La Balme-de-Sillingy Wastewater Treatment Plant | Secondary Treatment in Auvergne-Rhône-Alpes

The La Balme-de-Sillingy wastewater treatment plant is located in the commune of La Balme-de-Sillingy, within the Auvergne-Rhône-Alpes region of France. It serves a population of approximately 1,989 residents, classifying it as a small agglomeration under French and EU regulations. The plant is situated inland, more than 10 km from the coast, and treats wastewater from the local community. The plant operates with secondary treatment, which is the standard requirement under the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size discharging into freshwater. The designed capacity is 3,000 m³/day, and the current discharge volume is 354.83 m³/day, indicating ample capacity for current loads. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The treated effluent is discharged into a local watercourse that ultimately drains into the Rhône River basin. The Rhône is one of Europe's major rivers, flowing into the Mediterranean Sea. The plant plays a key role in protecting the local watershed and downstream aquatic ecosystems from pollution, supporting water quality in the region.

The plant discharges into a tributary of the Rhône River basin, which flows through southeastern France and into the Mediterranean Sea. The Rhône basin supports diverse aquatic life and is an important ecological corridor. The plant's secondary treatment helps reduce nutrient and organic loads, protecting downstream water quality in a region known for its lakes and rivers, including nearby Lake Geneva.