Christchurch City Council apologises over failings in management of city's chlorination

Christchurch began a temporary chlorination programme earlier this year. Photo / 123RF

Christchurch City Council has apologised to its residents after an external review into the chlorination of the city's water supply uncovered failings in its handling of the situation.

The city began a temporary chlorination programme earlier this year.

It came after an inquiry in Havelock North, where a widespread gastroenteritis outbreak in 2016 was traced back to E. coli in the water supply, found a risk of contaminants entering bore water through below-ground well heads.

The Christchurch City Council review was commissioned by its chief executive Dr Karleen Edwards and conducted by former assistant auditor-general Bruce Robertson to understand why Christchurch had lost secure water status late last year and how it had happened without prior warning.

Edwards says steps have been taken to address the issues raised in the review and a $35 million well head improvement programme is under way.

"Our key objective is to be able to return to supplying unchlorinated water to our community, which is why we have put in place a comprehensive water supply improvement programme ahead of the report being received," she said today.

"We've been keeping Mr Robertson informed of the steps we have taken and he has acknowledged the progress that we've made. Many of his other recommendations have already been addressed."

In his review, Robertson acknowledges the Havelock North drinking water contamination incident led to more rigorous assessment processes being applied by external assessors to the drinking water standards.

The review identified a number of issues within the council's Three Waters Unit, including a "lack of a cohesive system to manage compliance with all three criteria required for bore water security".

It found the unit had over-relied on one of the criteria requiring E. coli to be absent from the water.

The review also found a general failure to escalate the developing issue with the below-ground well heads.

"The review says it is unlikely we could have prevented the loss of secure bore status, and the subsequent temporary chlorination of our water, even if we had got this right in the second half of 2017,'' Edwards said.

"These issues should have been raised with the council's executive leadership team and with elected members from the middle of last year when it became apparent that the secure status was at risk.

"If that had happened, we could have managed the issues much better as they unfolded. We could have taken time to explain everything to our community so they could better understand the choices and decisions that needed to be made. I'm sorry we did not do that."

The Drinking Water Assessor and the Ministry of Health advised the council last December its security status was being changed from provisionally secure to unsecure.

Edwards said the Three Waters Unit now has systems and processes in place to ensure it can manage and monitor compliance with all three Drinking Water Standards criteria.

"We have put in place a comprehensive water supply improvement programme, with dedicated resources, that is aimed at upgrading our well heads as quickly as possible and looking for alternative ways of ensuring we can remove the chlorination within the deadline. We will keep the public informed," she said.