Senators James Inhofe (R-OK), Lisa Murkowski (R-AK), John Hoeven (R-ND), Mary Landrieu (D-LA), and Joe Manchin (D-WV), sent a September 27 letter to Environmental Protection Agency Administrator Lisa Jackson cautioning her that the agency is overstepping its jurisdiction in regards to the scale of its proposed guidance on fracking. The five senators also expressed concerns that the ambiguity of the proposed guidance could conflict with state regulation of fracking and the underground injection of waste fluids.