Unsafe levels of E. coli have been found in the Seine River for the third consecutive week, according to test results published on Friday, less than a month before the Paris Olympics.
The test results by monitoring group Eau de Paris reveal contamination levels consistently above the safe limit of 900 colony-forming units per 100 milliliters determined by the World Triathlon Federation for competitions.
Marathon swimming and triathlon events are scheduled to take place in the river near the Alexandre III bridge during the Olympics, which begin on July 26.
Persistent rainfall has exacerbated the issue, as rainwater infiltrates the sewer system, leading to the discharge of fecal bacteria into the Seine, the report said, adding that the flooding of the Yonne River, a confluence of the Seine, has increased the flow of the Seine.
A 50,000 cubic meter reservoir inaugurated in May to store excess rainwater was used for the first time on June 18 and 19, preventing 40,000 cubic meters of wastewater from seeping into the Seine.
Despite the continued high contamination levels, organisers remain optimistic.
"By the second half of July, things should settle down," said Tony Estanguet, head of the Paris 2024 organising committee.
Marc Guillaume, the Paris region prefect in charge of the Seine, suggested the weather would improve in coming weeks.
"At some point, we'll have summer weather," he said on Wednesday.
"That's when the plan will take full effect."
Water quality of rivers in major cities can be impacted by many things, from runoff to dumping of chemicals, sometimes illegally, and boat traffic.