Water testing has started in the settlement of Norsewood, in the hope a boil water notice can be lifted, Tararua District Council says.
The council issued the notice for water from the Norsewood public supply on Wednesday, after it found there might not be enough chlorine present to meet drinking standards, due to a fault at its treatment plant.
Dozen of households are affected.
A council spokesperson said the fault at the plant has now been fixed.
Once the council has three consecutive days of clear test samples, it will be able to lift the boil water notice.
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