PITTSBURGH (AP) — Seven Northeastern and mid-Atlantic states announced plans Tuesday to sue the Environmental Protection Agency, saying it is violating the Clean Air Act by failing to address methane emissions from oil and gas drilling, which has boomed in nearby states such as Pennsylvania and West Virginia.

New York Attorney General Eric T. Schneiderman said in a news release Tuesday that the EPA is violating the Clean Air Act by failing to address the emissions. Methane is a potent greenhouse gas, and the oil and gas industry is the largest source of emissions in this country. Other major sources come from landfills and livestock.