A new drive-through testing clinic will open on Tooth Street, Mitchell, on Saturday morning, following the closure of the Exhibition Park clinic on Friday after 21 months of use.

A pop-up clinic at Dickson College will also be established on Saturday.

Canberra Health Services chief operating officer Cathie O'Neill said testing demand in recent days had "come out of the blue", but had begun to drop off.

Authorities received 2152 negative test results in the 24 hours to 9am on Friday and 2461 negative results in the 24 hours to 9am on Thursday.

Ms O'Neill said health authorities were hopeful the surge of people getting tested before leaving on holidays had dissipated. She said testing clinics were reporting anecdotally about 60 per cent of presentations were people who needed tests for domestic travel.

"The issue for us is when Canberrans all decide to get there before we've even opened and that's when the queuing starts," Ms O'Neill said.

"So we would really encourage people just to spread their visit out through the day, because if the flow's constant, then we get through everyone without anybody having to wait."

The wait time at the Exhibition Park clinic on Friday for cars which arrived at the 8am opening time was two hours.

Ms O'Neill said the new Mitchell drive-through site would be able process about 1000 cars daily and the Exhibition Park clinic had recently been processing 1200 cars each day.

"With all these things, you can do what you like on paper. We will need a couple of days [at Mitchell] just to test that in reality," she said.

MORE COVID-19 NEWS:

A receptionist at the pathology unit at Canberra Hospital tested positive for COVID-19 on Thursday, and was likely unknowingly infectious at work on Tuesday and Thursday.

Ms O'Neill said there should be no impact on test turnaround times.

"Certainly there was no issue with staffing, and [pathology have] just confirmed they're staffing through the night, so we don't anticipate any significant delays at all. Results should be coming well within that 24-hour turnaround period," she said on Friday afternoon.

A radiation therapy department team member from Canberra Hospital also tested positive this week, and was likely unknowingly infectious at work on Tuesday and Wednesday.

The ACT reported 20 new cases of COVID-19 in the 24 hours to 8pm on Thursday, the highest daily total since November 18. Four people were in hospital.

with Hannah Neale and Miriam Webber

Our coverage of the health and safety aspects of this outbreak of COVID-19 in the ACT is free for anyone to access. However, we depend on subscription revenue to support our journalism. If you are able, please subscribe here. If you are already a subscriber, thank you for your support. You can also sign up for our newsletters for regular updates.

Our journalists work hard to provide local, up-to-date news to the community. This is how you can continue to access our trusted content: