Texas methane leaks raise new questions
Environmental group’s studies say previous estimates are way low for releases of greenhouse gas
Some natural gas operations in the Barnett Shale leaked more methane than previously thought, underscoring the need for better and more frequent monitoring and repair of equipment, new studies by the Environmental Defense Fund have found.
In a package of 11 studies released this week, researchers with the nonprofit group found that natural gas activity in the Barnett region may produce nearly 50 percent more methane than the U.S. Environmental Protection Agency indicated in previous estimates.
“The good news is that there are many costeffective ways to find and fix high-emitting sources,” the group’s chief scientist, Steve Hamburg, wrote in a blog post. “The bad news is, as easy and affordable as these solutions are, many companies simply are not using them. As long as they remain optional, it’s likely to stay that way.”
The oil and gas industry has trumpeted natural gas as a cleaner alternative to oil and coal, but environmental groups have grown increasingly worried about methane leaks associated with its production, transmission and processing. Natural gas is composed primarily of methane, a potent greenhouse gas.
In one of the studies, University of Houston researchers spent two weeks in October 2013 taking air samples from 152 sites near Fort Worth, including a dozen landfills, which naturally leak methane, as well as public roads near natural gas well pads, compressor
stations and processing plants.
The majority of the places researchers tested showed low emission rates for methane, but at 15 sites, the emission rates were vastly higher, raising questions about whether methane leaks undercut the climate advantages of cleaner-burning natural gas versus coal or oil.
“Nobody had any idea how much methane was being leaked in the Barnett area,” said Robert Talbot, a UH atmospheric chemistry professor who authored the paper.
Researchers weren’t allowed on-site, so they couldn’t pinpoint with certainty where the leaks originated, Talbot said, but they did find that air near compressor stations and processing plants had “considerably higher” releases than well pads, UH findings show.
Workers were at times at fault for causing problems by failing to fix broken valves or leaving hatches propped open, a situation made worse because some sites were left unattended for weeks, Talbot said.
“Methane is an important and strong greenhouse gas,” he said. “It is contributing to global warming. The industry needs to conduct better maintenance on these facilities.”
The industry says it is already working to tackle methane leaks with investments in new technologies aimed at curbing emissions.
The newly released study proves that a majorty of Barnett Shale operations had exceedingly low emissions, well below the point where natural gas loses its climate advantages, said Steve Everley, spokesman for Energy in Depth, which is backed by the Independent Petroleum Association of America, a trade group.
“While some people may try to emphasize the few examples of high emissions, no doubt as part of a push for even more EPA regulations, the ‘high emission’ sites were clearly the exception rather than the rule,” he said in an email.