"WASHINGTON — The Obama administration on Tuesday moved to exert more control over the injection of diesel fuel deep underground to extract oil and natural gas, its first foray into addressing the potential contamination of water from the controversial technique."

"The Environmental Protection Agency has little authority to regulate fluids used in hydraulic fracturing, or fracking, which involves pumping water laced with chemicals into shale formations to unlock trapped oil and gas. But the agency has been allowed since 2005 to regulate the use of diesel in fracking. Until Tuesday, it had not done so.

Companies must apply for permits from state or federal authorities to use diesel in fracking. But the EPA had not defined what it considered diesel, which comes in many formulations, complicating efforts to control its use."

Neela Banerjee reports for the Tribune Washington Bureau February 11, 2014. [2]