PRELES Wastewater Treatment Plant, Plateau de Diesse, Bern, Switzerland

PRELES is an advanced wastewater treatment plant located in Plateau de Diesse, in the Bern canton of Switzerland. It serves a small population of 800 residents, reflecting its role in a rural or peri-urban community. The plant is situated in the Jura bernois region, an area known for its rolling hills and agricultural landscape. The plant operates with advanced treatment processes, which go beyond the secondary treatment standard required by Swiss regulations for smaller agglomerations. Switzerland's Water Protection Act mandates that wastewater treatment plants meet stringent effluent quality standards, particularly in sensitive areas. The designed capacity of 1000 m³/day indicates that the plant is sized to handle the community's current and near-future needs, with a discharge volume of 363.14 m³/day suggesting moderate utilization. The treated effluent from PRELES is discharged into the local watershed, which ultimately drains into the Rhine River basin via the Aare River. The region's water bodies support diverse aquatic life and are important for both ecological balance and recreational use. The advanced treatment level helps protect downstream water quality, particularly in the Rhine, which flows through several countries before reaching the North Sea.

The plant discharges into the local watershed of the Jura bernois region, which drains into the Aare River, a major tributary of the Rhine. The Rhine basin is ecologically significant, supporting diverse fish species and serving as a migratory corridor. Advanced treatment at PRELES helps minimize nutrient and pollutant loads, protecting downstream aquatic habitats and water quality in the Rhine delta and North Sea.