E. coli Levels in Paris’ Seine River Exceed Safe Limits Before Olympics

Paris — According to test results published Friday, the Seine River in Paris has unsafe levels of E. coli, less than two months before swimming competitions are scheduled to take place during the Paris Olympics.

After a period of persistent heavy rain in Paris, the levels of bacteria such as E. coli and enterococci were found to be above the limits considered safe for athletes during the first eight days of June.

The report was published by the monitoring group Eau de Paris, a day after a senior International Olympic Committee executive stated there were “no reasons to doubt” that the races will proceed as planned in a historic downtown stretch of the Seine near the Eiffel Tower.

The first Olympic event in the cleaned-up Seine is the men’s triathlon, which includes a 1.5-kilometer (under 1 mile) swim, scheduled for the morning of July 30. The women’s triathlon follows the next day, and a mixed relay event is scheduled for Aug. 5.

Marathon swimming races over 10 kilometers (6.2 miles) for women and men are scheduled for Aug. 8 and 9, respectively, in waters that were historically polluted before a $1.5 billion investment ahead of the Olympics

“We are confident that we will swim in the Seine this summer,” stated IOC official Christophe Dubi on Thursday during an online briefing after receiving an update from Paris city officials and Olympic organizers.

Despite the IOC’s publicly expressed confidence, the final decision on approving the events as safe for athletes should rest with the governing bodies of individual sports, World Aquatics and World Triathlon.

The safety of the Seine water for the Olympics has been in question since some test events scheduled for last August were canceled, also after unseasonal heavy rains.

According to European standards, the safe limit for E. coli is 900 colony-forming units per 100 milliliters. The World Triathlon Federation uses the  to determine sufficient water quality for competitions.

During the first eight days of June, test results showed that E. coli levels frequently exceeded these thresholds. Enterococci levels were better, mostly staying within safe limits. The tests indicated an improvement, from high contamination levels on June 1 to more acceptable levels by June 9, mainly due to improved weather.

Rainwater infiltrates the sewer system, and to prevent street flooding, the excess water, carrying fecal bacteria, is diverted into the Seine. To address this, a massive reservoir capable of storing 50,000 cubic meters of water during heavy rainfall was inaugurated in May.

Water quality of rivers in major cities can be impacted by many things, from runoff to dumping of chemicals, sometimes illegally, and boat traffic.

Earlier this week, Paris’ mayor Anne Hidalgo reiterated her promise to take a dip in the river before the start of the competition. On Tuesday, she confirmed that her swim was postponed until after the snap elections in France, which end on July 7.