In the past five years, over 2,500 small earthquakes have occurred in Oklahoma, and scientists believe that the wastewater injection process has imposed stress on existing fault lines beneath the ground.
Cornell University’s Katie Keranen led a research team that examined four wastewater disposal wells in southeast Oklahoma City. The four million barrels of wastewater injected every month were found to travel beyond their pumping site, migrating along fault lines and “likely responsible” for earthquakes as far as 22 miles away.
As of this writing, Oklahoma experienced more earthquakes in 2014 than California. Several other states have also experienced greater earthquake activity than normal, including Ohio, Arkansas, Texas and Kansas – all corresponding to fracking activity in their respective areas.
At the moment these quakes have been small and not caused any major damage, but Gail Atkinson, an Earth Sciences professor at Western University, said that may change over time. “I think ultimately, as fluids propagate and cover a larger space, the likelihood that it could find a larger fault and generate larger seismic events goes up,” she said at a Seismological Society of America conference in May.
Ohio, California and Oklahoma have all passed legislation that requires hydraulic fracturing outfits to carefully measure the volume and pressure of their injections. Across the nation, towns and cities are taking more drastic measures. Denton, Texas is attempting to ban fracking within its borders and 178 towns in New York have already passed bans or moratoria on fracking. New York state is currently considering a statewide moratorium, which has been supported by groups like the Concerned Health Professionals of New York.
In a recent letter to the Acting Health Commissioner Howard A. Zucker, the CHPNY stated that in their extensive research they found “no evidence that fracking can be practiced in a manner that does not threaten human health.”
To read Keranen’s full report, click here.