Western Bay of Plenty learning lessons from Havelock North water contamination crisis

Noel Roberts, from Water New Zealand, during a lighter moment of a seminar dealing with proposed changes to make the country's water safer. Photo / Andrew Warner

Lessons learned from the Havelock North bore water contamination crisis will be applied to the Western Bay District Council.

Far-reaching recommendations from the inquiry into how hundreds of Havelock North residents fell ill with gastroenteritis are expected to have the biggest impact on small privately-owned water supply schemes in rural Bay of Plenty.

The Western Bay of Plenty district is reliant on bores for its town supplies, so there was a big turnout of council staff to Friday's seminar at Baypark organised by Water New Zealand.

''The inquiry recommendations are bold and propose far-reaching changes,'' councils have been told.

Water New Zealand said if the recommendations were implemented, water suppliers would need to adapt to a considerably changed drinking water environment.

''Indications at this stage are that most, if not all of the stage 2 Havelock North Inquiry recommendations will be imposed by the Government.''

Tauranga City Council is expected to be less impacted by the recommendations because the city draws its water from two spring-fed streams. It then goes through a microfiltration process after which chlorine is added to disinfect the water.

Western Bay District Council utilities manager Kelvin Hill suspected it would be small, private rural water supply schemes, typically linking houses in lifestyle subdivisions, that could be the most affected by the changes.

He said the council was not responsible for private water bores, but it was happy to provide guidance and information.

The council supplied water to 16,000 of the district's 23,000 households. Another 1500 could link into town supplies if they wanted. He predicted that some of these would join up once compliance with new standards became a lot harder.

Hill said the protection of water supplies to towns in the Western Bay began at the source, where it came out of the ground.

He explained that water for towns like Katikati and Te Puke came from deep bores, tapping into aquifers carrying water that was 100 years old.

''It has taken a long time to get to where it is.''

The water then went through treatment processes which, in the eastern end of the district removed high levels of iron and magnesium. Hill said calcium, a white milky substance, was another big issue for the council and was expensive to remove.

The last step in the treatment process was chlorination to prevent contamination of water in the reticulation system.

''We are in a pretty good space, but we can't rest on our laurels,'' he said.

Water supply schemes connecting 20 or more houses already needed water safety plans, even when they were privately owned. Houses that used rainwater off their roofs also needed some form of treatment.