COVID-19 wastewater testing

The Wastewater Surveillance Program tests untreated sewage from treatment plants for fragments of SARS-CoV-2. The program is constantly adapted to provide the most relevant data to the Department of Health and is being reviewed in the context of living with COVID.

COVID-19 wastewater testing in the community

Can I get coronavirus (COVID-19) from wastewater?

No. Current evidence shows that the virus cannot be spread through wastewater.

Does wastewater testing replace other types of testing for COVID-19?

No. Wastewater testing complements – but cannot replace – other kinds of COVID-19 testing, including nose and throat swabs. This is because wastewater testing does not tell us if an individual has COVID-19, only that it may be present in the broader community.

How can COVID-19 be detected in wastewater?

People who have had COVID-19 normally shed the virus when they do day-to-day activities like blowing their noses and going to the toilet. People can continue to shed the virus for several weeks after they recover from COVID-19, even when they are no longer infectious. The virus enters wastewater through drains and toilets, and travels through the sewerage network as viral fragments.

What are the wastewater samples used for?

The wastewater samples are tested for viral fragments of SARS-CoV-2, the virus that causes COVID-19.  Wastewater samples can be used to:

  • detect the presence or absence of the virus in a sewer catchment area
  • estimate the viral load in community using quantitative analysis and
  • identify the dominant variant of the virus in the community through genomic sequencing

The presence of virus fragments may provide an early warning of undiagnosed COVID-19 in the community if there are no known cases.

Quantitative analysis can be used to look at trends over time using an estimate of the viral load in sewer catchment areas. Quantitative analysis of SARS-COV-2 on wastewater samples is an emerging field and is being investigated as an additional part of the wastewater surveillance strategy.

Wastewater results can be used to complement other sources of data that are used in the management of the pandemic.

WA's COVID-19 wastewater testing program steering committee

WA Health has set up a steering committee to guide the wastewater surveillance strategy and to keep the program relevant as new research and techniques emerge.

The steering committee includes representatives from WA Health’s State Health Incident Coordination Centre, the Environmental Health Directorate (EHD), WA Country Health Service, the Water Corporation, and PathWest.

Last reviewed: 14-10-2022