Kawerau District Council is warning residents that minute traces of metal may be accumulating in the water supply.
Photo: 123RF
It said the water's low pH level meant some plumbing fittings could allow tiny traces of metals to accumulate in water sitting in the pipes for several hours.
The council said that although the risk was small, residents should run a cupful of water through the tap every morning to remove the dissolved metals.
It said homes on private and public water supplies should take the precaution.