Quad-City Times: More than a dozen senators, including Iowa’s Chuck Grassley and Joni Ernst, have written to the Environmental Protection Agency demanding to know which refineries were given waivers from the requirements of the Renewable Fuel Standard. The bipartisan group of 13 senators said 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 that no more waivers be granted.