LIGNAN SUR ORB Wastewater Treatment Plant, Lignan-sur-Orb, Occitanie

LIGNAN SUR ORB is a wastewater treatment plant located in Lignan-sur-Orb, a commune in the Hérault department of Occitanie, southern France. The plant serves a population of 3,800 and has a designed capacity of 6,000 m³/day, with an average discharge volume of 677.91 m³/day. The plant employs advanced treatment processes, exceeding the secondary treatment standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. Advanced treatment typically includes nutrient removal (nitrogen and phosphorus) to protect sensitive receiving waters. The plant discharges into the Orb River, which flows through the Hérault valley and into the Mediterranean Sea near Valras-Plage. The Orb River supports diverse aquatic life and is an important water resource for the region. The advanced treatment helps maintain water quality in the river and downstream coastal environment.

The plant discharges into the Orb River, which flows southward through the Hérault department and enters the Mediterranean Sea near Valras-Plage. The Orb River supports a diverse ecosystem, including fish species such as the European eel and various migratory birds. The advanced treatment level helps protect the river's water quality and the downstream coastal lagoon habitats, which are ecologically sensitive areas.