HERBIGNAC bourg Wastewater Treatment Plant, Herbignac, Pays de la Loire

HERBIGNAC bourg is a municipal wastewater treatment plant located in Herbignac, a commune in the Loire-Atlantique department of Pays de la Loire, France. The plant serves a population of 3,350 and has a designed capacity of 6,700 cubic meters per day, with a current discharge volume of approximately 598 m³/day. It is situated inland, more than 10 km from the coast, but within 50 km of the Atlantic Ocean. 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 operates under French regulations that implement the EU directive, ensuring compliance with discharge standards. Treated effluent from the plant is discharged into local watercourses that eventually drain into the Atlantic Ocean via the Vilaine River or nearby coastal wetlands. The region's aquatic ecosystems benefit from the advanced treatment, which reduces nutrient loading and helps maintain water quality in downstream environments, including the Gulf of Morbihan and the Loire estuary.

The plant discharges into local streams that flow toward the Atlantic coast, likely contributing to the Vilaine River basin or the Brière regional natural park wetlands. These areas support diverse aquatic life, including migratory fish species and waterbirds. Advanced treatment reduces nutrient pollution, protecting downstream estuarine and marine habitats from eutrophication.