BOULAZAC Wastewater Treatment Plant, Trélissac, Nouvelle-Aquitaine

BOULAZAC is a wastewater treatment plant located in Trélissac, near Périgueux in the Dordogne department of Nouvelle-Aquitaine, France. The plant serves a population equivalent of around 30,800, placing it in the medium agglomeration category under French and EU regulations. As a French facility, BOULAZAC operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for agglomerations of this size. The plant's treatment process and capacity are managed to meet national standards set by the French water agencies, ensuring compliance with environmental quality objectives. The treated effluent is discharged into the local watershed, which ultimately drains into the Dordogne River and then into the Gironde estuary and the Atlantic Ocean. The plant plays a key role in protecting the water quality of the Dordogne River, a major river in southwestern France that supports diverse aquatic life and is important for regional biodiversity.

The plant discharges into the Dordogne River basin, which flows westward through the Périgord region and joins the Garonne to form the Gironde estuary, the largest estuary in Europe. The downstream environment includes sensitive aquatic habitats and migratory fish species such as salmon and eels. The plant's operations help maintain water quality in this ecologically significant river system.