The EPA is extending by an additional three-day period the deadline for taking final action on petitions that eight States have submitted to require EPA to make findings that sources upwind of those States contribute significantly to nonattainment problems in those States. Under the Clean Air Act (CAA), EPA is authorized to grant this time extension if EPA determines that the extension is necessary, among other things, to meet the purposes of the Act's rulemaking requirements. By this document, EPA is making that determination.