Hawea residents are being told to boil their drinking water for the next three days as run-off into the lake is being blamed for bacteria.

Residents in the Central Otago town are being told to boil their drinking water for the next three days because bacteria has been found in the tap water.

Low levels of e-coli have been found in the town’s reticulated supply, the Queenstown Lakes District Council said on Tuesday.

It would be chlorinating the water as a precaution.

The requirement to boil water for drinking and food preparation will remain until three consecutive days of testing show a nil result.

“The source has not been identified but the most common source of e-coli in lake-sourced water is run-off from surrounding land,” the council said.