Contamination detected in Havelock North system earlier this year

Contamination was detected in Havelock North's water supply in Hawke's Bay earlier this year following multiple failures of a Te Mata Rd pipe.

In a report presented during a Hastings District council meeting today, it was revealed that after the mains on Te Mata Rd burst eight times in six days, low level contamination was detected.

The report, prepared by asset management group manager Craig Thew, was an update on the group's projects and activities as of June this year - which had been deferred from a Works and Services committee meeting in August.

In it, Thew stated over the autumn and winter period there had been a number of watermain failures.

As well a pipe burst on Nottingley Rd there had been the "unexpected incident" on Te Mata Rd.

"This was due to the type of asbestos cement pipe which can typically fail rapidly once it has been disturbed," Thew wrote.

A decision had been made to install a temporary overland pipe to take the main completely out of service, and the main had since been replaced.

Following the bursts, low level contamination was detected.

"Ground water may have entered the system at the time of failure creating the need to chlorinate the Havelock North supply for a short period," he said.

"There is an increased need to maintain exceptional hygiene and flushing practices during maintenance and repairs as our water supplies are not continually chlorinated which would otherwise provide an increased level of protection against contamination of this sort."

Conditions of the Havelock North site "revealed a perched water table and organic clays that may have deformed during the prolonged dry spell, contributing to the likely failure of this main. Other mains of a similar age and material will be tested to determine whether there is a similar failure potential".

Investigations had suggested the spate of bursts was more likely to be coincidental.