On August 8, Reps. Henry Waxman (D-CA), Ed Markey (D-MA), Diana DeGette (D-CO), and Rush Holt (D-NJ) sent a letter to Lisa Jackson of EPA asking her to define diesel in such a way that is “broad enough to protect human health and to address the specific reason why Congress singled out diesel fuel in the law—because it often contains benzene, toluene, ethylbenzene, and xylenes (the BTEX compounds).” The Energy Policy Act of 2005 reversed a federal court ruling exempted fracking fluids from regulation under the Safe Drinking Water Act, except for diesel fuels, which the act did not actually define. EPA is currently working on the guidance which may resolve the issue, but did not offer a deadline.