NATURAL GAS:

Man-made earthquakes -- should there be a law?

It's not illegal to cause an earthquake.

You can't contaminate groundwater, pollute the air or poison endangered species. But federal environmental laws impose no penalty for setting off a seismic rupture that collapses chimneys or buckles roads.

Still, when humans make the ground shake with activities tied to oil and gas drilling, or by injecting a power plant's carbon dioxide emissions underground, it tends to make the neighbors antsy. And a study issued late last week by the National Research Council says that industry and regulators could be doing more to prevent earthquakes (Greenwire, June 15).

"All of them should be talking together and coordinating," said Murray Hitzman, the Colorado School of Mines professor who chaired the study on man-made earthquakes for the council, which part of the National Academies. For example, they could check for fault lines before pumping toxic waste tied to oil and gas production deep underground.

Underground waste disposal, which the report deems the most likely energy industry activity to cause earthquakes, is regulated under the Underground Injection Control sections of the Safe Drinking Water Act. The regulations that enforce it do have requirements to test some proposed sites to see if wells could cause earthquakes, but they don't apply to wells connected to the nation's expanding onshore oil and gas fields.

The National Research Council did not call for federal mandates, Hitzman was careful to point out.

"That was not within the scope of what the committee was asked to say," he said in a conference call with reporters Friday. "It's up to people in Washington what they want to do with that information."

The committee's suggestions are "best practices," he said, which are usually voluntary for industry. But the report also outlined a "traffic light" approach that could trigger a shutdown of injection wells tied to or near earthquakes.

By raising the issue on a national level, some say the study inevitably invites questions about whether federal regulation might be needed.

"They're very cautious, but there are parts where it indicates this has been successful so far, but it may not work forever," said analyst Kevin Book, managing director of the Washington, D.C.-based consulting firm ClearView Energy Partners. "It seems to lead to a call for some sort of federal intervention."

It is an election year, and talk of federal intervention is politically sensitive. Such sentiments are unlikely to surface Tuesday when the Senate Energy and Natural Resources Committee holds a hearing on the National Research Council report. But that does not mean there isn't some support for more oversight of the U.S. drilling boom.

"It's wrong to say there isn't any will in Washington," Book said. "It just isn't on Capitol Hill."

More wells, more quakes

Many environmentalists do not share President Obama's reluctance to challenge the pre-eminence of state regulation. The Natural Resources Defense Council has petitioned U.S. EPA to end the hazardous-waste exemption for drilling companies, which would have the effect of requiring seismic standards for oil and gas waste injection wells (EnergyWire, March 22).

But even in the absence of federal regulation, the report suggests that in areas susceptible to man-made earthquakes, state officials could add seismic provisions to their permit approvals. Few states have done so, though some have shut down wells after earthquakes.

"The committee suggests that the agency with authority to issue a new injection permit, or the authority to revise an existing injection permit, is the most appropriate agency to oversee decisions made with respect to induced seismic events," the report states. "In many cases this responsibility would fall to state agencies that permit injection wells."

As dramatic as it may sound, it is established science that injecting industrial wastewater underground can lubricate faults and create earthquakes. Hydraulic fracturing and carbon capture and storage also can lead to "induced seismicity." But the small number of quakes linked to fracturing itself have been almost too small to be felt, and there is no carbon storage project large enough to cause a quake.

Fracturing in shale formations requires millions of gallons of water to be forced down wellbores to crack the rock and release gas. Much of that comes back up, as a brine laden with salt and toxins. Drillers dispose of it most commonly in deep underground injection wells. When the fluid is injected into or near a fault, it can lubricate the fault and cause an earthquake.

Such earthquakes are rare, but there are more instances of oil and gas disposal wells causing earthquakes than there are documented cases of water contamination from hydraulic fracturing.

As oil and gas drilling has increased in the past few years, there have been increasing numbers of earthquakes linked to underground injection of oil and gas waste.

"If we have more wells, we have more events. If we have more events, more likelihood of higher-magnitude events," Hitzman explained.

Oil and gas waste disposal has been linked to earthquakes in Arkansas, Colorado, Ohio and Texas. Scientists have linked Oklahoma's largest-ever earthquake, a magnitude-5.6 event in November, to brine injection from drilling. The earthquake injured two people and damaged 14 homes.

State officials have said linking the Oklahoma quake to oil and gas activity is premature, but one seismologist has warned that the state is risking another damaging quake if it continues to allow injection near faults (EnergyWire, April 19).

In need of more basic data

Sen. Jeff Bingaman (D-N.M.), chairman of the Senate Energy and Natural Resources Committee, asked for the National Research Council study two years ago, before many of the most high-profile earthquakes linked to drilling activity.

The study found there is a lack of basic data on how underground formations, faults and liquid interact underground and that more research is needed into the risks of man-made quakes.

The report's checklist proposal starts with the suggestion that regulators -- typically state oil and gas agencies -- evaluate the possibility of an earthquake at sites where companies want to use or drill a well. That is not usually done for wells that receive oil and gas waste. The report also suggests that well operators could install seismic instruments in areas where there have been earthquakes to record the strength and timing of earthquakes.

And its traffic-light protocol suggests that injection could be scaled back if it is tied to earthquakes and could even be stopped if it becomes a broader concern for public health and safety.

"The ultimate success of such a protocol," the report says, "is fundamentally tied to the strength of the collaborative relationships and dialogue among operators, regulators, the research community, and the public."

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