The U.S. EPA has come under fire for a draft report claiming that injection of hydraulic fracturing fluids into coal bed methane formations does not threaten drinking water and that no further study is needed. Critics charge that the agency misrepresented the study’s results and altered, misused or ignored data. If the report becomes final, it would support efforts to exempt hydraulic fracturing from regulation under proposed congressional legislation.

The report, on which comments were due October 28, is a response to a 1997 decision by the 11th U.S. Circuit Court requiring the state of Alabama to regulate hydraulic fracturing. Industry groups are concerned that EPA will expand the Alabama decision to require the regulation of hydraulic fracturing in other states, according to the American Association of Petroleum Geologists.

From 1992 to 2000, coal bed methane production from 13 states has increased 156% to a total of 1,379 trillion cubic feet per year, according to the EPA report. Production is expected to grow in concert with a predicted 45% increase in demand for natural gas over the next 20 years.

Hydraulic fracturing is a technology for recovering methane gas by forcing a gelatinous mixture of water, sand, and additives into coal formations at high pressure. The mixture creates fractures that allow the gas to flow toward the well. Although the fracturing fluid consists almost entirely of water, additives designed to improve performance can include chemicals such as benzene, toluene, and MTBE, most of which derive from the use of diesel fuel as an additive, the report says. EPA found that 10 of the 11 coal bed methane basins it studied lie within underground sources of drinking water and have nearly 14,000 producing wells, creating the potential for contamination by fracturing fluids.

EPA evaluated the potential for contamination by estimating the likelihood that fracturing fluids, ranging from 50,000 to 350,000 gallons, could migrate within a coal bed that was also an aquifer. On the basis of a literature review, 25–61% of the fracturing fluid is recovered when the well is pumped. Assuming that 60% of fluid is recovered and that fractures are 1500 feet long and 200 feet high, the report estimated that contaminant concentrations at the edge of the fracture zone would be roughly 30 times lower than the injected levels, driving most pollutant levels below groundwater standards.

The dilution factor of 30 is not realistic, and the report does not provide any justification for it, says a hydrologist with the U.S. Geological Survey. Assuming that only 20–30% of the fracturing fluids remain in the formation and the fluids include diesel fuel, the aquifer would be destroyed because the diesel will remain as a contaminant for generations, he adds.

Even with a dilution factor of 30, the report’s methodology predicts a host of pollutants still violate groundwater standards, says Steve Gurney, geologist with the environmental group Natural Resources Defense Council. At the edge of the fracture zone, the concentration of benzene is twice its maximum contaminant level (MCL), and the concentrations of other aromatic compounds from the diesel fuel are as much as 95 times higher than their MCLs, he says.

Norm Warpinski, senior scientist at Sandia National Laboratories and a member of EPA’s peer review panel for the report, counters that the agency’s estimates of pollutant concentrations at the edge of the fracture zone are probably too high. “Over the lifetime of a well, the large majority of contaminants are probably recovered,” he says. Because companies pump vast amounts of water from the wells, any mobile pollutant will probably be drawn out through the well. Companies only measure recovery of fracturing fluids for short periods of three to seven days after injection. In addition, the study used outdated models and overestimated the height that fractures can grow, which raises the risk that a fracture carrying contaminated fluid will grow too high and pierce an aquifer overlying the coal bed, Warpinski says.

However, one academic summed up the problems with the report as poor documentation and a lack of answers to whether hydraulic fracturing harms groundwater, in part, because the peer review panel did not include hydrologists. It is clear that the situation requires more study, he argues, including modeling of fracture propagation, analysis of fluid flow to and from fractures, and monitoring of pollutant transport using hydrocarbon fingerprinting.

Congressman Henry Waxman (D-CA) has charged that EPA staff, at a meeting with congressional staff, altered the report’s data in a manner that benefits industry. Waxman is requesting that EPA administrator Christine Todd Whitman provide Congress with a substantive explanation for the alleged changes.

Meanwhile, a section of the energy bill, which is expected to be reintroduced in 2003, would overturn the 1997 federal court decision that requires hydraulic fracturing to be regulated under the Safe Drinking Water Act. —JANET PELLEY