Residents of Pahiatua, in Tararua, can now drink their tap water following the latest clear test showing no signs of E. coli.
A boil-water notice had been in place since Friday when the Tararua District Council had put the measure in place as a precaution.
However, there have been no reported cases of illness relating to the water supply.
On Wednesday, the council received the latest test results from the bore supplying the town of Pahiatua, which came back with a clear reading.
The town reticulation is showing acceptable levels of what's called Free Available Chlorine in the system.
Adding this to the clear test, the council says it is confident it can lift the boil-water notice.
It will continue to test the water at the bore and reticulation each day.
Tararua District Council had previously said clear results from three consecutive days would be needed for the notice to be lifted.
But Mayor Roly Ellis says on advice from MidCentral Health, the District Health Board is happy the whole of the town's reticulation system is now well chlorinated.
Mr Ellis added that the level of E.coli picked up was "so small it's unbelievable".
Work is still going on to find out what caused the previous readings for E. coli in the bore.