Signing of the new public service concession contract for the Prairie de Mauves waste treatment and recovery center

Séché Environnement, through its subsidiary Alcea, currently treats part of the waste produced by the city’s inhabitants at the Waste Recovery and Treatment Facility at the Prairie de Mauves, as part of a Public Service Delegation (PSD).

During the metropolitan council session on December 12 and 13, 2024, Séché Environnement was awarded the new public service concession contract to provide for the redesign, operation, and maintenance of the Prairie de Mauves waste treatment and recovery center.

For this contract, which comes into effect on April 1, 2025, for a duration of 20 years, Nantes Métropole has partnered with 7 other local authorities as part of a regional alliance.

On Wednesday, January 29, 2025, Nantes Métropole, the 7 partner authorities, and Séché Environnement signed the new public service delegation contract for the Prairie de Mauves waste treatment and recovery center (CTVD).

Given the national regulations and the regional waste prevention and management plan aimed at reducing the landfilling of waste, the 7 partner authorities no longer have, in the short term, sufficient waste treatment resources to allow for the recovery of all household waste collected within their borders. A partnership was established in 2023 between Nantes Métropole and these local authorities to allow the processing of their household waste at the Prairie de Mauves waste treatment and recovery center. This 20-year partnership illustrates the challenges of regional cooperation in service of both residents’ day-to-day needs and the ecological transition.

For the redesign of the waste treatment center, the partners, organized as a public procurement group, are helping finance the necessary investments to enable the creation of a new high-performance facility, particularly from an environmental perspective (emissions thresholds below regulations, management of environmental impacts, optimized energy recovery, etc.). Nantes Métropole is coordinating the partnership and the awarding and execution of the new contract with Séché Environnement.

The Future CTVD

The new PSD, which will be effective from April 1, 2025, for a period of 20 years, assigns Séché Environnement the tasks of site redevelopment (originally built in 1987), as well as the operation and maintenance of both the current and future CTVD. The contract specifies the capacity of the future site, set at 270,000 tons. Around 1.5 million inhabitants will be affected by this project.

The significant investments and strict requirements set by the PSD contract will enable the creation of an efficient facility that will contribute to the ecological transition ambitions of the territory promoted by Nantes Métropole. In particular, it will provide the region with an Energy Recovery Unit adapted to future waste streams to be treated, including a portion of the sludge from Nantes Métropole’s wastewater treatment plants. It will ensure an exemplary model in terms of energy and environmental performance, minimizing the CTVD’s impact on the environment while maximizing energy production and recovery.