Study: Gas leaks from fracking sites fewer than thought
- Article by: Jim Efstathiou Jr. and Mark Drajem
- Bloomberg News
- September 16, 2013 - 8:52 PM
WASHINGTON – Natural gas leaks from production wells are lower than previous estimates and below the level that would erase the fuel’s climate benefit over coal, according to a University of Texas study backed by both industry and environmentalists.
The study released Monday, the first to use actual measurements of emissions, found that 0.42 percent of natural gas produced in the United States is released into the atmosphere. A 2010 Cornell University study using data provided by drillers estimated leakage at 0.6 to 3.2 percent.
“The question was, as we bring more natural gas on board, what are the methane emissions, and are they so high that we’re creating a problem for the climate,” said Steven Hamburg, chief scientist at the Environmental Defense Fund. “No process is going to be 100 percent tight.”
When it’s burned, natural gas emits about half the carbon dioxide, the main greenhouse gas, as coal. If too much methane escapes, the environmental benefit is lost.
Methane, the main component of natural gas, is 21 times more potent at trapping heat in the atmosphere than carbon dioxide, according to the Environmental Protection Agency. A boom in U.S. natural gas supplies brought on by hydraulic fracturing has opened a debate over whether expanding the use of gas sets back efforts to fight climate change.
The University of Texas worked with the Environmental Defense Fund and nine gas producers on the report. Over the course of a year, researchers took direct measurements at 190 well sites in the Gulf Coast, Great Plains, Rocky Mountain and Appalachian regions.
Wenonah Hauter, executive director of Food & Water Watch, a Washington-based environmental group, said too few wells were part of the study to “draw meaningful conclusions.” Companies that allowed methane measurements at their wells were likely to have removed any sources of leaks before researchers arrived, she said. “This industry-sponsored ‘study’ is more spin than science,” Hauter said.
Emissions lost in processing and delivering gas weren’t counted. The University of Texas is conducting studies to measure leakage at those points in the process.
The university found leakage at the initial stage of tapping a well when drilling fluids and sand used in hydraulic fracturing, or fracking, returns to the surface was less than found by the EPA. Leakage from equipment at the well pad, such as pumps and valves, was higher in the university study.
There are no emissions-control regulations for valves or connectors commonly found at oil or gas wells, according to the Environmental Defense Fund.
The EPA in 2012 issued the first rules to fight air pollution from gas drilling. The regulations, which take effect in 2015, require operators to use a technology in which escaping gas is captured. The rules will primarily affect the estimated 13,000 wells a year drilled by fracking to free gas trapped in shale formations.
© 2013 Star Tribune