Amends the Clean Air Act to direct the Administrator of the Environmental Protection Agency, in the case of a downwind ozone nonattainment area affected by transport of ozone pollution from an upwind area, upon application by a State, to: (1) reclassify the downwind area to reflect an adjusted ozone design value which excludes ozone concentrations attributable to transport from an upwind area; and (2) redesignate the downwind area as an attainment area if the adjusted ozone design value for the most recent applicable period does not exceed the national ambient air quality standard for ozone.

Requires State implementation plans for national primary and secondary ambient air quality standards to contain adequate provisions prohibiting sources within the State from emitting any air pollutant in amounts which will contribute significantly to nonattainment in, or interfere with maintenance by, any other area within the State with respect to any such air quality standard.