Scientists and planning authorities do not have enough information about underground water bodies for coal seam gas production to be approved anywhere in NSW, a University of Wollongong researcher has said.
John Bradd, a hydrogeologist specialising in the effects of coal seam gas on aquifers, said the effect of drilling into the coal seam could have a dramatically different impact on groundwater, depending on the geography of the site.
He said neither proponents of the industry, nor those opposed to it, had enough information upon which to base their conclusions.
"I think a lot of it is not being informed about the actual processes that are going on," he said.
"A lot of it is based on emotive information that's put out there, and not so much on the science behind it."
Dr Bradd is an honorary fellow at the UOW School of Environmental Sciences. Two of his honours students are studying the effect of CSG drilling on aquifers - one with AGL in its Camden operations, the other across the southern coalfields.
Their focus is on the "barrier zone" between the aquifer and the coal seam, which can be more than 500 metres down. Dr Bradd said working out how easily water and gas could move through this zone was the key to knowing where CSG drilling might be safe and where it might not.
But so far, there was not enough information to approve production - or oppose it.
"The regulatory requirements probably don't go into enough detail about getting a good understanding of this zone I'm talking about, between the coal seam and those upper aquifers," he said.
"We're just lacking that data on permeability and fracture densities, and leakiness, or hydraulic connectivity, between them."
Dr Bradd said the examples in Queensland bore little value for NSW, as the permeability of the rock differed. While the AGL operation at Camden might draw out four megalitres from 80 bores each year, he said Queensland operations were "pulling out about 16 megalitres per day".
"It's a huge difference and that's why you have to look at each geological area as its own unique situation - so not one size fits all when it comes to coal seam gas," he said.
The NSW government has stopped new CSG explorations pending a review of the industry by Chief Scientist Mary O'Kane.
Dr Bradd said the research into the barrier zone needed to be done independently. "There just needs to be a better understanding of it, and time, money put into gathering that understanding."