The U.S. has been experiencing a domestic fossil fuel boom. Natural gas withdrawals have grown by 23 percent since 2000 – that’s an increase of 5.6 million cubic feet per year. Domestic oil production is up a similar percentage since 2007, largely because of advances in technology.
Much of what is being produced today would have, at one time, been considered economically unrecoverable. New techniques such as tar sands production hydraulic fracking of oil and gas located in shale beds have made this possible. The question of whether these approaches are safe or environmentally sound has been the subject of considerable controversy.
How Fracking Works
A sizable 40 percent of natural gas produced last year came from shale formations, most of which were obtained through fracking. But this method has raised considerable public outcry, with some 250 communities passing resolutions banning fracking in their localities.
Anti-fracking groups are concerned about the chemicals that are injected into the ground to help fracture the rock layers because some of these chemicals are quite dangerous and could find their way into the water table. The EPA has found cases where fracking caused water contamination.
Fracking also produces a considerable amount of toxic waste that could potentially be released into the environmental through leakage or industrial accidents, both of which are common. Air pollution is also an issue.
Fracking supporters, however, tout the economic benefits of fracking to landowners and communities. They cite studies that have found no linkage between fracking and tainted water.
Now there is a new fracking-related concern: earthquakes.
Earthquakes Related to Fracking
Geologists have found a marked increase in the number of earthquakes in recent times. Specifically, over the past three years, there have been five times as many earthquakes than in previous years. These often occur near fracking sites, though an examination of the data by the US Geological Survey shows that it is not the fracking that is triggering the quakes. Careful investigation suggests a linkage between the wastewater wells, where the toxic fracking waste is injected underground, and in increase in tremor activity. Scientists think that these wastewater wells are putting additional pressure on underground faults.
Several earthquakes near Dallas, Oklahoma City and Youngstown, Ohio, in the past five years have been tied to wastewater that was injected at high pressure thousands of feet underground at sites that happened to be near fault lines.
Back in 2011, British fracking company, Cuadrilla Resources, announced after an investigation that, that fracking most likely led to seismic activity.
“Clearly it is happening. Earthquakes have been happening in some unusual parts of the United States,” says geophysicist William Ellsworth. “At this point, we do not know if all or just some part of that increase is attributable to industrial activities like wastewater injection.”
It’s worth noting that none of the more than 300 significant quakes registered between 2010 and 2012 were above a magnitude of 5.6, which is considered dangerous. No one has been killed yet, but structures have been damaged.
Experts such as seismologist Nicholas van der Elst of Columbia University suggest that the pressure from the wastewater wells makes the faults more susceptible to triggers like aftershocks from larger quakes.
Steve Everley of Energy in Depth, a fracking industry organization, responds by saying, “This phenomena has been known about for decades and it is exceedingly rare, so it is all about managing risk.”
Ellsworth suggests that the problem could be managed with better monitoring of immediate seismic activity and sudden pressure changes during disposal operations.
With funding for coal production losing support in many quarters, it may not be possible to back away from natural gas at this time, though neither that, nor the fact that gas is the cleaner fuel, justify any shortcuts or laxity in the administration of careful scrutiny that these operations clearly require.
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