VANCOUVER – A natural gas operation that halted work after a 4.6-magnitude earthquake in northeastern British Columbia last week has been linked to the largest earthquake in the province that’s been attributed to fracking.
Progress Energy, which is owned by Malaysia’s Petronas, paused its operations after the Aug. 17 quake that occurred 114 kilometres from Fort St. John.
The B.C. Oil and Gas Commission has previously said that hydraulic fracturing — or fracking — by the same company triggered a 4.4-magnitude earthquake that was felt in Fort St. John and Fort Nelson in August 2014.
Progress Energy responded late Wednesday, saying the cause of the recent quake has not yet been established.
“The northeast B.C. foothills is a seismically active area with more than 6,000 seismic events each year, 99 per cent of which measure a magnitude so low that they are not felt on the surface,” said a statement from spokesman Dave Sterna.
The company has voluntarily installed 17 seismic monitoring stations in its operating area, Sterna added.
A report by the commission said fracking has caused nearly 200 seismic events in the Montney Trend, which stretches from the B.C.-Alberta boundary near Dawson Creek to the B.C. Rocky Mountain foothills.
The report that investigated fracking, the process of fluid injection into rock to extract natural gas, looked into quakes recorded between August 2013 and October 2014.
A statement from Rich Coleman, B.C.’s minister for natural gas development, said drilling must stop immediately and the commission must be notified if seismic activity reaches a magnitude of 4.0 or higher.
“Operations can only resume once a mitigation plan — such as reduced pumping pressures — are agreed on by the commission,” he said.
Coleman said quakes related to hydraulic fracturing are rare, with only about 2.6 per cent of fracking operations in the Montney linked to a seismic event.
The province collects earthquake data at 10 stations throughout B.C.’s northeast.
“We implemented preventive measures that make sense for our province,” said Coleman. “Seismicity can be managed through geologic understanding, pumping protocols and monitoring.”
Energy giant Petronas is also working with the B.C. government on a $36-billion liquefied natural gas project, called Pacific Northwest LNG.
The commission did not respond to a request for comment.
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Note to readers: This story has a corrected headline. A previous version had a headline that said the fracking firm caused the recent quake, but as the story made clear the firm says the cause has not been established.