On July 8, the GAO released the report, Biofuels: Challenges to the Transportation, Sale, and Use of Intermediate Ethanol Blends, which highlights barriers to expanded use of E15 gasoline, up from E10 or gasoline with 10% ethanol, including infrastructure requirements to transport the fuel and pending safety regulations. The Energy Independence and Security Act of 2007 currently requires at least 36 billion gallons of ethanol or other renewable fuel in the nation's motor fuel supply by 2022. EPA has granted two partial Clean Air Act waivers approving E15 for model year 2001 and newer cars and light trucks.