Whether EPA's disapproval action is subject to review only in the D.C. Circuit under 42 U.S.C. 7607(b)(1), which channels to that court petitions to review EPA final actions that are 'nationally applicable' or are 'based on a determination of nationwide scope or effect'

The United States Environmental Protection Agency (EPA) took a final action under the Clean Air Act, 42 U.S.C. 7401 et seq ., to disapprove 21 States’ plans for implementing national ozone standards. EPA determined that those state plans would not adequately “prohibit[] * * * emissions activity within the State” from “ contribut[ing] significantly to nonattainment in, or interfer[ing] with maintenance by, any other State” of national ambient air quality standards. 42 U.S.C. The quest ion presented is as follows: Whether EPA’s disapproval action is subject to review only in the D.C. Circuit under 42 U.S.C. 7607(b)(1), which channels to that court petitions to review EPA final actions that are “nationally applicable” or are “based on a determination of nationwide scope or effect.” (II)