James Fenton

The (Farmington, N.M.) Daily Times

FARMINGTON, N.M. — Scientists Monday attributed most of the methane emissions contributing to a "hot spot" the size of Delaware recorded over the Four Corners region almost two years ago to natural gas production equipment and infrastructure.

Using data collected from air and land surveys covering about 1,200 square miles across the region in April 2015, researchers identified more than 250 sources for atmospheric methane, which included natural gas storage tanks, wells, pipelines and processing plants. Those sources released the greenhouse gas at rates ranging from a few pounds to 11,000 pounds per hour, according to the study, which was published Monday in the Proceedings of the National Academy of Sciences.

The hot spot was originally identified in a NASA report that used satellite imagery of the Four Corners, which includes the southwestern corner of Colorado, southeastern corner of Utah, northeastern corner of Arizona, and northwestern corner of New Mexico.

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The study also revealed other minor sources such as methane leaking from a coal mining "venting shaft" and natural seeps underground. Ten percent of the sources in the study were responsible for more than half of recorded emissions, according to the scientists' findings, which was the central point of the report.

A significant contributor to global warming, natural gas is 90% methane, a pollutant more than 80 times more potent than carbon dioxide over a 20-year time period, according to the U.S. Environmental Protection Agency.

Thomas Singer, senior policy adviser with the Western Environmental Law Center, said in a statement on Monday that he would like to see more follow-up studies conducted to pin down more sources.

“Given the over 20,000 (mainly older) wells, myriad storage tanks, thousands of miles of pipelines and several gas processing plants in the area, the finding that the oil and gas industry is mainly responsible for the hot spot isn’t surprising," Singer said. "Solving the problem will require the oil and gas industry to cut emissions from all sources, large and small. EPA and (Bureau of Land Management's) common sense oil and gas methane pollution standards currently in the works will go a long way to achieving this goal. New Mexicans should voice their strong support now to get these standards finalized.”

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According to a 2015 ICF International report, oil and gas production in New Mexico vented, flared or leaked a potential $100 million worth of gas into the atmosphere in 2013.

Wally Drangmeister of the New Mexico Oil and Gas Association said the study was limited and the region undeserving of the inflammatory "hot spot" label. Drangmeister also said that natural gas is far more environmentally friendly than coal as an energy source. He said the oil and gas industry has reduced emissions 15% since 1990 as production has increased nationally by more than 50%. He attributed those advances to the replacement of "high-bleed" with "low-bleed" pneumatics, which limit the amount of methane released during production, and other "green" retrofitting of well-site equipment.

"As an industry, we're not saying this is not an area for science and study, but the issue is that many groups exploit study findings like these unfairly," he said.

He also questioned the study's ability to accurately document methane sources given the temporal nature of when and for how long potential sources were recorded.

Lead author Christian Frankenberg of NASA's Jet Propulsion Laboratory and Caltech said in an email Monday that the report acknowledges the "snapshot effect." If possible, he said he would conduct separate study campaigns multiple times each year to more clearly delineate plume sources from anomalies.

"Ideally, we would have an observational system with similar capability in space," Frankenberg said. "Most of the area was indeed sampled just once using our initial aerial survey, thus providing a single snapshot in time. However, some of the sources have been sampled with multiple repeat overpasses, in many cases finding consistent patterns and dual detections."

Frankenberg added that the limited number of types of sources is the good news.

"The main point of our paper is the fact that a few sources contribute most to the total flux and that this can help industry to more efficiently curb methane emissions," he said.

Follow James Fenton on Twitter: @fentondt