Of the 14 samples taken near the venue of the tests, 12 would be unsuitable for swimming according to the French Agency for Environmental and Occupational Health Safety. Analyzes reveal concentration levels of escherichia coli and enterococcus bacteria, higher than what the thriathlon and swimming federations recommend to authorize swimming.

The NGO SurfRider wants proof of this and is asking for guaranteed access to the banks of the Seine during the events. The area will be closed from mid-May for developments linked to the Olympics.