FILE PHOTO: Paris 2024 Olympics - Triathlon - Mixed Relay - Alexander III Bridge, Paris, France - August 05, 2024. Alice Betto of Italy dives into the river Seine during the race. REUTERS/Molly Darlington/File Photo
PARIS (Reuters) - Open-water swimmers are hoping to plunge into the river Seine for 10km marathon races at the Paris Olympics on Thursday and Friday but pollution readings will have the final say.
Fluctuating levels of bacteria have given organisers headaches for months, forcing the postponement last week of triathlon training sessions and the 400m men's swim in that event.
Although the French authorities have spent 1.4 billion euros ($1.53 billion) on upgrading the capital's sewage systems, with cleaning up the Seine a top Olympic legacy, regular checks of the river's health continue to cause concern.
Multiple tests are being carried out daily, with the first of two planned familiarisation days cancelled on Tuesday after a situation meeting between World Aquatics, Paris 2024 organisers and city authorities.
World Aquatics said the latest water quality review showed E.Coli levels ranged from 'very good' to 'good' at four collection points but Enterococci levels exceeded maximum thresholds.
"World Aquatics and Paris 2024 remain confident that the Marathon Swimming competitions on 8 and 9 August will proceed as planned," the world body added.
Organisers have said they have a backup plan, with the Vaires-sur-Marne rowing and canoe venue available just outside the capital.
There is also the possibility of holding both men's and women's races on the same day if a postponement is deemed necessary, with the Games ending on Sunday.
Assuming the Seine passes the test, the races will offer some riverside spectators a free treat with the Olympic action taking place against a backdrop of a 200-year-old bridge and the looming Eiffel Tower.
The races -- women on Thursday and men on Friday -- feature a 1.67km loop completed six times between the Alexandre III bridge and Pont de l'Alma.
The first leg goes with the current, the return against it.
Germany's Florian Wellbrock is the defending men's champion, with Hungary's Kristof Rasovszky hoping to improve on his silver medal from 2021 and Italy's Gregorio Paltrinieri the same after bronze in Tokyo.
Wellbrock has something to prove after failing to qualify for the men's 1,500m final.
Brazil's Ana Marcela Cunha returns as reigning women's champion, along with world champion Sharon van Rouwendaal of the Netherlands who won gold in 2016 and silver in 2021.
Some of the contenders, such as Ireland's Daniel Wiffen, have won medals already in the distance events held in the Le Defense Arena pool.
"It's still on the agenda," Wiffen, who has long said his dream is to swim in the Seine, told reporters on Sunday night after adding a 1,500 metres bronze to the 800m gold he won last week.
Paltrinieri took silver in the 1,500m and bronze in the 800m and will be another hoping to win a medal in both pool and open water at the same Games.
(Reporting by Alan Baldwin, editing by Christian Radnedge)
