18 February 2012
VANCOUVER—Resistance to hydraulic fracturing in the U.S. has risen steadily in recent months. Citizens and politicians are worried that fracking deep shales to extract natural gas can contaminate groundwater, trigger earthquakes and release methane, the potent greenhouse gas, into the atmosphere. But a panel of experts not tied to industry told a large audience at the American Association for the Advancement of Science annual meeting here yesterday that the primary concerns can be solved if drilling and gas companies would impose tougher controls on their own operations, and if regulators would stiffen safety rules and crack down on violators who break them.
That realistic but optimistic tone arose primarily from conclusions made in a new study released a day earlier by the Energy Institute at the University of Texas, Austin. The study of shale drilling and gas extraction in Texas and Pennsylvania determined that three basic operations at the surface of wells have the greatest potential to taint drinking water with chemicals or methane. “We did not find that fracking the shale itself was likely to contaminate groundwater,” said Chip Groat, a geologist and professor of geoscience at the university who led the study. “We did find contamination from surface spills and leaks” at the top of the well.
The main culprits were above-ground spills of chemicals used in fracking; poor installation of metal casings and concrete in the top of the well that are supposed to prevent chemicals sent down the bore hole that later come back up, as well as the methane itself, from leaking; and sloppy handling of that “flowback” water plus other wastewater when it is transferred and stored in open pits or closed tanks.
Several concrete steps (pun intended) could clean up this act, according to David Layzell, head of the University of Calgary’s Institute of Energy, Environment and Economics.
- Impose tougher regulations on how wells are constructed, and increase inspections and penalties when it’s done badly, to prevent leaks.
- Clean and recycle the wastewater so it can be used again, instead of dumping it into ponds, which can leak, or injecting it back down into deep rock formations under high pressure for permanent storage, which has been linked to earthquakes.
- Require well operators to capture methane that now escapes from the top of the well into the atmosphere, which Layzell estimated at 4.0 to 7.5 percent of the gas that flows back up the well.
Groat added that industry and regulators must show that “these curable issues can get cured,” in order to build public confidence that fracking can be done cleanly and safely. “I would think the gas industry, in its own self-interest, would want to do that,” Groat said.
Layzell also called for more basic research, so industry and the public have a much more exact picture of how fracking changes the environment. “How much methane is already in groundwater” before fracking begins?” he asked. “How much methane is actually leaked at the well head? There is a crying need for better baseline data.” The panel agreed that the science of fracking lags behind the spread of the technology—and that it’s high time to catch up.