There’s a higher risk of earthquakes when wastewater from the hydraulic fracturing process is injected back into the ground, according to a report by the National Research Council, an arm of the National Academy of Sciences.
But a CNN story says it’s a small risk. Out of about 30,000 disposal wells nationwide, only a handful of noticeable tremors have been reported, with the strongest equivalent to a magnitude-4.8 earthquake, the panel of engineers and scientists concluded.
Hydraulic fracturing, commonly known as “fracking,” is a method of natural gas extraction that involves injecting a mixture of water and chemicals deep into the ground. The pressure causes shale rock formations to fracture, and natural gas is released. The fluid is extracted, and the gas is mined.
Fracking is employed in Pennsylvania’s Marcellus Shale region. It’s proven controversial because the chemically treated water contains benzene, a known carcinogen, and critics worry that it will contaminate groundwater.
Concerns that the process can also trigger earthquakes prompted Congress to request the National Research Council study in 2010.
The CNN report says seismic instruments around Youngstown, Ohio – a site of intense fracking activity — recorded nearly a dozen small quakes in 2011, with a magnitude-4.0 tremor reported December 31.
John Armbruster of Lamont-Doherty Earth Observatory, Columbia University, who’s been studying seismic events and fracking in the Youngstown area, is quoted as saying that it’s “virtually certain” an injection of fracking wastewater caused the New Year’s Eve tremor.
Depending on its location, “any disposal well that’s been pumping stuff into the ground for months can cause earthquakes,” Armbruster said.
Lopez McHugh is investigating Marcellus Shale injuries. If you have significant injuries, contact a Lopez McHugh attorney for a free evaluation.
See the CNN story here: