Drinking water very well protected against all viruses, including coronavirus

With the knowledge, experience and measurement methods that KWR has developed over the past decades within its Joint Research Programme with the water utilities, we are capable of quickly anticipating any potential threats. Over the last few weeks, microbiologist Gertjan Medema and his colleagues examined whether the drinking water in the Netherlands is well protected against the coronavirus. Conclusion: yes it is.

The Dutch drinking water utilities and the branch association Vewin also want to know whether the coronavirus represents any risks to the safety of drinking water. Medema: “Based on the knowledge that we’ve built up about viruses in drinking water over the years in the Joint Research Programme, we know that the drinking water in the Netherlands is well protected against those viruses that are known to be transmitted via water, for example, the Adeno-, Noro- and Enterovirus.”Drinking water utilities that produce their water from surface water sources have all set up multiple disinfection barriers for the purpose of removing bacteria, viruses and protozoa, which are also safeguarded by the Analysis of Microbial Safety of Drinking Water.

Groundwater, in turn, is well protected in the subsurface against all microbial contaminants, including viruses. Moreover, the strict hygiene regulations covering the installation of pipes and work on the distribution networks, ensure that the drinking water sector is well protected against all microbial contaminants.

“We have let the drinking water utilities and Vewin know that drinking water is very well protected against all viruses, including coronavirus.”
Prof. Gertjan Medema PhD
Prof. Gertjan Medema PhD

Reminder of SARS

When the first reports about the new coronavirus appeared in the media, Medema was immediately reminded of SARS. “Naturally, since it’s the same kind of virus and it also originated in South-East China, where it was transmitted from animal to human. I thought back on Amoy Gardens, the high-rise complex in Hong Kong where SARS coronavirus (CoV) spread through the indoor sewer system and the ventilation system. An infected person visited his brother, used the toilet and introduced SARS CoV virus via his stools into the indoor sewer system. Sewer water droplets carrying SARS CoV then spread via the building’s ventilation system to other apartments, making 300 people sick.”

Spreading through sewage

At that time, the World Health Organization (WHO) asked KWR researcher Medema, together with other international experts, to assess the risk of the spread of SARS CoV through the sewer and/or water. The main route for the transmission of the virus was not water, but contact with infected people and surfaces. Nor is water a transmission route – or not an important one – for other coronaviruses. These viruses do not survive well in water, and they are easier to remove and inactivate than those viruses, such as the Noro- and the Adenovirus, whose waterborne transmission is frequently described. Nevertheless, the Amoy Gardens case did indicate that the water route was also a possibility for SARS CoV.

A new virus

Meanwhile, the new coronavirus continued its advance. The first European cases were reported, and ‘outbreaks’ of this new virus already extended further than those of SARS CoV in 2003. There was therefore a possibility that the virus would also come to the Netherlands. This presented a chance for us to study the ‘water route’ of the new coronavirus – which incidentally is so similar to SARS CoV that it is now called ‘SARS CoV2’.

Very experienced with viruses

KWR has a great deal of experience with viruses in water, and the institute’s Microbiological Laboratory disposes of methods to concentrate, treat and detect viruses in water. Because the RNA code of the new coronavirus has been made widely available, we were able to rapidly get a detection method for the new coronavirus operational. Using this method we can determine whether the virus also ends up in sewage water and if it is detectable. Then we can investigate whether sewage screening turns out to be a sensitive method to demonstrate virus circulation in a population of people.

In consultation with microbiologists and virologists from China and Italy, Medema is looking into whether these countries also want to investigate the spread of the coronavirus via the sewage system.” They are, after all, ahead of us when it comes to circulation in sewage water. We could collaborate to see whether we could collect more hard data about this new virus and the water route, so as to effectively underpin our recommendations to the (international) water sector and WHO.”  Read about what KWR recently discovered about the spread of the new coronavirus SARS-CoV-2 in sewage.