Leave Ethanol Volumes at Existing Levels Act or the LEVEL Act This bill amends the Clean Air Act to revise the renewable fuel program by: (1) decreasing the volume of renewable fuel that must be contained in gasoline in 2017 through 2022 to 7.5 billion gallons for each year, and (2) requiring a volume of 7.5 billion gallons of renewable fuel in gasoline for each year thereafter. The bill revises the renewable fuel standard, including by eliminating separate volume requirements for the following renewable fuel categories: advanced biofuels, cellulosic biofuel (ethanol derived from certain types of biological matter), and biomass-based diesel. The bill revokes the requirement that the Environmental Protection Agency (EPA) ensure that renewable fuels emit fewer greenhouse gases than the fuel it replaces. One gallon of cellulosic biomass ethanol or waste-derived ethanol is considered to be equal to 2.5 gallons of renewable fuel. Petitions for waivers from requirements under the renewable fuel program may not be brought to the EPA by a person who is subject to the requirements of the program. The EPA may not permit or authorize the introduction into commerce of gasoline that: (1) contains greater than 10% ethanol, (2) is intended for general use in conventional gasoline-powered vehicles or engines, and (3) is not registered under the program and lawfully sold in the United States before this bill's enactment. This prohibition applies to EPA grants of waivers through the fuels and fuel additives waiver process as well, except for waivers for gasoline that is registered and lawfully sold in the United States before this bill's enactment.