AIGNAN Wastewater Treatment Plant, Aignan, Occitanie, France

The AIGNAN wastewater treatment plant is located in the commune of Aignan, within the Gers department of Occitanie, southwestern France. It serves a population of approximately 2,000 residents, providing essential sanitation for this rural community. The plant is situated inland, away from coastal areas, and operates as part of the region's municipal wastewater infrastructure. As a secondary treatment facility, the plant meets the standard required under the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. The directive mandates secondary treatment for populations between 2,000 and 10,000 in normal areas, which AIGNAN fulfills. The plant has a designed capacity of 1,200 m³/day and currently treats an average daily volume of 356.80 m³, indicating ample reserve capacity for future growth. The treated effluent is discharged into local watercourses that drain into the Adour River basin, ultimately reaching the Bay of Biscay in the Atlantic Ocean. The plant plays a key role in protecting the region's water quality, supporting both agricultural activities and the ecological health of downstream aquatic habitats.

The AIGNAN plant discharges into the local watershed of the Adour River basin, which flows through the Gers department and eventually reaches the Bay of Biscay. This region supports diverse aquatic life and is important for migratory fish species. The secondary treatment process helps reduce organic pollutants and nutrients, safeguarding the ecological balance of downstream rivers and the coastal environment.