Fracking rarely triggers earthquakes, geologist says

A University of Toronto geology professor says it is rare for hydraulic fracturing to trigger earthquakes.

Andrew Miall, a geologist with a research interest in unconventional methods of extracting fossil fuels, said reports linking the controversial mining practice to earthquakes are exaggerated.

“The fracking process of course itself is explosive and does trigger tiny earthquakes. And when I say tiny, they are about strength one or two, and even if you were standing right on top of the well as they were doing it, you wouldn't feel it,” Miall said.

Miall said in very rare cases, the process can trigger the release of stress on existing earthquakes. He said even that would only result in what he calls mild shaking.

Recently, the Council of Canadian Academies released a new report that examined the shale gas industry.

The report, which was commissioned by Environment Canada, suggested more information is needed on potential environmental impacts. The report by a panel of 14 international experts concludes "data about potential environmental impacts are neither sufficient nor conclusive."

The New Brunswick government has also attempted to collect more information about the industry. Premier David Alward has created the New Brunswick Energy Institute, which is intended to be an independent body with a mandate to examine the science surrounding emerging energy possibilities, including the possible development of a shale gas industry in New Brunswick.

The hydro-fracking process involves injecting water, chemicals and sand into the earth at high pressure to fracture shale rock to release the natural gas within it. Opponents say the process could harm groundwater supplies.

Miall said shale gas extraction should not necessarily be linked to methane in ground water.

He said most surface ground water contains some methane and the shale gas industry is too often blamed for this.

Miall said hydro-fracking can be accomplished safely but it all depends on well completion.

“Each well is supposed to have a steel casing installed, which protects the fluids going up and down the pipe from the ground itself, from the host rocks, the purpose being, of course, to prevent chemicals and methane leaking into surface groundwater,” he said.

“If this is done properly, then there's no environmental consequence to groundwater whatever, absolutely none. The problem of course is that this does require proper well completion and this requires safe practices, responsible performance and it can certainly use proper government oversight. If this is done then there really are no serious environmental effects.”