PARIS -- The organizing committee for the Paris Olympics has unveiled backup plans for open-water events if the Seine River is deemed unsuitable for swimming.

Triathlon and marathon swimming events are scheduled to take place in the famed river running through Paris, but unsafe levels of E. coli have been detected in recent weeks, raising questions about whether the events could go ahead as planned.

Organizers on Friday confirmed they have backup plans: the triathlon and marathon which are scheduled to take place near the Alexander III bridge between July 30 and Aug. 5, could be postponed by a few days if conditions are unsafe.

“The potential for unseasonal weather events requires us to be cautious,†a statement from the organizers said.

In a worst-case scenario, if heavy rain affects the Seine’s flow and increases bacteria levels, the triathlon could be changed to a duathlon, without the swimming portion.

The marathon swimming competition could be relocated to the Vaires-sur-Marne Nautical Stadium in the greater Paris region, which already hosts rowing and canoeing competitions and can accommodate up to 15,000 spectators, organizers said.

However, they expressed confidence in the Seine’s water quality, noting improvements in recent days. The latest reports on the Seine’s water quality published by Paris city hall attributed the significant improvement in bacteria levels to the sunnier weather and warmer temperature in the French capital last week.

“We have observed in the past week that results would have enabled events to be held in the Seine on seven out of nine days,†Paris 2024 organizers said.