Trucks carry fresh water to natural gas wells being used in fracking.Robert Nickelsberg/Getty Images
A fracking well in Ohio is believed to have triggered a series of earthquakes, according to a new study published in the Journal of Geophysical Research. The NorthStar 1 well, which went into operation in late 2010, is used to pump wastewater produced by hydraulic fracturing - fracking fracking in neighboring Pennsylvania.
Since recordkeeping began in 1776, residents of Youngstown, Ohio had never experienced an earthquake. That all changed in 2011, when seismometers recorded more than 100 earthquakes between that year and the well’s cessation in February 2012.
Fracking, a process of natural gas and oil extraction, is a controversial drilling method which pumps millions of gallons of water and chemicals into wells.
The study found that the onset, cessation, and temporary dips in earthquake tremors were all linked to the activity of the well. Dips in tremor activity correlated with the occurrence of major U.S. holidays, and other dates when work was temporarily halted.
The first earthquake occurred just 13 days after pumping began. The tremors ceased completely shortly after the Ohio Department of Natural Resources shut down the well.
The research showed that the well's deep injection of wastewater was inducing seismic activity.
"These shocks were likely due to the increase in pressure from the deep wastewater injection which caused the existing fault to slip," researcher Dr. Won-Young Kim told EurekAlert. "Throughout 2011, the earthquakes migrated from east to west down the length of the fault away from the well -- indicative of the earthquakes being caused by expanding pressure front."
The strongest tremor registered at a magnitude of 3.9 and occurred in December 2011.
Fracking wells go thousands of feet deeper than traditional natural wells and require up to 100 times more local freshwater than traditional extraction methods, according to Clean Water Action, a citizen-funded advocacy organization. The waste fluid produced by these wells, known as flowback, returns to the surface after each completed fracking process and is up to ten times saltier than the ocean. Because this water attracts radioactive elements and toxic metals like arsenic, it requires safe storage.
Ben W. Lupo, the owner of the company that operates the well, has a long history of run-ins with regulators. He was charged with violating the Clean Water Act earlier this year for instructing employees to dump brine water, a hazardous waste, into a drain that later made its way into the Mahoning River.
Over the years, environmental regulators have cited companies under Lupo's ownership more than 100 times for violations that took place across Ohio and Pennsylvania.
With Al Jazeera and wire services