To amend the Clean Air Act to permit areas not contributing to more than 35 percent of ozone concentrations to comply with Marginal Area requirements for purposes of ozone nonattainment.

Amends provisions of the Clean Air Act relating to rural transport areas to treat rural or nonrural areas as satisfying requirements for ozone nonattainment areas if the State makes implementation plan submissions applicable to Marginal nonattainment areas and if sources of volatile organic compound (and, where relevant, nitrogen oxides) emissions within such areas do not contribute to more than 35 percent of the ozone concentrations in such areas or in other areas.