The US Environmental Protection Agency faces challenges to facts it has offered to support a crackdown on air pollution from oil and gas wells. Producers and at least one research group think EPA is rushing to respond with regulation to an environmental problem it magnifies with flawed data. The pattern is familiar. This is the agency that came under criticism from its inspector general in September for cutting corners in technical documents underlying the monumental decision in 2009 to regulate greenhouse gases under the Clean Air Act.
At issue now is EPA's July proposal for new air pollution standards for oil and gas activities. The proposal directly targets volatile organic compounds, which are precursors to ground-level ozone, sulfur dioxide, and air toxics. But EPA argued for the new regulations strongly on the basis of reduced emissions of methane, a greenhouse gas, during completion of hydraulically fractured wells. Under the proposed rules, producers would have to capture and sell produced methane as soon as possible or flare it. They also would face new reporting requirements.
Overestimated releases
EPA says the regulations would cut industry-wide methane emissions by 26%/year. Because methane's potency as a greenhouse gas is 21-25 times that of carbon dioxide, the promise of so large a cut is compelling. But critics say it's illusory because EPA has greatly overestimated amounts of methane released during and after hydraulic fracturing.
In an August report, the research firm IHS CERA faulted EPA procedures that hiked methane-emissions estimates from 0.02 tonne/well in an earlier study to 0.71 tonne/conventional well and 177 tonnes/unconventional well. The report, by IHS CERA Directors Mary Lashley Barcella, Samantha Gross, and Surya Rajan, said EPA overestimated emissions from unconventional completions in part by relying on data about methane intentionally captured rather than accidentally released into the atmosphere. It also questioned EPA's assumption, in calculating that an average 9,175 Mcf of methane is emitted per unconventional well completion, that 49% of gas is vented and 51% flared. Those estimates, the report said, incorrectly assume producers don't flare gas unless required to do so.
Furthermore, most methane releases of hydraulically fractured wells occur during flowback, when fluid returns to the surface after injection. An average release as large as EPA estimates so early in a well's life "does not pass a basic test of reasonableness," the report said. "Methane emissions of 9,175 Mcf/well, if vented during a few days of well completion procedures, would create a toxic and hazardous environment around the well site. That serious accidents are rare in gas plays suggests that upstream emissions do not regularly rise to such dangerous levels."
The apparent overestimation is egregious. After IHS CERA published its study, Devon Energy Corp. analyzed data from its wells in 10 basins across the US. The Oklahoma City firm, an active developer of unconventional oil and gas resources, calculated that its 2011 methane emissions represent less than 7% of what EPA estimated. Devon has called on EPA to revert to its earlier methods and estimates for methane emissions from hydraulic fracturing. In October, the effort broadened when Oklahoma Atty. Gen. E. Scott Pruitt wrote EPA Administrator Lisa Jackson citing the problems reported by IHS CERA and seeking explanations of EPA's estimates and methods.
Adding to fear
By itself, adoption of what EPA proposes would not devastate hydraulic fracturing. The IHS CERA report said most producers already adhere to the proposed standards, whatever local authorities require. "Common industry practice is to capture gas for sale as soon as it is technically feasible," it said. "Gas that cannot be sold is generally flared rather than vented for safety reasons."
If EPA's numbers about methane remain unchallenged, though, or if EPA brushes aside questions about the factual basis of its initiative, global warming will join water contamination in propaganda against hydraulic fracturing. And a new element of unfounded fear will strengthen political resistance to the most important energy-supply development in recent US history.
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