LAHONCE 2011 Wastewater Treatment Plant, Lahonce, Nouvelle-Aquitaine

LAHONCE 2011 is a municipal wastewater treatment plant located in Lahonce, a commune in the Pyrénées-Atlantiques department of Nouvelle-Aquitaine, southwestern France. The plant serves a population of approximately 3,117 and is situated near the Adour River, close to the Bay of Biscay. It is part of the region's infrastructure for managing domestic wastewater in the Basque Country area. The plant provides secondary treatment, which is the standard biological treatment required under the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. With a designed capacity of 4,000 m³/day and an average discharge volume of 556.07 m³/day, the facility operates well within its capacity. The treatment process typically involves biological degradation of organic matter and settling, ensuring compliance with EU standards for secondary treatment. The treated effluent is discharged into the local watershed, which ultimately drains into the Adour River and then into the Bay of Biscay. The plant plays a key role in protecting the coastal and estuarine environment from nutrient pollution and pathogens, supporting the ecological health of the Adour estuary and the marine ecosystem of the Bay of Biscay.

The plant discharges into the Adour River basin, which flows into the Bay of Biscay, a part of the Atlantic Ocean. The Adour estuary supports diverse aquatic life, including migratory fish species such as salmon and eels. The coastal waters are ecologically sensitive, with seagrass beds and marine habitats that benefit from controlled nutrient inputs. The plant's secondary treatment helps reduce organic load and suspended solids, mitigating eutrophication risks in the downstream coastal zone.