PIERREFITTE NESTALAS nouvelle station - Advanced Wastewater Treatment in Beaucens, France

PIERREFITTE NESTALAS nouvelle station is an advanced wastewater treatment plant located in Beaucens, near Argelès-Gazost in the Hautes-Pyrénées department of Occitanie, France. The plant serves a population of approximately 3,100 people and has a designed capacity of 3,500 m³/day, with an average discharge volume of 553 m³/day. As an advanced treatment facility, the plant goes beyond secondary treatment to remove nutrients and other pollutants, ensuring high-quality effluent. This level of treatment is typical for plants discharging into sensitive environments under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires advanced treatment for agglomerations above 10,000 population equivalent in sensitive areas. Although the plant serves a smaller population, its advanced treatment reflects local environmental requirements. The plant's treated effluent is discharged into the local watershed, which ultimately drains into the Gave de Pau river and then into the Adour river before reaching the Bay of Biscay in the Atlantic Ocean. The surrounding area is part of the Pyrenees mountain range, with sensitive aquatic ecosystems that benefit from the plant's advanced treatment processes.

The plant discharges into the Gave de Pau river, a tributary of the Adour river, which flows into the Bay of Biscay (Atlantic Ocean). The receiving waters support diverse aquatic life, including migratory fish species such as salmon and trout. The advanced treatment helps protect these ecosystems from nutrient pollution and organic matter, maintaining water quality in a region known for its mountainous terrain and tourism.