Dozens of residents at a time stood in slow-moving queues today to be tested at the Gundagai Racecourse, which the Murrumbidgee Local Health District has transformed into a pop-up clinic.

Residents were put on notice after the town was added to the list of potential COVID-19 exposure sites linked to a traveller from Victoria who stopped in the town on May 19 on their way from Melbourne to the NSW South Coast.

NSW Health issued an alert on Wednesday night for three Gundagai exposure sites, which prompted 191 residents to get tested at the racecourse and another 32 people at the GP clinic today.

Cootamundra-Gundagai mayor Abb McAlister said he was hopeful because more than a fortnight had already passed since the positive case visited his town.

He said said the sewage would also be tested today and on Monday as a precaution.

"The mood's pretty good. They understand what's happening, the issues. We've just got to do our job the best we can, and the health department is doing a good job," he said.

"[But the pandemic] has been very hard on our businesses, particularly our food retailers. Being a highway town, we rely so much on travellers and tourists going past and experiencing our beautiful town."

He said Gundagai residents had grown accustomed to the risk of coronavirus exposure being a "part of life".

"We'll probably be more on alert all the time than a town out west that's not near a highway," he said.

MLHD pandemic lead Emma Field congratulated Gundagai residents for being "proactive and vigilant".

"I think if you have any positive COVID that certainly raises concerns for communities because that brings in the virus. But again, the community has had that before so they do know what to do," she said.

One resident who was at the pop-up clinic said he had some mild-flu like symptoms and was getting tested as a precaution.

"We're not really worried. I reckon we should be able to get over it pretty quickly," he said.

The MLHD pop-up clinic is open again today at the Gundagai Racecourse from 10am to 4.30pm. The health district's COVID testing hotline is 1800 020 080.