ALLANCHE BOURG Wastewater Treatment Plant, Allanche, Auvergne-Rhône-Alpes

ALLANCHE BOURG is a wastewater treatment facility located in the commune of Allanche, within the Cantal department of the Auvergne-Rhône-Alpes region in central France. The plant serves a small population of 637 residents and has a designed capacity of 3,500 cubic meters per day, indicating it is sized for seasonal or future growth. 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 discharges an average volume of 113.64 m³/day, well below its capacity. The treated effluent is discharged into the local watershed, which ultimately drains into the Alagnon River, a tributary of the Allier River, part of the Loire basin. The Loire River flows into the Atlantic Ocean. The advanced treatment helps protect the aquatic ecosystems of the Alagnon and downstream rivers, supporting biodiversity and water quality.

The plant discharges into the Alagnon River, which flows into the Allier River, a major tributary of the Loire River. The Loire basin is ecologically significant, supporting diverse fish species and migratory birds. Advanced treatment at this plant helps reduce nutrient loading, protecting downstream water quality in the Loire estuary and the Atlantic Ocean.