If small streams make big rivers, when they flow into the Seine, tons of waste also flow into it. A phenomenon that the Rouen-Normandy Metropolis (Seine-Maritime) will try to reduce by installing anti-waste nets at the exit of four pipes - outlets - located in Rouen and upstream, in Amfreville-la-Mivoie. “As early as November 2020, we had already laid three similar nets on a river, the Cailly. And the first results encouraged us to think bigger by launching a similar approach on the Seine, ”recalls Nicolas Mayer-Rossignol, the president of the community who benefited from the patronage of a handful of companies to finance this operation, including the cost is around € 120,000 plus around € 30,000 for the annual maintenance of the nets.
Anti-waste nets have been installed on the Seine and designed to resist in particular the very marked tidal phenomenon in Rouen.
In one year, more than two tonnes of waste have been recovered by these first devices, the two most effective of which will also be renewed.
“We have to pick them up to empty them between 3 and 4 times a year.
For those that we have just installed in the Seine, we think that it will have to be done more often ”, indicates one of the technicians in charge of logistics.
Designed by the Pollustock company, this is the first time that this type of net has been installed on a river.
"In Rouen, it was necessary to take into account in particular tidal phenomena and we have made changes to our products accordingly", indicates Stéphane Asikian, the creator of this company based in Mandelieu-la-Napoule (Alpes-Maritime) which has since its originates from an environmental fiber.
“Ten years ago, hardly anyone was concerned about this problem of waste which, as we know, ends up in the sea. Today, we feel that mentalities are changing and we are increasingly called upon by communities around of these questions ”.
In Rouen (Seine-Maritime), two anti-waste nets of this type have been installed at the outlet of outlets which flow into the Seine.
Two others were further upstream at Amfreville-la-Mivoie
A precise study must be made at the beginning of next year on the type of waste, found in particular in the Cailly.
“But overall, it's unsurprisingly a lot of plastic.
There is a lot that comes from take-out catering.
But there are also cigarette butts, cans, wipes, packaging with the explosion of e-commerce… ”, details Marie Atinault, the vice-president of the Metropolis in charge of the ecological transition.
“Our objective with these nets is obviously not to eliminate all waste in the Seine.
But it is to analyze where they come from in order then to sensitize those who produce them and try to modify their behavior ”.