Paris Est Marne & Bois territory has set up a dedicated team to support owners of properties that are still non-compliant. Less than four months before the Olympic Games and the challenge of making the Seine swimmable, by August 1, the date of the whitewater events.

The problem lies underground. In this complex on the banks of the Marne in Joinville-le-Pont, the wastewater and rainwater networks of two residences mingle. At the risk of polluting the river.