The Petite Californie wastewater plant is to feed the gas network

Located in Trentemoult, the Petite Californie wastewater plant treats the sewage of seven municipalities, equivalent to 180,000 inhabitants. Since 2011 it has been used to produce biomethane, a renewable gas, but only 55% of the biogas was put to use, the rest being burned off. Presented to residents on 8 December 2020, a new system designed with operator Suez was meant to use all of it: from June 2021 the biogas would be injected into the GRDF network, a first in Loire-Atlantique. It would produce 10.7 gigawatt-hours a year, the consumption of 2,140 homes, for an investment of €2.8 million by Nantes Métropole.