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“COVID-19: mitigating transmission via wastewater plumbing systems”

“By its very design, the wastewater plumbing system is a harbinger of pathogenic microorganisms with, under some circumstances, the potential to enable airborne transmission of viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19).”

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“We recommend the following steps be taken to ensure that transmission through the wastewater plumbing system is minimised: (1) do not ignore unexplained foul smells in bathrooms, kitchens, or wash areas; (2) make sure that all water appliances in bathrooms and kitchens are fitted with a functioning U-bend; (3) to prevent the loss of the water trap seal within a U-bend, open a tap on all water appliances for at least 5 s twice a day (morning and evening) paying special attention to floor drains in bathrooms and wet rooms; (4) if the wastewater pipework from an appliance appears to be disconnected or open, seal it immediately (ie, use an elastic rubber glove to cover the end; a plastic bag and some tape will suffice, ensuring the bag has no holes); (5) if there appears to be any crack or leak in pipework, seal with tape or glue; and (6) continuously monitor
whole system performance (for large or tall buildings). The potential for a substantial viral load within the wastewater plumbing system (and therefore the main sewer system), in combination with the potential for airborne transmission due to aerosolisation of the virus, calls for wastewater plumbing systems to be considered as a potential transmission pathway for COVID-19. The interconnectedness of the wastewater plumbing network can facilitate exposure to SARS-CoV-2 within, or even between, buildings. This is of particular concern in high- risk transmission settings such as hospitals and health-care buildings. Following the recommendations set out above will help to minimise the risk of transmission.”

https://www.thelancet.com/action/showPdf?pii=S2214-109X%2820%2930112-1