River Seine Pollution Could Cancel Paris Olympics Events—Here’s Why

Public swimming in the city’s river has been banned for over a century, amid concerns about pollution in the water.

Some swimming events in the 2024 Paris Olympics could be canceled or postponed, officials said, after a French charity warned about “alarming levels” of pollution in the River Seine amid a decades-long clean-up effort—though French President Emmanuel Macron and Paris Mayor Anne Hidalgo claimed the river will be clean in time for the events.

Surfrider Foundation Europe completed 14 tests on water samples taken from two spots on the Seine—including the starting spot for the Olympic and Paralympic triathlon and marathon swimming events—between September and March, none of which met European Union regulations, the group said.

Only one spot did not indicate alarming levels of bacteria like E. coli and enterococcus faecalis, a bacteria found in human fecal matter, according to the group.

Tony Estanguet, president of the Paris Organizing Committee, reportedly said Tuesday that while officials are “confident that it will be possible to use the Seine,” there could be a “final decision where we could not swim,” specifically referring to a scenario involving heavy rain, which could lead to increased E. coli levels in the river.

The International Olympic Committee said in a statement to NBC News the triathlon could be canceled or turned into a duathlon—just running and cycling—if the river’s water is too polluted.

WHAT TO WATCH FOR

Pierre Rabadan, Paris’ deputy mayor in charge of the Olympics, told the New York Times if there’s rainfall in Paris for “a week continually before the races,” the Seine’s water quality “probably won’t be excellent.”

CHIEF CRITIC

Ana Marcela Cunha, the Brazilian gold medal winner of the women’s marathon 10-kilometer swim at the 2020 Tokyo Olympics, told Agence France-Presse there is “a concern” about pollution in the Seine. Olympic officials “need a plan B in case it’s not possible to swim in the Seine,” Cunha said, adding the river is “not made for swimming.”

CONTRA

Macron and Hidalgo said they plan to personally swim in the Seine to showcase the city’s efforts to clean the river. Macron said it would be “an important legacy” of the Olympics for the Seine to be included in the events.

BIG NUMBER

$1.5 billion. That’s how much Paris has spent during a decades-long effort to clean the Seine for public use, which includes projects to upgrade the city’s sewage system and stormwater treatment facilities.

SURPRISING FACT

World Aquatics—the world’s governing body for swimming—canceled the Open Water Swimming World Cup Paris last year after officials determined the Seine’s water quality “remained below acceptable standards for safeguarding swimmers’ health.” The organization noted it was “clear that further work” is needed to “ensure robust contingency plans are in place” for the Olympics.

KEY BACKGROUND

Public swimming in the Seine has been banned since 1923, after officials determined the water was unsafe, according to the BBC. Paris operates with a “single system” drainage infrastructure that becomes oversaturated during heavy rainfall, causing excess water to be drained into the river. Parisian officials said clean-up efforts, in addition to updated sewage and sanitation systems, will allow the city to open three open-air swimming areas by 2025.