The safety of tap water can no longer be taken for granted and unless lakes, rivers and aquifers are cleaned up there will be more contamination crises, the Greens say.
A report into the Havelock North gastro outbreak last August that was caused by contaminated water, released on Wednesday, found about 5500 people were struck down with campylobacter. The report linked the outbreak to the deaths of three elderly people.
The report identified major failings by Hastings and Hawke's Bay Regional councils in their responsibilities to deliver safe drinking water, and concluded the outbreak likely came from sheep faeces travelling through a "vulnerable" aquifer.
Catherine Delahunty, the Greens' water spokeswoman, says tap water must be clean.
"It's not good enough to say we'll just chlorinate the water and that will take care of pollution," she said.
''More than 5000 people getting sick from the water in their own taps was horrific - if we don't take action to clean up our rivers, lakes and aquifers we will face issues like this more often."
Ms Delahunty says the Havelock North incident was "the canary in the coal mine".
"We need to look at infrastructure and land uses to ensure the water in our aquifers, many of which supply drinking water, are kept safe."
Outgoing Hastings Mayor Lawrence Yule says the risks around untreated drinking water need to be better known.
"About 30 percent of New Zealand has untreated drinking water, and the management of that will come under a lot more scrutiny into the future. I think it's a national issue."
He accepts the findings of the report.
"I am incredibly sympathetic and understanding of the fact 5000 people became gravely unwell. Three people actually died with campylobacter. This is a huge issue for us and our community, and it needs to be responsibly and transparently handled."
NZN / Newshub.