Fracking – is it safe?

In the research for my novel, Backfill, I read articles linking earthquakes and contaminated water to fracking. But the issue is controversial. In Backfill, a corrupt gold mine owner secretly partners with a shale gas fracking company who injects mine wastewater into deep rock formations as part of the fracking process. The process contributes to earthquakes and water well contamination in the region.

Fracking image by Mikenorton, CC BY-SA 3.0 https://en.wikipedia.org/wiki/Hydraulic_fracturing

Can Backfill’s scenario be true? Does fracking really cause earthquakes and well contamination?  Here are some facts.

What is fracking?  Fracking, shorthand for hydraulic fracturing, is a procedure to create cracks in deep-rock formations through which gas or oil can flow more freely. It is often associated with shale gas which is natural gas trapped within a shale formation, a type of sedimentary rock. When fracking, a well is drilled vertically several thousand feet, and then horizontally into the gas-bearing formation. A pressurized liquid composed of water, sand and chemicals is injected. Cracks or fissures created by the mixture allow the gas to flow more freely back up into the well by holding the cracks open long enough for the gas to escape.

Why has fracking been associated with earthquakes?
The wastewater that is recovered from the fracking process must be collected for disposal, treatment or reuse. Sometimes the wastewater is injected into disposal wells located even deeper than the shale, into porous rock. The water may move through the rock to existing faults, creating pressure and causing faults to slip, causing an earthquake.

–Then does fracking cause earthquakes?
The actual fracking process apparently is not the culprit, at least in the U.S. (Canada says different) It’s the injection of the fracking wastewater into deep wells that is the problem. Wastewater is created at nearly every oil and gas extraction well, whether or not it is fracked. This toxic water is injected deep underground for “safe” storage. It fills up porous bedrock, changes pressure underground and opens up otherwise stable fault lines.  There has definitely been an increase in induced or human-caused earthquakes due to oil and gas activity, primarily in Oklahoma and Texas, long known as oil country. Oklahoma has been hardest hit. Before 2009 there were only two earthquakes per year of magnitude 3 or greater. In 2015, there were over 900.  SOURCE

An e-mail I received from Professor William Ellsworth, Dept. of Geophysics at Stanford University says that fracking plays a limited role in injection-induced earthquakes. He writes, “It is a mistake to conflate everything to do with oil and gas wells and earthquakes as “fracking”. Fracking makes only a minor contribution to the hazard.” (E-mail 9/29/2016). Dr. Ellsworth has written articles about the subjects (see list below) and has been quoted in news articles such as The American Spectator.

–Can fracking cause water well contamination?
EPA has spent years studying this issue and a report published last year says that fracking poses a risk to drinking water in some circumstances. SOURCE Several articles I found on-line indicate that fracking can cause groundwater contamination. However, Dr. Ellsworth pointed out that all Class II disposal wells (those associated with oil and gas) must be designed and constructed to prevent a connection between the well and potable aquifers. (E-mail 12/5/2017).  The EPA website that describes the requirements for injection wells is HERE.

THE BOTTOM LINE –  Fracking and it’s related processes can cause environmental problems including earthquakes and contaminated groundwater. So the scenario in Backfill could happen – HOWEVER  – I must add that the bad guys didn’t bother to get the proper permits for their operations!  Thanks to Dr. Ellsworth for his input, and for keeping me honest.

Below is a list of a few articles from my research –read for yourself.  I welcome comments!

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