Boris Johnson mistakenly said that Covid-19 could be monitored through the water supply

12th May 2020


Boris Johnson said that an alert system for Covid-19 could involve detecting the infection in the water supply.


It is true that Boris Johnson said this, however, he misspoke according to his spokesperson. He was referring to a potential scheme that could detect genetic material from the virus in sewage: not in the water supply.

“The intention is that the covid alert system, in time, will be sufficiently sensitive and flexible to detect local flare-ups, so that, for instance, if the covid is detected in the water supply of a certain town or in a school in an area, steps can be taken...”

Boris Johnson, 11 May 2020

During a statement on the government’s Covid-19 strategy, Prime Minister Boris Johnson spoke about an alert system that would allow for the detection and management of “flare ups” in local cases. As part of this he said Covid-19—the infection caused by the new coronavirus—could be detected in the water supply. 

Video clips of this statement have been shared via social media.

A spokesperson for Number 10 has told us that Boris Johnson misspoke: he meant to say wastewater, not water supply. The spokesperson said that this alert scheme, which would involve monitoring levels of Covid-19 infection in the population through sewage, is something the government is looking into (but is not something that is in place currently).

There is some evidence showing that genetic material from the new coronavirus can be detected in wastewater and researchers in several countries have begun to assess whether this could be used as an early-warning tool.

There is no evidence that Covid-19 can be found in treated water

A briefing by the World Health Organisation, published on 23 April, states that Covid-19 has not been detected in drinking water and “the risk of coronaviruses to water supplies is low.”

The Drinking Water Inspectorate, which independently assesses the public water supply in England and Wales, says that the UK public should continue to use tap water as normal. They explain that routine disinfection of drinking water in the UK “removes all harmful pathogens including viruses”.