Review into why city water needs to be chlorinated

"This is looking at process and how we got in this position and what we can learn from the experience." Council chief executive Karleen Edwards

The Christchurch City Council hopes an external review will uncover all the events leading to the city’s water supply having to be chlorinated.

In late December the city’s supply was stripped of its secure bore status, meaning it no longer met the drinking water standards without being treated. It had been discovered many of the city’s pumps were in disrepair and vulnerable to pollution from dirty surface groundwater.

The council last month decided to chlorinate the water supply for up to a year while the bore heads were repaired. The water was expected to be chlorinated from late March.

The extent of the problem became clear to council officials in December, but Mayor Lianne Dalziel and the councillors were only made aware of the issue in January.

The terms of reference and scope of the independent and external review were approved by councillors at a meeting yesterday.

Cr Pauline Cotter said she was looking forward to finding out what happened with communications and she wanted to make sure the ‘‘gulf in communication between governance and management’’ did not happen again.

The review’s prime objective was to provide the council assurance about the future of the city’s unchlorinated water supply, the report said.

It would assess how the matter arose and was handled, and provide recommendations for improvements in procedure, practice, levels of service and reporting. Existing practices, monitoring and assessment regimes and controls would also be looked at.

A detailed timeline of all relevant meetings and events between August 2015 and January 25 would be included.

Council chief executive Karleen Edwards said the review would assess the council’s handling of the situation, the adequacy of existing practises and procedures, and whether things could have been done better. She said the review was being treated with urgency, but would not slow down the work being done to repair the bore heads.

‘‘This is looking at process and how we got in this position and what we can learn from the experience moving forward.’’

The city’s 16 councillors and Dalziel voted 14 to three on January 25 to chlorinate water at the city’s 56 pumping stations for up to a year.

It is likely only the second time there has been city-wide treatment in Christchurch, the only major New Zealand city without a chlorinated water supply. It was temporarily chlorinated in the aftermath of the February 2011 earthquake.