Supplying water not chlorinated is like driving without a seatbelt. It is no longer safe, it it ever was.

Iain Rabbitts is water and wastewater manager at the engineering and design consultancy, Harrison Grierson.

The Havelock North water crisis continues with misinformation, misdirection and people being economical with the truth.

Let's get this straight. The water industry knew this was just a matter of time. The Ministry of Health knew it was just a matter of time. The politicians knew it was just a matter of time. But the public had no idea it could happen.

The Mayor of Hastings, Lawrence Yule, said on TV3's The Nation on Saturday that the Havelock North supply had been secure for 35 years and there was no reason to suspect it could be contaminated. In 1969, I was involved in a car crash. The car had no seat belts. I broke my femur and my parents went through the windscreen, permanently disabling my mother.


It wasn't safe to drive a car then without seatbelts but people had been doing it for over 35 years - why the change? Well speeds had increased, the number of cars on the road had changed - circumstances had changed. This is what happens - life is different from how it was 35 years ago. We need to change our approach and our water supply from what it was 35 years ago because it's no longer safe to have an unchlorinated supply (if it ever was). We need to grow up.

But a seatbelt is not the whole answer to protecting people in a car. In the same way chlorine isn't the whole answer to making water safe to drink. In a car we have added airbags and side impact systems. In water treatment we may need additional processes like filtration and UV disinfection to counter the pathogens not removed by chlorine. Chlorine needs to be part of an overall solution in the same way that seatbelts are part of the solution to protecting people in cars.

Yule said the water was sampled twice weekly. However, he said the sample "produces 70 per cent false positives". Let's be clear here, a false positive is a positive reading for E.coli that is not backed up by the result of a second test. A test takes 24 hours to get a result. If you get a positive test, you take a second test and wait another 24 hours for the result.

If you get a second positive, you take action. This means you're 48 hours into an event before you know you have a problem. It's like not knowing you had a car crash until 48 hours later. In my mother's case it was 168 hours later as she was unconscious for a week. In today's society, how is this acceptable?

How did we get to this state of relying on a test that produces so many false positives that nobody trusts it? Talking to the Ministry of Health last week, they told me that the most vociferous submitters on the Drinking-water Standards for New Zealand 2005 were those councils with bore supplies that didn't want chlorine in their supplies - Yule being among that vocal minority.

Political pressure overrode good engineering practice, good health protection and common sense. There was political expediency from mayors right through to the minister. We are making these decisions based on a three year electoral cycle.

The Drinking-water Standards are not even mandatory. What the Health (Drinking Water) Amendment Act 2007 says is that all water suppliers should take, "all practicable steps" to comply with the Drinking-water Standards. Given that the Drinking-water Standards allow Hastings District Council to behave in the way it has, relying on a notification not sooner than 48 hours after a contamination event, is pretty toothless.

So what happens next? The public inquiry is a great step forward but let's ensure that we have a fresh set of eyes on this. Let's make sure that the people involved in the inquiry are not those that succumbed to the political pressure over the Drinking-water Standards for New Zealand 2005 or those that exerted that pressure. Bring in people who have not been involved in the failed system to date. Because it has definitely failed for the people of Havelock North.

We need to remove the ability of water suppliers to supply unchlorinated water. We need to remove political interference from water supply.

We need to give a strong regulator teeth to ensure that compliance with the standards is better than "all practicable steps".