The Ninth Circuit denied an environmental group's petition to review EPA's approval of a Montana SIP revision. The group argued that the approval was arbitrary and capricious because Montana's Department of Environmental Quality interpreted one of the SIP's provisions less stringently than the CAA a...

The D.C. Circuit vacated EPA's rule delaying the 2017 Chemical Disaster Rule, which established safety standards for chemical facilities. The Agency argued that it had authority under CAA §112 to delay the effective date of the Rule beyond the ninety-day limit set forth in CAA §307 because ninety ...