Olympic organizers have postponed the men’s triathlon race originally scheduled for Tuesday morning, conceding that the Seine River remains unsafe for swimming.
Organizers bumped the men’s event to Wednesday, and it’s now scheduled to take place after end of the women’s triathlon, scheduled for the same day.
“Despite the improvement on the water quality levels in the last hours, the readings at some points of the swim course are above acceptable levels,” World Triathlon, the international governing body for the sport at the Olympics, said in a statement on X.
The statement said the organizers could move the race to Friday as a contingency, if needed.
“Paris 2024 and World Triathlon reiterate that their priority is the health of the athletes,” the statement said, referring to the organizers of the Games.
Ahead of the Olympics, the city of Paris and local water agencies spent about $1.5 billion to clean up the Seine, retrofitting an antiquated sewer system that overflows into the river when it is overwhelmed by heavy rain. As part of the upgrades, the city built a massive underground basin to hold stormwater for treatment.
The hope was to get the river clean enough for swimming, but the efforts have not been enough. The most recent published monitoring report, from testing conducted July 17 through 23, showed that E. coli levels spiked at the Pont Alexandre III bridge, where athletes are meant to start and finish the individual triathlon events, after a day of heavy rain on July 20. At its peak, contamination was at least double the level typically considered acceptable under World Triathlon competition rules.
Routine monitoring in the months leading up to the games similarly showed that levels of E. coli — an indicator of fecal matter — regularly spiked to unsafe levels, particularly after rainstorms sent runoff from Paris streets into the river and raised the odds that sewage would enter the water.
Unsafe levels of fecal matter in swimming water can cause gastrointestinal disease. It’s a common problem in urban waterways across the world.
Sunlight can inactivate bacteria, so Paris Olympics organizers had hoped for sunny, clear conditions. Had the weather cooperated, the Seine’s wastewater system wouldn’t have gotten tested by high flows, and the sun would have had time to do its work.
But instead, Paris was drenched with rain during Friday’s opening ceremony, and the showers continued into Saturday.
Organizers canceled triathlon swim training on Sunday and Monday because the Seine remained too dirty and then chose to move the event by at least one more day.
Looming worrisome weather could scramble those plans and other events, too: Meteo France, the country’s meteorological agency, predicts scattered thunderstorms starting as early as Tuesday afternoon in Paris.
Other events depend on conditions’ improving: The mixed relay triathlon is scheduled for Aug. 5, local time, followed by the marathon swimming events on Aug. 8 and 9.
Most strains of E. coli are harmless, but their presence is a sign that other, potentially harmful bacteria are present.
“High bacteria means there’s too much poop in the water, and poop carries germs that make people sick,” Daniel Nidzgorski, an ecologist who monitors water quality in the U.S.
Swimming hasn’t been allowed in the Seine for about a century because of contamination, and many people remained skeptical about whether authorities could clean it up in time for the Games.
Last year, Olympics organizers planned to hold test triathlon events in the Seine to make sure the competitions could run smoothly, but several of the events were canceled after the river failed pollution tests in August.
Then, in April, the nonprofit Surfrider Foundation Europe shared independent results from six months of tests, which showed that almost all samples exceeded the permitted levels of contamination.
Regular monitoring by Eau de Paris, the city’s main water supplier, showed that levels of E. coli spiked after stormy weather throughout May, June and July.
Nonetheless, to show off the river’s cleanliness, Paris Mayor Anne Hidalgo, Paris 2024 Olympic President Tony Estanguet and other officials took a ceremonial plunge in the Seine this month.
The water level was reportedly above the safety limit when they swam.