CARNAC Kergouellec Wastewater Treatment Plant, Carnac, Brittany

The CARNAC Kergouellec wastewater treatment plant is located in Carnac, a coastal town in the Brittany region of France. The plant serves a population of about 29,525, placing it in the medium agglomeration category under EU classification. Under the EU Urban Waste Water Treatment Directive (91/271/EEC), plants serving agglomerations of this size are required to provide secondary treatment as a minimum. In sensitive areas, such as those near coastal waters, tertiary treatment may be mandated to reduce nutrient loads and protect marine ecosystems. The plant discharges treated effluent into the local watershed, which ultimately drains into the Atlantic Ocean. The coastal environment of the Gulf of Morbihan and the Quiberon Bay area supports diverse marine life and is ecologically sensitive, making effective wastewater treatment crucial for preserving water quality and biodiversity.

The plant's treated effluent flows into the local coastal watershed, eventually reaching the Atlantic Ocean near the Gulf of Morbihan. This area is ecologically sensitive, supporting diverse marine habitats including seagrass beds and nursery grounds for fish. Nutrient pollution from wastewater can lead to eutrophication, so advanced treatment is important to protect the coastal ecosystem.