SAINT CAST LE GUILDO SEMAPHORE Wastewater Treatment Plant, Saint-Cast-le-Guildo, Brittany

SAINT CAST LE GUILDO SEMAPHORE is a wastewater treatment plant located in Saint-Cast-le-Guildo, a coastal commune in the Côtes-d'Armor department of Brittany, France. The plant serves a population of approximately 11,310, placing it in the medium agglomeration category under French and EU regulations. As a French facility, the plant operates under the EU Urban Waste Water Treatment Directive 91/271/EEC, which requires secondary treatment for agglomerations of this size discharging into coastal waters. The plant's treated effluent is discharged into the local watershed, which drains into the English Channel. This coastal environment supports diverse marine life and is important for local fisheries and tourism. The plant plays a key role in protecting the water quality of the nearby beaches and coastal ecosystems.

The plant discharges into the local watershed that flows into the English Channel near Saint-Cast-le-Guildo. This coastal area supports diverse marine habitats, including rocky shores and sandy beaches, and is important for migratory birds and local fisheries. The receiving waters are ecologically sensitive due to their proximity to recreational beaches and shellfish harvesting areas.