Ohio, et al., Applicants v. Environmental Protection Agency, et al.

The Supreme Court temporarily blocked the Environmental Protection Agency's "Good Neighbor Plan," which aimed to reduce ozone pollution crossing state lines, finding that the agency likely failed to adequately explain why the plan's emissions controls remained reasonable after several states were removed from coverage. The Court ruled that the challengers were likely to succeed on the merits of their claim that the EPA's action was arbitrary and capricious under the Administrative Procedure Act.