Both of Iowa's US Senators don't want the EPA to touch the renewable fuel standard. Senators Chuck Grassley and Joni Ernst were two of nearly three dozen senators to sign on to a letter that was sent to EPA Administrator Scott Pruitt. The letter comes as the EPA is taking comments on a plan that may reduce the total volume of renewable fuels over the next two years. The senators' letter says jobs could be lost in addition to investments not being made in biofuels if changes are made.