STEP SOUBEY Wastewater Treatment Plant, Soubey, Jura, Switzerland

STEP SOUBEY is a municipal wastewater treatment plant located in the village of Soubey, within the Jura canton of Switzerland. The facility serves a small population of 107 residents, reflecting its role in a rural alpine community. The plant is situated in the Franches-Montagnes district, an area characterized by rolling hills and forests. The plant provides secondary treatment, which is the standard biological treatment stage 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 most inland plants. The facility has a designed capacity of 250 m³/day and currently treats an average daily flow of 48.57 m³, indicating ample reserve capacity. The treated effluent is discharged into a local watercourse that eventually drains into the Doubs River, a tributary of the Saône, which flows into the Rhône and ultimately the Mediterranean Sea. The plant's operation helps protect the sensitive karstic groundwater systems and surface waters of the Jura region, which support diverse aquatic life and are important for regional biodiversity.

The plant discharges into a small stream that feeds the Doubs River, which forms part of the Rhône basin. The Doubs River flows through the Jura Mountains and supports a variety of fish species, including brown trout and grayling. Downstream, the river joins the Saône, which flows into the Rhône and reaches the Mediterranean Sea. The region's karst geology makes groundwater particularly vulnerable to contamination, so effective wastewater treatment is critical for protecting local springs and drinking water sources.