Corn industry lobbyists are pressuring Congress to stop the Environmental Protection Agency from waiving so many refineries’ compliance obligations under the Renewable Fuel Standard.

The RFS requires that refiners mix certain amounts of ethanol into their gasoline; the waivers exempt small refineries facing economic hardships from having to meet the mandate. The lobbyists claim the Trump administration is granting exemptions recklessly, undermining the congressional intent of the RFS in the process. But what exactly was the original intent for the RFS?