Hundreds of thousands of rural New Zealanders remain vulnerable to contamination in their drinking water, despite the formation of a body to provide oversight of water quality.
Research by University of Otago research fellow and freshwater expert Marnie Prickett highlights how, despite an inquiry into the 2016 Hawke’s Bay campylobacter outbreak, major holes remain in NZ’s drinking water standards and surveillance.
Prickett’s report on the public health implications of nitrate contamination in drinking water was recently published in the Australian Journal of Water Resources. Funding for the work came in part from a Health Research Council of NZ grant.
Prickett has also been the leader and spokesperson for Choose Clean Water, a student led campaign that began in 2015 and aimed at strengthening NZ’s freshwater policies.
Estimates are 800,000 New Zealanders are served by potentially hazardous water supplies.
Prickett examined the 2022 Waimate District Council nitrate issues that resulted in that town having to shut supply, with residents compelled to source their drinking water elsewhere due to a spike in nitrate levels.
Environment Canterbury (ECan) attributed the spike in nitrate levels at the time to persistently high rainfall events. However, Prickett found the exceeding of safe nitrate levels had been predicted seven years earlier, prior to the Hawke’s Bay contamination.
An inquiry into the Hawke’s Bay event had found drinking water standards had been inconsistently applied and there had been little responsibility clearly nailed to regional councils.
“As a document, the Hawke’s Bay inquiry is incredibly valuable, with a lot of lessons that its authors acknowledge need to be locked in place sooner than later, otherwise people forget, move on and things will not change for the better.”
Prickett’s investigations into Waimate found little had changed from the Hawke’s Bay experience, despite coming six years later, and some clear recommendations coming out of the Hawke’s Bay inquiry.
That inquiry had recommended the formation of Taumata Arowai as an oversight body, tasked to recommend drinking water standards, review council safety plans, and monitor supplies. This has been done.
However, in the wake of the Waimate nitrate issue, Prickett says, Taumata Arowai lacks the capability to enforce the standards that came out of the Hawke’s Bay inquiry. She is hopeful it is gaining momentum as it is bedded in.
“It has only just started, and having an independent body for drinking water is a very good thing,” she says.
The Waimate experience highlighted continuing weaknesses in how source water for drinking is protected, and the continuing lack of accountability regional councils have for protecting drinking water sources.
She found ECan had knowledge in 2015 of the “significant risk” to drinking water sources posed by land use change and a switch to spray irrigation in Mid Canterbury. There was an estimate that one third of bores would exceed maximum safe drinking water levels for nitrates at some point.
After Hawke’s Bay, Taumata Arowai has focused on district councils’ “supply side” responsibility for quality water supply.
“When we did the analysis of Waimate, ECan really should have been responsible for protecting Waimate’s water. Now it is polluted they [ECan] say Waimate has to deal with it. Waimate now needs a de-nitrification plant, at significant cost.
“The big thing still being missed is the source water protection. Taumata Arowai could, if they had proper resourcing, focus on source water protection.
“Regional councils are the only ones who have responsibility to manage land use and waterways, if they are not on board with drinking water source protection the supplier [local councils] don’t have a chance to change it at their end.”
She said at present, given the costs involved, many district councils may be forced to accept greater risk than they would otherwise, had regional councils taken a more precautionary and preventative approach to source water.
“At present if you have your own bore and it is contaminated by what is happening around you in the catchment, how do you as an individual have enough clout to change that? We have found even district councils have not had that clout.”
She urged Taumata Arowai to step up and provide an official view on what powers and responsibilities it actually has and play a strong role as a drinking water advocate, similar to what the Department of Conservation does for conservation.
It also needs to be given enough funding to institute legal proceedings against councils where consenting for protection of drinking water is clearly inadequate.
“We also do not consider public health enough when we do land and water plans, we think about environmental health and recreation but drinking water doesn’t get considered. We have done this trick where we think we can separate human health from environmental health.
“My thought is it would be really good to have public health people with an advisory role required to be part of regional planning to give greater focus on public health.”
Responding to the report, Jim Graham, Taumata Arowai’s chief adviser on water science, says the agency’s responsibilities and mandates do not extend to the level Prickett’s report expects them to reach.
“It is important to understand the scope and mandate of Taumata Arowai under the Water Services Act. It does not extend to identifying problems in in regional plans and taking regional councils to task on it,” he says.
He says Taumata Arowai also rejects Prickett’s criticisms of the agency’s nitrate monitoring. He points to the requirement for larger suppliers to conduct a monthly nitrate test (among other impurities), with medium-sized suppliers submitting an annual test and small suppliers one every three years.
“It was also suggested there was no national database on nitrate in drinking water. All drinking water suppliers are going into a database being held by Taumata Arowai. It is now underway, and we will have in the region of 350 suppliers providing monthly nitrate results.”
He says the key legal responsibility lies with the water supplier to provide safe drinking water, while protection of the environment rests with regional councils.
“It would be totally inappropriate of us to investigate nitrate levels and say regional council rules are inadequate. It is not in our brief.”