II 116th CONGRESS 1st Session S. 1840 IN THE SENATE OF THE UNITED STATES June 13, 2019 Mrs. Fischer (for herself, Ms. Duckworth , Mr. Thune , Ms. Ernst , and Mr. Grassley ) introduced the following bill; which was read twice and referred to the Committee on Environment and Public Works A BILL To establish certain requirements for the small refineries exemption of the renewable fuels provisions under the Clean Air Act, and for other purposes.