The Other Shoe Drops On Upwind Ozone States

On Tuesday, the District of Columbia Court of Appeals vacated EPA's "Close-Out Rule," which basically concluded that upwind states contributing to exceedances of the National Ambient Air Quality Standard for ozone in downwind states did not have to undertake any additional actions to reduce their contribution to downwind state ozone concentrations. The decision was inevitable following last month's decision in Wisconsin v. EPA, in which the D.C. Circuit ruled that upwind states must eliminate any substantial contribution to downwind NAAQS exceedances by the same deadline faced by those downwind states to meet the ozone NAAQS.

As the Court noted in yesterday's decision: