Schluein Gruob Wastewater Treatment Plant, Ilanz/Glion, Graubünden, Switzerland

The Schluein Gruob wastewater treatment plant is located in Ilanz/Glion, within the Surselva region of Graubünden, Switzerland. It serves a population of around 20,513, making it a medium-sized agglomeration in the Alpine context. The plant is situated in the Rhine basin, contributing to the protection of local water resources. As a Swiss facility, the plant operates under the Swiss Water Protection Act (Gewässerschutzgesetz), which mandates advanced treatment for discharges into sensitive water bodies. For agglomerations of this scale, secondary treatment with nutrient removal is typically required to meet stringent effluent standards. The plant's treatment processes are designed to comply with these federal regulations, ensuring minimal environmental impact. The treated effluent is discharged into the Rhine River system, which flows through Switzerland, Germany, and the Netherlands before reaching the North Sea. The plant plays a crucial role in maintaining water quality in the Alpine Rhine, a region known for its pristine aquatic ecosystems and biodiversity. By reducing nutrient loads, the facility helps prevent eutrophication downstream in Lake Constance and the Rhine delta.

The plant discharges into the Rhine River basin, which drains into the North Sea via the Rhine-Meuse-Scheldt delta. The Alpine Rhine section supports sensitive aquatic habitats, including spawning grounds for migratory fish like the Atlantic salmon. The facility's nutrient removal helps protect downstream Lake Constance, a major drinking water reservoir, from algal blooms.