How could a thousand people fall ill anywhere in New Zealand from drinking tap water? That is the question the Hastings District Council will need to answer over the contamination of its water supply to Havelock North. Outbreaks of campylobacter infection are usually associated with a faulty dish of food and the illness is isolated to those who have eaten it. The risk should not lie in a municipal water supply, not in New Zealand.

The bug made its presence felt in schools and rest homes around Havelock North on Friday when scores of pupils called in sick and pharmacies and medical centres were inundated with people seeking treatments for gastric illness. Two of the three rest homes in the district reported cases. Two residents were taken into intensive care at Hawke's Bay Hospital and one death, of an elderly woman in a rest home, may have been attributable to the disease.

The council has found E. coli present in one of its underground bores and has been flushing chlorine through its water pipes over the weekend. It appears to have contained the disease but the question remains: how did it happen? Normal municipal water treatment plants remove these sort of contaminants. What went wrong here? "I think there's a problem somewhere," said the district's mayor, Lawrence Yule, on Saturday. "We've had three of these [incidents] in the last year. There is certainly a problem with those bore fields." There certainly is. The previous contaminations have been traced to a different bore, now closed for investigation, but clearly there is a wider problem.

Some residents are also asking whether the council warned them on Friday as soon as it knew the water supply was suspect. In at least one case, a woman started drinking more water after falling ill, as doctors advise when vomiting and diarrhoea cause dehydration. Her husband had gone fishing that day equipped with water bottles filled from the tap. Many heard of warnings about the water from schools and word of mouth before they heard from the council.


An apology from the council placed in the Hawke's Bay Today newspaper yesterday stated the presence of E. coli was detected on Thursday but the result was "not available" until Friday. By the time the result was received, "patterns of illness" were already being discussed with the Hawke's Bay District Health Board. The council says Havelock's water supply is separated from that for Hastings and Flaxmere. It comes from a different aquifer free of surface contaminants and the water pumped from its bores is untreated except for the addition of fluoride.

Residents need to be boiling their drinking water, or buying it in bottles, until the council can tell them it is safe again. By then it needs to have discovered the source of all three infestations of the aquifer in the past year. Of course, the source of the contamination needs not just to be identified, but dealt with in a substantial way - and a permanent solution found. It should also examine whether any water should be supplied untreated, no matter how deep the aquifer or how free of contaminants from the surface it seems to be.