Olympics men triathlon postponed pollution river seine – Breaking News & Latest Updates 2026
Skip to main content

There’s too much E. coli in the Seine for athletes to swim in it

The Olympic men’s triathlon has been postponed due to river pollution.

The Olympic men’s triathlon has been postponed due to river pollution.

A view of the Seine with the Eiffel Tower in the background.
A view of the Seine with the Eiffel Tower in the background.
Paris 2024, before the triathlon, view of the Seine with the grandstands and the Eiffel Tower in the background.
Photo: Getty Images
Justine Calma
is a senior science reporter covering energy and the environment with more than a decade of experience. She is also the host of Hell or High Water: When Disaster Hits Home, a podcast from Vox Media and Audible Originals.

The men’s triathlon event at the Paris Olympics was postponed today because of pollution levels in the Seine, where the swimming leg of the event was supposed to be held. Now, the event is tentatively scheduled for Wednesday — if the water quality improves by then.

Bacteria in the river, including E. coli, has been a concern leading up to the Summer Games. Paris spent the equivalent of roughly $1.5 billion on cleanup efforts before the Olympics to prevent sewage and wastewater from contaminating the Seine, The Associated Press reports. But rain seems to have stymied efforts to keep bacteria at safe levels.

“The tests carried out in the Seine today revealed water quality levels that did not provide sufficient guarantees”

“Paris 2024 and World Triathlon reiterate that their priority is the health of the athletes. 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,” World Triathlon, the sport’s international governing body, said in a statement today.

Human fecal contamination is “the most important risk factor” in triathlon competitions, according to World Triathlon. Swimming in water contaminated with feces can potentially lead to skin rashes, diarrhea, and E. coli infections. And athletes can be more prone to infection during or right after the event due to hormonal stress and other factors that might affect the immune system.

E. coli levels should stay at or below 900 colony-forming units per 100 milliliters for “sufficient” water quality, according to World Triathlon. Only 1 of 4 test sites along the Seine showed levels below that limit, AP reports.

Training events had already been postponed with elevated bacteria levels following the downpour over the opening ceremony. Heavy rain can overwhelm sewage and wastewater systems, allowing untreated water to reach the river.

There’s more rain in the forecast for Paris tonight. But for now, both the women’s and the men’s triathlon events are scheduled for Wednesday at 8AM and 10:45AM local time, respectively. There’s also a backup date of August 2nd.

Follow topics and authors from this story to see more like this in your personalized homepage feed and to receive email updates.