Seine well below contamination limit before Olympic triathlon, organizers say

The River Seine’s pollution levels were well below harmful limits when athletes dove in for the Olympic triathlon on Wednesday morning, the 2024 Paris Olympic organizing committee confirmed on Thursday.
The organizing committee has been conducting daily tests to monitor the impact of weather events on concentration levels of hazardous bacteria known as E-coli in the Seine, ahead of major swimming events set to take place in the river throughout the tournament.
European safety standards state that waters with E-coli concentration levels above 1000 colony-forming units (cfu) per 100 milliliters of water are considered unsafe for swimming.
World Triathlon, the governing body for international competitions in the sport, uses a different threshold set at 900. Overexposure to E-coli can lead to illnesses like intestinal infections and conjunctivitis, but also more serious health conditions like hepatitis A.
Following encouraging results from sampling conducted on Tuesday, the authorities decided to go ahead with the triathlon on Wednesday morning, despite concerns over accuracy, given the 21.5 hour delay between the water sampling and when results come in.
But the delayed results also showed safe levels of E-coli.
“The samples taken yesterday between 5am and 6am showed levels of E-coli between 192 and 308 which is considered very good by World Triathlon,” Anne Descamps, the spokesperson for the Paris Games’ organizing committee, told the press Thursday morning.
Later in the day, however, Fluidion — a company contracted by the city of Paris to test and monitor bacteria levels in the river for years before the Games — said its own tests conducted at the start and during the triathlon showed much higher E-coli levels than what the Paris organizers shared, although still below the threshold.
“The official results significantly underestimate the real E.coli count, and the actual risk for the athletes is not managed and remains unknown,” Fluidion said on its website.
Cleaning up the Seine in time for the Olympics has been a decade-long dream for France.
 “Here we are! Thanks to a massive investment by the State, with Paris and the Val-de-Marne [region], we have achieved in 4 years what has been impossible for 100 years: the Seine is swimmable,” French President Emmanuel Macron said on social media on Wednesday when the triathlon began.