A boil water notice for people in Kawerau will remain in place for at least two more days.
The notice affects just under 300 residents in the Bay of Plenty town.
E coli was detected in the water supply yesterday, but another test done overnight has come out negative.
However a spokesperson for Kawerau District Council, Tania Humberstone, said people must continue boiling water.
"The boil water notice stays in place for a further two days because we need to have three consecutive negative readings, so boiling your jug is not sufficient, it's a rolling boil for a minute over the pot on the stove, it's the ideal way to ensure water's safe to consume."