Saur France and Stereau win contract to modernize and operate-maintain Wattrelos wastewater treatment plant

The aim is to modernize the Wattrelos wastewater treatment plant to increase its capacity and improve the management of pollution during rainy weather, in response to the growing needs of the MEL. By combining effective rainwater treatment, optimized wastewater treatment and the production of renewable, local energy, the new Wattrelos wastewater treatment plant will embody a model of environmental excellence.
This contract covers the extension and modernization of the plant, worth 200 million euros, and its operation by Saur France for a 12-year period, worth 93 million euros. Showcasing the expertise of the group’s members, the future facility has been designed to blend harmoniously into its environment, with no impact on biodiversity and no nuisance for local residents.

A major project to increase and modernize treatment capacity
The project to extend and rebuild the Wattrelos wastewater treatment plant will significantly increase the capacity of the existing plant, which was commissioned in 1986 and renovated in the early 2000s. Today, it treats the wastewater of 417,000 population equivalents from 15 municipalities in the Lille European Metropolis and the municipality of Mouscron in Belgium.
On completion of the modernization project in 2031, the plant’s capacity will be increased by more than 20% to 511,500 population equivalents. This simple, high-performance project is based on innovative technologies. Its evolutionary design anticipates the site’s future needs, to comply with future regulations and integrate new solutions, such as micropollutant treatment or reuse of treated wastewater (REUT).

A new plant that produces energy and respects the environment
The future Wattrelos wastewater treatment plant will embody a model of energy performance, contributing to the decarbonization of the region. It will produce more energy than it consumes. It will be equipped with high-efficiency, energy-saving equipment. Among these installations, 6,000 m² of photovoltaic panels and several hydroelectric turbines will cover more than 10% of the plant’s electricity needs. The remainder of the plant’s electricity needs will be covered by a green energy purchasing contract and the recovery of waste heat from the equipment. In addition, biomethane will be produced from the sludge generated by the treatment process, equivalent to the annual gas consumption of 2,800 residents, and the dried sludge will be used to heat 1,500 homes.

Operating to the highest standards
Operation of the Wattrelos wastewater treatment plant is based on strong commitments in terms of performance, respect for the environment and the well-being of local residents. The plant’s long-term viability will be guaranteed by ISO 55 001 certification, which provides a framework for sustainable, optimized asset management, reinforcing the longevity and value of this essential infrastructure.

Estelle Grelier, President of Saur France: “This large-scale project is in line with the Saur Group’s strategy, which places water transition at the heart of its development. As a driver of local sustainable ecology, the future facility will represent a strategic asset for the region, leaving a solid legacy for future generations. By becoming a net energy producer, it will embody an inspiring model of resilience, combining innovative technologies and scalable design to meet the most demanding standards. Its thrifty, secure and forward-looking management will contribute fully to the quality of life and sustainable balance of the region”.

Hugo Bardi, Chairman of Stereau: “With this new extension-reconstruction project, Stereau confirms its expertise and ability to design and build major structures. Once again, Stereau has demonstrated its ability to meet complex environmental challenges by providing simple, high-performance, scalable solutions. Designed to become a model of environmental performance, the site will combine optimal wastewater treatment with the production of green, local energy, meeting the challenges of the coming years in terms of resource conservation, the circular economy and decarbonization.

*Grouping :

• Agent and operator : Saur France
• Wastewater treatment: Stereau
• Civil engineering: NGE GC (GC consortium leader) and Demathieu Bard
• Architects: HB Architectes associés (lead architects) and Atelier 9.81
• Project management: Artelia