Dr Marianne Gale - the state deputy chief health officer - said NSW Health was seriously concerned following the detection of two positive cases of COVID-19 in Orange on Saturday.

Those two cases were part of the record 830 detected in NSW to 8pm on Saturday night, with a further four cases in Orange, all believed to be linked, confirmed in addition to that.

That takes the number of current active cases in Orange to six, and follows positive detections of the virus in Bathurst, Wellington, Mudgee, Narromine and Dubbo.

The Western NSW Local Health District revealed a list of exposure sites on Sunday morning:

Several notifications of venues in Orange will be identified with people at locations at the indicated times considered to be casual contacts. Investigations and contact tracing is continuing and additional venues of concern may be identified.

NSW Health advice for casual contacts is to get tested and self-isolate until a negative result is received.

Dr Gale said it was crucial residents of Orange got tested, with additional testing capabilities now open on Sunday - drive-thru testing clinics are open at Wade Park and the Orange Showground.

There were further detections of fragments of the virus in Orange as well. Parkes and Lithgow have also had detections of the virus in their sewage.

Overall, 36 new cases were detected in the Western NSW LHD, with the bulk of those again in Dubbo.

NSW Health Minister Brad Hazzard on Sunday announced the state had added 830 cases and three more deaths in the 24 hours to 8pm on Saturday.

That takes the outbreak's death toll to 71. A total of 94 people are in intensive care across NSW.

Dr Gale said a testing backlog had not slowed any positive testing results, but the large testing number reported on Sunday - 206,000 - was actually boosted by those tests being put through.

The true figure for the 24-hour period was closer to 140,000, she said.

Mr Hazzard said one silver lining was the state's vaccination rate, which he said he had been advised was among the fastest in the world.

"I am pleased, very pleased, that the vaccination rate in NSW is quite extraordinary," he said.

"Even though we might be the best in the world at the moment, NSW can do better."

137 of the new cases are linked to known cases or clusters, with the origins of infection for the remaining 693 under investigation.

NSW Health said 67 cases were in isolation while infectious, 19 isolated for part of their infectious period and 50 were infectious in the community.

The isolation of 694 remain under investigation.

Statewide case numbers soared into the 800s on Saturday, a worrying sign for Sydney despite some positives in the regions.

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