Earthquakes located near underground fracking disposal wells are being reported more frequently, but according to a new Reuters report, these seismic events are preventable. However, it’s unlikely the industry will be willing to adopt the costly safeguards this requires unless the evidence tying fracking wastewater injection wells to earthquakes becomes irrefutable.
Fracking disposal wells are used to store the millions of gallons of briny wastewater that is the byproduct of hydraulic fracturing. According to Reuters, the pressure caused by injecting the fracking waster underground causes it to enter fissures and lubricates fault lines. This can cause earthquakes in places otherwise free of them.
Over the weekend, Ohio environmental officials shuttered a fracking injection well in Youngstown, following a 4.0 magnitude earthquake that occurred Saturday. According to a report from The New York Times, the earthquake was the 11th since mid-March to occur near the injection well.
“In our minds, we were already pretty convinced that these events were connected to the well,” John Armbruster, a seismologist with Columbia University’s Lamont -Doherty Earth Observatory, told the Times. “Having that many earthquakes fairly close to a well in Ohio, where there aren’t a lot of earthquakes, was suspicious.”
Last year, a similar occurrence in Arkansas prompted the closure of several underground fracking waste disposal sites. At the time, it was reported that 90 percent of the earthquakes recorded in Arkansas since 2009 had occurred within six kilometers of salt water disposal sites associated with fracking operations. In 2009, the disposal of fracking wastewater was also named a possible suspect in a series of earthquakes that plagued North Texas, in the Dallas-Fort Worth area, prompting Chesapeake to close two nearby disposal wells as a precautionary measure. A possible link to fracking and earthquake activity has also been investigated in West Virginia and Colorado.
According to Reuters, before an injection well is constructed, a bore hole is drilled, which takes a limited sample of a rock formation but gives no hint of faults lines or plates. However, conducting a seismic survey to assess tracts of rock below where oil and gas drilling fluid is disposed of could help detect quake prone areas. But that comes with a $10 million price tag for a single injection well.
Though there’s no way to guarantee total safety, precautions can also be taken to mitigate risks of earthquakes near disposal wells, Reuters said. These include lowering injection pressure and avoiding areas with a history of seismic activity.