STEP SAULCY Wastewater Treatment Plant, Saulcy, Jura, Switzerland

STEP SAULCY is a municipal wastewater treatment plant located in Saulcy, in the Jura canton of Switzerland. It serves a small population of 271 residents, reflecting the rural character of the area. The plant is situated in the District de Delémont, near the border with France. The plant provides secondary treatment, which is the standard biological treatment stage required under Swiss water protection legislation. With a designed capacity of 633 m³/day and an actual discharge volume of 123.01 m³/day, the facility operates well below its capacity, indicating ample headroom for future growth or seasonal variations. Swiss regulations, aligned with the EU Urban Waste Water Treatment Directive, mandate secondary treatment for agglomerations of this size. The treated effluent is discharged into local watercourses that ultimately drain into the Rhine River basin via the Birs River, which flows through the Jura region. The Rhine is a major European waterway, and the plant's discharge contributes to the overall water quality in this transboundary river system. The surrounding Jura landscape is characterized by limestone karst and forests, making groundwater protection a key environmental consideration.

The plant discharges into small streams in the Jura region, which are part of the Rhine River basin via the Birs River. The Rhine flows through Switzerland, Germany, and the Netherlands before reaching the North Sea. The Jura watershed supports diverse aquatic life, including brown trout and other cold-water species, and the karst geology makes the area sensitive to pollution. Protecting water quality in this headwater region is critical for downstream ecosystems and drinking water supplies.