Will The Seine Be Clean Enough By The Olympics? Not Even The Experts Know Yet

PARIS — A concern remains with the Paris Olympics, which are less than two weeks away: Will the Seine River be clean enough for athletes to swim in?

Triathlon and marathon swimming are set to occur in the Seine, where swimming has been prohibited for over a century. Despite the city’s efforts to clean up the long-polluted river, the water has tested dangerous for humans in recent weeks while remaining clean on other days. The Games run from July 26 to August 11.

To clean up the river, Paris spent 1.4 billion euros ($1.5 billion) on equipment to collect more stormwater when it rains — the same water that carries bacteria-laden wastewater that enters the river after heavy rains and makes swimming dangerous.

In May, Paris officials opened a massive underground water storage basin near the Austerlitz train station to catch excess rains and prevent effluent from entering the Seine. The basin can hold the equivalent of 20 Olympic swimming pools of polluted water, which will now be cleansed, and it is the focal point of huge infrastructure improvements that the city has hastened to complete not only in time for the Games but also to ensure that Parisians have a cleaner Seine in the years ahead.

Will The Seine Be Clean Enough By The Olympics? Not Even The Experts Know Yet

However, a few periods of heavy rain could send E. coli levels above the World Triathlon Federation’s safe competition limit of 900 colony-forming units per 100 milliliters.

“The Seine is not a special case,” said Metin Duran, a Villanova University civil and environmental engineering professor and stormwater management researcher. “It really is a complicated and very costly problem.”

Like many other old cities around the world, Paris has a combined sewer system, meaning that wastewater and stormwater are routed through the same pipes. With severe or sustained rain, the pipes’ capacity is surpassed, and untreated wastewater flows into the river rather than a treatment plant.

The monitoring group Eau de Paris tests the river water daily. In recent weeks, findings showed hazardous E. coli levels, followed by results that showed improvement in early July.

According to Paris Olympic organizers, if significant rain disrupts the flow of the Seine during the Games, the triathlon will be canceled, and the marathon swimming competition will be moved to the Vaires-sur-Marne Nautical Stadium in the greater Paris region.

“It’s not very common, but it has happened a few times,” said Ollala Cernuda, head of communications at World Triathlon, the sport’s international governing body, on the potential of canceling the swim phase.

“And it’s always linked with water quality issues,” Cernuda said.

However, organizers are optimistic that drier, sunnier weather than what the French capital saw in June will allow the activities to proceed as scheduled despite the infrastructure modifications. The sun’s UV rays kill germs such as E. coli in water.

According to an Associated Press examination of weather data, Paris will have the second-most rainy days since 1950 in 2024, trailing only 2016.

Importantly for the Seine’s water quality, there have been only a few days without rain.

According to the data, Paris experienced only one weeklong dry spell this year — in early June — but between 1950 and 2020, the city was expected to have at least three such spells by the end of June.

“Predictions of rainfall have become much more accurate up to a week in advance,” said Jennifer Francis, a researcher at the Woodwell Climate Research Center in Massachusetts. “But the seasonal patterns of past decades no longer provide reliable guidance in our warmer world.”

As the Games approach, the heated discussion over the cleanliness of the Seine River has become a cause of frustration for certain athletes, like Léonie Périault, a French triathlete who earned a bronze medal at the 2020 Tokyo Olympics.

“Every time I meet someone, they worry that I’m going to swim in the Seine,” Périault recalled. “But I have been swimming in this river for numerous years. In youth contests, we swam routinely in the Seine and never had any concerns.”

Last year, Périault participated in a test event on the Seine.

Will The Seine Be Clean Enough By The Olympics? Not Even The Experts Know Yet

“The setting was incredible with the Eiffel Tower as a backdrop and the water conditions were not worse than anywhere else in the world,” she told me.

On Saturday, Amélie Oudéa-Castéra, the French Sports Minister, took a dip to demonstrate that the renowned river is clean enough. Paris Mayor Anne Hidalgo has also announced that she will swim in the Seine this week.

Dan Angelescu, founder and CEO of Fluidion, a water-monitoring tech startup based in Paris and Los Angeles, said the river has improved since the city’s new infrastructure went online, but the Seine’s water quality remains vulnerable. His organization has been measuring the Seine’s pollution levels for numerous years.

Angelescu said it’s difficult to forecast what will happen later this month based on data from prior years because the water storage basin and other facilities did not operational until a few months ago.

“It’s difficult to tell,” Angelescu remarked in early July after the water in the Seine tested clearer than it had in previous weeks.

“To see such a drastic improvement and so rapidly could be a sign that something is working,” added the physician.

SOURCE | AP