A large-scale fire partially destroyed the largest wastewater treatment plant in Europe at Achères, near Paris, in early July. Three months later, fears and questions remain.

REPORTAGE

An ecological disaster on the outskirts of Paris has so far gone unnoticed: a fire in a Seveso factory, as in Lubrizol, but this time in a wastewater treatment plant. The largest wastewater treatment plant in Europe, in Achères, 30 kilometers from Paris, burned partially on July 3, causing extensive pollution of the Seine. Three and a half months later, the local elected officials, who organize Wednesday evening a public meeting in Achères, still fear a new incident.

"There is a clear risk of pollution"

The Achères site, classified Seveso-haut, treats 60% of wastewater in the Paris region, or one million cubic meters per day, discharged into the Seine. But since the fire, the station is forced to drastically reduce its capacity. Suddenly, the fear of a new pollution of the Seine returns to each storm. For Arnaud Pericard, the mayor of Saint-Germain-en-Laye, the plant will be literally overwhelmed in case of heavy rains. "There is a clear risk of pollution, with significant discharges of untreated water into the Seine.In July, 10 tons of dead fish were victims of these discharges," said the elected.

A risk of pollution until the repair of the site

The Siaap, union for the sanitation of the Paris region, which manages the treatment plant, does not deny this risk of pollution. "It would be dishonest to say that there is no risk, it is the weather that is for us the determining factor on this fish mortality," admits Jacques Olivier, CEO of Siaap. Indeed, my risk of pollution of the Seine will exist every summer until the complete repair of the site, in three to five years. The reasons for the disaster remain unclear, the Siapp evoking a "likely" short circuit.