Residents of Roma have been exposed to water contaminated with E.coli after an electrical fault caused a disused bore to pump unchlorinated water into the town's reservoir.
Maranoa Regional Council issued a warning on Wednesday urging residents, mainly in the western part of town, to boil tap water to avoid ingesting the bacteria.
The source of the contamination had been found, Maranoa Mayor Tyson Golder said.
"This bore has now been physically disabled and the reservoir has been manually dosed with chlorine to restore disinfection," he said.
"Council will continue to work with Queensland Health over the coming days to undertake further testing of the water, to confirm the contamination has been removed."
Water should be boiled and cooled before drinking, brushing teeth, preparing food and bathing infants.
"Consuming unboiled drinking water could lead to illness, especially for ... those who are very young, elderly or immune compromised," the council said in a statement.
Updates are expected on Thursday morning and people can check if their property has been affected on a map available on the Maranoa council website.
It's expected the alert will be in place for several days as mains systems in the town are flushed and treated with chlorine.
