Wastewater, increasingly injected into deep disposal wells amid the energy boom, appears to be the culprit in an increase in U.S. quakes.
In a study out today that provides the strongest link to date between wastewater wells and quakes, seismologists and geologists say U.S. earthquakes have become roughly five times more common in the past three years. They warn about inadequate monitoring of deep wastewater disposal wells that are setting off these small quakes nationwide.
There are more than 30,000 such deep disposal wells nationwide. They’re increasingly used as mile-deep dumping grounds for fluids left over from the more shallow hydraulic fracturing, or “fracking,” wells responsible for surging U.S. natural gas production. The earthquakes have been linked to the wastewater wells but not the fracking drilling wells themselves.