Paris: Organisers will decide on Wednesday at 4am (0200 GMT) if Paris Olympics' triathlon competitions can go ahead later in the day after the men's event was postponed on Tuesday due to pollution levels in the Seine.
France has invested heavily to make the Seine swimmable as a key legacy of the Games, and spent 1.4 billion euros (Rs 12,672 crore) on wastewater infrastructure to contain sewage and minimise spillage into the waterway.
But the gamble that the river would be clean enough on the day of the triathlon was never guaranteed to pay off, especially as water quality varies widely day-to-day.
Tuesday's men's race was postponed until Wednesday at 10:45 am local time (0845 GMT), immediately after the women's event, which is scheduled for 8 am that day.
The decision whether it can indeed go ahead on Wednesday will be made using a sample taken on Tuesday at 5am, Paris 2024 organisers said, as well as a discussion between experts on overnight weather.
Tuesday's sample results are expected to be good because of a sunny, dry weather that day, but storms are forecast overnight. Key to the final decision will be the flow of the river, Paris 2024 said.
A World Triathlon spokesperson said other contingency dates as well as Friday were being explored, in case the race cannot go ahead on Wednesday.
Elements taken into account include previous weather, weather forecast, and a medical official also does a sanitary inspection of the water, the spokesperson added.
The Olympic triathlon course was conceived to maximise the wow factor, with the river swim a key element.
After diving into the Seine from a pontoon next to the Alexandre III bridge, athletes are set to race past the Musee d'Orsay and Grand Palais during the bike and run stages before ending back where they started.
Crossing the finish line on the bridge, they will be framed by stone columns topped with gilt-bronze statues of Pegasus, with the golden dome of the early 18th century Invalides monument as a backdrop.
'Dissappointment'
Australia's Olympic team chief Anna Meares said news of the postponement had not deterred the triathletes.
"The athletes are really looking forward to having that stage and that platform to perform on," she told reporters.
"They actually want to swim in the river.
French triathlon federation technical director Benjamin Maze told FranceInfo they were taking steps to help athletes deal with the situation.
"Of course there is a little bit of anger and a lot of disappointment," he said.
The federation had been working with psychologists to help athletes prepare mentally for the uncertainty, Maze added.
Around 50 spectators had gathered on the sun-drenched Invalides bridge by 7 am to watch the race, only to learn it had been postponed.
Magnus and Kristine Hagelsteen from Lund, Sweden, had packed pains au chocolat to have for breakfast while watching the race and cheering on Norway's Kristian Blummenfelt, who won gold at the Tokyo Olympics.
"It's a pity for everyone but especially for the ones that are going to do the triathlon; I would be so disappointed -- you're nearly there, ready to start, and then it's cancelled," said Magnus, who planned to come back on Wednesday.
For Ortrun Guendisch, visiting from Munich, the postponement meant she and her 14-year-old son Adrian would miss the event entirely as they were starting their journey home later in the day.
"We actually woke up very early to come here and we found out when we got here that it's cancelled, so we are pretty disappointed," Guendisch said.
Paris Mayor Anne Hidalgo took a dip in the river herself earlier this month, in a bid to convince doubters. City authorities have announced plans for three Seine swimming sites to open to the public by June next year.
Rainfall often causes sewer systems to overflow into the river, significantly increasing concentrations of infection-causing bacteria such as E. coli.
Seth Rider, one of 55 triathletes entered in the men's race, has been taking unconventional measures to prepare for exposure to bacteria.
"We know that there's going to be some E. coli exposure, so I just try to increase my E. coli threshold by exposing myself to a bit of E. coli in your day-to-day life," the US athlete said in a press conference on Saturday.
"Just little things throughout your day, like, not washing your hands after you go to the bathroom and stuff like this."