Fracking triggered 2014 earthquake in northeastern B.C.

Frackingtriggered a 4.4-magnitude earthquake in northeastern B.C. last year, CBC News has learned,making it one of world'slargest earthquakesever triggered by the controversial process.

B.C.'s Oil and Gas Commission confirmed the cause of the earthquake in an email statement to CBC this week, sayingit was "triggered by fluid injection during hydraulic fracturing."

The 4.4-magnitude quake was felt inFort St. John and Fort Nelsonin August 2014.It was preceded by a 3.8-magnitude earthquake in late July, also caused by fracking.

B.C.'s Oil and Gas Commission told CBC thatseveral companies were doing hydraulic fracturing in the area at the time, and several more weredisposing of fracking waste.

But the commission says it was Progress Energy's operations that were "associated with triggering this event."

Hydraulic fracturing, often called fracking, is the process of injectingwater, sand and chemicalsat high pressuredeep underground to break rockand free gas.

Fracking fluid reduced

Since the 2014 earthquake, Progress Energy has been ordered to reduce the volume of fracking fluid being used, and the company has complied, according to the commission.

As well, new seismic equipment has been set up in the area. No new earthquakes have beendetected in the immediate area.

Last week,Progress Energy temporarily shut down anotherfrackingsite after a4.6-magnitudeearthquakehit just threekilometres away.

Responding to The Canadian Press late Wednesday,Progress Energy saidthe cause of therecent quake has not yet been established.

"The northeast B.C. foothills is a seismically active area withmore than 6,000 seismic events each year, 99 per cent of whichmeasure a magnitude so low that they are not felt on the surface,"said a statement from spokesperson Dave Sterna.

The company has voluntarily installed 17 seismic monitoringstations in its operating area, Sterna added.

Officials say it will take several more weeks to determine if the 4.6-magnitudequake was triggered byfracking.

Sign of things to come?

Progress Energy is owned by Petronas of Malaysia, which also owns Pacific NorthWest LNG, the firm planning to build a giant liquefied natural gas export facility near Prince Rupert, B.C.supplied by gas fracked in northeastern B.C.

Matt Horne, withclean energy advocatethePembina Institute,calls the significant earthquake "another warning sign for what could be down the road.

"If B.C. goes down the LNG road in a big way, it's reallyimportant when we're debating LNG proposals, we're eyes wide open.... to both the benefits and impacts. Increased earthquakes is one of those impacts," said Horne.

B.C.'s Oil and Gas Commission declined a taped interview, providing only background information by email.

Minister says events are 'rare'

In a statement, B.C.Minister of Natural Gas DevelopmentRich Coleman said "felt seismic events related to hydraulic fracturing are rare."

"The province has a leading role in North America in the detection and mitigation of induced seismicity associated with unconventional gas development and works closely with the Oil and Gas Commission and industry," the statement said.

The statement went on to emphasize that drilling must stop immediately if "seismicity reaching a magnitude of 4.0 is detected."

"Operations can only resume once a mitigation plan such as reduced pumping pressures are agreed on by the Commission," it said.

Peace MLAs Mike Bernier and Pat Pimm didn't respond to requests for comment.

In January, Alberta's energy regulator reported fracking likelycaused a 4.4-magnitudeearthquake in the northern town of Fox Creek. Scientists told CBC at the timethe quakewas the largest in the world evercaused by fracking.