Dr Gale said positive COVID-19 results had been detected in sewage at a number of locations around the state.
She said the positive results had been found at Uralla and Inverell in the Hunter New England LHD, along with Coffs Harbour, Cowra, Narooma and Young in the rest of the state.
A positive COVID-19 case has been recorded in Young, and overnight their household contacts also tested positive.
“There are a number of exposure sites in Young and as we speak, NSW Health is providing advice to government around recommendations for the people of Young,” Dr Gale said.
In Sydney, suburbs of concern include Greenacre, Guildford, Auburn, Bankstown, Merrylands, Blacktown and Liverpool.
“Similarly, I’d like to ask residents of the Central Coast and Illawarra where we are seeing increasing case numbers, to please be vigilant for symptoms, please get one, please get tested,” Dr Gale said.