Watch: Mayor Lianne Dalziel: I will vote for chlorination of our drinking water


I started writing this column last week and began with the words “happy new year and may 2018 bring all that you hope for. I hope that those who have had holidays over Christmas have come back refreshed and ready to take advantage of all the opportunities that our city offers.”

When I came back to work on Monday, January 15, I was told that my regular column started this week, so I thought I could just submit it a week later. However, on the same day, I was given an update on our obligations as a drinking-water supplier under the Health Act.

It transpired that on the last working day before Christmas, the Canterbury drinking water assessor had removed our secure groundwater status.

Let me explain. The Drinking Water Standards currently have three criteria for achieving secure groundwater status:

  1. Bore water is not directly affected by surface or climate influences.
  2. The bore head must provide satisfactory protection by being sealed at the surface.
  3. Demonstrating an absence of past E. coli positive results.

Water drawn from confined aquifers that satisfies the three criteria is considered secure bore water.

Unfortunately, we could not satisfy the second of the criteria, as the independent engineers who are engaged each year to sign off on the security of the bore-heads would not sign off on them this time. I immediately asked that the recess committee be called together, so that as many city councillors as were available could be briefed on the situation and to ensure we could get a paper to the first city council meeting of the year.

One of the questions that was asked was what had changed? We were meeting the criteria before, but suddenly we were not?

There is a view that since the Havelock North incident, the appreciation of the risks (both likelihood and consequences) has brought a sharper focus to Drinking Water Standards compliance and greater diligence in signing off secure bore status.

The risks haven’t changed – the probability remains low and the consequences remain high, which is why we have had a more rigorous testing regime than strictly required.

That’s also why city council staff had the below ground well-heads investigated in June last year and why work is already under way to bring each of them up to secure status.

The issue for the city council is that without the engineers sign off on the well-heads, we are advised that we have an obligation to consider another layer of protection in order to meet our duty to ensure that the drinking water is safe.

Our city council takes its drinking water responsibilities very seriously. And that is why today I am supporting measures required to restore our secure groundwater status and the temporary chlorination of our drinking water in the meantime.

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