Does fracking for natural gas cause earthquakes?

The technique for liberating natural gas from subterranean shale formations — popularly called fracking — involves pumping water and chemicals into the ground, fracturing the rock below and inducing tiny earthquakes, unfelt but detectable directly above.

But seismologists in Ohio have implicated a different part of the process in a series of much more powerful quakes that recently shook Youngstown: disposing of the leftover “waste water” by pumping it underground, in different geological conditions. Ohio officials shut down suspect waste-water wells following a 4.0 quake on New Year’s Eve. Arkansas regulators did the same after earthquakes there. Some environmentalists, meanwhile, are using these quakes as the latest evidence that fracking is too dangerous.

Yet fracking in America’s massive Marcellus Shale formation could provide a large, domestic source of energy with fewer harmful emissions and half of coal’s carbon output. Fuel switching could produce carbon savings that would give cleaner sources of energy more time to become affordable. It would also provide jobs: Ohio steel mills are producing heavy-duty pipe for fracking operations. And Ohio has geological formations suitable for waste-water disposal. The state has already permitted 194 disposal wells.

Inevitably, extracting unconventional natural gas will have unexpected and possibly unattractive consequences. The business is scaling up so quickly that state and federal regulators are only now catching up. More study and probably more regulation will be needed.

Fracking will produce waste water, but energy companies can dispose of it more carefully. Reuters reports that one idea — requiring a full seismic study of disposal sites before pumping waste water into them — is extremely expensive. But regulators might not need to go that far; the U.S. Geological Survey’s Arthur McGarr points out that, of the 144,000 storage wells of this type in America, only a tiny fraction have been linked to earthquakes. Mr. McGarr suggests seismic monitoring at active well sites, so that operators can shut down operations at the first sign of trouble, and storing waste water farther from population centers. Lowering water pressure in wells could help. Waste-water treatment techniques could also improve, making underground storage unnecessary and reducing fears of drinking-water contamination.

Washington Post