Ecocentric

Deep Disposal Wells from Oil and Gas Drilling Linked to Earthquakes

A new study finds that the deep disposal wells used to store drilling wastewater—not fracking per se—may help trigger earthquakes. Regulators and the industry should take notice—and find ways to recycle that wastewater, instead of throwing it down a hole.

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Jon Mullen via Getty Images

A well drilling rig works in Colorado. A new study linked drilling disposal wells to earthquakes

The headlines were clear: fracking causes earthquakes. Yesterday an important study came out in Science that found a strong link between the injection of wastewater into deep underground wells and nearby earthquakes. Hydraulic fracturing—used in the process of developing shale gas and oil wells—also involves pumping millions of gallons of water and chemicals underground, in an effort to essentially pry fossil fuels out of tight layers of rock. Therefore, fracking causes quakes. Right?

Not exactly. The Science study, led by researchers from Columbia University’s Earth Institute, looked at deep wastewater disposal wells, which are different than the shale gas wells where fracking actually takes place in the way that a landfill is different from a garbage can. Injection wells are designed to hold the wastewater created by drilling many wells—for that reason, far more water goes into a deep injection well than into a fracked gas or oil well. The researchers found that 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. It’s the injection wells—not the fracking per se—that are specifically linked to those temblors in this study.

Does that mean fracking is off the hook? Not really. Many of the fluid-injection wells studied by the Science researchers—in Texas, Oklahoma, Colorado, Arkansas and Ohio—have been in operation much longer than shale gas and oil fracking has been active. But each shale gas well can produce several million gallons of wastewater, and in much of the country, that wastewater is disposed by being pumped into one of the more than 30,000 deep disposal wells around the country. As the oil and gas industry likes to point out, underground disposal wells are an accepted way to dispose of wastewater, and they’ve been used for decades. But as the shale gas and oil boom ramps up, the industry will be producing vast amounts of wastewater tainted with sometimes toxic fracking chemicals. It’s worrying to know that there is growing scientific evidence linking those fluid-injection wells to earthquakes—even if so far the quakes that have been linked to the wells have all been relatively minor.


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The good news from this research is that we may be slowly getting closer to the holy grail of seismology: accurately predicting when quakes will strike. The fact that the seismic waves from a distant but powerful quake triggered swarms of small quakes near the studied well sites—which were then followed by a moderately sized temblor around those well sites—demonstrates that the faults near the injection sites were already critically stressed. Such “remote triggering” can offer scientists an indication that the injection sites have passed a critical seismic threshold, leaving the area in greater danger from a larger quake. It’s not exactly an earthquake weather forecast, but since we remain utterly unable to predict when temblors will strike with any precision, it’s certainly a start.

As the authors put it in the conclusion of their article, the Science study “underlines the importance of improved seismic monitoring in areas of subsurface fluid injection.” In other words, if we’re going to keep injecting millions upon millions of gallons of fracking wastewater into underground wells as the shale gas and oil boom continues, we need to ensure that we keep close track of the seismic side effects. That something to consider as the Environmental Protection Agency continues its long, drawn out review of hydraulic fracturing.

Or better yet, the industry can work on ways to clean, recycle and reuse wastewater from wells, eliminating the need for the deep injection wells. Recycling wastewater would also help allay the concerns that fracking will stress the water supplies of already arid areas. In states like Pennsylvania, which lack the geology needed for deep injection wells, recycling wastewater may be the only way to ensure that fracking has anything close to a sustainable future. And companies are exploring ways to effectively recycle that wastewater, though the reuse is generally more expensive and more cumbersome than simply injecting it into the deep wells.

I know it seems pedantic to point out that it is the deep injection wells, not fracking itself, that has been linked to these earthquakes—especially since it is the wastewater created by fracking that is now flowing into many of those wells, putting more pressure on fault lines. Why not just make the leap: fracking causes quakes? But when it comes to an issue as white-hot as fracking—with both sides utterly convinced of their righteousness— a little pedantry can help.

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6 comments
JudyLTS
JudyLTS

What puzzles me is that this water is being injected into reservoirs that previously contained oil, gas and water.  So how is it that reinjecting a fluid into a reservoir that previously contained fluids could cause additional stress? 

johnst1001a
johnst1001a

If you check the seismic activity over a coal mine blasting underground or blowing the tops off mountains, you will also get a reading like an earthquake. 

ShawnStevens
ShawnStevens

There isn't any fracking going on in the Fayette Plateau area of West Virginia, (Lochgelly, Oak Hill, Fayetteville) but plenty of sick people who have been exposed to toxic air and water pollution for the past several years as a result of the fracking wastewater being hauled in from other areas (including PA).  The fracking wastewater is dumped into sediment pits near our public schools and residential neighborhoods.  It's no wonder that so many people are dying from cancer, nerve damage, kidney disease.  The WVDEP OOG has been aware of this ongoing pollution for years, but has yet to do anything about it.

One of the biggest worries for most residents isn't the earth quakes, but the gas explosions instead.  Since there are so many coal mines under the frack dump site and the injection well, most folks are worried that there will be a huge gas explosion in the coal mines since flammable chemicals are injected underground and dumped into the pits.

I suppose I would be more worried about the earth quakes if I didn't have to worry about so many people dying in my community.

You can view the frack dump by going to:  www.DirtyWaterWV.com

JackWolf
JackWolf

When the earthquake hit in neighboring Youngstown, I called my Allstate insurance agent to see how much earthquake coverage would cost.  It turns out that it would double the cost of my homeowners insurance.  

If there is such a low risk, why is the premium so high?  You would think insurance companies would jump on a low risk rider by providing low cost riders.  They are either gouging or they know something we don't.

And, no I didn't sign up for it, because I don't think it would cover man made earthquakes caused by fossil fuel interests.  After all, why should Allstate underwrite that is clearly not my liability or mother nature's fault. 

MorganLFriedman
MorganLFriedman

Hydro Fracking is dirty dangerous and unnecessary.  The safe disposal of this highly dangerous by-product "waste water" has always been an elusive query.  Now knowing that this popular method has been proven to reek havoc on local faults is a scary one. The scariest part for me is the clear increase we are seeing not in earthquakes but in the expansion of this industry!

JoanneCorey
JoanneCorey

Fracking waste water can only be recycled a limited number of times. At that point, PA usually sends it off to OH disposal wells because the process needed to remove the contaminants to the point that the water can be discharged on the surface is very expensive and results in solid waste that has high enough levels of uranium, radium, and other radioactive elements that they are too hot for low-level radiation disposal facilities to handle. Or wastewater gets spread on roads for de-icing or dust suppression or illegally dumped down drains or in the woods. Sometimes they get caught at it and fined, but the damage has already been done.