There were 18 new cases of COVID-19 detected in NSW in the past 24 hour period, with the vast majority of those contracted through community transmission.
With known outbreaks and the number of cases not linked to other sources continuing to grow, Premier Gladys Berejiklian has warned further measures could be introduced if the community does not increase its use of masks and distancing compliance.
Businesses, especially those in the hospitality industry, also have been put on notice with Ms Berejiklian warning she would "take further action" if more businesses did not register their COVID safe plans.
NSW Chief Health Officer Dr Kerry Chant said one of the new cases found in the 24 hours to 8pm on Tuesday was from an overseas traveller and two were from interstate travellers.
Read more: Vic records 21 virus deaths, 410 new cases
She said 13 of the new cases were locally acquired with links to existing outbreaks, and two did not have any links to known sources.
The Tangara School for Girls outbreak has grown to 19, and Dr Chant said tracing this outbreak was "challenging" for health officials. The source of this outbreak is still not known.
Also in today's numbers, a second health care worker at Hornsby Hospital was diagnosed with COVID-19, but did not work while infectious.
A third confirmed case was identified at Our Lady of Mercy College, which is not directly linked to the previous two cases.
Further, Parramatta Public School will not be open for on-site learning today after a student tested positive to COVID-19. The school is working closely with NSW Health to identify and notify close contacts.
NSW Health also confirmed yesterday's reports that two people who were infectious with COVID-19 attended the Wildginger restaurant in Huskisson on August 8 from 7.45pm to 10.30pm.
Patrons and staff who were at the venue during this time must self-isolate for 14 days and get tested for COVID-19, NSW Health said.
"Over the past six weeks we have seen a number of locally acquired cases where the source has not been able to be identified," Dr Chant said.
"Those are mainly occurring in Western Sydney and South Western Sydney."
She said people in those communities should come forward for testing with even the most minimal symptoms, and warned everyone to be on high alert.
"It's also time to reflect on our behaviours," she said, saying mask wearing and physical distancing was essential.
I want to see a greater uptake in all those categories. If we don't, we will consider further measures in which we can increase that uptake.Premier Berejiklian
"It is also essential at this moment that we reflect on our movement. We don't want non-essential travel, especially into our rural and regional areas."
Also in the morning's media update, Ms Berejiklian announced that NSW residents returning from Victoria will have their hotel quarantine fee waived for the next month to ease the financial burden on returnees.
The charge will be waived retrospectively and apply to NSW residents already in hotel quarantine after travelling from Victoria.
"Hotel quarantine is key to reducing the risk of seeding of COVID-19 from Victoria into NSW," Ms Berejiklian said.
"We have listened to the concerns of NSW residents who say they cannot afford to come home to NSW and will now give them more time to return.
"We are asking any NSW residents who are in Victoria and want to come home to make their way back to NSW before Friday, 11 September if they want to avoid paying for hotel quarantine."
Once again, Premier reminded residents that NSW was "on high alert" and said she wanted to see an higher uptake of distancing measures.
"Whether it is a school extra-curricular activity which shouldn't occur, whether it's the recommendation for people to wear masks when they can't guarantee social distancing on public transport or in supermarkets, or whether it's the way in which we've asked businesses to approach a COVID-safe environment, compliance is absolutely critical," she said.
"I want to see a greater uptake in all those categories. If we don't see a greater uptake in the next little while, we will consider further measures in which we can increase that uptake."
"Some business are doing so well with COVID safe... and other businesses seem to be applying a partial model."
She said officials remained concerned about the number of different outbreaks, and the number of cases which did not have a known source.
Dr Chant said there had been roughly 20 cases which did not have a known source over the past six weeks.