Bivio Wastewater Treatment Plant, Surses, Graubünden, Switzerland

The Bivio wastewater treatment plant is located in the Swiss Alps, serving the municipality of Surses in the canton of Graubünden. This facility treats wastewater from a population of approximately 1,087 residents, reflecting its role as a small alpine community plant. The plant is situated in a mountainous region, where cold temperatures and seasonal tourism can influence wastewater flows. As a secondary treatment plant, Bivio employs biological processes to reduce organic matter and suspended solids. The plant has a designed capacity of 2,500 m³/day, with an average discharge volume of 493.41 m³/day, indicating ample reserve capacity. Under Swiss water protection law (Gewässerschutzgesetz), all wastewater treatment plants must meet stringent effluent standards, and secondary treatment is the minimum requirement for discharges into sensitive alpine waters. The treated effluent is discharged into local streams that feed the Albula River, a tributary of the Rhine. The Rhine ultimately flows into the North Sea. The alpine watershed is ecologically sensitive, supporting diverse aquatic life and providing critical habitat for species such as the brown trout. The plant's operation helps protect downstream water quality in this pristine mountain environment.

The Bivio plant discharges into small alpine streams that flow into the Albula River, part of the Rhine basin. The Rhine travels through Switzerland, Germany, and the Netherlands before reaching the North Sea. The local watershed is characterized by oligotrophic conditions and supports sensitive aquatic ecosystems, including cold-water fish species. Protecting water quality in this alpine region is vital for maintaining biodiversity and the ecological integrity of downstream habitats.