Perth metropolitan areas, Peel and south west regions of WA will be declared COVID-19 hotspots by the ACT Chief Health Officer Kerryn Coleman from 2pm on Monday.

Anyone in the ACT who has been in any of the hotspots must get tested and self isolate until Friday night.

The government will be reinstating the online COVID-19 declaration and exemption process, requiring people travelling from the hotspots to fill out an online form.

Non ACT-residents who have been in the hotspots since January 25 will only be allowed to enter Canberra if they are granted an exemption.

ACT residents can return home but will be required to get tested for COVID-19 and self-isolate until 9pm, February 5.

The restrictions are in place after a security guard at a quarantine hotel in Perth tested positive for the virus.

He had visited a number of public locations while potentially infectious.

It came as Dr Coleman renewed calls for Canberrans to get tested for COVID-19, especially those in the Belconnen area.

Wastewater testing recently detected fragments of the virus.

It could indicate that someone who has recently had COVID-19 is still shedding the virus, or it could indicate there has been an undetected case in the community.

"There remains no evidence to date ... that it is an undetected case," Dr Coleman said.

"However we do continue to urge anyone who lives in, or has recently visited the Belconnen area to get tested for COVID-19 even if you are experiencing the mildest of symptoms.

"This is particularly important for anyone who has recently travelled outside the ACT."

Dr Coleman said 300 people had been tested for COVID-19 in the ACT in the 24 hours prior to midday Monday.

"But this is not at the level that I would like to see just yet," she said.

"Testing is crucial in the immediate response to a positive wastewater detection.

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