Organisers say race is postponed to Wednesday and blame excessive pollution in river on heavy rains.
The Olympic men’s triathlon was postponed hours before its scheduled start after water quality tests showed unhealthy pollution levels in the Seine, organisers say.
In a joint statement on Tuesday, Paris 2024 and World Triathlon blamed the excessive pollution on heavy rains that deluged the French capital on Friday and Saturday.
“Paris 2024 and World Triathlon reiterate that their priority is the health of the athletes,” the statement said.
The race has been postponed to 10:45am (08:45 GMT) on Wednesday after the women’s event at 8am (06:00 GMT).
But if bacteria levels remain high on Wednesday morning, the men’s and women’s races will likely be moved to Friday, the contingency day reserved for events.
If the water quality is still not healthy enough to swim in by Friday, then the swimming leg of the event will be scrapped.
“The tests carried out in the Seine today revealed water quality levels that did not provide sufficient guarantees to allow the event to be held,” the organisers’ statement read.
“Unfortunately, meteorological events beyond our control, such as the rain which fell over Paris on 26 and 27 July, can alter water quality and compel us to reschedule the event for health reasons.”
Reporting from Paris, Al Jazeera’s Bernard Smith said the organisers hope that swimming in the Seine would have been the event’s “wow factor” as the triathlon route was designed around Parisian monuments.
After diving into the Seine from a pontoon next to the Alexandre III Bridge, athletes were set to race past the Musee d’Orsay and Grand Palais during the bike and run stages before ending back where they started.
Crossing the finish line on the bridge, they would be framed by stone columns topped with gilt-bronze statues of Pegasus with the golden dome of the early 18th century Invalides monument as a backdrop.
Much of the money used to clean up the river was spent on “giant tanks, reservoirs to hold overflow water” when it rained, which it did so for “almost 48 hours” on Friday and Saturday, Smith said.
“That increased the levels of water in the tanks, and what happens as well is that sewage run-off ends up being released in the Seine if water levels are too high,” Smith said. “That has pushed up levels of E coli, and that is why the river is not considered safe enough to swim in just yet.”
Authorities in Paris have spent 1.4 billion euros ($1.51bn) on wastewater infrastructure to contain sewage and make the Seine swimmable.
The city’s mayor, Anne Hidalgo, swam in the river before the Olympics to persuade doubters that the river was clean enough to enter.
Benjamin Maze, the technical director of the French Triathlon Federation, told FranceInfo radio that there was “little a bit of anger and a lot of disappointment” among competitors.
Despite the news of the postponed event, Australia’s Olympic team chief, Anna Meares, said her team had not been deterred.
“The athletes are really looking forward to having that stage and that platform to perform on,” she told reporters.
“They actually want to swim in the river.”