Avers Cresta Wastewater Treatment Plant, Avers, Graubünden, Switzerland

Avers Cresta is a municipal wastewater treatment plant located in the small Alpine village of Cresta, part of the municipality of Avers in the canton of Graubünden, Switzerland. The plant serves a population of 97 and operates with secondary treatment, which is typical for small, remote communities in the Swiss Alps. Its designed capacity is 228 m³/day, and it currently treats an average of 44.03 m³/day of wastewater. As a Swiss plant, Avers Cresta operates under the Swiss Water Protection Act (Gewässerschutzgesetz), which mandates secondary treatment for discharges into sensitive water bodies. The plant's secondary treatment ensures effective removal of organic matter and suspended solids, meeting national standards for small agglomerations. The facility is part of Switzerland's comprehensive wastewater infrastructure, which achieves high connection rates even in mountainous regions. The treated effluent from Avers Cresta is discharged into the local Alpine watershed, which ultimately drains into the Rhine River via the Hinterrhein system. The receiving waters are ecologically sensitive, supporting cold-water fish species and pristine aquatic habitats. 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 Alpine watershed of the Hinterrhein, a headwater tributary of the Rhine River. This high-altitude catchment is characterized by oligotrophic conditions and supports sensitive aquatic life, including brown trout and other cold-water species. The Rhine ultimately flows through several countries to the North Sea, making local treatment crucial for downstream ecosystem health and international water quality agreements.