STEP SAIGNELEGIER Wastewater Treatment Plant, Saignelégier, Jura, Switzerland

STEP SAIGNELEGIER is a municipal wastewater treatment plant located in Saignelégier, in the District des Franches-Montagnes, Jura, Switzerland. The plant serves a population of around 2,500 people, making it a small-scale facility within the Swiss wastewater infrastructure. Switzerland enforces stringent water protection standards under the Swiss Waters Protection Act (Gewässerschutzgesetz). For agglomerations of this size, secondary treatment with nutrient removal is typically required to protect sensitive receiving waters. It operates within this robust regulatory framework. The plant discharges treated effluent into local watercourses that drain into the Doubs River, which flows through the Franches-Montagnes region and eventually into the Rhine basin. The surrounding area is characterized by karst landscapes and ecologically sensitive streams, making effective wastewater treatment critical for protecting aquatic habitats and groundwater quality.

The treated effluent from STEP SAIGNELEGIER ultimately reaches the Doubs River, a tributary of the Rhine, which flows through the Jura region and into the North Sea. The local watershed includes karst formations and ecologically sensitive streams that support diverse aquatic life, including fish species such as brown trout. Protecting water quality in this area is essential for maintaining the ecological integrity of the Doubs River and downstream Rhine ecosystem.