A project stopped dead in its tracks right in the center of Saint-Nazaire last March following the discovery of hydrocarbon pollutions. At this location, the future Maison de l’Habitat will be built.
The soils before throwing the first pickaxe blows had been surveyed in 2022. It is therefore a recent pollution. The depollution project which begins this Wednesday until the end of July will cost more than a million euros to the agglomeration.
On this busy street a stone’s throw from the markets: shops, apartments and therefore fuel and solvents. Pumping operations and the installation of absorbent bags were quickly carried out. Then, the analyzes and samples taken over weeks in the neighborhood are clear – there will be others in the summer to confirm – no pollution above regulatory thresholds in the air or soil.
Three months to measure the extent and severity of pollution
But it took three months to measure the extent of this pollution, that is to say its seriousness, and without however reaching the origins.
The analyzes completed, here is theentry into the scene of depollution companies. A program until the end of July which will take place in two phases.
First one excavation des sols sufficiently deep where the pollution was discovered. “The land will be evacuated to specialized treatment sites” assures Saint-Nazaire agglo in its press release. And during all this time, to avoid odors, a suction system will be put in place as well as an odor masker.
Second step: you will have to treat the ground with “biological oxidation”. In short, they are microorganisms which ingest underground pollution, i.e. an accelerated but natural degradation of pollution.
A crawl space all around with gas capture
The main work, the construction of the Maison de l’Habitat, will not resume until the start of the school year. But as a precautionary measure, “a crawl space will be created throughout the building to allow mechanical ventilation and thus capture any residual gases. And a sensor in the patio will allow monitoring of air quality over time.”
The regional health agency (ARS) is informed of the results and the decontamination protocol.
Complaint against X in progress
The Nazairian agglomeration must, to clean up, pay more than a million euros. She hopes for state subsidies as part of the wasteland fund and still suspects a malicious act. on complaint against follows its course.
