Seine Still Fails Water Quality Tests Two Months Out From Olympic Games

With barely 50 days until the start of the Paris Olympics, questions persist about the viability of using the Seine for the open water and triathlon events.

The latest water quality tests done by Surfrider Foundation Europe show levels of E. Coli and enterococci bacteria “higher than authorized levels set by sports federations and European bathing standards,” per AFP.

Surfrider is a non-profit organization that has been conducting regular tests on the Seine’s water quality. They are specifically testing for E.Coli and enterococci and collect samples from the Pont de l’Alma and the Pont Alexandre III, a section of the river slated for use during the Games. In April, they released findings from a six-month period that found only one of the samples had satisfactory water quality with regards to the two types of bacteria.

According to the same AFP report, “one reading for E.Coli at the Alexandre III bridge was more than three times higher than the maximum level authorized by the triathlon and open-water swimming federations.”

Heavy rainfall during May is likely a major factor for what Surfrider deemed  “poor” water quality. The heavy rainfall also forced Games organizers postponed the opening ceremony rehearsal on the Seine for the second time as the water levels were too high.

Paris officials recently inaugurated the Austerlitz water tank, which can hold 13.2 million gallons of water. The tank is expected to go into operation in early June. Its goal is to prevent the Paris sewer system–which carries both rain and wastewater–from getting overwhelmed and releasing everything into the Seine.

But even the tank does not entirely remove the rain’s threat. In spring 2023, deputy mayor Pierre Raabadan told The New York Times if it rains the week before the Games “we know the quality of the water—even with all the work we’ve done—probably won’t be excellent.”

Organizers maintained throughout the spring that there is no alternative venue if the Seine’s water quality is poor. Tony Estanguet, president of the Paris 2024 organizing committee, held a press conference in April warning about the consequences of heavy rain. At the conference, he reiterated “the first part of the contingency is to postpone the dates. That’s why we have programmed the triathlon at the beginning of the Games.”

The individual triathlon races are scheduled for July 30 and 31 with the mixed relay on August 5. There is less flexibility for the open water swimming events, slated for August 8 and 9. The triathlon international federation could also rule to shorten the triathlon to a duathlon.

According to AP, officials will test the Seine’s water every day at 3 a.m. during the Games to determine whether events can proceed. On their website, Surfrider notes that they are now unable to continue to monitor the river’s water quality. The closing of the quays in the lead-up to the Games makes it impossible for the organization, though in an open letter they have asked for continued access to sampling sites for the duration of the Games.

So, even though organizers declared they were “on time” with construction at the Austerlitz basin’s inauguration, the new infrastructure does not fully answer the lingering questions about water quality. And as March’s floods and May’s heavy rain shows, those questions will remain through the Olympic Games.

Both the president of France Emmanuel Macron and the mayor of Paris Anne Hidalgo have promised to swim in the Seine before the Olympics, with organizers saying multiple times that their confidence is so high that there is “no plan B”.