflecting its role in a rural Alpine community. Its location in the Albula region places it in a mountainous environment with sensitive water resources. The plant provides secondary treatment, which is the standard biological treatment required under Swiss wastewater regulations. Swiss law mandates that all wastewater treatment plants achieve secondary treatment or higher, with tertiary treatment required in sensitive areas. The plant has a designed capacity of 325 m³/day and currently discharges 63.10 m³/day, indicating it operates well below capacity. The treated effluent is discharged into the local watershed, which ultimately drains into the Rhine River via the Hinterrhein system. The Alpine streams in this region support diverse aquatic life, including brown trout and other cold-water species. The plant's operation helps protect downstream water quality in the Rhine basin, which flows through Switzerland, Germany, and the Netherlands before reaching the North Sea.

The plant discharges into the local watershed of the Albula region, a tributary of the Hinterrhein, which joins the Rhine River. The Rhine flows through Switzerland, Germany, and the Netherlands, eventually reaching the North Sea. The Alpine streams in this area are ecologically sensitive, supporting cold-water fish species and contributing to the overall health of the Rhine basin. The plant's secondary treatment helps reduce organic pollution and protect downstream aquatic habitats.