Pollution levels in the Seine river in Paris remain well above what is allowed for bathing, according to a water quality report released on Friday.

The report, completed last week and released by the Paris mayor’s office, comes less than a month before the Olympic Games, in which the French capital's iconic waterway is set to see athletes dive into the waters for swimming events.

"Water quality continues to be impaired due to unfavourable hydrological conditions — rainfall, high flow velocity, low solar radiation, temperatures below the seasonal norm and pollution in the upper reaches of the river," the report stated.

What is the level of contamination?

The data showed that bacteria such as enterococci and E. coli remained well above legal limits at all four test sites along the river on Sunday.

At the Alexandre III bridge, one of the venues for the swimming leg of a triathlon event, enterococci exceeded a concentration of 1000 colony-forming units (cfu)/100 ml on Sunday. That is more than double the limit of 400 cfu/100ml set by European law. E. coli was also almost four times higher than allowed.

French authorities have invested €1.4 billion ($1.5 billion) in wastewater treatment plants and sewer system in the greater Paris area. The French capital is trying to clean up the Seine so people can swim in it again, as they did during the 1900 Paris Olympics. 

City hoping for better weather

The Paris mayor's office said on its website that water pollution levels spike during periods of heavy rain, as has been the case in recent weeks.

At higher temperatures and lower water levels, disease-causing viruses and bacteria can be broken down more quickly, according to city officials. So they are now hoping for better weather.

"We had a period of historic rainfall in May and a lot of rainfall in June. But that didn't worry us, because we knew that with a significant improvement in weather conditions, we'd get back to summer-like levels," Pierre Rabadan, the Paris deputy mayor in charge of sport and the Olympic games, told Reuters news agency.

dh/rm (dpa, Reuters)