Everyone involved with ethanol needs to be "very aggressive between now and November" in making sure that the Environmental Protection Agency's volumetric requirement for ethanol use in 2019 is the full 15 billion gallons that the law requires, Sen. Charles Grassley, R-Iowa, told reporters Tuesday.

Grassley noted that when Donald Trump was campaigning for president he said in Iowa he would support the full 15 billion gallon requirement. But EPA Administrator Scott Pruitt has issued so many waivers from the requirement to oil refiners that usage is now only about 13.8 billion gallons.

"We need to know the waivers ahead of time, not have them floated out the rest of 2019," Grassley added.

Asked by a reporter if Pruitt has declared war on the ethanol industry, Grassley responded he would rather say Pruitt "hasn't been fully supportive of the ethanol industry the way the president has, and has not been serving the president well." Grassley added that Pruitt may have hurt Trump's standing with farmers and with the ethanol industry.