(Paris) A Seine that meets bathing criteria, despite gloomy weather and a flow that is too high: on Friday, the Paris city hall announced good results from the water analysis, exactly two weeks before the start of the Olympic Games which include events in the river.
The Bathing Plan, into which the State and the communities of the Paris region have injected 1.4 billion euros (2.07 billion Canadian dollars) over the past decade to clean up the river, with the Olympic Games as an “accelerator”, is working. In any case, this is what the Île-de-France prefecture and the Paris city hall have been repeating since the first good results of the bacteriological analysis of the river, dating back to the end of June.
On Tuesday, Prefect Marc Guillaume had indeed announced “extremely positive water quality trends which demonstrate the power of the Bathing Plan”.
On Friday, more good results are expected, even though it is raining in the host city. The weather, which has a major impact on water quality, is still not up to par with the summer.
Nor one of its corollaries, the flow rate, which increased sharply around 550 m3/second, compared to 450 the day before, while it is normally between 100 and 150 m in summer3/s.
A plan C revealed
On the other hand, the river’s content of the faecal bacteria E. coli, one of the two measures for authorising or not bathing, is increasingly within the limits.
Between July 3 and 9, the sampling point at the Pont Alexandre-III, the Olympic site, only exceeded the standard of 1000 colony forming units (CFU)/100 ml on Wednesday 3.
Two other sampling points showed five days out of seven in the green and a third six days.
Despite a flow rate “three times higher” than normal in summer, “80% of the analyses” are “in line with the thresholds of the European directive”, the organisers of the Olympic Games maintain.
The Paris City Hall, through the deputy for the Olympic Games and the Seine, Pierre Rabadan, displayed measured confidence after these good results.
“I’m not saying that we are very confident given the weather, but we have no concerns about our ability to hold the competitions on time,” Pierre Rabadan said on RFI.
“With adjustments, if necessary,” he added, however, a week after the revelation of a plan C consisting of moving the marathon swimming event to Vaires-sur-Marne (Seine-et-Marne), 25 kilometers east of the French capital.
Plan B consists of postponing the triathlon events (July 30 and 31, August 5), marathon swimming (August 8 and 9) and paratriathlon (August 1) by a few days.er and September 2) in case of bad weather.
In the event of heavy rainfall, untreated water – a mixture of rain and wastewater – can be discharged into the river, a phenomenon that retention structures inaugurated before the Games are intended to prevent.
Water releases upstream
Paris Socialist Mayor Anne Hidalgo is set to set an example by bathing in the Seine soon. According to a partner organization of the event, the meeting is scheduled for the morning of the 17th, not far from the Hôtel de Ville.
Although the level of pollution in the river is generally in the green, according to the organizers, the flow rate remains very problematic for swimming, but also for the opening ceremony on the Seine.
On July 5, the prefecture of Haute-Marne, in eastern France, issued a decree authorizing “water releases to recover upstream storage capacity.”
According to Prefect Marc Guillaume, the regulations allow going “roughly up to 450 m3/s” to allow the events to take place. As for the boats that will sail on the Seine on July 26, “half a dozen” of the hundred planned will have to be changed if the flow of the Seine remains at very high levels.
Because the flow rate can also be partly correlated with the height of the water, potentially problematic for passing under certain bridges in Paris.
Rehearsals, postponed precisely because of the high number of visitors, must be held in the four days preceding the opening ceremony.