"Congress acted on several Clean Air Act (CAA) issues in legislation that it passed and sent to the President in late July. The most significant of these issues, dealing with ethanol and reformulated gasoline (RFG), were addressed in the Energy Policy Act of 2005, H.R. 6 (P.L. 109-58). The act eliminates a requirement that RFG, used in the nations most polluted areas, contain at least 2% oxygen. In its place, the act requires that the total gasoline supply contain increasing amounts of a specific oxygenate, ethanol, which is generally made from corn. Under the bill, use of ethanol will more than double by 2012. Congress also amended the Clean Air Act in H.R. 3 (P.L. 109-59), the transportation bill that the President signed August 10. H.R. 3 addresses the requirement that state and local transportation planners demonstrate conformity between their transportation plans and the timely achievement of air quality standards. Under the act, the frequency of conformity determinations and the time horizon over which conformity must be demonstrated will both be reduced, making the requirement less burdensome. Failure to demonstrate conformity can lead to a temporary suspension of federal highway funds."
CRS Issue Brief for Congress, IB10137