Hydraulic fracturing is used to enhance the recovery of natural gas. Increasing the supply of domestic natural gas lowers energy prices, creates jobs, and generally helps the overall health of the economy. However, hydraulic fracturing, or fracking, has come under a great deal of criticism due to concerns about potential contamination of underground sources of drinking water (USDW).
In very simple terms, hydraulic fracturing involving pumping specially engineered fluids containing chemicals into a well to create and hold open fractures in the formation. These fractures increase the exposed surface area of the rock in the formation and, in turn, stimulate the flow of natural gas.
EPA does not yet regulate hydraulic fracturing. It has, however, conducted one study and is embarking on a second that could form the basis of national regulations.
The EPA recently completed a ground water investigation near the town of Pavillion, Wyoming, which was initiated in response to complaints by well owners regarding taste and odor problems in well water. The objective was to determine the presence of contamination in the Wind River Formation, which is the principal source of water in the area of Pavillion.
Groundwater was sampled and hydrocarbon contamination was found. EPA concluded that “the data indicates likely impact to ground water that can be explained by hydraulic fracturing.” Draft Investigation of Groundwater Contamination near Pavillion, Wyoming, EPA600/R-00/000, Dec. 2011. It is important to note that hydraulic fracturing occurred at very shallow depths in the area. Currently, hydraulic fracturing occurs at much lower depths, well below the USDW. The report is currently in a public comment period, which ends on January 27, 2012.
EPA is also undertaking a national study to understand the potential impacts of hydraulic fracturing on drinking water resources. EPA will release initial study results in a 2012 report and an additional report at the end of 2014. The scope of the study includes the full lifespan of water in hydraulic fracturing, from acquisition of the water, through the mixing of chemicals and actual fracturing, to the post-fracturing stage, including the management of flowback and produced water and its ultimate treatment and disposal.
EPA recently issued a report detailing its approach to the study. Plan to Study the Potential Impacts of Hydraulic Fracturing on Drinking Water Resources, EPA600/R-11/122, Nov. 2011. According to EPA, the study will use existing data, case studies, computer modeling, and laboratory studies to address and answer five fundamental questions regarding drinking water resources:
- Water Acquisition: What are the potential impacts of large volume water withdrawals from ground and surface waters?
- Chemical Mixing: What are the possible impacts of surface spills on or near well pads of hydraulic fracturing fluids?
- Well Injection: What are the possible impacts of the injection and fracturing process?
- Flowback and Produced Water: What are the possible impacts of surface spills on or near well pads of flowback and produced water?
- Wastewater Treatment and Waste Disposal: What are the possible impacts of inadequate treatment of hydraulic fracturing wastewaters?
EPA currently protects USDW by, among other things, regulating the injection of waste through the Underground Injection Control (UIC) Program. The national study currently underway must be monitored to ensure scientific accuracy and unbiased results as the outcome of the national study could be used impose controls and possibly permitting requirements on hydraulic fracturing that are similar to those currently imposed on underground injection in the UIC Program.