With Pahiatua's water bore testing positive for E. coli in two tests over two days, the Tararua District Council issued a boil-water notice at noon yesterday, Peter Wimsett, the Tararua District Council's district strategy and development manager, said.

"The Pahiatua reticulation [pipe] system hasn't had an E. coli result, but because of the 1 E. coli in a 100mm sample in the bore, people should boil their water for drinking, ice-making, food preparation, brushing their teeth and preparing infant or toddler formula."

Mr Wimsett said that after receiving two consecutive days of positive results for E. coli in the supply at the source - the bore - the council notified MidCentral District Health Board, who after consultation with the Ministry of Health, directed the council to issue the boil water notice.

"We've had no notifications of illness and at this stage no contamination has been detected in the reticulated supply," he said. "Co-incidentally we were installing a chlorination system in the Pahiatua bore on Friday which is now operational. The Pahiatua bore is deemed to be a secure water source and we'll continue with the testing regime over the next couple of days."


Test results are returned within a 12-hour period, Mr Wimsett said.

"The boil water notice will be in place until we've received three consecutive days of clear results."

Pahiatua resident Samantha Taylor told the Dannevirke News notice of the contamination came quickly in the town, with posters up and people she presumed were from council door knocking.

"I found out through Facebook. It's pretty intense and I'll be grabbing some water from the supermarket for myself and my 5-year-old daughter. But we don't know anything other than there's some contamination."

At their monthly meeting on Wednesday, Tararua District councillors were told the council was proceeding to chlorinate the Pahiatua water bore and investigating if it was possible to do the same at Norsewood. These were the only two council water supplies which were not treated.

Recent events in Havelock North had highlighted the risks to drinking water where chlorination wasn't used, chief executive Blair King said in his report to councillors.

However, Mr King said chlorine alone doesn't deal with the two parasites, cryptosporidium and giardia, which cause common stomach upsets, but these parasites can be killed with the correct use of ultraviolet light (UV) and all new plants commissioned in the district have ultraviolet light (UV) to deal with 99.99 per cent of microorganisms.

Meanwhile, a council water tanker arrived outside its Pahiatua Service Centre at 136 Main St, at 5.30pm yesterday, Mr Wimsett said.

"The tanker has been super-chlorinated and flushed and filled with normal, treated water from the Dannevirke supply."

-Updates will continue to be posted on the Tararua District Council website - tararuadc.govt.nz and Facebook page - facebook.com/tararuadc.