Saint-Loup-sur-Semouse Wastewater Treatment Plant, Bourgogne-Franche-Comté, France

The Saint-Loup-sur-Semouse wastewater treatment plant is located in the commune of Saint-Loup-sur-Semouse, within the Bourgogne-Franche-Comté region of eastern France. The facility serves a population of 4,274 and is classified as a small agglomeration under French regulations. The plant employs advanced treatment processes, exceeding the secondary treatment standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. With a designed capacity of 6,000 m³/day and an average daily discharge of 762.47 m³, the plant operates well below its capacity, indicating room for future growth or seasonal variations. The treated effluent is discharged into the local watershed, which ultimately drains into the Saône River and then the Rhône River, flowing toward the Mediterranean Sea. The plant plays a key role in protecting the water quality of the Semouse River and downstream aquatic ecosystems.

The plant discharges into the Semouse River, a tributary of the Lanterne, which flows into the Saône River and eventually the Rhône River, reaching the Mediterranean Sea. The watershed supports diverse aquatic life and is part of a larger river network that provides habitat for fish species such as brown trout and European eel. The advanced treatment helps minimize nutrient and pollutant loads, protecting downstream water quality in this ecologically sensitive region.