The drinking water of 20 per cent of the country is at risk – and an inquiry has recommended all drinking water be urgently treated.
The inquiry into Havelock North's drinking water contamination released a damning 296 page report into the safety and security of New Zealand's drinking water supply.
It makes 51 recommendations and says urgent action is needed.
It's the second stage of an inquiry launched following the August 2016 water contamination in Havelock North, which left 5000 people sick.
Led by Hon Lyn Stevens, Dr Karen Poutasi and Anthony Wilson, it says: "These findings point to a widespread systemic failure among water suppliers to meet the high standards required for the supply of safe drinking water to the public.
"The industry has demonstrated that it is not capable of itself improving when the standards are not met."
Eighty per cent of New Zealanders live in areas where the inquiry has determined that water standards are adhered to – generally people on reticulated water systems.
But the recommendations made in the report are focused on bringing the rest of the country up to standard – those who rely on untreated water in places like Hawke's Bay, Christchurch and Lower Hutt.
A number of recommendations need to be made urgently, the authors say.
That includes universal treatment of all drinking water – likely to be controversial and expensive.
It says the Ministry of Health needs to overhaul drinking water standards and introduce six new principles aimed at ensuring a safe and secure supply.
"The Director-General of Health can and should, in the interests of public safety and welfare, exercise effective and practical leadership to encourage water suppliers to use appropriate and effective treatment without delay."
A whole new drinking regime should be introduced, and offences created of supplying water unfit for human consumption – with costs if convicted of an offence.
"Complacency" over water supply by a number of authorities is also a problem.
Two recommendations directly relate to the Havelock North contamination - no new underground bores should be permitted and clearer advice must be provided when boil water notices are issued.
Local Government Minister David Parker says the Government is now considering the recommendations, and is addressing some of them straight away.
"The Government has today written to Mayors and DHBs throughout New Zealand. We've asked them to check the water they’re supplying residents meet current standards, given the report finds significant non compliance."
The Health Minister will urgently brief Cabinet – before Christmas – on the next steps, short and long term.
Mr Parker says it is a matter of priority for the government.