As more and more towns experience tremors in regions that have historically never reported seismic events, scientists are investigating whether hydraulic fracturing could be responsible for earthquakes.
A study conducted in 2012 by the National Research Council examined whether hydraulic fracturing, or fracking, and the disposal of injection waste could catalyze earthquakes.
What researchers found was that the greatest risk for earthquakes does not come from the fracking’s method of cracking deep shale with pressurized water and chemicals, but rather from pumping the wastewater from those operations back down into deep sandstone or other formations for permanent disposal.
Geologists looked at destabilizing cracks in underground shale deposits which subsequently triggers movement of nearby faults.
The study’s findings corroborated earthquakes that occurred in Jan. 2013 in Youngstown, Ohio, on Christmas Eve and again on New Year's Eve, measuring 2.7 and 4.0 on the Richter scale, respectively.
Another later study published in Science in 2013, led by researchers from Columbia University’s Earth Institute, looked at deep wastewater disposal wells, (which, again, are different than the shale gas wells where fracking actually takes place). What they found was no different from National Research Council’s conclusion.
“…the pressure created by pumping millions upon millions of gallons underground seemed to put extra pressure on nearby fault lines—so much so that when major quakes struck thousands of miles away, like the March 2011 quake in northern Japan that caused an epic tsunami, the resulting seismic waves could trigger swarms of small quakes near the injection sites."
A third major study found that earthquakes (specifically, those near Oklahoma drilling sites) were likely attributable to underground injection of wastewater derived from "dewatering,” separating crude oil from the soupy brine reaped through a drilling technique that allows previously inaccessible oil to be pumped up.
The study, published in 2013 Geology by scientists from the USGS and Columbia University's Lamont-Doherty Earth Observatory, investigated the effects of wastewater injection from oil production.
Currently, wastewater is disposed by being pumped into one of the more than 30,000 deep disposal wells around the country. Although underground disposal has long been an industry-accepted form of wastewater disposal, the natural gas boom in recent years promises to exacerbate the amount of water (sometimes tainted with harmful hydraulic fracturing fluids) produced by gas extraction projects. Together, oil and gas extraction and production generate about 878 billion gallons of wastewater annually, roughly what tumbles over Niagara Falls every two weeks. More than a third is injected back into disposal wells. With natural gas production on the rise—it has jumped 26 percent since 2007.
At The Wilderness Society, we work to ensure that any natural gas extraction developed on America’s wildlands is done responsibly. This means:
- Requiring gas companies to disclose chemicals used in drilling processes
- Honoring the rights of surface owners to protect their lands and waters in split-estate situations
- Closing loopholes in federal laws that protect drinking water and surface water quality
While there are currently no oil and gas industry standards that regulate wastewater injection as it relates to earthquakes, we can mitigate the effect of development on sensitive wildlands and cultural sites by marking them as off-limits to oil and gas leasing and development.