The EPA has issued a new guidance memo accompanied by technical recommendations for writing underground injection control (UIC) permits for oil and gas hydraulic fracturing (fracking) activities using diesel fuels. Primarily the documents are intended to aid federal and state permit writers. However, the EPA says it anticipates that well owners and operators may find the technical recommendations useful in understanding the factors permit writers may consider in issuing permits for HF operations using diesel fuels.
In 2005 amendments to the Safe Drinking Water Act (SDWA), Congress exempted fracking O&G activities from UIC Class II permitting requirements, except when diesel fuels are used in fracturing fluids or propping agents. In the amendments, Congress did not define diesel fuels. Accordingly, in the memo, the EPA interprets the term “to enable implementation of the UIC program under the SDWA and to alleviate uncertainty.”
The EPA says its analysis of data on fracking fluids posted in 2012 on the chemical disclosure registry website FracFocus2 found that diesel fuels appeared in fewer than 2 percent of the wells.
BTEX
The memo emphasizes risk posed to groundwater by benzene, toluene, ethylbenzene, and xylene (BTEX) compounds, “chemicals of concern” that occur in diesel fuels and are highly mobile in groundwater. Health risks associated with exposure to BTEX include anemia and an increased risk of cancer from benzene exposure; problems with the nervous system, kidneys, or liver from toluene exposure; and problems with the liver or kidneys from ethylbenzene.
Under the SDWA, the EPA has established maximum contaminant levels (MCL) and maximum contaminant level goals (MCLG) for each BTEX compound. Both the memo and the technical recommendations state the Agency’s intention to work with states and industry to promote the use of safe alternatives to BTEX compounds.
Five fuels
The memo lists five fuels and their Chemical Abstracts Services Registry Numbers (CASRNs) as “the most appropriate interpretation” of the statutory term diesel fuels to use for permitting diesel fuel HF under the UIC program nationwide. Each of the following CASRNs has multiple synonyms for the primary name, which are listed in the memo.
- 68334-30-5—primary name: fuels, diesel
- 68476-34-6—primary name: fuels, diesel, No.2
- 68476-30-2—primary name: fuel oil, No. 2
- 68476-31-3—primary name: fuel oil, No. 4
- 8008-20-6—primary name: kerosene
Technical recommendations
The technical recommendations for permit contents cover areas such as delineating a site-specific area of review, corrective action to prevent fluid or gas migration, mechanical integrity tests (MITs) to ensure that the protective physical components of the well, including the casing and cement, are competent before injection and throughout the life of the well; high injection pressures that occur during HF, which have the potential to damage the mechanical integrity of the well, causing leaks; and baseline and postfracture water quality monitoring to help ensure that a permitted well has not endangered an underground source of drinking water.
According to the EPA, the technical recommendations are “consistent with the discretion accorded under the existing UIC Class II regulations, and reflect existing UIC requirements for other well classes, voluntary industry standards, state rules, and other model guidelines for HF.” However, the Agency emphasizes that permit writers have the discretion to consider alternative approaches and decisions about permitting HF operations that use diesel fuels. Permitting contents are determined on a case-by-case basis, considering the facts and circumstances of the specific injection activity and applicable statutes, regulations, and case law, says the EPA.
Permitting Guidance for Oil and Gas Hydraulic Fracturing Activities Using Diesel Fuels
Memo and technical recommendations