But whether the leakage around the San Juan Basin is the result of energy-industry activities or the result of a natural occurrence is a topic of debate.
There is evidence to suggest the hot spot largely is naturally occurring. That evidence is backed up by studies from Taku Ide, founder and chief executive of Koveva, Ltd., which specializes in ways to capture fugitive methane.
Ide made his findings after studying underground coal fires. While they pose a threat to the environment and the health of those living in its proximity, they largely are naturally occurring, though they can be human-caused.
Fugitive methane is methane that freely is escaping to the atmosphere from both natural settings and as a result of human activities.
Reports to the Colorado Oil and Gas Conservation Commission support natural occurrences that are decreasing.
A report in September 2013 on the Fruitland outcrop in La Plata County, prepared by LT Environmental Inc., an Arvada-based environmental and engineering firm, found that the total reportable methane release in 2013 was estimated to be 30 percent less than the 2012 results.
The Fruitland Formation of the San Juan Basin is the second-largest gas-producing basin in the United States. It covers portions of northern New Mexico and Southwest Colorado. The geologic formation itself is responsible for natural seepage.
But there is uncertainty about how coalbed methane production from the Fruitland outcrop may affect the environment. Coalbed methane is gas that lines cracks and pores within coal.
Reports of widespread vegetation dying off has been rampant in the region, though some of that vegetation appears to be coming back.
A report from August by LT Environmental Inc., for the COGCC, revealed that plant growth in La Plata has occurred in areas previously devoid of vegetative growth.
Christi Zeller, executive director of the La Plata County Energy Council, pointed out that the NASA study is a bit outdated. The years studied were from 2003 to 2009, before the state enacted methane standards and before energy producers in the area began using new capturing and detection technologies.
"Before concluding the high ambient methane concentrations in the Four Corners area are due solely or largely to fugitive leaks from coalbed methane production, the Energy Council believes these other sources of methane should be accounted for, and the data from NASA from 2003-2009 is not recognizing mitigation that is occurring on the outcrop seeps," Zeller said.
The hot spot reported by NASA, along with researchers at the University of Michigan, covers about 2,500 square miles. Researchers used satellite data to compile the study.
The report suggested that methane emissions should not be attributed to hydraulic fracturing but instead to leaks in natural gas production.
"The problem is that we can't ignore that we've had this natural methane seepage here that's being partially mitigated, and then (the NASA report) doesn't account for why is the Four Corners the only hot spot," Zeller said.
"If it has to do with any sort of well count, then we should be seeing this in Weld County," she said.
Weld County is one area in northwest Colorado that has heavy oil and gas production, as well as cattle feedlots, which emit methane.
