BOLTIGEN Wastewater Treatment Plant, Reidenbach, Switzerland

BOLTIGEN is a wastewater treatment plant located in Reidenbach, a locality within the municipality of Boltigen in the Bern/Berne canton of Switzerland. The plant serves a population of approximately 1,400 people, placing it in the small agglomeration category under Swiss regulations. The facility operates with advanced treatment, which goes beyond the secondary treatment standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC). Although Switzerland is not an EU member, its water protection legislation aligns with high standards, ensuring effective removal of nutrients and pollutants. The plant has a designed capacity of 2,500 m³/day and currently discharges 635.49 m³/day, indicating significant reserve capacity. The treated effluent is discharged into the local watershed, which ultimately drains into the Simme River, a tributary of the Kander River, and then into the Aare River, a major tributary of the Rhine. The Rhine flows through several countries before reaching the North Sea, making the plant's advanced treatment important for downstream water quality and ecosystem health.

The plant discharges into the Simme River catchment, which flows into the Kander River and then the Aare River, part of the Rhine basin. The Rhine is a major European waterway supporting diverse aquatic life and providing drinking water for millions. Advanced treatment at this plant helps reduce nutrient loads, protecting downstream ecosystems and maintaining water quality in the Rhine delta and the North Sea.