Health authorities have issued an urgent warning for several suburbs in NSW after Covid-19 fragments were detected in sewage systems.
Detections of "particular concern" were in Castle Hill-Cattai, Penrith and Port Kembla, which are areas that have "no known cases".
This news emerged as Premier Gladys Berejiklian announced 77 new locally-acquired coronavirus cases on Sunday.
Worryingly, this is the third time fragments have been detected at the Penrith sewage treatment plant, which serves about 97,000 people.
It takes the suburbs of Cambridge Gardens, Cambridge Park, Leonay, Emu Plains, Glenbrook, Penrith, South Penrith, Glenmore Park, Jamisontown, Regentville, Lapstone, Orchard Hills, Kingswood, Castlereagh, Cranebrook, Llandilo, Sun Valley, Mount Riverview, Emu Heights, Jordan Springs, Mulgoa, Warrimoo, Blaxland and Yellow Rock, as well as the Blue Mountains National Park.
Meanwhile the Castle Hill-Cattai sewage treatment plant serves about 8400 people in the suburbs of Glenhaven, Dural, Kenthurst, Kellyville and Castle Hill.
The third area is covered by the Port Kembla sewage network covers and serves 49,000 people.
That network takes in suburbs including Windang, Lake Heights, Cringila, Warrawong, Koonawarra, Brownsville, Dapto, Berkeley, Kanahooka, Horsley, Avondale, Cleveland, Unanderra, Kembla Grange, Primbee and Port Kembla.
"People in these areas are asked to be especially vigilant for the onset of any cold-like symptoms, and if they appear, to be tested immediately and isolate until a negative result is received," NSW Health said.
Premier's triple-digit prediction for Monday
Ms Berejiklian has warned new daily coronavirus infections in NSW could balloon to triple digits on Monday.
The premier made the chilling prediction as she confirmed a new Covid death – a woman aged in her 90s from southwest Sydney.
Thirty-three of Sunday's new cases were out in the community while infectious.
"Given the number of people exposed in the community overnight, I'm anticipating the numbers in New South Wales will be greater than 100 tomorrow," she said.
"Now, that's what I'm anticipating. And I'll be shocked if it's less than 100 this time tomorrow, of additional new cases.
"So we can't stress enough the importance of not only following the rules but also realising the risk that the people who will suffer the most, if you don't worry about yourself, that's fine.
"But think about your closest family members, your closest people in your life, they're the people that are most impacted."
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