Testing wastewater could prevent local Covid-19 outbreaks

The Water Corporation says it has the technical capability to test wastewater in certain areas but it is up to the Department of Health to determine if sampling happens in WA. Picture: Water Corporation

TESTING wastewater in WA’s regional and metropolitan areas has been suggested as one way of checking for potential Covid-19 outbreaks as restrictions are relaxed.

Associate Professor Nick Golding from Curtin’s School of Public Health said testing wastewater would create an early warning system and show if there were any infected people in a community sharing a common wastewater treatment plant.

“As we start to think about relaxing social distancing restrictions it will become even more critical to stop local outbreaks before they get too big, so that could be a really useful tool,’’ he said.

Associate Professor Golding said checking wastewater for remnants of genetic material from the Covid-19 virus would indicate if the virus was circulating in the population – as opposed to serology which would indicate the virus there in the past.

Water Corporation head of water quality Rachael Miller said it would be up to the Department of Health to determine if sampling happened in WA but the corporation had the technical capability to test wastewater in certain areas.

“It is technically possible for samples to be taken from wastewater pump stations within the wastewater catchment to provide more granular data, which would be carried out at the request of Department of Health,’’ she said.

“For example, if the Water Corporation was to sample at wastewater treatment plants only, this would provide data from an entire wastewater catchment scale, which is generally many hundreds of thousands of people across multiple suburbs.

“In the case of City of Wanneroo, wastewater from households and businesses within the city’s boundaries is treated at both the Alkimos wastewater treatment plant (which treats wastewater from around 80,000 people) and the Beenyup wastewater treatment plant in Craigie (which treats wastewater from around 660,000 people).

“Generally speaking, in smaller regional towns there is usually one wastewater treatment plant to service an entire town.

“Within the Shire of Gingin, the Water Corporation only treats wastewater from Ledge Point, Lancelin and Seabird.’’

On May 5 a McGowan Government spokesman said the WA Department of Health was aware of a proposed national research project aiming to determine whether the detection of Covid-19 in wastewater would be useful in monitoring and managing the virus.

“The department will continue to track the progress of the project to ensure WA is in a position to participate in its future development, if initial results suggest the technology may be applicable to ongoing surveillance and management of Covid-19 in WA,’’ he said.

In April University of Queensland (UQ) and Australia’s national science agency CSIRO said they had demonstrated the presence of SARS-CoV2, the virus which leads to the disease Covid-19, in untreated wastewater (sewage).

Researchers found RNA fragments of SARS-CoV2 in untreated sewage which would have been shed in the wastewater stream by Covid-19 infected people – this built on work by research groups in the Netherlands and the United States of America.

Federal Health Minister Greg Hunt said a national program based on the work could add to the broader suite of measures the federal government could use in the identification and containment of Covid-19.