Bonvillars Wastewater Treatment Plant | Advanced Treatment in Vaud, Switzerland

The Bonvillars wastewater treatment plant is located in the municipality of Bonvillars, within the Jura-Nord vaudois district of Vaud canton, Switzerland. It serves a small population of 401 residents, reflecting the rural character of the area. The plant is situated near the A5 motorway and operates under Swiss federal water protection regulations. The facility provides advanced treatment, which goes beyond the secondary treatment standard required by Swiss law for smaller agglomerations. With a designed capacity of 938 m³/day and an actual discharge volume of 182.02 m³/day, the plant operates well below its capacity, indicating room for future growth or seasonal variations. Advanced treatment typically includes nutrient removal (nitrogen and phosphorus) to protect sensitive water bodies. The treated effluent is discharged into the local watershed, which ultimately drains into Lake Neuchâtel, one of Switzerland's largest lakes. Lake Neuchâtel is part of the Rhine basin and supports diverse aquatic life. The plant's advanced treatment helps maintain water quality in this ecologically important lake, which is used for recreation and drinking water supply downstream.

The Bonvillars plant discharges into a local watercourse that flows into Lake Neuchâtel, the largest lake entirely within Switzerland. Lake Neuchâtel drains via the Thielle Canal into the Aare River, which joins the Rhine and eventually reaches the North Sea. The lake supports a rich ecosystem, including fish species such as perch and pike, and is an important migratory corridor for birds. Advanced treatment at the plant helps control nutrient loading, preventing eutrophication in the lake.