Water does not appear to play a role in the spread of the coronavirus SARS-CoV-2. This has been confirmed by the World Health Organization (WHO). However, coronavirus monitoring in sewage can be used to see whether the virus is spreading in the population.

Drinking water

The coronavirus SARS-CoV-2 has not been found in our tap water. There are strict laws in the Netherlands to ensure the microbiological safety of drinking water. Protection against viruses is also taken into account. This is fairly unique worldwide, and also protects us against SARS-CoV-2.

Risk of Legionella in drinking water

Many different measures have been implemented since the coronavirus SARS-CoV-2 emerged in the Netherlands. Many buildings are or were temporarily not in use, or hardly used at all. As a result, some of the tap water in these buildings has been standing in the pipes for some time. Buildings that are considered ‘priority institutions’, such as hotels, swimming pools and saunas, are required to actively take steps to prevent the growth of Legionella in their pipe systems. Other buildings do not need to take those precautions. That includes gyms, sport clubs, schools and offices. The risk of becoming ill from Legionella bacteria is minimal at these locations. Tips to limit exposure to Legionella in these buildings are available on the RIVM page on Legionnaire’s disease.

Bathing water

The partner organisations in the swimming pool sector have drawn up a Protocol for Responsible Swimming. Using the guidelines set out in this protocol, swimming pools can ensure that everyone can swim safely and responsibly. The protocol is based on the hygiene recommendations provided by RIVMNational Institute for Public Health and the Environment . The municipalities determine whether local swimming pools are permitted to be open. If you would like to know if the swimming pool in your municipality is open, please check with the municipal authorities in your area.

Fountains

There are fountains that are in surface water and fountains that are placed in stone basins on public streets. All fountains produce water spray. The water in fountains may contain pathogens of various origins. Fountains need to be well designed, maintained and managed to ensure good water quality and safe fountains. Research shows that a fountain placed in such a way that the water spray cannot be felt does not pose a health risk.

Risk of Legionella in drinking water

Many different measures have taken effect since the coronavirus SARS-CoV-2 emerged in the Netherlands. Many buildings are hardly being used, or not being used at all. As a result, some of the tap water in these buildings has been standing in the pipes for some time. Buildings that are considered ‘priority institutions’, such as hotels, swimming pools and saunas, are required to actively take steps to prevent the growth of Legionella in their pipe systems. Other buildings do not need to take those precautions. That includes gyms, sport clubs, schools and offices. The risk of becoming ill from Legionella bacteria is minimal at these locations. There are tips to limit exposure to Legionella in these buildings.

Sewage

Genetic material (RNA) from the coronavirus SARS-CoV-2 has also been detected in sewage in the Netherlands. It is still uncertain whether the virus found in faeces or in sewage is infectious to humans. Evidence of human infection via sewage has not yet been found. In nearly half of all people with COVID-19, the genetic material from the virus is found not only in the nose, but also in the faeces, and several were found to have the virus present in their urine. Some studies have isolated infectious virus from faeces, but other studies did not succeed in doing so. It is not yet clear whether the virus particles found in sewage could be infectious. It is also unknown how long the virus survives when it ends up in sewage. RIVM is researching this topic.

Most people do not come into contact with sewage. The advice is to follow the hygiene measures at all times. Wash your hands with soap and water after every visit to the toilet, and clean the toilet area regularly.

People who work with sewage should avoid direct contact with the sewage, and should avoid ingesting, swallowing and/or breathing in spray or mist from the water. Sewage always contains many different pathogens. Faecal matter excreted by sick people, but also by people who are not ill at all, always contains all sorts of pathogens that can make others sick if they are transmitted via hands, water or food. These pathogens are discharged into the sewage via the toilet and sewage system. Established protective measures for people working with sewer water offer effective protection against the various types of pathogens in sewage, including coronaviruses. For that reason, people who work with sewage must wear personal protective equipment appropriate to their work. All these protective measures for safe working practices involving wastewater are listed in the occupational health and safety catalogue of the water management authorities (in Dutch).

If you have questions about the Health and Safety Catalogue, please contact your Health and Safety Coordinator. It is also important that employees at the sewage treatment plant follow the hygiene protocols:

  • Wash your hands often with soap and water
  • Cough and sneeze into your elbow
  • Use paper tissues
  • Do not shake hands

Well-functioning sewers in houses and buildings

If the sewer system is working properly, people cannot come into contact with faeces or air from the sewers, which could potentially contain virus particles. A well-functioning sewer does not leak and has a venting and aeration system that allows air to escape. It is not necessary to touch the system at all. If you can smell the air from the sewers, this is often an indication that venting and aeration are not working properly. In that case, find out where the sewer smell is coming from and seal it off, or arrange to have it sealed off.

Specific considerations:

  • Make sure that all connections to the building’s sewer system in toilets, kitchens, bathrooms etc. are equipped with well-functioning water traps (also known as a P-trap or siphon). A layer of salad oil on the water in siphons through which no or very little water flows will prevent the water in the water trap from evaporating;
  • If the toilet seat is equipped with a lid, flush the toilet with the lid closed to prevent splashing droplets and aerosols from spreading;
  • Do not ignore foul odours in the toilet, kitchen or bathroom. This could indicate a sewer leak. Find the cause and resolve the problem, or arrange to have it fixed. A sewer pipe that is no longer connected to anything must be capped and sealed.

More information:
Press release by Techniek Nederland (in Dutch): Preventing the spread of SARS-CoV-2 by sewage systems in buildings
Press release from RIONED (in Dutch): Preventing the spread of SARS-CoV-2 by sewage systems in buildings

Frequently asked questions

Is drinking water in the Netherlands safe?

Yes. The coronavirus SARS-CoV-2 has not been found in our tap water. Drinking water quality is monitored continuously, so its safety is guaranteed. 

You can use public drinking water taps. Do not touch the tap where the water flows out. Make sure you do not sneeze or cough in the direction of the tap. If possible, turn the water on with clean hands or a clean tissue. 

Can I use ditch water to irrigate my garden or vegetable patch?

The coronavirus SARS-CoV-2 has been found in untreated sewage in the Netherlands. It is possible for untreated sewage (and treated sewage) to end up in surface water, such as ditch water. When sewage is discharged into surface water, the sewage is diluted in the surface water. This also dilutes the coronavirus, leading to a lower concentration of virus particles per litre. The extent to which the virus is diluted depends on the amount of sewage and whether or not the sewage has been treated. The degree of dilution will therefore vary depending on the location. It is not yet known whether the coronavirus SARS-CoV-2 remains infectious in surface water, and if so, for how long. Since the concentration of coronavirus particles in the water is probably low due to dilution, the risk of contamination with the coronavirus SARS-CoV-2 as a result of spraying with surface water is probably minimal.

Irrigation with surface water, such as ditch water, is not recommended anywhere near sewage discharge outlets. This is not only important because of the possible presence of the coronavirus SARS-CoV-2, but also because of other pathogens. 

When irrigating with surface water (not taken from anywhere near sewage discharge outlets), it is advisable to ensure that you do not come into contact with water droplets or spray during irrigation. For example, water the plants close to the ground, instead of letting the water rain down over the plants from an elevated position.