More than 1100 people have been tested for coronavirus in the past 24 hours as the ACT records a fifth day without a new case.
In the territory's biggest day of testing since the outset of the pandemic in March, 1129 received a negative result.
There are currently five active COVID-19 cases in the ACT, all linked to the Victorian outbreak.
Two people returned from a Melbourne hotspot on July 2 and a further three cases have been identified as close contacts.
The ACT had previously gone one month without an active case.
There has been a surge in demand for testing prompting the ACT Government to open new centres at the Garran pop-up hospital and at West Belconnen Child and Family Centre.
It comes as Canberrans are urged not to travel to Sydney locations of Liverpool or Campbelltown.
Health Minister Rachel Stephen-Smith said the outbreaks in NSW and Victoria were of concern.
"I want to assure everyone that we are in, and remain in, a good position to respond to any new case of COVID-19 here in the ACT," she said.
NSW recorded 13 cases on Wednesday. There are now 34 cases linked to the outbreak at the Casula Crossroads Hotel.
Canberrans who visited the Crossroads Hotel between July 3 and 10, and anyone who visited the Picton Hotel on Saturday July 4, Thursday July 9, or Friday July 10, are urged to isolate immediately and get in touch with ACT Health through the COVID-19 Helpline on (02) 6207 7244.
These people are also encouraged to get tested for COVID-19, regardless of whether they are showing symptoms.