Veolia helps the metropolis of Montpellier to design wastewater treatment plant that will “produce twice as much energy as it consumes”

A visualisation of the planned wastewater treatment plant in Montpeiller

The metropolis of Montpellier has comissioned 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. 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 €165m, 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 the 19 municipalities. An initial capacity increase of 50,000 PE aims to be reached by the end of 2023, in order to meet the immediate urban development challenges of the metropolis. The Veolia Group hopes that its panel of technologies 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 — nine years in total. The company hopes that this action would “guarantee continuity of service and close management of the water and carbon footprint”.

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.

Once the work is completed, the Maera wastewater treatment plant aims to be geared towards the production of renewable energies (biomethane, heat and electricity), with the goal of covering 205% of its energy consumption by 2031. The plant also aims to reduce its net CO2 emissions by more than half, with the optimisation of its energy consumption and the maximisation of by-product energy recovery. The excess energy produced could 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 could also free up to 2,500 m2 of space, which could be used to implement large-scale wastewater reuse systems, rendering a possible recovery of 70,000 m3/d. This water could cover the station’s internal industrial uses and can also be reused, among other uses, for agricultural needs.

The Maera project is also part of an agroecological pilot to initiate the use of treated wastewater in agriculture, operated by Veolia’s partner D2VE. It has been suggested that a rooftop vegetable garden and greenhouses on the ground could 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.

Veolia hopes to combat climate change and its impacts on the water cycle through floods and droughts by ensuring the operational area is resilient and capable of resisting and adapting to unforeseen events. To meet that need, Veolia hopes to implement a control centre from 2025 onwards for the Maera project. Veolia aims to create a steering centre that will be organised around an information system that allows the plant’s systems to be managed in real time on a daily basis, monitor the plant’s performance, and anticipate heavy rainfall in order to minimise spills and manage crises.

Veolia also aims to support people in social and professional difficulty by allowing them to “regain autonomy” in their job search process by “promoting the emergence of the professions of tomorrow”, particularly around wastewater reuse and agroecology.

In response to this news, 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 odours (coverage of all structures, enhanced deodorisation).”

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.”