Bore security needed before chlorine removed for Napier

Chlorine is set to remain in Napier's water supply for awhile yet. Photo / File

The taste of chlorine is set to remain in Napier's water until the security of two bores can be proven.

Chlorine has been added to the city's water supply twice this year after positive E. coli readings. It has been chlorinated since May, when a positive reading was found at a Park Island site. In February E. coli was detected at the Enfield Rd reservoir.

The May chlorination was initially expected to last a matter of weeks. The Napier City Council then announced a roll out of work to the entire water network - including the inspections of 11 reservoirs, and a full bore-head water-quality review of the bores.

Yesterday council chief executive Wayne Jack said chlorination of the network would continue until the council could show two of their 10 bores were secure.

"We appreciate that some people don't like the chlorine, or don't fully understand why this precaution continues to be taken," he said.

He said a progress meeting was held yesterday, at which the Hawke's Bay District Health Board (HBDHB) and Drinking Water Assessor (DWA) were satisfied that all required maintenance to the physical infrastructure was well under way.

"We have lifted bore heads above ground wherever we can, and upgraded our testing points. However, the programme of work has uncovered new challenges."

The DWA wanted the council to demonstrate it had sufficient information relating to the security of two bores, but at this stage it was "very difficult" to validate how the bores operated within the aquifer. They would be able to gain a deeper understanding of those two bores with an upcoming GNS Science report into the Heretaunga aquifer.

The council remained on track to complete their maintenance by the end of the month.

Napier Mayor Bill Dalton said he was disappointed the city's water supply was still chlorinated.

"I've said so many times that one thing Napier prides itself on is its pure water supply, and I am really keen to get back to being in that position. The problem we have is that ... the decisions on these things have effectively been taken out of our hands."

An HBDHB spokeswoman said there was no set, or agreed date to reinstate the secure status.

"There are set drinking water standards that need to be met before the security status of the source water would be reinstated," she said.

"Part of that is making sure bore heads are secure, as well as eliminating any other risk before the Drinking Water Assessor would lift the requirement to chlorinate."

She said they and the DWA were working with the council to meet the requirements so security could be reinstated.

The council would be delivering information in the next fortnight on the requirement to add chlorine to the network until further notice, how it fits into the government legislation, and what Napier residents can expect to happen over the coming weeks and months.