Ten sites across regional Western Australia are being added to the State Government's COVID-19 wastewater testing program which could provide an important warning sign.
The Department of Health, the WA Country Health Service, the Water Corporation, and PathWest will collect weekly samples from wastewater treatment plants and look for traces of the virus.
Albany, Busselton, Northam, Geraldton, Kalgoorlie, Karratha, and Broome were added to the program earlier this month.
Bunbury, Esperance, and Port Hedland will join next week.
Health Minister Roger Cook said the program would provide extra insight into any presence of COVID-19.
"Ultimately we want to have as much coverage of the Western Australian population as possible, just to make sure that we've got another way that we can continue to scan the horizon to see if there's any outbreak of the disease anywhere in the community," he said.
He said a positive detection would not necessarily mean the disease was spreading through the community as people could 'shed' the virus for weeks after recovery.
He stressed the program did not change the importance of people getting tested for COVID-19 if they experience symptoms.
No nasty surprises in Perth results
WA authorities began collecting wastewater samples in April as they worked to understand how the testing would be done.
The weekly program, which has become permanent, only began in November and covered six of Perth's treatment plants.
Mr Cook said the Subiaco plant was the only one to detect the virus, but it processed water from quarantine hotels.
"We expect to see some positive results coming from that particular wastewater treatment facility," he said.
Australian Medical Association WA president Dr Andrew Miller said the state was "way behind the others" when it came to wastewater testing, but he welcomed the move.
"Certainly, it's a very useful piece of information to target a blitz on testing and to try and ask if there is anyone in the community with symptoms, or find the explanation for why it's gone positive in a particular area," he said.
