Decarbonizing our activities by transforming wastewater into green energy

For local authorities, converting wastewater treatment plant sludge into biogas is a major lever for reducing sludge volumes, minimizing their environmental footprint and meeting regulatory requirements.

The methanization of sludge from wastewater treatment plants offers an alternative to fossil fuels and a new source of revenue, whether through on-site reuse of the energy produced or sale of the same energy to the GrDF network. 

By treating the organic matter contained in our wastewater to transform it into biogas and then into biomethane that can be injected into the natural gas network, methanization helps to decarbonize wastewater treatment facilities. Stereau has already implemented this technology at the Aubenas (Ardèche) and Saint-Etienne (Loire) wastewater treatment plants. In Montauban, the future Verdié wastewater treatment plant will be home to a methanization unit from 2024, enabling the injection of 5 GWh/year of biogas into the municipal gas network, equivalent to the annual consumption of 1,200 low-energy households in the Greater Montauban area.