The Murrumbidgee Local Health District director of public health Tracey Oakman said the testing specifically for COVID-19 had begun last month as part of a monitoring regime that also included Perisher and Jindabyne in the Snowy Mountains.

Council and NSW environmental health officers collect samples which are then sent to a water testing laboratory in Sydney for analysis.

Ms Oakman said they were searching for fragments of the SARS-CoV-2 virus which may have been broken down over a four-week period after a person has had the virus.

In addition to faeces, the virus may be deposited into the sewage when bits are brushed off hands and bodies while washing at sinks or in showers.

Ms Oakman said the testing was about detecting the presence of the virus rather than pinpointing active cases.

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"It's really an alert system for us to try and increase testing to make sure there is no-one with the virus," Ms Oakman said.

There had no positive results returned from testing Albury samples and Ms Oakman said if there was the public would be notified of that outcome.

The testing at Perisher did uncover coronavirus and as a result increased testing was done in that area, but no cases were detected.

Ms Oakman said there were plans to expand the program to Wagga.

North East Water which administers waste treatment in Wodonga and Wangaratta is not undertaking any monitoring for the virus, although Melbourne Water in June flagged a testing project.

Member for Albury Justin Clancy said he had spoken about the issue with NSW Deputy Premier John Barilaro and said testing in the North East would be a boost.

"Anything that provides added confidence or assurance around the possibility of undetected transmission would be important," Mr Clancy said.

"Moving forward, more broadly speaking, coronavirus is going to be with us for awhile and using different methods for surveillance is going to be really important.

"If it's effective, and I don't have expertise on those things, it's of great benefit."

The testing locations in NSW have been decided by a committee with the state's chief health officer Kerry Chant having deemed them areas of concern.

After the virus was found at a beach wastewater treatment plant at Newcastle earlier this month, Hunter New England Health's public health controller for COVID-19 David Durrheim expressed shock.

"It's quite a surprise for us to actually detect the virus in the sewage at this time with only a small number of cases in the community," Dr Durrheim said.

He said it showed cases may have been missed and showed the need for testing.