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No conclusive link between hydraulic fracturing and water contamination -- EPA
APRIL REESE, LAND LETTER 7/15/04
The injection of hydraulic fracturing fluids into coalbed methane wells poses little threat to underground drinking water sources, according to a recent report by the U.S. EPA.
The EPA analysis, released in late June, examined about 200 peer-reviewed studies and state documents, covering the nation's 11 major coal basins, including the three biggest CBM-producing regions: the Powder River Basin in Wyoming and Montana, the San Juan Basin in Colorado and New Mexico, and the Black Warrior Basin in Alabama. Researchers also spoke with state energy officials and landowners who have complained of water contamination from CBM operations.
Map courtesy of the U.S. EPA.
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Taken collectively, the documents and interviews do not provide strong evidence of a link between hydraulic fracturing and pollution of underground drinking water supplies, the agency concluded. "Although thousands of CBM wells are fractured annually, EPA did not find confirmed evidence that drinking water wells have been contaminated by hydraulic fracturing fluid injection into CBM wells," the report said.
Hydraulic fracturing, which involves injecting a mixture of water and other fluids into a well at high pressure to crack the rock, is used to increase the flow of oil and gas to production wells. The process allows energy companies to extract hydrocarbons that would not be accessible using conventional drilling techniques.
Among the documents EPA examined for the study was a 1998 survey of state oil and gas boards by the Ground Water Protection Council, a nonprofit group whose members include federal and state agencies. The council found that, in general, hydraulic fracturing of CBM wells has not resulted in groundwater contamination.
Colorado, a hot-bed for coalbed methane development, has investigated several complaints about contamination and found nothing to merit concern, said Morris Bell, a spokesman for the Colorado Oil and Gas Conservation Commission. "We haven't found any evidence that hydraulic fracturing is causing any problems with water wells," he said.
But Kevin Williams of the Western Organization of Resource Councils, a network of environmental groups in seven Western states, said EPA should have conducted its own investigation instead of relying on existing studies done by other agencies. "It seems to me that if they're not going to take the time to go out and do some independent testing in these areas, I think it's a stretch for them to say there's no link," he said.
The effects of CBM development are of increasing concern to private landowners and environmental groups as production increases. According to EPA, CBM production in 13 states skyrocketed to 1.353 trillion cubic feet in 2000 -- a 156 percent increase over eight years. The Energy Department estimates that natural gas demand is likely to rise at least 45 percent in the next 20 years, with coalbed methane meeting much of that demand.
The EPA study was conducted partly in response to a court decision that essentially made hydraulic fracturing an EPA issue. The 11th U.S. Circuit Court of Appeals concluded in 1997 that hydraulic fracturing operations in Alabama fit the Safe Drinking Water Act's definition of underground injection. Previously, EPA had argued that regulating hydraulic fracturing was beyond its purview because the practice was not addressed under the SDWA.
In some cases, diesel and other substances are injected directly into aquifers during fracturing operations. EPA notes in the report that the use of diesel fuel in fracturing fluids introduces benzene, toluene, ethylbenzene and xylenes -- substances that are regulated under the SDWA -- into underground drinking water sources.
"Much of the concern stems from the contaminants in diesel regulated under the Safe Drinking Water Act," said EPA spokeswoman Kathy Milbourn. "But we don't have the authority to directly prohibit the use of diesel as a fracturing fluid."
Instead, the biggest CBM producers have agreed to voluntarily stop using diesel in fracturing operations.
Williams and other critics contend that voluntary measures are not enough.
"We're putting potentially nasty chemicals into underground drinking water supplies," Williams said. "Wouldn't it be better to take a more precautionary approach from the beginning?"
Milbourn said most of the injected fluids biodegrade or stay put, making it unlikely that they would migrate into aquifers and drinking water wells.
EPA officials acknowledged that fracturing could be linked to the draining of aquifers but emphasized that the focus of the study was on the potential for contamination of drinking water sources.
EPA could conduct additional studies of the effects of hydraulic fracturing if necessary, the agency said.
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