By Steven Mufson
Washington Post Staff Writer
Thursday, December 3, 2009
Oil and gas companies have figured out how to turn shale rock into natural gas gushers, but they have also hit a deep well of anxiety about the environmental impact of drilling in some of the country's most scenic areas.
The debate revolves around a technique known as hydraulic fracturing, which unlocks natural gas by shattering shale rock with high-pressure blasts of water, chemicals and sand.
Starting up a well requires 3 million to 7 million gallons of water. Drillers mix in chemicals that environmentalists say can imperil rivers and springs. Critics say natural gas can seep into drinking supplies, too.
Large volumes of water, containing leftover chemicals and mineral waste, return to the surface once a well is complete; that water requires safe disposal or treatment. Residents fear accidents, even if firms take precautions such as using steel tanks.
Cabot Oil & Gas has been mired in two disputes. Earlier this year, residents of the Dimock, Pa., area reported evidence of natural gas in their water supplies. Inspectors from the state's Department of Environmental Protection discovered that the casings on some of Cabot's gas wells were cemented improperly, allowing contamination.
On Sept. 16, Cabot's contractors, Baker and Halliburton, spilled 7,980 gallons of fluids in Dimock. Cabot said that it included only 0.5 percent chemical lubricating "gel" and that the mixture was "not hazardous or dangerous." But the DEP suspended the company's drilling activities.
Gas exploration companies say that proper drilling techniques seal off wells with concrete and that the shale layer is a mile or more below drinking-water aquifers, providing protection. Moreover, they assert, the water pumped underground contains only a tiny percentage of chemicals. Once the rock is fractured, no further water is needed. Larry Nichols, chief executive of Devon Energy, said the water needed to "frac" a well equals what's needed to water a golf course or fill three Olympic swimming pools.
What chemicals are used isn't clear. In 2005, Congress exempted chemicals used in hydraulic fracturing from the Safe Drinking Water Act and said firms need not disclose the chemicals, which are often viewed as trade secrets. This is widely known as the "Halliburton loophole," after the company whose former chief executive, Dick Cheney, was then vice president.
The Endocrine Disruption Exchange, a nonprofit group run by Florida public health advocate Theo Colborn, has identified 344 hazardous chemicals used in fracturing, including 2-butoxyethanol and formaldehyde. Sen. Robert P. Casey Jr. (D-Pa.) and three House members have introduced bills that would repeal the exemption.
"The environmentalists have come out with long chemical names, but most are in baking soda and things we have around our houses," Nichols said.
Some companies are voluntarily disclosing the chemicals they use. "We as an industry need to demystify [hydraulic fracturing]," Chesapeake Energy chief executive Aubrey McClendon told a conference, according to Reuters.
Oilfield services giant Schlumberger said it is developing "green" fracturing fluids. Range Resources said it has figured out how to recycle 100 percent of the waste water from drilling.
Many environmentalists aren't satisfied. "While toxic chemicals may be found in commonly used household products, they should not be in a home's drinking water," said a report by Environment America. The group's legislative director, Anna Aurilio, said, "Natural gas might be a little cleaner than coal, but drinking water is precious to us."