GUER Wastewater Treatment Plant, Guer, Bretagne, France

The GUER wastewater treatment plant is located in Guer, a commune in the Morbihan department of Bretagne, France. It serves a population of approximately 4,788 people, classifying it as a small to medium agglomeration under EU classification. The plant is situated inland, away from coastal areas, and treats wastewater from the local community. 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. With a designed capacity of 6,000 m³/day and an average discharge volume of 854.17 m³/day, the facility operates well below its capacity, indicating potential for future growth or seasonal variations. The advanced treatment ensures high-quality effluent suitable for discharge into sensitive environments. The treated effluent is discharged into local water bodies that eventually drain into the Vilaine River basin and the Bay of Biscay. The plant plays a crucial role in protecting the region's waterways from nutrient pollution and maintaining water quality for downstream ecosystems, including the Gulf of Morbihan and the Atlantic coast.

The GUER plant discharges into the local watershed that feeds the Vilaine River, which flows into the Bay of Biscay on the Atlantic coast. This region supports diverse aquatic life and is important for migratory fish species. The advanced treatment helps reduce nutrient loads, protecting downstream estuaries and coastal waters from eutrophication.