Controversy remains over long-delayed Environmental Protection Agency guidance for writing permits for hydraulic fracturing that uses diesel. Some Democrats in the House of Representatives are eager to see the guidance finalized, but both industry and environmental groups have concerns, for different reasons.

In an Oct. 25 letter, Rep. Henry Waxman (D-Calif.) asked the Office of Management and Budget to expeditiously review EPA's guidance, proposed in draft form in May 2012, and reject "any industry efforts to weaken or delay it." The new guidance would require U.S. oil and gas companies to obtain additional permits under the Class II Underground Injection Control program when diesel fuels are used. The guidance would apply to only the 13 states in which EPA oversees such permitting, including Pennsylvania and New York.

But Lee Fuller, Independent Petroleum Association of America vice president of government relations, says the guidance is unnecessary. He says diesel fuel has been largely eliminated from fracking. He adds that, because the guidance applies to only states in which EPA has permitting authority, oil and natural-gas firms could be vulnerable to lawsuits from environmental groups in states that regulate hydraulic fracturing through well-construction programs. Environmental groups don't find much that they like in the guidance, either. They would prefer a tough, formal regulation that would ban use of diesel fluids in fracking. A 2011 study by House energy committee Democrats found that, between 2005 and 2009, more than 32 million gallons of diesel fluids were used during fracking in the U.S.