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Hydraulic Fracturing: Testing the Waters

EPA Researchers combine public and technical input on a study of the potential environmental and human health impacts of a technique used to drill for natural gas.

Burning natural gas

“Natural Gas Now Viewed as Safer Bet,” declares a recent headline in The New York Times (March 21, 2011). From the aftermath of the tragic earthquake and tsunami in Japan that crippled the Fukishima nuclear reactor, to the BP oil spill, and continued political turmoil in the Middle East, a convergence of energy-related events all seem to be shinning an ever brighter spotlight on natural gas development.

In 2010, the U.S. Congress tasked EPA with planning and conducting a transparent, peer-reviewed study of the relationship between hydraulic fracturing—a method that relies on large amounts of water, sand and chemicals injected at high pressure to crack open underground rock formations to extract natural gas—and its relationship to drinking water resources. (See Hydraulic Fracturing: Drilling for Answers, “Science Matters” Vol 1, No. 2.)

On February 8, 2011, EPA released the Draft Hydraulic Fracturing Study Plan (PDF) (140pp, 2.3 MB).

One of the unique aspects of the development strategy has been the amount of public engagement the Agency has solicited and incorporated into the draft study plan. More than 9,500 people provided written comments, participated in webinars, or spoke up at EPA-held meetings in Texas, Colorado, Pennsylvania, New York, and Washington, DC.

EPA scientist Jeanne Briskin, who is helping lead the hydraulic fracturing study, emphasizes the importance of public input in designing the study. “From each and every group, we have learned important and interesting things that will help make our study better,” she says.

Since the Congressional request for the study, Briskin, along with technical lead Dr. Robert W. Puls, and their colleagues have listened carefully. “We’ve gotten comments from an incredible diversity of stakeholders,” says Briskin. “Some feel that hydraulic fracturing and gas development are extremely important because natural gas is an important fuel for our country’s future. Others have raised concerns about potential impacts on their air, their water, and their community.”

“We feel that not only because Congress told us to, but just in general it is important for us to have a very open and transparent process as we put together our approach to studying this issue so that people can see what we’re doing, why we’re doing it, and how we’re doing it,” explains Briskin.

Managing the public input process has been integrated with researching the scientific evidence related to the potential environmental impacts associated with hydraulic fracturing and formulating a scientific strategy for the study plan. Briskin says that “making strong, scientifically-validated information available to the public is important to addressing their concerns and ensuring that policy makers have access to data that will assist them in decision- making.”

Combining both public input and scientific strategies is consistent with recommendations made in a key 1996 National Academy of Sciences (NAS) Report, Understanding Risk:  Informing Decisions in a Democratic Society. Exit EPA Disclaimer According to the report, five objectives are important to combining public input and science:

  • Getting the science right
  • Getting the right science
  • Getting the participation right
  • Getting the right participation
  • Developing an accurate, balanced, and informative synthesis.

The Draft Hydraulic Fracturing Study Plan

Hydraulic Fracturing Lifecycle

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Briskin and her colleagues followed the objectives illuminated in the NAS report to produce the draft study plan, while focusing on providing the science Congress and the Agency need to make key decisions and on the research needed to advance the sustainability of water resources.
The heart of the study plan is research questions that address each stage of the lifecycle of water used during hydraulic fracturing operations. The five critical stages in this lifecycle are:

  • Water acquisition—Large volumes of water are transported for the fracturing process.
  • Chemical mixing—Equipment mixes water, chemicals, and sand at the well site.
  • Well injection—The hydraulic fracturing fluid is pumped into the well at high injection rates.
  • Flowback and produced water—Recovered water (called flowback and produced water) is stored on-site in open pits or storage tanks.
  • Wastewater treatment and disposal—The wastewater is then transported for treatment and/or disposal.

Flowback and produced water is generated when the injection pressure in the well is reduced, which allows theses wastewaters to return to the surface. The wastewater contains injected chemicals, natural gas and contaminants that are found in the subsurface rock formation (e.g., dissolved solids, metals and radionuclides).

The wastewater can be treated and used in another hydraulic fracturing operation. More common, however, is treatment followed by disposal in an underground injection control well. In areas without underground injection control wells, such as the Northeastern U.S., the wastewater may be treated and discharged via a publicly-owned treatment plant. Many publicly-owned treatment plants may not be able to remove some of the components of hydraulic fracturing wastewater, such as radionuclides and the high levels of dissolved solids. This is of concern particularly in the Northeastern U.S., where there has been increased activity and interest in natural gas development.

Briskin explains that the research plan is designed to identify which stage of the hydraulic fracturing water lifecycle warrants the closest exploration. Accordingly, her team is planning a series of forward- and backward-looking case studies, scenario evaluations, laboratory work, and an evaluation of the toxicity of chemicals. EPA also will be collaborating with the Department of Energy—which has strong wastewater and radioactivity research programs—in carrying out the study plan, as well as with other Federal partners.

Briskin and her EPA colleagues continue to welcome stakeholder involvement from members of the public, states, industry, tribes, sister Federal agencies, technical experts, and other stakeholders as they select locations for case studies and revise the draft study plan released on February 8, 2011.

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