"Study: Bakken Oil Field Leaks 275,000 Tons Of Methane Yearly"

"BISMARCK, N.D. -- The oil-producing region of North Dakota and Montana leaks 275,000 tons of methane annually, a significant amount of the greenhouse gas but less than previously believed, a study released Wednesday said.

The data, collected in two years ago by an airplane over the heart of western North Dakota's oil patch, was the first field study of methane emissions done in the Bakken shale formation that spans western North Dakota and eastern Montana, said Jeff Peischl, the study's lead author from the Cooperative Institute for Research in Environmental Sciences at the University of Colorado in Boulder.

After carbon dioxide, methane, the primary component of natural gas, is the second-most prevalent greenhouse gas emitted from the U.S. and the majority of such emissions come from natural gas and petroleum systems, the Environmental Protection Agency has said."

James MacPherson reports for the Associated Press May 11, 2016.