District council chief executive Peter Till said now reticulated water was available at people's homes, the council had heard stories of people using the water for other purposes.
"Until the Medical Officer of Health gives the all-clear, council is unable to sanction the use of the water for drinking, cooking and washing," Mr Till warned.
"On Wednesday we took water samples from five properties that have flushed their plumbing with the new water source to test for hydrocarbons. We are expecting these results back tomorrow."
Mr Till said earlier testing had shown only a minor detection of hydrocarbons from a single tap at the medical centre.
"Council's water tanker delivery service, the stationary tanker on the main street and the household delivery of bottled water will all continue until the all-clear is given and potable reticulated water is available at every home."