Investigations are underway after E. coli was found in south Taranaki's water supply.
The South Taranaki District Council says routine checks picked up the problem in Waverley.
"At this stage tests have indicated the water bores are clear of the bacteria," it posted on Facebook.
Council spokesperson Gerard Langford says around 300 residents are being told to boil their drinking water.
"We're on our way right now to Waverly to door-to-door knock and hand out 'boil water' notices. It's a small community so it won't take us long to get around."
It's not yet known what caused the contamination.
In 2016 a third of Hawke's Bay's Havelock North population became ill with campylobacter when the town's water supply was contaminated after its believed sheep faeces were washed into a water bore.
Three deaths were linked to the outbreak and more than 40 people were hospitalised.