VERNOSC LES ANNONAY Wastewater Treatment Plant, Vernosc-lès-Annonay, France

VERNOSC LES ANNONAY is a municipal wastewater treatment plant located in Vernosc-lès-Annonay, a commune in the Ardèche department of the Auvergne-Rhône-Alpes region in southeastern France. The plant serves a population of 4,600, classifying it as a small to medium agglomeration under French and EU regulations. The facility provides secondary treatment, which is the standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size in non-sensitive areas. The plant has a designed capacity of 2,500 m³/day and currently treats an average daily flow of 820.63 m³, indicating significant spare capacity for future growth. The treated effluent is discharged into the local watershed, which ultimately drains into the Rhône River via the Cance River. The Rhône is a major European river that flows into the Mediterranean Sea. The plant plays a key role in protecting the water quality of the Cance and Rhône rivers, supporting aquatic life and downstream uses.

The plant discharges into the Cance River, a tributary of the Rhône River, which flows into the Mediterranean Sea. The Rhône basin supports diverse aquatic ecosystems, including fish species such as the European eel and various migratory fish. The plant's secondary treatment helps reduce organic pollution and nutrient loads, protecting water quality in the downstream river system and the Mediterranean coastal zone.