• This project supports the orientations of the Plan Climat-Air-Énergie Territorial (Territorial Climate-Air-Energy Plan) of the Montpellier Metropolis by reducing the carbon footprint of the wastewater treatment plant, producing renewable energies and preserving water resources.
• The extension and upgrade of the Maera wastewater treatment plant will allow the Metropolis to reuse its treated wastewater as well as produce twice as much energy as the plant will consume.
• The excess energy produced will be used, among other things, to supply gas to 9,000 homes and heat to more than 7,500 households.
• Following the 165 million euro upgrade, the plant will be able to treat 210,000 m3/day, gradually increasing from 470,000 to 695,000 Population Equivalent.

The Metropolis of Montpellier entrusted Veolia, through its subsidiaries OTV and Veolia Eau France, with the extension and upgrade works as well as the operation of the Maera wastewater treatment plant, located in the town of Lattes (34). OTV will lead a consortium made up of Veolia Eau, Razel Bec, GTM TP GC SO, Egis Eau, Cabinet Merlin, Bouygues Energies and Services, Tourre Sanchis Architectes, AI Project, as well as many local players. Worth 165 million euros, this 9-year contract will enable the Maera wastewater treatment plant, through a sustainable development approach, to produce twice as much energy as it needs and to reuse wastewater following treatment.

The extension works will gradually increase the plant’s treatment capacity from 470,000 to 695,000 Population Equivalent (PE), covering the needs of 19 municipalities. An initial capacity increase of 50,000 PE will be reached by the end of 2023 in order to meet the immediate urban development challenges of the Metropolis. A panel of flagship technologies from the Veolia Group will not only improve the quality of treatment at the current plant, but also enable the production of energy and the reuse of treated wastewater. Veolia will continue to operate the site throughout the duration of the works and for the following four years — that is nine years in total — guaranteeing permanent continuity of service and close management of the water and carbon footprint.

Exemplary environmental performance

This project supports the orientations of the Plan Climat-Air-Énergie Territorial (Territorial Climate-Air-Energy Plan) of the Montpellier Metropolis by reducing the carbon footprint of the wastewater treatment plant, producing renewable energies and preserving water resources.

The plant will also reduce its net CO2  emissions by more than half thanks to the optimization of its energy consumption and the maximization of by-product energy recovery

Once the work is completed, the Maera wastewater treatment plant will be a sober unit, geared towards the production of renewable energies (biomethane, heat and electricity) which will make it possible to cover 205% of its energy consumption by 2031. The plant will also reduce its net CO2  emissions by more than half thanks to the optimization of its energy consumption and the maximization of by-product energy recovery. The excess energy produced will be used, among other things, to supply gas to 9,000 homes and heat to more than 7,500 households.

The plant’s compact design also frees up 2,500 m2 of space to implement large-scale wastewater reuse systems, rendering possible a recovery of 70,000 m3/d. This water will cover the station’s internal industrial uses and will also be reused, among other things, for agricultural needs. The Maera project is indeed part of an agroecological approach to initiate the use of treated wastewater in agriculture. A rooftop vegetable garden and greenhouses on the ground will be created and watered by treated water from the station, in addition to testing other types of uses such as fire control, cleaning of streets, public spaces and networks, and watering green spaces, vines or any other crops close to the site. The agroecological pilot is operated by our partner DV2E.

A resilient facility in the face of climate change

Given the current context of climate change and the significant impacts it is having on the water cycle (floods, drought), territories must evolve to become more resilient, capable of resisting and adapting to unforeseen events. From 2025, Maera will benefit from a control center up to the challenge. A true management and decision-making tool, the steering center will be organized around an information system that will make it possible to manage the plant’s systems in real time on a daily basis, to monitor the plant’s performance, and to anticipate heavy rainfall in order to minimize spills and manage crises.

A social and societal project

Revitalizing the territory also involves creating back-to-work jobs; our Group aims to support people in social and professional difficulty by allowing them to regain autonomy in their job search process. Maera also promotes the emergence of the professions of tomorrow, particularly around wastewater reuse and agroecology.

René Revol, President of the Montpellier Méditerranée Métropole Water Authority and Vice President in charge of water and sanitation, declared: “The extension of the treatment capacity combined with the proposed improvements will allow us to face the future more serenely and to offer a structure that is better integrated with an overall strategy for limiting noise (reinforcement of acoustic devices) and odors (coverage of all structures, enhanced deodorization).”

Arnaud Valleteau De Moulliac, Managing Director of OTV, added: “The purpose of our Group, which is to act for and commit to ecological transformation, has guided all the processes and technological decisions of the project. Lowering carbon footprint, reducing constraints on natural resources and protecting biodiversity have been the non-negotiable principles that have shaped our thinking. We are proud to bring our expertise to the service of the Metropolis of Montpellier to transform its wastewater into valuable contributions for the city and its citizens, and for the environment.”