Canberra's health authorities were on high alert on Tuesday following the announcement of a COVID-19 case on the territory's doorstep.
ACT and NSW Health were scrambling to determine whether any ACT residents were among the contacts of an infected person who worked at a Goulburn construction site.
The Sydney painter, who was an essential worker who travelled to the construction site at the Goulburn hospital, has sparked debate over who should get exemptions to travel.
It was expected to be known late on Tuesday whether any Canberrans were among the contacts as NSW Health worked through all those who attended the construction site.
"NSW Health is continuing their risk assessment to identify the number of close and casual contacts and how many of these people are ACT residents," An ACT government spokeswoman said.
"Once this work is complete, ACT Health will assess any impact this may have in the ACT and update health advice and information appropriately."
Anyone who has been contacted by NSW Health should also contact ACT Health.
NSW Health has reported the man was infectious at the site on July 9 and has been in isolation since July 10. The site has reportedly been shut down.
Meanwhile, Hungry Jacks at Marulan on the Hume Highway has been added to a list of exposure sites in NSW.
Anyone who attended the venue on Saturday, July 10 between 5pm and 5.30pm is a casual contact and must get tested and isolate until they receive a negative result.
ACT Chief Minister Andrew Barr said the situation highlighted the difficulties involved in closing the ACT border.
"There were a range of protocols in place on construction sites for essential workers. So, one would hope that those measures provide a degree of protection," he said.
"I do need to be clear that there will be some movement of people across the ACT and NSW for any regime that we put in place, there will be more exemptions and movement than there would be people being kept out."
"We're not defending ourselves from Queanbeyan, Jerrabomberra and Googong - our issue is Sydney.
"There's quite a journey in between here and there, and quite a lot of NSW responsibility as it relates to enforcing their own public health directions in their own state."
Goulburn mayor Bob Kirk said the person who tested positive was a painter working on the construction of the new Goulburn Hospital.
"The Covid disease doesn't ask people if they have a travel exemption or not, it just attaches to whoever it can," he said on Tuesday.
"But I understand he is a painter ... I don't know how that qualifies as essential right now."
"I know there are more than a few painters around this place that could step up if needed."
University of Sydney epidemiologist Professor Alexandra Martiniuk said long-distance movement for essential work should be restricted, including long commutes to work at a certain place or across multiple venues.
"I think of medical professionals who need to work a few days in one hospital, another few days in another, then also a day in private practice for instance," she said.
"These movements between venues are not ideal from an infection control perspective."
NSW Health Minister Brad Hazzard said people in the Fairfield council area should rethink leaving, "even if you consider your work essential".
Those leaving Greater Sydney will now need to carry evidence they've had a test in the past seven days. Essential workers from the Fairfield area must get tested every three days.
Mr Hazzard rebuffed suggestions the government should define "essential work" to provide clarity, saying creating a definition was challenging and people would always find loopholes.
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Bosses and their workers know whether each worker is essential, he said.
"So it will be left to the worker and to the employer," he said.
"But my message - to the employers particularly - is if you don't need to have someone come from an area that is suspect and obviously has major COVID concerns presently, then perhaps it might be an idea to make arrangements for a worker from another area."
NSW recorded another 89 cases of coronavirus overnight, 21 of which were infectious in the community prior to testing positive. A man in his 70s also died of COVID-19 on Monday. He was a resident of the eastern suburbs.
NSW Chief Health Officer Dr Kerry Chant told media on Tuesday that essential workers, from her perspective, were those who made up the health network.
"We have to balance having no workforce," Dr Chant said.
"This is about balancing competing risk and benefits."
Premier Gladys Berejiklian did not respond to a question on whether she would consider lockdowns in more regional areas, following the Goulburn case.
Queensland Premier Annastacia Palaszczuk was first to confirm the NSW case in Goulburn, about an hour north from the ACT, during her address on Tuesday morning.
She stopped short of closing the border between Queensland and NSW, saying health experts would be monitoring the situation closely.
- with AAP
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