The U.S. Environmental Protection Agency (EPA) on Tuesday released revised underground injection control (UIC) program permitting guidance for wells that use diesel fuels during fracking activities.

EPA said it developed the guidance to clarify how companies can comply with a 2005 law passed by Congress that exempted fracking operations from the requirement to obtain a UIC permit, except in cases where diesel fuel is used as a fracturing fluid.

“Although developed specifically for hydraulic fracturing where diesel fuels are used, many of the guidance’s recommended practices are consistent with best practices for hydraulic fracturing in general, including those found in state regulations and model guidelines for hydraulic fracturing developed by industry and stakeholders,” EPA said Tuesday. “Thus, states and tribes responsible for issuing permits and/or updating regulations for hydraulic fracturing may find the recommendations useful in improving the protection of underground sources of drinking water and public health more broadly.”

EPA issued the guidance alongside an interpretive memorandum, which clarifies that class II UIC requirements apply to fracking activities using diesel fuels, and defines the statutory term diesel fuel by reference to five chemical abstract services registry numbers. The guidance outlines for EPA permit writers, where EPA is the permitting authority, existing class II requirements for diesel fuels used for fracking wells, and technical recommendations for permitting those wells consistently with these requirements.

EPA said decisions about permitting fracking operations that use diesel fuels will be made on a case-by-case basis, considering the facts and circumstances of the specific injection activity and applicable statutes, regulations and case law, and will not cite this guidance as a basis for decision.

The topic of diesel fuel regulation in fracking has been a hot one in recent years, with a bipartisan coalition of senators during the fall of 2012 accusing EPA of overreaching. The senators expressed concerns that EPA was attempting to expand its definition of diesel fuels in the draft permitting guidance to gain more federal control over fracking (see Shale Daily, Oct. 4, 2012).

“EPA’s draft guidance is yet another example of how [the Obama] administration continues to move ahead using every means possible to gain more federal control over hydraulic fracturing,” wrote Sen. James Inhofe (R-OK), the ranking member of the Senate Environmental and Public Works Committee, and other coalition members in a letter in October 2012 to then-EPA Administrator Lisa Jackson.

EPA claims responsible development of America’s unconventional oil and natural gas resources offers important economic, energy security, and environmental benefits, and that the agency is working with states and other key stakeholders to help ensure that extraction of these resources does not come at the expense of public health and the environment.

“In particular, the EPA is moving forward on several initiatives, such as the diesel guidance, to provide regulatory clarity with respect to existing laws and using existing authorities where appropriate to enhance public health and environmental safeguards,” the agency said.

EPA released a draft of the guidance in May 2012 and held a 105 day public comment period to gain input on the guidance from a wide range of stakeholders (see Shale Daily, May 7, 2012).