GORRON Wastewater Treatment Plant, Gorron, Pays de la Loire, France

The GORRON wastewater treatment plant is located in Gorron, a commune in the Mayenne department of the Pays de la Loire region, northwestern France. The facility serves a population of approximately 3,390 residents and operates with a designed capacity of 3,600 cubic meters per day, with an average discharge volume of 604.77 m³/day. As an advanced treatment plant, GORRON goes beyond secondary treatment to remove nutrients and other pollutants, meeting stringent standards under French regulations transposing the EU Urban Waste Water Treatment Directive (91/271/EEC). For agglomerations of this size (under 10,000 population equivalent), the directive requires appropriate treatment, and France mandates advanced treatment in sensitive areas to protect water quality. The treated effluent is discharged into local watercourses that eventually drain into the Mayenne River, a tributary of the Loire River, which flows into the Atlantic Ocean. The plant plays a key role in safeguarding the region's water resources and supporting aquatic ecosystems in the Loire basin.

The GORRON plant discharges into the local watershed that feeds the Mayenne River, part of the larger Loire River basin. The Loire is one of France's longest rivers and supports diverse aquatic life, including migratory fish species such as Atlantic salmon and European eel. The advanced treatment helps reduce nutrient loading, protecting downstream water quality and the ecological health of the Loire estuary and the Bay of Biscay.