Amends the Clean Air Act to require the Administrator of the Environmental Protection Agency (EPA) to issue a decision on each request submitted by a state for a waiver of preemption under that Act: (1) within 30 days, but in no case later than September 30, 2007, for requests submitted before January 31, 2006, but pending as of the date of enactment of this Act; and (2) within 180 days after receipt for requests submitted after enactment of this Act.