It is perhaps the largest source of methane release in the United States and accounts for about a tenth of the annual gas industry amount.
[1][2][5] The San Juan Basin contains the Fruitland coal formation.
Ashley Ager, a geologist with LT Environmental, Inc., a company with oil and gas industry contracts, has argued that the leak is naturally occurring due to this formation contacting the surface.
[6] However, NASA researchers concluded in 2016 that oil and gas production and distribution activities were principally responsible for the methane releases.
[7] The Four Corners area includes other methane sources such as seepage from coal mines, but researchers found these sources too small to explain the bulk of the observed emissions.