NSW has recorded 18 new COVID-19 cases with the vast majority from local clusters within the state.
NSW Chief Health Officer Kerry Chant said the 18 new cases recorded in the 24 hours to 8pm on Tuesday came from 20,104 tests.
Thirteen of the cases were locally acquired and linked to known cases, one was a returned traveller from overseas, two were locally acquired without a known source and two were acquired in Victoria.
Premier Gladys Berejiklian urged people to wear a mask if social distancing was not possible and said businesses, especially hospitality venues, must register a plan.
"And if we don't see greater compliance we will need to take further action," she said.
"So we've given certainly a grace period for businesses, for organisations, for different establishments to step up their COVID safe plans and if they don't do that we will have to go a step further," she said.
She also announced NSW residents returning from Victoria would be granted a month's grace period and not be charged for the 14 days mandatory hotel quarantine.
"Yes you do have to have to do hotel quarantine, but you won't be required to pay for it," she said.The NSW Department of Education said Parramatta Public School was closed on Wednesday for cleaning after a student tested positive to COVID-19.
Tangara School for Girls in Cherrybrook, northwest of Sydney, Tuesday, 11 August, 2020. Source: AAP
The school is close to Our Lady of Mercy College in Parramatta, where two students tested positive for coronavirus earlier this week.
There are growing concerns about other school clusters, particularly in Sydney, with 19 cases now linked to the Tangara School for Girls at Cherrybrook in the city's north west. Authorities expect that number to increase.
The Eremeran Hills Study Centre linked to the coronavirus cluster at Tangara has also closed for deep cleaning.
The Castle Towers shopping centre was closed on Tuesday afternoon after NSW Health issued an alert asking anyone who visited the centre on Friday between 3.30pm and 5pm to monitor for COVID-19 symptoms and get tested if symptoms develop.
Huskisson restaurant Wildginger is also closed after two holidaying patrons who dined there on Saturday evening received positive test results for COVID-19.
Concern about community cases
Meanwhile, NSW authorities are urging people in coronavirus hotspots to get tested.
"We have seen a number of locally-acquired cases where the source has not been able to be identified," Dr Chant told reporters on Wednesday.
"These cases are predominantly in western and south western Sydney. We are urging people in those areas to come forward for testing if they have the most minimal of symptoms."
NSW Health Minister Brad Hazzard stressed the need for people to wear masks.
"Clearly, there continues to be transmission in parts of Sydney," he said on Wednesday.
"It's fair to say we all need to be reminded that this virus has not gone away.
"Treat everybody as if you have the virus. The bottom line here is masks. You're doing yourself a favour and you're doing others a favour."
Emeritus Professor of Public Health and Community Medicine at the University of Sydney Stephen Leeder said NSW needed to remain vigilant, but that so far, the public health strategy was largely working.
"Clusters that we have seen recently will continue, but we need to keep up the strategies that we know are working, testing and tracking down those contacts," he told SBS News.
With concern mounting over the school outbreaks, Professor Leeder said he supported calls to make masks mandatory for students in senior schools.
"The more people that wear them, the better. Senior students attending school should be encouraged, if not required, to wear masks. It's a very small imposition and we know it can cut down on the transmission of the virus," he said.
The Independent Education Union is also urging the state government to mandate mask use for students and staff at senior schools to prevent further outbreaks in schools.
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.