Thousands of Victorian workers are returning to the office for the first time in nine months.

Since the first wave of COVID-19 hit in March, Victorians able to carry out their duties from home were told to steer clear of offices including Melbourne’s CBD.

That will change from Monday, with workplaces welcoming 25 per cent of their staff back on site.

It means businesses with fewer than 40 staff can have 10 on-site, as long as they comply with prescribed density limits.

Professor Brett Sutton feels confident Victorian workplaces can welcome back some of their staff as long as coronavirus rules are followed. Photo:AAP

Premier Daniel Andrews announced the change more than a week ago, with Chief Health Officer Brett Sutton confirming it would come into effect just before midnight on Sunday.

The state’s public service is not incorporated in the new edict and Professor Sutton clarified office workers must wear face masks when indoors.

The latest rule change comes as Victoria notched its 30th consecutive day without a new coronavirus case.

The state reported no new cases or lives lost on Sunday from just under 6000 tests.

Epidemiologists classify 28 days with no new locally acquired infections as the marker for virus “elimination”, given that period represents two 14-day incubation periods.

The milestone means other states have started welcoming travellers from previously virus-hit Victoria once again.

NSW lifted restrictions for Victorian travellers last Monday, while Queensland and South Australia will reopen their borders from Tuesday.

Western Australia is now the only state or territory with closed borders to Victoria, but Premier Mark McGowan expects to give an update this week.

Victoria’s Department of Health and Human Services, meanwhile, has detected coronavirus fragments in sewage at a treatment plant in Corio.

Those who live in or visited Geelong’s northern suburbs and Lara between November 21 and 23 should seek testing if they experience any respiratory symptoms.

-AAP