CERONS Wastewater Treatment Plant, Cérons, Nouvelle-Aquitaine, France

The CERONS wastewater treatment plant is located in Cérons, a commune in the Gironde department of Nouvelle-Aquitaine, southwestern France. The plant serves a population of approximately 2,768 residents and operates with advanced treatment processes to ensure high-quality effluent. As an advanced treatment facility, CERONS goes beyond secondary treatment to remove nutrients and other pollutants, meeting stringent French and EU standards. The plant has a designed capacity of 2,000 m³/day and currently discharges 493.81 m³/day, indicating operational headroom. Under the EU Urban Waste Water Treatment Directive (91/271/EEC), plants serving agglomerations of this size are required to provide secondary treatment, but CERONS exceeds this requirement with advanced treatment. The treated effluent is discharged into the local watershed, which ultimately drains into the Garonne River and then the Gironde estuary, a major ecological and economic resource. The advanced treatment helps protect downstream aquatic life and supports the health of the estuary, which is important for fisheries and biodiversity.

The plant's discharge enters the Garonne River basin, flowing into the Gironde estuary, the largest estuary in western Europe. This estuary supports diverse aquatic life, including migratory fish species such as salmon and sturgeon. Advanced treatment at CERONS reduces nutrient loading, helping to prevent eutrophication in the sensitive estuarine environment.