ST MATHURIN Saint Mathelin Wastewater Treatment Plant, Saint-Mathurin, Pays de la Loire

ST MATHURIN Saint Mathelin is a wastewater treatment plant located in Saint-Mathurin, within the Vendée department of Pays de la Loire, France. The facility serves a population of approximately 2,323 people and is situated near the coastal town of Les Sables-d'Olonne. As a small agglomeration, it plays a key role in managing local wastewater in this western French region. 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 3,200 m³/day and a current discharge volume of 414.42 m³/day, the facility operates well within its capacity. Advanced treatment typically includes nutrient removal, helping to protect sensitive coastal waters. The treated effluent is discharged into the local watershed, which ultimately drains into the Bay of Biscay via the Atlantic coast. The proximity to the coast (within 10 km) means the plant's discharge can affect coastal water quality and marine ecosystems. The advanced treatment level helps minimize nutrient loading and supports the ecological health of the nearby coastal environment.

The plant discharges into the local watershed that flows into the Bay of Biscay, a part of the North Atlantic Ocean. The coastal area supports diverse marine life, including fish and shellfish populations, and is an important zone for migratory birds. Advanced treatment reduces nutrient pollution, which is critical for preventing eutrophication in these sensitive coastal waters.