Montalieu-Vercieu Wastewater Treatment Plant | Auvergne-Rhône-Alpes, France

The Montalieu-Vercieu wastewater treatment plant is located in the commune of Montalieu-Vercieu, within the Isère department of the Auvergne-Rhône-Alpes region in southeastern France. It serves a population of approximately 5,172 residents, classifying it as a small to medium agglomeration under French and EU regulations. The plant employs advanced treatment processes, going beyond 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 4,083 m³/day and an average daily discharge of 922.68 m³/day, the facility operates well within its capacity, ensuring effective treatment of local wastewater. The treated effluent is discharged into the local watershed, which ultimately drains into the Rhône River basin. The Rhône is one of Europe's major rivers, flowing into the Mediterranean Sea. The advanced treatment level helps protect downstream aquatic ecosystems and supports water quality in the Rhône corridor, a vital ecological and economic artery.

The plant discharges into the Rhône River basin, which flows southward through the Auvergne-Rhône-Alpes region and into the Mediterranean Sea via the Camargue delta. The Rhône supports diverse aquatic life and is an important migratory corridor for fish species. Advanced treatment at this plant reduces nutrient and pollutant loads, helping to maintain water quality in the river and its downstream environments, including the ecologically sensitive Mediterranean coastal zone.