Saint-Vallier-de-Thiey Wastewater Treatment Plant, Alpes-Maritimes, France

The Saint-Vallier-de-Thiey wastewater treatment plant is located in the Alpes-Maritimes department of Provence-Alpes-Côte d'Azur, France. It serves a population of 5,208 in the commune of Saint-Vallier-de-Thiey and surrounding areas. The plant is situated inland, approximately 30 km from the Mediterranean coast. The plant provides secondary treatment, which is the standard required under the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations with a population equivalent between 2,000 and 10,000. Its designed capacity is 5,200 m³/day, and it treats an average daily volume of 929 m³, indicating significant spare capacity. The plant is operated as part of France's municipal wastewater infrastructure, regulated by the French water agencies and local authorities. Treated effluent is discharged into local watercourses that drain toward the Mediterranean Sea. The plant plays a key role in protecting the region's rivers and coastal waters from nutrient pollution, supporting the ecological health of the Côte d'Azur's marine environment. Its secondary treatment reduces organic matter and suspended solids, helping to maintain water quality in the sensitive karst landscape of the Alpes-Maritimes.

The plant discharges into local streams that flow into the Siagne River, which ultimately reaches the Mediterranean Sea near Cannes. The receiving waters support diverse aquatic life and are important for recreational and tourism activities along the French Riviera. The region's karst geology makes groundwater particularly vulnerable to contamination, so effective wastewater treatment is critical for protecting both surface and groundwater resources.