BAIS LA PATRIERE Wastewater Treatment Plant, Bais, Pays de la Loire

BAIS LA PATRIERE is a municipal wastewater treatment plant located in Bais, within the Mayenne department of Pays de la Loire, France. The facility serves a population of around 2,154, classifying it as a small agglomeration under French and EU regulations. The plant is situated inland, away from coastal areas, and its operations are part of the region's water management infrastructure. The plant provides secondary treatment, a standard level for communities of this size under the EU Urban Waste Water Treatment Directive (91/271/EEC). The directive requires secondary treatment for all agglomerations above 2,000 population equivalent discharging into freshwater. The plant's designed capacity is 2,083 cubic meters per day, with a reported discharge volume of 384.27 cubic meters per day, indicating operational capacity well within design limits. Treated effluent from the plant is discharged into the local water system, which ultimately drains into the Mayenne River, a tributary of the Loire River. The Loire basin is the largest river basin in France and supports diverse aquatic ecosystems. The plant's secondary treatment helps protect water quality in the Mayenne and downstream environments, contributing to the ecological health of the Loire estuary and the Bay of Biscay.

The plant discharges into the local watershed, which flows into the Mayenne River, a tributary of the Loire River. The Loire basin is ecologically significant, supporting diverse fish populations and migratory species. The secondary treatment provided helps reduce organic pollution and nutrient loads, protecting downstream water quality in the Loire estuary and the Bay of Biscay.