Acting chief executive Karena Prevett said Portland District Health was aware that COVID-19 viral fragments had been detected in wastewater samples in Portland on October 4.

Detections may be due to an active but undiagnosed case in the area, or due to someone who has had COVID-19 but is no longer infectious and is shedding the virus.

"The wastewater testing program is designed as an early warning system and a cautious approach is always taken when these detections are found," Ms Prevett said.

PDH does not have any further information at this stage but will keep the community informed as details come to hand.

Ms Prevett said PDH was not wanting to panic the community but people should remain cautious about the virus and get tested if needed.

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"Anyone who lives in, works in, or has visited an area where viral fragments have been detected should watch for even the mildest of COVID-19 symptoms and get tested as soon as possible if symptoms develop," she said.

Anyone experiencing symptoms should get tested at the PDH drive-through clinic. People must phone 5521 0387 in advance to confirm a drive-through time.

The COVID testing clinic is open 10am-4pm Monday to Friday and will be open this Saturday and Sunday from 9am-12.30pm.

People can preregister details to speed up the process at bit.ly/PDHCovidTest

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