swimming impossible since September due to bacteria, study finds

The NGO Surfrider Fondation has been taking samples from the Seine since September 2023, at the Pont de l’Alma and the Pont Alexandre III. France Inter consulted the results of the latest study.

108 days before the start of the Paris Olympic Games, a new study carried out by the NGO Surfrider Fondation, consulted by France Inter, reveals that the Seine is still not suitable for swimming. Several samples taken in Paris since September 2023 indicate the presence of several bacteria at levels which exceed the standards set by the International Swimming Federation.

The NGO Surfrider Fondation has itself carried out, since September 2023, regular samples, at the Pont de l’Alma and the Pont Alexandre III, where the marathon swimming and triathlon events must take place. and paratriathlon during the Paris Olympics next summer.

Among the 14 samples taken, 13 revealed the presence of bacteria

Among the 14 samples taken, 13 revealed the presence of certain bacteria, notably Escherichia coli and enterococci, at levels higher than the standards defined by the International Swimming Federation. Water quality thresholds deteriorate particularly after very intense rainy episodes which saturate the sewers and lead to discharge of wastewater into the Seine.

“We are two to three times above the minimum mandatory standards for healthy practice by athletes during the season”, alerts Marc Valmassoni, Campaign Coordinator at the NGO. A bacteriological presence which has potentially serious consequences for athletes: “In health terms, they are exposed to pathologies such as gastroenteritis, conjunctivitis, otitis or skin problems.”

Last month, the prefect of the Île-de-France region reaffirmed that there was no “no plan B” for these open water swimming events in the event of pollution of the Seine. Paris town hall is counting on the new retention basin, very close to Austerlitz station, to store rainwater, but for the NGO, a bathing water specialist, this may not be enough.

“That leaves a chance if there are moderate rainy episodes,” specifies Marc Valmassoni, but “the basin will not be able to store all of the runoff if a rainy event is very significant. So, from the moment it is unable to store everything, the additional water will completely run off or flow into the Seine and will have an impact on the bacteriological quality.” of the river.

By the Olympic Games, all barges will have to be connected to the sanitation network to make the Seine ‘swimmable’. To date, around 20 barges out of the 250 at the quay still have to comply. Paris City Hall has invested more than a billion euros to clean up the Seine in order to keep the promise of making it swimmable. But until then, Surfrider Foundation wants to continue its samples to check the quality of the water in complete transparency.

The prefecture of the Île-de-France region, in charge of the file, reacted Monday morning to the Sports Department of Radio France, explaining that it was not surprised by these results. She maintains in fact that the work is not finished and that the water treatment plants are not yet active.