Two natural gas drillers in Arkansas have agreed to stop using two injection wells in the state until it can be determined if they are causing earthquakes in the area. The injection wells, located near Greenbrier and Guy, are used to dispose of wastewater from nearby hydraulic fracturing operations.
As we’ve reported previously, Arkansas has recently experienced a surge in seismic activity, including the biggest earthquake recorded by the state in more than three decade. That quake, which occurred on February 27, had a magnitude of 4.7. According to a new Fox News report, the U.S. Geological Survey has recorded dozens of small earthquakes in the area over the past few weeks as well, ranging in magnitude from 1.8 to 3.8.
According to Fox, 90 percent of the earthquakes recorded in the state since 2009 have occurred within six kilometers of salt water disposal sites associated with fracking operations. Steve Horton, an earthquake specialist at the University of Memphis and hydrologic technician with the U.S. Geological Survey, told Fox the coincidence is too big to ignore.
There are seven injection wells in operation in the area of Arkansas where the earthquakes have occurred, according to Fox. The Arkansas Oil and Gas Commission believes the two closed wells – operated by Oklahoma City-based Chesapeake Energy and Clarita Operating of Little Rock – are near a previously unknown or unmapped fault, leading to these specific issues. Both companies have halted operation of the two wells, following an emergency meeting of the Commission earlier this month.
We’ve reported on this phenomenon before. Last year, Chesapeake Energy and environmental officials in West Virginia were trying to determine if a spike in seismic activity in Braxton County was associated with an injection well located in the town of Frametown. About ten million gallons of drilling fluid had been pumped into the well since the spring of 2009. Last April, Braxton County experienced a 3.4 magnitude earthquake. Between April and the end of August the area was the site of at least six more, according to West Virginia Public Broadcasting. Most were around a 2.7 magnitude.
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. According to a Wall Street Journal report filed at the time, Chesapeake Energy shut down two disposal wells in the area “as a precautionary measure†due to the upswing in seismic activity.
