9th Circuit upholds EPA approval of Montana's Clean Air Act implementation plan
Tuesday, September 4, 2018
Posted by: Joe Menden
A three-judge appeals court panel last week denied a Montana environmental group's challenge of a revision to Montana's federal Clean Air Act implementation plan.
Montana Environmental Information Center alleged that the U.S. Environmental Protection Agency's approval Montana’s plan was arbitrary and capricious because the Montana Department of Environmental Quality interpreted "actual emissions" less stringently than the Clean Air Act allows.
The panel ruled that it was appropriate to give deference to the EPA’s reasonable interpretation of ambiguous text in the 1994 revised implementation plan. Since EPA's interpretation controlled, its approval of the succeeding 2015 implementation plan was not arbitrary or capricious.