VANCOUVER — The sight of homeowners setting their drinking water on fire is pretty dramatic.

But scientists say the controversial and fast-growing energy sector practice of "fracking" to get at natural gas pockets underground has been unfairly blamed for the contamination.

It is more likely the flammable water, reported by some people living near some U.S. fracking operations, is linked to ground spills and problems that are not unique to the process also known as hydraulic fracturing, says Chip Groat of the University of Texas.

He led a study, released here Thursday at the annual meeting of the American Association for the Advancement of Science, that found "no direct connection" between groundwater contamination and fracking.

The process, used in many parts of the U.S. and Western Canada, pumps millions of litres of water and chemicals deep underground to fracture rock and extract natural gas.

It has fuelled widespread concern about groundwater contamination, with some landowners pointing to their flammable tap water as evidence.

"They were able to set the water on fire, so something in going on," says Groat.

But he and his colleagues could find no link between the flammable tap water and the fracking process going on thousands of metres underground.

Their study, which looked at areas where fracking has taken place in Texas, Pennsylvania and New York, found that the groundwater contamination often can be traced to above-ground spills or mishandling of wastewater associated with the gas extraction process.

"These problems are not unique to hydraulic fracturing," says Groat, who undertook the study to try separate "fact from fiction." It was funded by the Energy Institute at University of Texas.

Hydraulic fracturing been described as a "game-changer" since it could provide enough clean and affordable natural gas to meet North America's energy needs for decades to come.

"I think it is, in fact, a revolution," says Groat.

Given the enormous potential he and his colleagues say it is important to better understand and monitor the impacts. Along with groundwater contamination, there are concerns fracking operations are producing huge amounts of waste water and releasing methane, a potent greenhouse gas, into the atmosphere. It also has been linked to seismic activity.

Fracking has been associated with many small earthquakes in northeastern British Columbia. The earthquakes ranged from 2.5 to 3.5 on the Richter scale, which is not enough to cause damage.

"Small to potentially moderate-size earthquakes have been triggered by the re-injection of waste water during the fracking process," says geologist John Claque, from Simon Fraser University, who will discuss the issue at the conference Friday.

"Large earthquakes are unlikely, but one cannot completely rule them out," he said by email.

Clague sees "possible water contamination" as the larger issue.

"My advice is to focus to the risks to drinking water and the greenhouse gas implications of fracking," he says.

Environmental concerns have slowed fracking in some areas and have led to moratoriums in Quebec and New Jersey.

Groat says groundwater contamination in some areas probably can be traced to natural sources that were present before the onset of shale gas operations.

But the lack of data on what the groundwater was like before fracking operations started "hobbles" efforts to evaluate the impacts.

Fracking, says Clague, is "a case of science lagging behind technology."

mmunro@postmedia.com

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