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EPA’s Study of Hydraulic Fracturing and Its Potential Impact on Drinking Water Resources

EPA’s Study of Hydraulic Fracturing and Its Potential Impact on Drinking Water Resources

Assessment of the Potential Impacts of Hydraulic Fracturing for Oil and Gas on Drinking Water Resources (External Review Draft)

This assessment provides a review and synthesis of available information concerning the potential impacts of hydraulic fracturing for oil and gas on drinking water resources in the United States. This is a draft report that has been made available for public comment and shared with the EPA Science Advisory Board for expert peer review. [Press Release Jun 4, 2015]

Cover of the external review draft of the hydraulic fracturing drinking water research report This assessment provides a review and synthesis of available scientific literature and data to assess the potential for hydraulic fracturing for oil and gas to impact the quality or quantity of drinking water resources, and identifies factors affecting the frequency or severity of any potential impacts. The scope of this assessment is defined by the hydraulic fracturing water cycle which includes five main activities:

  1. Water acquisition – the withdrawal of ground or surface water needed for hydraulic fracturing fluids;
  2. Chemical mixing – the mixing of water, chemicals, and proppant on the well pad to create the hydraulic fracturing fluid;
  3. Well injection – the injection of hydraulic fracturing fluids into the well to fracture the geologic formation;
  4. Flowback and Produced water – the return of injected fluid and water produced from the formation to the surface, and subsequent transport for reuse, treatment, or disposal; and
  5. Wastewater treatment and waste disposal – the reuse, treatment and release, or disposal of wastewater generated at the well pad, including produced water.

This report can be used by federal, tribal, state, and local officials; industry; and the public to better understand and address vulnerabilities of drinking water resources to hydraulic fracturing activities.


Jeff Frithsen

phone:  703-347-8623



U.S. EPA. Assessment of the Potential Impacts of Hydraulic Fracturing for Oil and Gas on Drinking Water Resources (External Review Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-15/047, 2015.
from GreenWire:   LINK:


EPA study finds no ‘widespread’ impact on drinking water

Hydraulic fracturing can contaminate drinking water but has not caused “widespread” impacts, U.S. EPA found in a highly anticipated study released today.

The landmark findings, published in a final draft still subject to public comment and peer review, assessed the potential “life-cycle” effects of fracking — from water acquisition to injection to wastewater management — and identified vulnerabilities in the process that have led to contamination of surface water and groundwater in several cases.

“Of the potential mechanisms identified in this report, we found specific instances where one or more mechanisms led to impacts on drinking water resources, including contamination of drinking water wells,” EPA said in an executive summary. “The number of identified cases, however, was small compared to the number of hydraulically fractured wells.”

The report upsets the industry line that fracking has never contaminated drinking water but concludes that the evidence does not indicate “widespread, systemic impacts on drinking water resources in the United States.”

The two-layer message of the findings was evident in stakeholders’ immediate reaction, with environmentalists trumpeting the news that EPA linked fracking to water contamination and industry heralding the study as reaffirmation that fracking is safe.

“After more than five years and millions of dollars, the evidence gathered by EPA confirms what the agency has already acknowledged and what the oil and gas industry has known,” the American Petroleum Institute’s Erik Milito said in a statement. “Hydraulic fracturing is being done safely under the strong environmental stewardship of state regulators and industry best practices.”

Environmentalists, meanwhile, seized on the fact that the Obama administration has formally acknowledged instances of contamination.

“Today EPA confirmed what communities living with fracking have known for years, fracking pollutes drinking water,” Earthworks Policy Director Lauren Pagel said in a statement. “Now the Obama administration, Congress, and state governments must act on that information to protect our drinking water, and stop perpetuating the oil and gas industry’s myth that fracking is safe.”

The agency won’t issue policy recommendations from the study but noted in a statement that the study provides a tool for states and industry to adopt changes as needed.

“EPA’s draft assessment will give state regulators, tribes and local communities and industry around the country a critical resource to identify how best to protect public health and their drinking water resources,” EPA science adviser Thomas Burke said in a statement after the release.

“It is the most complete compilation of scientific data to date, including over 950 sources of information, published papers, numerous technical reports, information from stakeholders and peer-reviewed EPA scientific reports.”

Beyond the numbers

The study has been a political football for nearly five years. It was requested by House Democrats in 2010 and immediately became a point of contention between supporters and opponents of expanded domestic oil and gas production.

A final draft was originally planned for late 2012, but the agency instead published an interim progress report and pushed the final draft to 2014 — a deadline that then slipped to late spring 2015.

Early on, drilling critics packed hearing halls for the “scoping” process, while environmental groups and industry lobbied to get their favored scientists on the peer review panel (Greenwire, Dec. 21, 2012). The agency tangled with Halliburton Co. about what information the company should hand over, even issuing a subpoena at one point.

In 2012, EPA dropped a water contamination enforcement case against Range Resources Inc. in Texas in part because the company agreed to cooperate with the study, according to an inspector general report.

Differing interpretations of “fracking” fueled further controversy. Though the word refers to a specific state of the production process, in which crews use high-pressure water to crack open rock formations, many critics use the term as a catch-all description of the whole drilling process.

Industry has argued that EPA’s study should look only at what happens when fracturing fluid is injected at high pressure, instead of taking a life-cycle approach. Environmental groups, by contrast, have pushed to broaden the review into how expansion of the drilling industry, facilitated by advances in fracturing technology, will affect the environment, economy and quality of life in the regions where it’s taking place.

For both sides, the study has represented more than just a compilation of data. Industry fears the study will form the basis for more EPA regulation of drilling. And environmentalists are wary because a previous EPA study of the issue was used to justify a broad exemption for fracturing from the Safe Drinking Water Act.

That study, released in 2004, concluded that further study was not needed because fracturing in coalbed methane formations posed “little or no threat” to aquifers


2 Responses to “EPA’s Study of Hydraulic Fracturing and Its Potential Impact on Drinking Water Resources”

  1. Tom Pendergast says:

    Regarding the key phrase, ” . . . to assess the potential for hydraulic fracturing for oil and gas to impact the quality or quantity of drinking water resources . . . “, I’d like to make the following observations:

    While the U.S. EPA quite rightly included activities that are peripheral to hydraulic fracturing and certainly do have the potential to adversely impact the quantity and quality of our drinking water supplies, it never makes the claim that hydraulic fracturing itself has such impacts.

    The potential for adversely affecting the quantity and quality of our drinking water supplies applies to all hydrocarbon exploitation technologies whether they be from unfracked conventional vertical wells (virtually the only kind we have in Licking County) or unconventional hydraulically fractured ones (and, for that matter, the exploitation of coal-bed methane; but I’m not well-versed in that method).

    The greatest potential for adverse impacts on potable water supplies occurs within the first 100 feet of the surface, not two-, three-, four-, five- or six-thousand feet below the surface. I would say that the deeper the well goes before fracturing operations commence, the less likely there will be an adverse impact on drinking water supplies. In fact, the deeper you go before fracturing begins, the risk of adverse impacts on drinking water supplies probably decreases exponentially.

  2. Tom Pendergast says:

    Comments on what the U.S. EPA did not say:

    Home > USA > Energy and Natural Resources
    United States: Little Fracking Risk, Despite EPA Disclaimers
    Last Updated: July 1 2015
    Article by Jeffrey D. Dintzer and K. Darcy Elgin
    Gibson, Dunn & Crutcher LLP

    With nearly 30,000 new injection wells being drilled each year, hydraulic fracturing, or “fracking,” is a rapidly expanding method of oil and gas extraction which involves injecting large volumes of fluid or sand at high pressure into an underground well to extract oil and gas from fractures created in the underground rock. Fracking’s proliferation has been contentious, and last week, the U.S. Environmental Protection Agency aligned itself with fracking industry advocates when it released its long-awaited assessment of the impacts of hydraulic fracturing on drinking water.

    After evaluating the various mechanisms by which fracking could impact drinking water resources, the EPA found no evidence that hydraulic fracturing has led to widespread, systemic change in the quality or quantity of drinking water resources in the United States. The only evidence of fracking’s impacts on drinking water were isolated incidents, almost all of which are traceable to the small subset of fracking wells that fail to meet current industry safety standards. The study concludes that modern fracking technology, when properly implemented, is protective of both ground and surface waters.

    Anti-fracking factions, however, have jumped on the EPA’s choice to couch its well-supported findings based on the disclaimers included in the report. A careful reading of the EPA’s conclusions throughout the study, however, is enough to assuage any significant concern about the core conclusion from the EPA’s assessment: Hydraulic fracturing activities pose little danger to drinking water. We address each disclaimer in turn below:

    Disclaimer 1: The false assertion that there have been insufficient pre-and-post-fracturing data on water quality

    While the EPA claims it lacks a point-of-reference to evaluate changes in water quality, it does not claim insufficient water quality data. This is a crucial distinction, as water quality standards are not set by the change in concentration of a particular contaminant, but rather by absolute concentrations. For drinking water, the EPA sets maximum contaminant levels (MCLs).

    Although the deltas of various substances’ concentrations may be needed to assess any impacts to waters, they are not needed to assess the more pragmatic question raised by the EPA: whether fracking activities cause widespread, systemic change in the quality or quantity of drinking water resources in the United States. Instead, the EPA’s evaluation of water sources near fracking activities largely revealed what existed before fracking operations began: a body of water which could serve as a source of drinking water.

    The EPA’s assessment also notes that even a moderate change in the concentrations of certain compounds would be noted by treatment plants. Elevated bromide levels, for example, can make it difficult for plants to meet drinking water MCLs, as bromide interacts with a disinfectant, such as chloride, forming a tertiary compound which is then difficult to remove.

    Disclaimer 2: The unfounded contention that there have been few long-term studies

    The EPA states longer-term studies would account for the “several years” it can take for spilled fluid to infiltrate soil and then leach into ground water. Fracking, however, has been quite active during the past 10 years, and even long before that. Absent a specifically identified spill or slow-moving chemical impact, which the EPA has not identified, there is no reason to believe we aren’t already seeing and evaluating the long-term impacts of fracking.

    The EPA further qualifies its findings by noting that the chemical makeup of wastewater produced from fracking is rarely assessed as part of spill response. It follows, says the EPA, that the chemicals contained in the wastewater, along with their relative concentrations, usually remain unknown, meaning the wastewater’s long-term potential impacts to drinking water are also unknown. But this assumes a significant number of fracking spills impact drinking water. In the course of its assessment, the EPA evaluated 457 spills related to fracking activities which occurred between 2006 and 2012, only 151 of which involved the fracturing fluid or its chemical additives. Of those spills, the median volume was only 420 gallons, only 13 reached any surface water, and none reached groundwater. Given only 13 of 457 spills even touched a potential source of drinking water, the chemicals in fracking wastewater are unlikely to have caused unknown impacts to drinking water.

    Disclaimer 3: The misguided claim that other sources of contamination preclude a definitive link between fracking and drinking water impacts

    The EPA’s study is misleading to the extent that it implies that but for “other sources” of contamination, fracking would be linked to pollution. To use one of the EPA’s own examples, a fracking well located near natural methane concentrations may result in methane naturally migrating into, and contaminating, groundwater. Thus, when methane gas is eventually found in the groundwater, it may be unclear whether the gas originates from the well or from the natural source.

    Scientists and statisticians, however, can establish the origin source, both through modeling and by analyzing the isotopic composition of the gas, in the case of methane contamination. The “other sources” therefore do not preclude finding a definitive link between fracking and pollution. The studies cited by the EPA are unable to correlate the pollution and fracking activities in this manner.

    Disclaimer 4: The misleading assertion that inaccessibility of some information on hydraulic fracturing activities and potential impacts

    The assessment makes clear that the EPA is unsettled by the 70 percent of fracking wells that still withhold from disclosure at least one injection chemical compound based on confidentiality concerns. The report compiles a list of 1,076 different compounds used in injection solutions, issuing a warning that it has not begun to assess the health impacts of even a fraction of these. But according to the EPA’s report, the number of unique chemicals per well range from four to 28, with a median of only 14. These chemicals include not only those known to be toxic at certain concentrations, but also the more mundane, such as acetic acid (better known as vinegar). Given the limited number of chemicals used per well, the risks of sparsely used compounds with less-studied impacts is attenuated.

    The EPA’s assessment offers broad support for the position that hydraulic fracturing activities pose little danger to drinking water. The caveats in the EPA’s study, while unnecessary, do little to undermine its cardinal premise: that it has found no evidence to support the contention that hydraulic fracturing has led to widespread, systemic change in the quality or quantity of drinking water resources in the United States.

    Originally published in The Daily Journal – June 2015

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