With the Paris Olympics just around the corner, the French capital is a step closer to the dream of swimming in the River Seine again, as bacteria levels go down to an acceptable level.

Swimming in the iconic river has been banned since 1923, but athletes and Parisians may soon be able to take a dip thanks to cleanup efforts for the Olympic Games.

“Historically there's been pollution from industry, from farms upstream of Paris, and then from the city itself, from frankly raw sewage that goes into the river,” said Matthew Heberger, a Paris-based hydrologist at the San Francisco Estuary Institute.

The latest water quality tests show that the river is mostly safe for swimming under standards set by international swimming and triathlon federations.

But the biggest risk, as Heberger explained, is "that if there's a large rainstorm in the 24 hours before one of the swimming events that could wash a lot of storm water off of the land surfaces around the city which brings with it pollution".

From July 30, the Seine is set to host outdoor swimming events during the Games. But the triathlon could be postponed or changed to a duathlon without swimming if the river water is unsafe.

SAR triathlete Jason Ng is expecting to race in the river that day. But while he cannot guarantee that his event will go ahead, Ng said he will just focus on what he can control.

“I would prefer the swim not to be cancelled as I've qualified for triathlon, and I would prefer to actually race the event that I've qualified for in the Olympics,” he said.

“Of course having the swim cancelled will favour some athletes who are not as strong swimmers, but again I think you just have to deal with what comes.”

Paris mayor Anne Hidalgo took a dip in the Seine in mid-July to convince doubters that the water is safe enough for the Games.

A local surnamed Boutin told RTHK that he too wants to take a dip if all goes well.

“It’s going to be a new future for Paris and I think it’s going to be a good thing. It was a little browner, now it’s greenish. There’s a colour change,” he said.

And another Parisian, Kelfa, said he hopes the river will stay clean so people can swim even after the Games.

“I do believe the numbers of the studies, like they’ve been saying recently it was too high of bacteria for us to swim in it, which I do believe,” he said.

“And now apparently they’ve invested a lot to clean it and the numbers are better. I guess we should trust them.”