Fragments of the COVID-19 virus have been detected in a sample of wastewater testing at Macquarie Point.
The Macquarie Point sewage treatment plant services the centre where the positive case diagnosed previously in Launceston was accommodated.
Director of Public Health, Dr Mark Veitch, said the result, collected on October 5, was believed to be linked to the positive case.
The other 15 wastewater sample results that were received this week were negative - which included nine samples from the Launceston area.
Dr Veitch said it was important to get vaccinated as it was the greatest defence against the virus.
The government is aiming to reach an 80 per cent vaccination rate by November 2 and 90 per cent by December 1 as part of its Spring into Summer campaign.
Tourism, Hospitality and Events Minister Sarah Courtney said pop-up clinics would be available across the state in the coming days and weeks.
"There are thousands of appointments available over the next few weeks across the state and I again encourage everyone: Don't wait. Vaccinate," she said.
More information is available at coronavirus.tas.gov.au.