MISERIEUX Wastewater Treatment Plant, Sainte-Euphémie, Auvergne-Rhône-Alpes

The MISERIEUX wastewater treatment plant is located in Sainte-Euphémie, a commune in the Ain department of the Auvergne-Rhône-Alpes region, France. It serves a population of approximately 2,250 residents, classifying it as a small agglomeration under French and EU regulations. The plant is situated inland, away from coastal areas, and its operations are part of the regional water management infrastructure. The plant employs advanced treatment processes, which go beyond the secondary treatment standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. With a design capacity of 2,433 m³/day and an actual discharge volume of 401.40 m³/day, the facility operates well below its capacity, indicating room for future growth or seasonal variations. The plant's advanced treatment ensures high-quality effluent, reducing nutrient loads and protecting receiving waters. The treated effluent is discharged into local watercourses that ultimately drain into the Rhône River basin, a major hydrological system in Europe. The Rhône flows into the Mediterranean Sea, making the plant's performance important for downstream water quality and marine ecosystems. The advanced treatment helps mitigate eutrophication risks and supports biodiversity in the region's rivers and wetlands.

The plant discharges into local streams that feed into the Saône River, a major tributary of the Rhône River. The Rhône basin supports diverse aquatic life and is an important migratory corridor for fish species. The advanced treatment reduces nutrient and pollutant loads, helping to protect downstream water quality in the Rhône delta and the Mediterranean Sea. The region's temperate climate and agricultural land use make nutrient control particularly important for preventing algal blooms.