Treffiagat Keristin Wastewater Treatment Plant, Léchiagat, Brittany

Treffiagat Keristin is an advanced wastewater treatment plant located in Léchiagat, within the commune of Treffiagat in the Finistère department of Brittany, France. The plant serves a population of approximately 3,636, placing it in the small agglomeration category under French and EU regulations. The plant employs advanced treatment processes, which go beyond secondary treatment to remove nutrients and other pollutants. It has a designed capacity of 7,200 m³/day and currently discharges 648.66 m³/day of treated wastewater. As a French facility, it operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires appropriate treatment for discharges into sensitive areas and coastal zones. The treated effluent is discharged into the coastal waters of the Atlantic Ocean near the Pays Bigouden region. This area supports diverse marine life and is important for local fisheries and tourism. The plant's advanced treatment helps protect the sensitive coastal ecosystem from nutrient pollution and other contaminants.

The plant discharges into the Atlantic Ocean near the coast of Brittany, a region known for its rich marine biodiversity and productive fisheries. The receiving waters are part of the Iroise Sea, which supports kelp forests, seabird colonies, and marine mammals. Advanced treatment at this plant reduces nutrient loads that could otherwise contribute to eutrophication in coastal waters.