Pont Saint Martin 1 Beau Pretre Wastewater Treatment Plant, Pont-Saint-Martin, Pays de la Loire

Pont Saint Martin 1 Beau Pretre is an advanced wastewater treatment plant located in Pont-Saint-Martin, a commune in the Loire-Atlantique department of Pays de la Loire, France. The plant serves a population equivalent of 3,067 and is designed with a capacity of 5,233 cubic meters per day, with an average discharge volume of 547.15 m³/day. As an advanced treatment facility, it goes beyond secondary treatment to remove nutrients such as nitrogen and phosphorus, which is typical for plants discharging into sensitive areas under the EU Urban Waste Water Treatment Directive (91/271/EEC). For agglomerations of this scale (under 10,000 PE), the directive requires appropriate treatment, and France's national regulations often mandate advanced treatment in sensitive catchments. The plant's treated effluent is discharged into the local watershed, which ultimately drains into the Loire River and then the Bay of Biscay (Atlantic Ocean). The Loire estuary is a major ecological corridor supporting migratory fish like Atlantic salmon and European eel, and the plant's advanced treatment helps protect water quality in this sensitive environment.

The plant discharges into the Loire River basin, which flows through the Pays de la Loire region into the Bay of Biscay. The Loire estuary is a dynamic ecosystem supporting diverse aquatic life, including migratory fish species and important bird populations. Advanced treatment at this plant reduces nutrient loads, helping to prevent eutrophication in downstream waters and contributing to the ecological health of the Loire River and its estuary.