Montpellier is testing a mobile wastewater recycling system designed to turn treated urban wastewater into a reusable resource for applications ranging from irrigation and street cleaning to firefighting and industrial use.
Developed under the European-funded LIFE ReWa programme, the mobile treatment unit combines ultrafiltration and UV-C disinfection technologies to produce up to 110,000m³ of recycled water annually. The project is led by Montpellier Méditerranée Métropole Water Authority in partnership with DV2E and the University of Montpellier’s European Membranes Institute.
The treatment system incorporates BIO-UV Group’s RW UV-C reactor and was engineered by Chemdoc Water Technologies. The mobile unit is designed to produce four different grades of recycled water at flow rates between 25 and 40m³/h, depending on end use requirements.
Trials will take place at five wastewater treatment plants across the Montpellier metropolitan area — Lattes, Fabrègues, Cournonterral, Villeneuve-lès-Maguelone and Saint-Georges-d’Orques — to assess treatment protocols for a range of municipal and agricultural applications, including sewer flushing, green space irrigation, road cleaning and fire protection.
The initiative forms part of a wider regional strategy to reduce pressure on freshwater supplies in southern France, where climate change and seasonal droughts are increasing demand for alternative water resources.
Currently, Montpellier’s 13 wastewater treatment plants discharge around 32 million m³ of treated wastewater into rivers and the Mediterranean Sea each year, with less than 0.01% being reused.
Laurent Emmanuel Migeon, CEO of BIO-UV Group, said: “We are delighted to be part of this truly pioneering project in France and Europe, alongside our partner Chemdoc, which will provide valuable technical data and help define specifications for treatment processes and water qualities depending on applications. These data will be essential for the use of treated wastewater in urban environments in the coming years.”
Salvador Pérez, Director of Chemdoc Water Technologies, said: “The REWA project truck is a fantastic demonstrator of the possibilities offered by water purification and disinfection technologies for new uses of urban wastewater reuse, from the simplest to the most demanding, aligned with drinking water standards. BIO-UV Group has been supporting us for years, sharing its expertise in disinfection.”
The LIFE ReWa programme is co-funded by the European Union, the Occitanie Region and the Rhône Méditerranée Corse Water Agency. Project partners say the scheme is intended to serve as a model for wider urban water reuse deployment across Europe.
Anne-Bénédicte Wommelsdorf, LIFE ReWa Project Coordinator, said: “The LIFE ReWa project is both a technical and administrative adventure, driven by a strong ambition to demonstrate that wastewater can become a valuable resource. Innovative, multi-site, and multi-use, [the mobile unit] will provide water adapted to a wide variety of uses, including cleaning public spaces, sewer flushing, firefighting, watering green spaces, and agricultural irrigation. LIFE ReWa is a concrete, pioneering initiative in France to preserve water resources and build a more sustainable future.”
The current pilot programme runs until September 2026. Long-term plans for the region include scaling recycled water production to 1 million m³ annually by 2041 through the deployment of two additional mobile treatment units.
According to project partners, around 20% of the Mediterranean region’s population already experiences persistent water stress, rising to 50% during summer months, while by 2030 water shortages could affect half of Europe’s catchment areas.
