The Trump administration is considering expanding the ethanol fuel waiver in the Clean Air Act (CAA) to allow E15 fuel (gasoline containing up to 15% ethanol) to be sold year round. The Environmental Protection Agency has indicated that it has been exploring this action as well, and the ethanol industry has been lobbying for years in pursuit of this change. There’s just one problem: EPA does not have the authority to expand the waiver, only Congress can do so by changing the law.