Himmelried_Westschindelboden Wastewater Treatment Plant, Himmelried, Solothurn

Himmelried_Westschindelboden is a municipal wastewater treatment plant located in Himmelried, a village in the Solothurn canton of Switzerland. The plant serves a small population of 390 residents and operates with a designed capacity of 600 m³/day, currently discharging 177.03 m³/day of treated effluent. The plant provides secondary treatment, which is the standard biological treatment required under Swiss water protection regulations. Switzerland's Water Protection Act (Gewässerschutzgesetz) mandates that all wastewater receive appropriate treatment before discharge, with secondary treatment being the minimum for communities of this size. The plant's capacity utilization is well within its design limits, indicating adequate headroom for current loads. The treated effluent is discharged into the local Kaltbrunnental stream, which flows into the Birs River, a tributary of the Rhine. The Rhine ultimately drains into the North Sea. The plant plays a key role in protecting the water quality of the Birs and Rhine basins, supporting aquatic ecosystems and downstream water uses.

The plant discharges into the Kaltbrunnental stream, a small watercourse in the Jura region that feeds into the Birs River. The Birs flows into the Rhine near Basel, and the Rhine carries water to the North Sea. The watershed supports diverse aquatic life, including fish species such as brown trout and grayling, and is ecologically sensitive due to its karst geology and seasonal flow variations.