NEW CASTLE, Pa. (KDKA/AP) – The state Department of Environmental Protection is investigating whether fracking contributed to two small earthquakes near a western Pennsylvania drilling operation.

DEP spokeswoman Melanie Williams says Hilcorp Energy Co. stopped fracking at the Mahoning Township site at about noon Monday. That was about 12 hours after the U.S. Geological Survey recorded an earthquake and about 10 hours before another quake was recorded.

The Hilcorp Energy Company has ceased its fracking operations in Lawrence County ever since two small earthquakes struck on Monday. It’s not clear if fracking caused the quakes, but the Pennsylvania Department of Environmental Protection wants to know for sure.

“We are paying very close attention to the issue in Lawrence County. It is a big concern to us,” said DEP Secretary John Quigley. “We are going to do everything we can to ensure that we are protecting the public.

The issue has become serious enough that the DEP has set up a statewide seismic monitoring network to measure earthquake activity around the state.

Even so, this week’s quakes were small, a 2.4 magnitude. They couldn’t even be felt.

“It was, all things considered, small in magnitude. But any movement of earth that is man-caused is an issue of concern for the agency,” said Quigley.

Fracking appears to be here to stay. The DEP says its priority is to make it safer with tougher regulations. Now they plan to start screening seismic conditions before issuing fracking permits.

“Fracking causing an earthquake is a rare event,” Quigley said. “Its only happened a handful of times, actually worldwide, that we know of.”

The DEP plans to release its findings on the Lawrence County quakes in a few weeks.

KDKA contacted Hilcorp Corporate Headquarters in Houston, Texas. So far they haven’t returned those phone calls.

There were no reports of property damage.

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