France looks to river barriers to cut plastic pollution

The success of a floating litter barrier in Toulouse could spawn similar initiatives internationally to stop pollution in rivers reaching the sea.

The barrier was installed on the river Garonne at Blagnac, a suburb of Toulouse, in September last year and has since collected eight tonnes of plastic. Stretching all the way across the river, it has gates to allow kayaks and canoes to pass.

How the floating barrier works

The barrier is fixed via steel cables at an angle to the current, designed to create a vortex in the water. Litter is blocked by a rubber skirt extending 40cm below the waterline. It is then directed via the vortex towards a waste collection point near the riverbank with a capacity of 16m³.

There, it is sorted by hand before being recycled through the metropolitan waste management system.

Patrick Thaunay, co-founder of Plastic Vortex, the company behind the barrier, said: “We find that 90% of the collected material is made up of wood, algae and other organic matter, but a lot of that is polluted, especially by polystyrene balls, such as those used for insulation or packaging, and so it is not put back in the river.

“There were also plastic bottles of all sorts, tyres, cigarette butts and plastic bags – all kinds of rubbish.”

Normal winter floods do not affect the barrier. In extreme conditions, it can simply be lifted until the river falls to its usual level.

Could more barriers be installed in France?

Installation costs vary according to location, but should be €200,000-€600,000.

The company compares this to the cost of cleaning up beaches in coastal communes.

Nice, for example, spends €2million a year keeping its beaches clean.

Financial support for the initiative came from six national and local authority agencies and two co-operative banks.

Mr Thaunay estimates that with 31 barriers positioned at strategic locations in France, 70% of floating waste that would otherwise end up in seas could be captured – equivalent to nine million plastic bottles.

“That is our primary objective, but convincing local authorities and the government to cough up is a problem, even though the government has a policy of reducing the amount of plastic in the sea,” he said.

“We are also looking for corporate sponsors and partnerships, and hope to be able to announce something soon to let us continue building these barriers.”

Interest from France and abroad

Arrangements have been made with plastic recycling firms to take nearly all of the plastic recovered, meaning that relatively little is incinerated. “In general, the plastic we get from the river is in good condition, and not as dirty as some plastic recovered from land,” said Mr Thaunay.

The success of the Garonne barrier has prompted requests for similar systems to prevent bridges, weirs and other river structures being damaged by floating wood.

There has also been interest from other EU countries and the UK.

Mr Thaunay said the firm’s priority is to install more systems in France.