Every Monday, we’ll answer your questions on Covid-19 and health in a feature published online. You can submit a question here.
This week, HuffPost UK reader Jillian asked: “If sewage systems are being tested for Covid, as it is carried in urine and we are all drinking water that has been through treatment plants, could Covid be caught through the tap water we are drinking?”
Worries about Covid-19 appearing in drinking water aren’t unfounded. We know that the virus has been found in people’s faeces, and that it’s also been found in wastewater. So naturally, people are wondering whether the tap water we drink could also be home to the virus.
The short and sweet answer is: no. There is no evidence that people can get Covid-19 by drinking tap water or that the virus that causes it – SARS-CoV-2 – has been found in this water. In fact, the UK is considered to have one of the safest and purest water supplies in the world.
Wastewater from toilets is treated at sewage treatment works before being safely returned to our rivers. This is where our drinking water also comes from, in addition to groundwater or reservoirs, however it goes through complex treatment processes to make it safe to drink.
One caveat is that events, such as disinfection failures or leaks, occasionally occur that might impact on the quality or sufficiency of the water supplied.
It remains unclear whether if this did happen, Covid-19 transmission could then occur.
Dr Jeremy Rossman, honorary senior lecturer in virology at the University of Kent, points out that at present, there is no evidence that Covid-19 is found in urine. Some virus can be found in the faeces, though it’s not clear if this virus plays a role in transmission of the disease, he adds.
The main way the virus behind Covid-19 spreads is through person-to-person contact, not through the water system. “All evidence from the spread of the virus shows that the drinking water supply is not a route for transmission of the virus,” says a spokesperson for the Department for Environment, Food and Rural Affairs (Defra).
Water UK, a trade association representing the UK’s major water companies, says drinking water supplies are routinely disinfected as part of the treatment process – and this process removes all harmful pathogens including viruses.
A spokesperson told HuffPost UK in an email: “There is absolutely no risk of contracting Covid-19 from your water supply.”
Dr Rossman explains that UK tap water goes through multiple purification processes, including disinfection, and these treatment processes are “very effective” at removing any potential pathogens from the water supply.
“Covid-19 should not be an exception,” he adds. “There is no evidence to suggest that sewage plays a role in Covid-19 transmission and the virus has never been found in the water supply.”
It’s much more likely that someone would get Covid-19 from a contaminated cup that an infected person happened to touch, than from the water in the cup, he says.
Professor Timothy LaPara, from the Department of Civil, Environmental, and Geo-Engineering at University of Minnesota, agrees it’s not an issue in areas where water is treated. He has been looking for SARS-CoV-2 in the US water system as part of a body of research.
“The primary system that protects public health is the drinking water treatment system,” he tells HuffPost UK. “These technologies are exceptionally robust at removing all particles in the size range of viral, bacterial, and protozoan pathogens.
“Public water supplies in the developed world are, with few exceptions, exceptionally safe to consume.”
On top of that, SARS-CoV-2 virus is “not especially difficult to disinfect or treat,” he adds. “Our drinking water system is designed to eliminate far more difficult pathogens and it does so very effectively.”
There would be a concern of Covid-19 contamination in areas where water isn’t disinfected or if people are using private wells which collect groundwater.
“We normally assume that groundwater is safe to drink and free from microbiological contaminants (like SARS-CoV-2) but research done over the last 10-15 years has shown that viruses are often present in groundwater at levels that can get people sick,” says Prof LaPara.
“Our research has looked for SARS-CoV-2 in our water system and so far we have yet to find it. That said, the number of people sick with Covid is increasing, which means that chances of SARS-CoV-2 getting into our groundwater is also increasing. So, we’re still looking.”
Water UK advises that people should continue to use tap water as normal, including for drinking, hand washing, bathing, cooking, and cleaning teeth.
- Update: this article has been amended to explain that events can happen where a water system might be compromised.