Fracking earthquakes are rare, isolated events, says B.C. Oil and Gas Commission

Earthquakes from fracking are rare and usually not felt, says the B.C. Oil and Gas Commission, in response to a report released last week that show a definite link between hydraulic fracturing and large earthquakes.

The report says 90 per centof all large earthquakes with a magnitude larger than 3.0 in northeastern B.C are linked to fracking. It is simply a matter of time before a fracking-triggered earthquake causes damage, said one of the report's lead authors.

• Fracking triggers 90% of large quakes in B.C., Alberta oil and gas patch

However, the report also said less than one percent of fracking wells directly trigger earthquakes.That's the piece of information the oil and gas industry is highlighting.

"These are isolated events, they're rare events. It's very rare that they are ever felt at surface," said Ken Paulson, chief operating officer for the B.C.Oil and Gas Commission.

Mitigating risks

Any wells that cause a 4.0 magnitudeor larger earthquakemust shut down and implement measures that mitigate the risk for another earthquake, said Paulson.

"You can reduce the pressures or you can reduce the pump rates," he said.

Alternatively, well operators can choose to avoid the fault altogether.

"If it looks like you've intersected a fairly large fault, then what you can do is just skip that stage and move on to other stages. So avoiding the fault and avoiding any further movement on the fault."

The oil and gas commission will continue to work with researchers to monitor seismic activity in the area, said Paulson.

The commission has worked with researchers to install nine new seismic detection centres in northeastern B.C. in recent years, he said. There are now 11 detection centres in the region, allowing the industry to keep better track of earthquakes.

"We're very comfortable that hydraulic fracturing is conducted every day safely here in British Columbia and can continue to be," said Paulson.

With files from CBC Radio'sThe Early Edition