Iowa senators, other lawmakers: RFS waivers violate the law

More than a dozen senators have written to the Environmental Protection Agency, demanding to know which refineries were given waivers from the requirements of the Renewable Fuel Standard.

Citing news reports, 13 senators, including Democrats and Republicans, said in the letter that the EPA granted hardship waivers to large refineries under a provision of the law aimed at providing flexibility for small operations.

"These waivers fall well outside the bounds of the letter or the spirit of this provision in the law," said the letter, which was dated last week. The senators announced Tuesday they requested no more waivers be granted.

The lawmakers include Sens. Chuck Grassley and Joni Ernst, Iowa Republicans.

The senators asked that the EPA identify recipients of all waivers granted for 2016, 2017 and 2018.

Reports of the waivers are the latest flashpoint between biofuels supporters and EPA Administrator Scott Pruitt. For months, there has been tension over the decade-old law requiring a certain amount of biofuels be blended into the nation's gasoline supply.

Some in the industry have estimated the waivers have shaved a billion gallons from demand.

The latest renewable fuel levels call for 15 billion gallons of corn-based ethanol to be blended into the fuel supply and just over 19 billion gallons of biofuels overall.