A further 11 coronavirus deaths have been recorded in Victoria, taking the state toll to 694 and the national figure to 781, with a spike in new cases of 76.
It's the first time since Saturday that fatalities have been in double figures.
Epidemiologist Adrian Esterman is predicting Victoria should be down to 20 cases a day in two weeks if current trends continue.
While active regional cases dropped further to 82, Premier Daniel Andrews said it was still early to talk about lessening restrictions outside Melbourne.
The government also urged people in and around the coastal town of Apollo Bay to come forward for testing, after viral fragments were detected in wastewater.
Testing of sewage samples collected in Apollo Bay has shown fragments of SARS-CoV-2, the virus that causes COVID-19.
It was detected on Friday from a sample collected from the entry pipe to the sewage treatment plant last Tuesday. Further testing has confirmed the positive result.
People in Apollo Bay and surrounding areas with even mild symptoms are being urged to get tested.
More than 60 locals have already been tested since the weekend with no positive results to date.
Testing of up to 300 sewage samples a week is now taking place at 25 surveillance sites across the state to detect the spread of the virus.
A healthcare worker conducts a coronavirus test on a patient at a COVID-19 testing facility in Bonbeach, Melbourne. Source: AAP
Melbourne Water's Nick Crosby said the results were well validated and a similar approach had previously been used to monitor the spread of polio.
He said researchers were working on methods to ensure samples could be traced back to particular suburbs as case numbers continued to fall.
"In a (Melbourne) population of five million, we do have two large treatment plants. One covers two million and one about 1.8 million," he said on Wednesday.
"If you get a detect, it will be very challenging to find an individual or a small cluster without an efficient traceback."
People who have been infected may shed the virus or virus fragments on used tissues, off their hands and skin when washing or in their stool.
It can take several weeks for people to shed the virus, making it a potentially valuable detection tool as the number of cases detected through routine testing reduces.
Victoria is collaborating with other states and New Zealand in a research project to better understand the presence of viral fragments in wastewater testing.
Victorians are now fixated on the two-week case average, a key indicator for the government's "roadmap" out of the state's second wave of COVID-19.
Melbourne's average on Wednesday was 74.5. The regional average was five and the state figure was 80.8.
It means some Melbourne workplaces and schools are inching closer to reopening from September 28 if the average drops below 50.
The state has also enlisted the support of NSW to boost its much-maligned contact tracing efforts.
In the face of criticism from the prime minister, Mr Andrews said a team of officials would visit NSW later this week to look at that state's contact tracing system.
"NSW are dealing with very small numbers of cases," he told reporters.
"That's a different challenge to dealing with hundreds and thousands.
"They may have some insights into what we can expect to confront. Not right now, but in three weeks, four weeks, five weeks time."
Asked if the NSW contact tracing system could have contained Victoria's hotel quarantine outbreak, federal Health Minister Greg Hunt said: "Yes, that's my belief."
Victorian chief health officer Brett Sutton told 3AW he wished the system was as "robust" then as it is now but couldn't say if NSW's team would have stopped the second wave.
Metropolitan Melbourne residents are subject to Stage 4 restrictions and must comply with a curfew between the hours of 8pm and 5am. During the curfew, people in Melbourne can only leave their house for work, and essential health, care or safety reasons.
Between 5am and 8pm, people in Melbourne can leave the home for exercise, to shop for necessary goods and services, for work, for health care, or to care for a sick or elderly relative. The full list of restrictions can be found here.
All Victorians must wear a face covering when they leave home, no matter where they live.
People in Australia must stay at least 1.5 metres away from others. Check your state’s restrictions on gathering limits.
If you are experiencing cold or flu symptoms, stay home and arrange a test by calling your doctor or contact the Coronavirus Health Information Hotline on 1800 020 080. News and information is available in 63 languages at
