A proposed Clean Air Act rewrite would redefine when 'actual construction' begins - potentially letting contractors do non-emitting sitework like foundations, pads, and access roads before the federal air permit is in hand. What the New Source Review change means for anyone bidding industrial, energy, and data-center work, and the schedule math it unlocks. Clean Air Act New Source Review · begin actual construction rule · pre-permit sitework · NSR air permit construction