ROUSSES Wastewater Treatment Plant, Les Rousses, Bourgogne-Franche-Comté

The ROUSSES wastewater treatment plant is located in Les Rousses, a commune in the Jura department of Bourgogne-Franche-Comté, France. It serves a population of 2,925 people, placing it in the small agglomeration category under French regulations. The plant is situated in the mountainous Jura region near the Swiss border. The plant employs advanced treatment processes, which go beyond the secondary treatment required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. Advanced treatment typically includes nutrient removal (nitrogen and phosphorus) to protect sensitive receiving waters. The plant has a designed capacity of 9,470 cubic meters per day and currently discharges an average of 521.81 cubic meters per day, indicating significant spare capacity. The treated effluent is discharged into local watercourses that drain into the Bienne River, a tributary of the Ain River, which flows into the Rhône River and eventually the Mediterranean Sea. The plant plays a key role in protecting the sensitive aquatic ecosystems of the Jura region, which are known for their karst geology and diverse freshwater habitats.

The ROUSSES plant discharges into the Bienne River watershed, which flows through the Jura mountains into the Ain River, a major tributary of the Rhône. The Rhône drains into the Mediterranean Sea. The region's karst landscape features porous limestone, making groundwater particularly vulnerable to contamination. The plant's advanced treatment helps protect downstream aquatic life and supports the ecological health of the Bienne and Ain rivers, which host species such as brown trout and European crayfish.