ST PALAIS 2 Wastewater Treatment Plant, Saint-Palais, Nouvelle-Aquitaine

ST PALAIS 2 is an advanced wastewater treatment plant located in Saint-Palais, in the Pyrénées-Atlantiques department of Nouvelle-Aquitaine, France. The plant serves a population of 3,225 and has a designed capacity of 9,000 m³/day, with an average discharge volume of 575.33 m³/day. As an advanced treatment facility, it provides a higher level of pollutant removal beyond secondary treatment, which is typical for plants in sensitive areas under the EU Urban Waste Water Treatment Directive (91/271/EEC). The plant's advanced treatment process ensures compliance with stringent European standards for nutrient removal and water quality. The facility's classification as advanced indicates it likely employs tertiary filtration or nutrient reduction technologies. For agglomerations of this size (3,225 PE), the EU directive requires at least secondary treatment, but the plant exceeds this baseline with advanced treatment. The treated effluent is discharged into the local watershed, which ultimately drains into the Adour River basin and then into the Bay of Biscay (Atlantic Ocean). The plant plays a key role in protecting the region's water resources, supporting aquatic life in the downstream rivers and estuaries, and contributing to the ecological health of the coastal marine environment.

ST PALAIS 2 discharges treated wastewater into the local tributaries of the Adour River, which flows through the Basque Country and into the Bay of Biscay. The Adour basin supports diverse aquatic ecosystems, including migratory fish species such as salmon and eels. The advanced treatment at this plant helps reduce nutrient loading and protects downstream water quality in the estuary and coastal zone, which are ecologically sensitive areas.