Fracking — a method of extracting underground pockets of natural gas — caused several earthquakes in northwestern Pennsylvania last year, scientists have confirmed.
That’s reason for concern, two local science professors said this week — although it’s doubtful that fracking will cause the ground to shake in Lancaster County.
“It is pretty far away,” Charles K. Scharnberger, professor emeritus at Millersville University and operator of the university seismograph station said.
“They’re so small, there won’t be any far-field effects from these quakes,” agreed Timothy D. Bechtel, director of science outreach and a professor of earth and environmental sciences at Franklin & Marshall College.
According to StateImpact Pennsylvania, a collaboration between NPR affiliates WITF and WHYY, the state’s first fracking-related earthquakes occurred in April 2016 in Lawrence County, northwest of Pittsburgh.
A Texas-based energy company was fracking two wells in the Utica Shale near New Castle when seismic monitors nearby detected five tremors measuring between 1.8 and 2.3 on the Richter scale, the report says.
Pennsylvania is the second-largest producer of natural gas in the country, behind Texas, according to NPR.
Scharnberger said there are no natural gas reserves in the Lancaster region.
As a result of the quakes, the state Department of Environmental Protection set up a “stop-light” procedure to halt fracking operations if there’s a quake greater than 2.0 on the Richter scale or three successive quakes between 1.5 and 1.9.
Although the Lancaster region does have earthquakes, the professors said fracking-related tremors won’t have any impact here.
“They’re highly localized, and very tiny,” Bechtel said. “And they’re plenty far enough from the Lancaster seismic zone.”
“I hate to make a 100 percent certain statement, but it’s very unlikely that something that’s going on in the natural gas fracking region will be felt here,” Scharnberger added.
However, Scharnberger said, the fact that the earthquakes are occurring at all is “fairly significant.”
Quakes in other states were caused by wastewater disposal, not fracking itself, officials noted.
The process — deep-injection disposal of fracking wastewater — has caused some “serious earthquakes, damaging earthquakes” in other states, Bechtel said.
The fracking industry may have to revise its standards on well depths and underground pressure to reduce the potential for further quakes, Scharnberger noted.
But Pennsylvania frackers don’t use that method of wastewater disposal, he noted. “They’re treating it and disposing of it in surface streams.”
Confirmation of fracking-related earthquakes in Pennsylvania comes as “no surprise,” Bechtel said.
“It just makes sense,” he said. “Fracking creates micro-earthquakes. And nothing ever happens in nature without happening in a spectrum.”
A person standing at ground zero is unlikely to know an earthquake is occurring, Bechtel said. “But they’re definitely happening.”
The earth is an active place, he said, and “these micro-earthquakes are occurring all around the world, all the time. ... Fracking adds to a constant background of tiny little earthquakes.”
Consequently, the report doesn’t concern Bechtel, although he said scientists should keep an eye on the consequences of fracking, from earthquakes to wastewater and gaseous emissions.
“You have to weigh the benefits of having natural gas,” Scharnberger added, “which I think is a beneficial source of energy, cleaner than oil or coal — although not as clean as solar or wind — against the impact. Everything has its positives and negatives.”