Traces of Covid-19 in water in Paris? We unravel the true from the false

• Sunday, the mayor of Paris said that tiny traces of Covid-19 had been detected in its network of non-potable water.
• If the tap water is safe to drink, the water circulating in the sanitation networks may contain traces of the virus.
• As a consequence, traces of Covid-19 are present in sewage sludge or in natural environments.

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Sunday, the laboratory of the municipal water authority Paris indicated that they had discovered
traces of Covid-19 in minute quantities on four of the 27 points of withdrawal from the non-potable water network. Even if the latter is used only for cleaning streets, watering gardens or fountains, the town hall immediately suspended its use in the name of the “precautionary principle”. While hammering that there was no risk on the other network, that of drinking water.

What cause suspicion on tap water, but also on the presence of the virus in general, whether in wastewater or in French rivers and rivers. Right where the water used to feed people is taken. As in Paris, where the water comes from the Seine and the Ourcq Canal.

20 minutes unravel the true from the false about the presence or not of the virus in water … all waters.

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At the start of the epidemic of coronavirus, some French people have decided to turn to mineral waters, filling their carts with plastic bottles, for fear of finding the famous Covid-19 in the trickle of water flowing from their tap.

Until those responsible for this sector undermine this preconceived idea and assert that drinking water remains well drinkable and is not a possible source of contamination for the populations.

Safe tap water

“Viruses do not withstand the treatments usually given to water to make it drinkable. Health agencies, including the World Health Organization, have indicated that the virus does not show particular resistance to these treatments. There’s no risk of Covid in tap water, that’s for sure. It is safe and essential to fight the spread of the virus, to wash your hands and to stay at home, “said Tristan Mathieu, General Delegate of the Professional Federation of Water Companies (FP2E) contacted by 20 minutes.

The water professionals are formal: “There is no risk in drinking tap water, it is not a vector of transfer of Covid-19, bactericidal treatments for drinking water (chlorine, UV, ozone ) cover all fields. ” # COVID19 #WATER

– FP2E – Federation of Water Companies (@ fp2e_) April 19, 2020

To be sure nothing gets through the cracks, many French water managers, with the approval of the regional water agencies, have increased the chlorine level.

This is the case for the Rennes basin, which, in order to “maintain effective disinfection of the distributed water” in the Breton capital, authorized that the chlorine concentration leaving the drinking water plants can go up to twice the usual content. As in Caen and in many other French cities.

????In the current context # COVID19 #Caenlamer would like to remind you that there is no need to worry about the quality of tap water. The virus is very sensitive to chlorine, and therefore disinfection of water is effective
????https://t.co/IMVLdfWzc3 @Fleury_sur_Orne pic.twitter.com/JLJ070bLDG

– Caen la mer (@Caenlamer) April 21, 2020

Water with a more chlorinated taste than usual which can have another origin. “The confinement of the population and the cessation of certain industrial and tertiary activities can have an effect on consumption habits, and therefore on the circulation of water in pipes. Larger and more frequent uses in residential areas cause a greater renewal of water in certain pipes, and bring tap water from drinking water production plants which can be more “freshly chlorinated” , explains Jean-Charles Laclau, director of the Water Cycle at Toulouse Métropole.

Presence in wastewater

But if it is safe to drink, water, when consumed, can be polluted by Covid-19 sufferers. This is how the virus is found in wastewater, which flows straight into treatment plants. Whether through the feces or the wipes thrown into the toilet, France Nature Environment in a file devoted to the question.

A proven presence, to the point that teams of researchers believe that in the future we could detect the presence of the virus and the extent of an epidemic thanks to the analyzes carried out in these sanitation sites.

While waiting to get there, the authorities had to deal with a much more urgent matter. What to do with the recovered sludge once the water has been filtered? Because usually, these are intended to be spread on agricultural fields to fertilize the soil, in the same way as manure and slurry.

To avoid spreading the virus, National Agency for Food, Environmental and Occupational Health Safety (ANSES) has decided to take measures and no longer allow spreading “during the epidemic without prior sanitation,” she said in early April. A possible treatment thanks to lime, composting or drying.

“With regard to unhygienized sludge, which corresponds to 16% of the sludge produced, the precautionary principle must lead to not spreading it as far as the virus can be present in this sludge and we do not know for the moment its life span in this environment. A circular was therefore sent to the prefects with specific instructions to this effect. This implies that the State services study with the operators of the treatment plants concerned the solutions to be put in place, ”said 20 minutes the
Ministry of Ecology.

And in aquatic environments too

The wastewater, once decontaminated and “clean”, leaves from where it was originally taken to supply the drinking water network. In Toulouse, they leave for the Garonne, in Paris for the Seine.

“Tiny” traces of # COVID19 in non-potable water at #Paris ? “There are always traces of epidemics in the sewage, they are in the feces”, explains @Celia_Blauel, president of @eaudeparis, guest of #RTLPetitMatin with @JSellier pic.twitter.com/5qCUWXOGQC

– RTL Petit Matin (@RTLPetitMatin) April 21, 2020

“It is a classic of epidemics, we always find in sewage traces of epidemic, whether it is gastroenteritis, classic flu, and today the Covid because very simply when people are sick, they go to the toilet. And this virus is in the feces. Fortunately, after the sewers, he arrives at the treatment plant. The virus is widely treated there, but there are still traces that leave in the natural environment, and that is why it is found in particular in non-potable water “, has developed in RTL microphone, Célia Bauel, president of Eau de Paris and deputy mayor of the capital.

Is the presence of the virus in water dangerous for humans?

Should having tiny traces of the Covid-19 worry the population? Not really if we believe the specialists. Anne Goffard, virologist at Lille University Hospital interviewed by LCISpecifies that once it is found in water “the coronavirus is degraded very quickly, its viral envelope is destroyed and suddenly the virus is no longer infectious, it loses all its ability to infect”.

Especially since, as Karine Lacombe, head of the infectious diseases department at the Parisian Saint-Antoine hospital specifies, “we know that the virus cannot multiply in the environment because it needs human cells and take over enzymes from human cells to multiply. ”

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