Data from the Paris City Council revealed that the level of E. coli contamination in the Seine River exceeded the recommended standard on the day Paris Mayor Anne Hidalgo swam in the river that flows through the capital.
"The threshold values recommended by the health authorities were exceeded on July 17 in the Pra-Marie (swimming area), where the mayor of the French capital swam," France Info radio reported.
City Hall data indicated that in the area where the mayor was swimming, the bacteria concentration was 985 npc (most probable number) per 100 ml of water, exceeding the limit recommended by the European directive of 900 npc/per 100 ml.
Hidalgo swam the Seine on the eve of the Olympics to prove that the capital's river was safe for competitions. She took part in the swim with the city's mayor and president of the Paris Games Organizing Committee Tony Estanguet, and the prefect of the capital region, Marc Guillaume.
The mayor's office said that in order to compete, several treatment facilities and sewage systems had been upgraded, with the water purification measures costing around €1.4 billion. Water samples taken from the river at the end of June showed that it was safe to swim in the Seine.
The Seine River has been closed and swimming is prohibited since 1923 due to high levels of E. coli and other disease-causing bacteria.
Anne Hidalgo's swim in the Seine was postponed twice, first in June due to strong currents in the river, and then Hidalgo deemed the swim inappropriate in light of the ongoing campaign for the French special legislative elections.
On July 17, Paris Mayor Anne Hidalgo fulfilled a promise she made in January to swim in the Seine, nine days before the opening ceremony of the 2024 Olympics, in an attempt to prove the river is safe for competitions.
The Olympic Games will be held in Paris from July 26 to August 11, and the Paralympics from August 28 to September 8. Triathlon and open water swimming events are scheduled to take place in the River Seine.