Fracking – the shattering of rock deep underground to release shale gas – isn't causing surface water pollution, but other activities associated with drilling may be, a new study says.
The research by the Energy Institute at the University of Texas, released on Thursday at the annual conference of the American Association for the Advancement of Science, is expected to have broad reverberations because governments in both Canada and the United States are looking at the rapidly expanding industry to see if more regulatory controls are needed.
In some areas there are calls for moratoriums on shale gas development over environmental concerns, but Charles Groat, associate director at the Energy Institute, said "we found no direct evidence" that hydraulic fracturing is causing groundwater pollution problems.
Above-ground spills, leaking drill casings and the mishandling of wastewater produced by shale gas drilling may be responsible for incidents of groundwater pollution – but fracking, the most controversial aspect of shale gas development – is not to blame, Dr. Groat said.
"To some people, hydraulic fracturing means anything that has anything to do with shale gas development [but]... to technical people, hydraulic fracturing is injecting fluid and sands at depth ... and our evidence is that the hydraulic fracturing, in the technical sense, hasn't caused the kind of problems [critics have raised]" he said.
The shale gas industry has been accused of polluting drinking water sources, and the problem was highlighted in the popular Josh Fox film Gasland, in which a land owner lights tap water on fire after gas drilling activity in the area.
Dr. Groat said he doesn't dispute that tap water in some places has become flammable, but he said deep, hydraulic rock fracturing is not responsible.
"We undertook our study ... with the avowed purpose of identifying the concerns that were being expressed about hydraulic fracturing ... to determine what were the actual causes. In other words, was it hydraulic fracturing, the fracturing of rock several thousand feet beneath the surface, or was it some other aspect of geo gas development [that caused surface water pollution]" he said.
"The bottom line [is that]we found no direct evidence that hydraulic fracturing itself – the practice of fracturing the rocks – had contaminated shale groundwater or was causing concerns," Dr. Groat said.
He said more research is needed to confirm what activities are causing groundwater pollution, but it is suspected the problems are the same as those affecting the broader petroleum industry.
"We conclude there isn't the need for pervasive new [regulations]... by and large they're doing a good job," Dr. Groat said.
Tom Huffaker, vice-president for policy and environment at the Canadian Association of Petroleum Producers, said the research findings support the industry's long-held belief that hydraulic fracturing has not been causing groundwater pollution.
"We think there is a lot of evidence their conclusions are right," he said, noting that thousands of gas wells have been drilled in Western Canada without causing any groundwater pollution.
But Mr. Huffaker said the study also underscores the need for proper management of all other aspects of drilling operations to control potential pollution sources from related activities.
He said the industry is committed to doing that.
"It is terribly important to get the well [drilling]right, it is highly important to get surface water handling right ... and we take this issue very, very seriously," he said.