Fracking could contaminate underground aquifers, like the one under the Heretaunga Plains, but a report into the controversial oil and gas drilling technique found no reason to put a moratorium on the practice in New Zealand.
Parliamentary Commissioner for the Environment Dr Jan Wright released her interim report into fracking yesterday, a study that she began in March.
"My interim conclusion echoes a similar report on fracking by UK Royal Society and some might say it's giving a tick of approval for fracking, but that was not the case and it is certainly not what I am doing today."
In a media conference, she said she could not be confident best practices were "actually being implemented and enforced in this country" when it came to fracking. But the risk to health and safety could be "managed effectively".
"And that is going to be the focus of the second part of my investigation."
Dr Wright said her study showed fracking had been used in Taranaki for 23 years, but it could not be seen as a gauge to show how safe the method was for plans to explore gas and oil in Hawke's Bay.
"Taranaki is using fracking in tight sand areas, whereas on the East Coast fracking may be used in shale, so it's a different kind of fracking that would be used.
"Hawke's Bay, Gisborne and Wairarapa differ from Taranaki. They have different geology, rocks on the East Coast are folded, it has different hydrology. The East Coast is also drier and therefore uses its aquifers more. It also has more seismic activity."
The potential for aquifers to be contaminated as a result of fracking was "very real". The salty water from deep underground, brought to the surface via fracking, could contaminate ground water, Dr Wright said.
Protecting Hawke's Bay's environment should be paramount when it came to oil and gas production.
"An oil company supposedly said the East Coast could become the Texas of the south, but I think that would not gladden the hearts of New Zealanders."
She showed a photo of oil and gas plants in Wyoming, US, where the industry had operated for more than 127 years. "I hope there is no possibility of Hawke's Bay ending up like this and we want to make sure it doesn't."
Dr Wright said oil companies had failed to win over the public when it came to explaining the pros and cons of fracking. "We talk about having a social licence, it's about earning the public trust. It has not been earned and the concern about fracking is widespread, not just in New Zealand. Full disclosure of fracking fluids might go some way to earn that public trust."
Hawke's Bay Regional Council requested a study into fracking in March after interest in the region from companies such as Tag Oil. The Green Party went further asking for a moratorium on fracking while the study was in progress.
"I am not calling for a moratorium at this stage," Dr Wright said. "That is a big thing to do. The industry is big business and employs lots of people here.
"But I am an environmental commissioner so the environment must be my primary concern. I have not seen anything that is of urgent concern. However ... if I find things that are sufficiently worrying, I will not hesitate to call for a moratorium."
Dr Wright said she found it difficult to understand how government and councils dealt with regulating fracking as each had different policies.
The second phase of her inquiry would focus on how well the environmental risks associated with fracking were regulated and monitored.