The San Juan Basin operations were ranked as the second-most prolific greenhouse-gas polluter in the nation among onshore oil and gas systems. The company's basin operations pumped out 5.57 million metric tons of "carbon-dioxide equivalent" in 2011, the EPA reported.
Natural gas has been promoted as the answer for many of the nation's energy challenges, and as a cleaner-burning alternative to coal. And President Obama has gotten behind the natural gas revolution, backing the fuel in his last two State of the Union addresses.
On Tuesday, Obama said, "the natural-gas boom has led to cleaner power and greater energy independence. We need to encourage that. And that's why my administration will keep cutting red tape and speeding up new oil and gas permits."
Much of the environmental concern regarding hydraulic fracturing has focused on the potential for water contamination, which has largely proved unfounded in the San Juan Basin. The EPA data released last week highlights another byproduct of the drilling process — airborne emissions that contribute to global warming.
The EPA for the first time included oil-and-gas emissions in its annual report, and critics say that needs to be taken into account.
"This is a wake-up call that it's a pretty significant source of emissions," said Mike Eisenfeld, New Mexico energy coordinator for the environmental group San Juan Citizens Alliance.
A ConocoPhillips spokesman, Jim Lowry, said the company's emissions are in line with its presence in the basin. The company has more than 10,000 operating wells and 1.3 million net acres leased in the basin.
"Our emissions volume reflects the sheer size of our operation," Lowry said.
Lowry said ConocoPhillips is "working to improve our environmental performance in San Juan."
Since 2007, all ConocoPhillips wells in the basin have used "green completions," which minimize the release of methane and other gases when wells are finished. Last year, the EPA made the practice mandatory.
ConocoPhillips also participates in the EPA's Natural Gas STAR program, a voluntary initiative to improve efficiency and reduce emissions. Locally, the company is working to install cleaner equipment like low-bleed pneumatic devices and solar pumps on wells, Lowry said.
ConocoPhillips wasn't the only local producer that ranked among the nation's top oil-and-gas industry carbon emitters.
XTO Energy's basin operations ranked 13th, emitting 947,729 metric tons of carbon dioxide in 2011. The top oil and gas onshore emitter was in the Arkoma Basin, based in Houston, with 6.19 million metric tons of reported emissions.
Also in the San Juan Basin, Energen Resources, Dugan Production Corp., Black Hills Exploration and Production, McElvain Energy and Coleman Oil and Gas Inc. also made the list as significant polluters.
The EPA's data included combustion, venting, leakage and flaring emissions.
"The bottom line is that some of these larger natural-gas facilities do have some pretty significant emissions, and it needs to be brought into the equation when planning the energy for our future," said Eisenfeld.
Power plants remained the largest source of greenhouse gas emissions, producing about ten times that of the oil-and-gas industry.
Four Corners Power Plant in Fruitland, west of Farmington, was the 21st-highest emitter in the U.S., producing 13.2 million metric tons of carbon dioxide equivalent pollution.
Plant operator Arizona Public Service Co. is planning to decommission three of the plant's five units later this year. The utility says the move will dramatically reduce emissions from the plant.