EPA Hydraulic Fracturing Study Plan
November 2011
v>EPA
United States
Environmental Protection
Agency
EPA/600/R-11/122A
November 2011
Plan to Study the Potential
Impacts of Hydraulic Fracturing
on Drinking Water Resources
Office of Research and Development
US Environmental Protection Agency
Washington, D.C.
November 2011
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table of Contents
List of Figures vi
List of Tables vi
List of Acronyms and Abbreviations vii
Executive Summary viii
1 Introduction and Purpose of Study 1
2 Process for Study Plan Development 3
2.1 Stakeholder Input 3
2.2 Science Advisory Board Involvement 5
2.3 Research Prioritization 6
2.4 Next Steps 7
2.5 Interagency Cooperation 7
2.6 Quality Assurance 8
3 Overview of Unconventional Oil and Natural Gas Production 9
3.1 Site Selection and Preparation 12
3.2 Well Construction and Development 13
3.2.1 Types of Wells 13
3.2.2 Well Design and Construction 13
3.3 Hydraulic Fracturing 15
3.4 Well Production and Closure 16
3.5 Regulatory Framework 16
4 The Hydraulic Fracturing Water Lifecycle 17
5 Research Approach 20
5.1 Analysis of Existing Data 20
5.2 Case Studies 20
5.3 Scenario Evaluations 21
5.4 Laboratory Studies 21
5.5 Toxicological Studies 21
6 Research Activities Associated with the Hydraulic Fracturing Water Lifecycle 22
6.1 Water Acquisition: What are the potential impacts of large volume water withdrawals from ground and
surface waters on drinking water resources? 22
6.1.1 Background 22
6.1.2 How much water is used in hydraulic fracturing operations, and what are the sources of this water?24
-------
EPA Hydraulic Fracturing Study Plan November 2011
6.1.2.1 Research Activities - Source Water 24
6.1.3 How might water withdrawals affect short- and long-term water availability in an area with hydraulic
fracturing activity? 25
6.1.3.1 Research Activities - Water Availability 25
6.1.4 What are the possible impacts of water withdrawals for hydraulic fracturing operations on local water
quality? 27
6.1.4.1 Research Activities - Water Quality 27
6.2 Chemical Mixing: What are the possible impacts of surface spills on or near well pads of hydraulic
fracturing fluids on drinking water resources? 28
6.2.1 Background 28
6.2.2 What is currently known about the frequency, severity, and causes of spills of hydraulic fracturing
fluids and additives? 28
6.2.2.1 Research Activities - Surface Spills of Hydraulic Fracturing Fluids and Additives 29
6.2.3 What are the identities and volumes of chemicals used in hydraulic fracturing fluids, and how might
this composition vary at a given site and across the country? 30
6.2.3.1 Research Activities - Hydraulic Fracturing Fluid Composition 30
6.2.4 What are the chemical, physical, and toxicological properties of hydraulic fracturing chemical
additives? 31
6.2.4.1 Research Activities - Chemical, Physical, and Toxicological Properties 31
6.2.5 If spills occur, how might hydraulic fracturing chemical additives contaminate drinking water
resources? 32
6.2.5.1 Research Activities - Contamination Pathways 33
6.3 Well Injection: What are the possible impacts of the injection and fracturing process on drinking water
resources? 34
6.3.1 Background 34
6.3.1.1 Naturally Occurring Substances 34
6.3.2 How effective are current well construction practices at containing gases and fluids before, during,
and after fracturing? 35
6.3.2.1 Research Activities-Well Mechanical Integrity 35
6.3.3 Can subsurface migration of fluids or gases to drinking water resources occur, and what local geologic
or man-made features may allow this? 37
6.3.3.1 Research Activities - Local Geologic and Man-Made Features 38
6.3.4 How might hydraulic fracturing fluids change the fate and transport of substances in the subsurface
through geochemical interactions? 40
6.3.4.1 Research activities - Geochemical Interactions 40
6.3.5 What are the chemical, physical, and toxicological properties of substances in the subsurface that
may be released by hydraulic fracturing operations? 41
ii
-------
EPA Hydraulic Fracturing Study Plan
November 2011
6.3.5.1 Research Activities - Chemical, Physical, and Toxicological Properties 41
6.4 Flowback and Produced Water: What are the possible impacts of surface spills on or near well pads of
flowback and produced water on drinking water resources? 42
6.4.1 Background 42
6.4.2 What is currently known about the frequency, severity, and causes of spills of flowback and produced
water? 43
6.4.2.1 Research Activities - Surface Spills of Flowback and Produced Water 44
6.4.3 What is the composition of hydraulic fracturing wastewaters, and what factors might influence this
composition? 44
6.4.3.1 Research Activities - Composition of Flowback and Produced Water 45
6.4.4 What are the chemical, physical, and toxicological properties of hydraulic fracturing wastewater
constituents? 45
6.4.4.1 Research Activities - Chemical, Physical, and Toxicological Properties 46
6.4.5 If spills occur, how might hydraulic fracturing wastewaters contaminate drinking water resources? .47
6.4.5.1 Research Activities - Contamination Pathways 47
6.5 Wastewater Treatment and Waste Disposal: What are the possible impacts of inadequate treatment of
hydraulic fracturing wastewaters on drinking water resources? 48
6.5.1 Background 48
6.5.2 What are the common treatment and disposal methods for hydraulic fracturing wastewaters, and
where are these methods practiced? 49
6.5.2.1 Research Activities-Treatment and Disposal Methods 49
6.5.3 How effective are conventional POTWs and commercial treatment systems in removing organic and
inorganic contaminants of concern in hydraulic fracturing wastewaters? 50
6.5.3.1 Research Activities-Treatment Efficacy 50
6.5.4 What are the potential impacts from surface water disposal of treated hydraulic fracturing
wastewater on drinking water treatment facilities? 51
6.5.4.1 Research Activities - Potential Drinking Water Treatment Impacts 51
Environmental Justice Assessment 53
7.1.1 Are large volumes of water for hydraulic fracturing being disproportionately withdrawn from drinking
water resources that serve communities with environmental justice concerns? 54
7.1.1.1 Research Activities-Water Acquisition Locations 54
7.1.2 Are hydraulically fractured oil and gas wells disproportionately located near communities with
environmental justice concerns? 54
7.1.2.1 Research Activities-Well Locations 54
7.1.3 Is wastewater from hydraulic fracturing operations being disproportionately treated or disposed of
(via POTWs or commercial treatment systems) in or near communities with environmental justice
concerns? 55
-------
EPA Hydraulic Fracturing Study Plan
November 2011
7.1.3.1 Research Activities-Wastewater Treatment/Disposal Locations 55
8 Analysis of Existing Data 56
8.1 Data Sources and Collection 56
8.1.1 Public Data Sources 56
8.1.2 Information Requests 56
8.2 Assuring Data Quality 58
8.3 Data Analysis 58
9 Case Studies 58
9.1 Case Study Selection 58
9.2 Retrospective Case Studies 63
9.3 Prospective Case Studies 66
10 Scenario Evaluations and Modeling 67
10.1 Scenario Evaluations 68
10.2 Case Studies 69
10.3 Modeling Tools 69
10.4 Uncertainty in Model Applications 71
11 Characterization of Toxicity and Human Health Effects 71
12 Summary 73
13 Additional Research Needs 81
13.1 Use of Drilling Muds in Oil and Gas Drilling 81
13.2 Land Application of Flowback or Produced Waters 81
13.3 Impacts from Disposal of Solids from Wastewater Treatment Plants 81
13.4 Disposal of Hydraulic Fracturing Wastewaters in Class II Underground Injection Wells 82
13.5 Fracturing or Re-Fracturing Existing Wells 82
13.6 Comprehensive Review of Compromised Waste Containment 82
13.7 Air Quality 82
13.8 Terrestrial and Aquatic Ecosystem Impacts 83
13.9 Seismic Risks 83
13.10 Occupational Risks 83
13.11 Public Safety Concerns 83
13.12 Economic Impacts 84
13.13 Sand Mining 84
References 85
iv
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Appendix A: Research Summary 98
Appendix B: Stakeholder Comments 110
Appendix C: Department of Energy's Efforts on Hydraulic Fracturing 113
Appendix D: Information Requests 114
Appendix E: Chemicals Identified in Hydraulic Fracturing Fluid and Flowback/Produced Water 119
Appendix F: Stakeholder-Nominated Case Studies 151
Appendix G: Assessing Mechanical Integrity 159
Cement Bond Tools 159
Temperature Logging 159
Noise Logging 160
Pressure Testing 160
Appendix H: Field Sampling and Analytical Methods 162
Field Sampling: Sample Types and Analytical Focus 162
Field Sampling Considerations 163
Use of Pressure Transducers 164
Development and Refinement of Laboratory-Based Analytical Methods 164
Potential Challenges 165
Matrix Interference 165
Analysis of Unknown Chemical Compounds 166
Data Analysis 166
Evaluation of Potential Indicators of Contamination 167
Glossary 170
v
-------
EPA Hydraulic Fracturing Study Plan
November 2011
List of Figures
Figure 1. Fundamental research questions posed for each identified stage 2
Figure 2. Natural gas production in the US 9
Figure 3. Shale gas plays in the contiguous US 10
Figure 4. Coalbed methane deposits in the contiguous US 11
Figure 5. Major tight gas plays in the contiguous US 12
Figure 6. Illustration of a horizontal well showing the water lifecycle in hydraulic fracturing 13
Figure 7. Differences in depth between gas wells and drinking water wells 13
Figure 8. Well construction 14
Figure 9. Water use and potential concerns in hydraulic fracturing operations 19
Figure 10a. Summary of research projects proposed for the first three stages of the hydraulic
fracturing water lifecycle 74
Figure 10b. Summary of research projects proposed for the first three stages of the hydraulic
fracturing water lifecycle 74
Figure 11a. Summary of research projects proposed for the last two stages of the hydraulic
fracturing water lifecycle 74
Figure lib. Summary of research projects proposed for the first three stages of the hydraulic
fracturing water lifecycle 74
List of Tables
Table 1. Research questions identified to determine the potential impacts of hydraulic fracturing
on drinking water resources 17
Table 2. Research activities and objectives 20
Table 3. Comparison of estimated water needs for hydraulic fracturing of horizontal wells in
different shale plays 22
Table 4. An example of the volumetric composition of hydraulic fracturing fluid 29
Table 5. Examples of naturally occurring substances that may be found in hydrocarbon-containing
formations 35
Table 6. Public data sources expected to be used as part of this study 57
Table 7. Decision criteria for selecting hydraulic fracturing sites for case studies 59
Table 8. Retrospective case study locations 60
Table 9. General approach for conducting retrospective case studies 64
Table 10. Tier 2 initial testing: sample types and testing parameters 64
Table 11. Tier 3 additional testing: sample types and testing parameters 65
Table 12. General approach for conducting prospective case studies 66
Table 13. Tier 3 field sampling phases 67
vi
-------
EPA Hydraulic Fracturing Study Plan
November 2011
List of Acronyms and Abbreviations
AOE area of evaluation
API American Petroleum Institute
ATSDR Agency for Toxic Substances and Disease Registry
BLM Bureau of Land Management
CBI confidential business information
CWT commercial wastewater treatment facility
DBP disinfection byproducts
DOE US Department of Energy
EIA US Energy Information Administration
EPA US Environmental Protection Agency
FWS US Fish and Wildlife Service
GIS geographic information systems
GWPC Ground Water Protection Council
mcf/d thousand cubic feet per day
mg/L milligram per liter
mmcf/d million cubic feet per day
NGO non-governmental organization
NIOSH National Institute for Occupational Safety and Health
NYS rdSGEIS New York State Revised Draft Supplemental Generic Environmental Impact Statement
ORD Office of Research and Development
pCi/L picocuries per liter
ppmv parts per million by volume
POTW publicly owned treatment works
PPRTV provisional peer-reviewed toxicity value
OA quality assurance
QAPP quality assurance project plan
QSAR quantitative structure-activity relationship
SAB Science Advisory Board
TDS total dissolved solids
UIC underground injection control
USACE US Army Corps of Engineers
USDW underground source of drinking water
USGS US Geological Survey
VOC volatile organic compound
vii
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Executive Summary
Natural gas plays a key role in our nation's clean energy future. Recent advances in drilling
technologies—including horizontal drilling and hydraulic fracturing—have made vast reserves of natural
gas economically recoverable in the US. Responsible development of America's oil and gas resources
offers important economic, energy security, and environmental benefits.
Hydraulic fracturing is a well stimulation technique used to maximize production of oil and natural gas in
unconventional reservoirs, such as shale, coalbeds, and tight sands. During hydraulic fracturing, specially
engineered fluids containing chemical additives and proppant are pumped under high pressure into the
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 or oil to the wellbore. As
the use of hydraulic fracturing has increased, so have concerns about its potential environmental and
human health impacts. Many concerns about hydraulic fracturing center on potential risks to drinking
water resources, although other issues have been raised. In response to public concern, the US Congress
directed the US Environmental Protection Agency (EPA) to conduct scientific research to examine the
relationship between hydraulic fracturing and drinking water resources.
This study plan represents an important milestone in responding to the direction from Congress. EPA is
committed to conducting a study that uses the best available science, independent sources of
information, and a transparent, peer-reviewed process that will ensure the validity and accuracy of the
results. The Agency will work in consultation with other federal agencies, state and interstate regulatory
agencies, industry, non-governmental organizations, and others in the private and public sector in
carrying out this study. Stakeholder outreach as the study is being conducted will continue to be a
hallmark of our efforts, just as it was during the development of this study plan.
EPA has already conducted extensive stakeholder outreach during the developing of this study plan. The
draft version of this study plan was developed in consultation with the stakeholders listed above and
underwent a peer review process by EPA's Science Advisory Board (SAB). As part of the review process,
the SAB assembled an independent panel of experts to review the draft study plan and to consider
comments submitted by stakeholders. The SAB provided EPA with its review of the draft study plan in
August 2011. EPA has carefully considered the SAB's recommendations in the development of this final
study plan.
The overall purpose of this study is to elucidate the relationship, if any, between hydraulic fracturing and
drinking water resources. More specifically, the study has been designed to assess the potential impacts
of hydraulic fracturing on drinking water resources and to identify the driving factors that affect the
severity and frequency of any impacts. Based on the increasing development of shale gas resources in
the US, and the comments EPA received from stakeholders, this study emphasizes hydraulic fracturing in
shale formations. Portions of the research, however, are also intended to provide information on
hydraulic fracturing in coalbed methane and tight sand reservoirs. The scope of the research includes
the hydraulic fracturing water use lifecycle, which is a subset of the greater hydrologic cycle. For the
purposes of this study, the hydraulic fracturing water lifecycle begins with water acquisition from
viii
-------
EPA Hydraulic Fracturing Study Plan
November 2011
surface or ground water and ends with discharge into surface waters or injection into deep wells.
Specifically, the water lifecycle for hydraulic fracturing consists of water acquisition, chemical mixing,
well injection, flowback and produced water (collectively referred to as "hydraulic fracturing
wastewater"), and wastewater treatment and waste disposal.
The EPA study is designed to provide decision-makers and the public with answers to the five
fundamental questions associated with the hydraulic fracturing water lifecycle:
• Water Acquisition: What are the potential impacts of large volume water withdrawals from
ground and surface waters on drinking water resources?
• Chemical Mixing: What are the possible impacts of surface spills on or near well pads of
hydraulic fracturing fluids on drinking water resources?
• Well Injection: What are the possible impacts of the injection and fracturing process on drinking
water resources?
• Flowback and Produced Water: What are the possible impacts of surface spills on or near well
pads of flowback and produced water on drinking water resources?
• Wastewater Treatment and Waste Disposal: What are the possible impacts of inadequate
treatment of hydraulic fracturing wastewaters on drinking water resources?
Answering these questions will involve the efforts of scientists and engineers with a broad range of
expertise, including petroleum engineering, fate and transport modeling, ground water hydrology, and
toxicology. The study will be conducted by multidisciplinary teams of EPA researchers, in collaboration
with outside experts from the public and private sector. The Agency will use existing data from hydraulic
fracturing service companies and oil and gas operators, federal and state agencies, and other sources.
To supplement this information, EPA will conduct case studies in the field and generalized scenario
evaluations using computer modeling. Where applicable, laboratory studies will be conducted to
provide a better understanding of hydraulic fracturing fluid and shale rock interactions, the treatability
of hydraulic fracturing wastewaters, and the toxicological characteristics of high-priority constituents of
concern in hydraulic fracturing fluids and wastewater. EPA has also included a screening analysis of
whether hydraulic fracturing activities may be disproportionately occurring in communities with
environmental justice concerns.
Existing data will be used answer research questions associated with all stages of the water lifecycle,
from water acquisition to wastewater treatment and waste disposal. EPA has requested information
from hydraulic fracturing service companies and oil and gas well operators on the sources of water used
in hydraulic fracturing fluids, the composition of these fluids, well construction practices, and
wastewater treatment practices. EPA will use these data, as well as other publically available data, to
help assess the potential impacts of hydraulic fracturing on drinking water resources.
Retrospective case studies will focus on investigating reported instances of drinking water resource
contamination in areas where hydraulic fracturing has already occurred. EPA will conduct retrospective
case studies at five sites across the US. The sites will be illustrative of the types of problems that have
been reported to EPA during stakeholder meetings held in 2010 and 2011. A determination will be made
ix
-------
EPA Hydraulic Fracturing Study Plan
November 2011
on the presence and extent of drinking water resource contamination as well as whether hydraulic
fracturing contributed to the contamination. The retrospective sites will provide EPA with information
regarding key factors that may be associated with drinking water contamination.
Prospective case studies will involve sites where hydraulic fracturing will occur after the research is
initiated. These case studies allow sampling and characterization of the site before, during, and after
water acquisition, drilling, hydraulic fracturing fluid injection, flowback, and gas production. EPA will
work with industry and other stakeholders to conduct two prospective case studies in different regions
of the US. The data collected during prospective case studies will allow EPA to gain an understanding of
hydraulic fracturing practices, evaluate changes in water quality over time, and assess the fate and
transport of potential chemical contaminants.
Generalized scenario evaluations will use computer modeling to allow EPA to explore realistic
hypothetical scenarios related to hydraulic fracturing activities and to identify scenarios under which
hydraulic fracturing activities may adversely impact drinking water resources.
Laboratory studies will be conducted on a limited, opportunistic basis. These studies will often parallel
case study investigations. The laboratory work will involve characterization of the chemical and
mineralogical properties of shale rock and potentially other media as well as the products that may form
after interaction with hydraulic fracturing fluids. Additionally, laboratory studies will be conducted to
better understand the treatment of hydraulic fracturing wastewater with respect to fate and transport
of flowback or produced water constituents.
Toxicological assessments of chemicals of potential concern will be based primarily on a review of
available health effects data. The substances to be investigated include chemicals used in hydraulic
fracturing fluids, their degradates and/or reaction products, and naturally occurring substances that may
be released or mobilized as a result of hydraulic fracturing. It is not the intent of this study to conduct a
complete health assessment of these substances. Where data on chemicals of potential concern are
limited, however, quantitative structure-activity relationships—and other approaches—may be used to
assess toxicity.
The research projects identified for this study are summarized in Appendix A. EPA is working with other
federal agencies to collaborate on some aspects of the research described in this study plan. All research
associated with this study will be conducted in accordance with EPA's Quality Assurance Program for
environmental data and meet the Office of Research and Development's requirements for the highest
level of quality assurance. Quality Assessment Project Plans will be developed, applied, and updated as
the research progresses.
A first report of research results will be completed in 2012. This first report will contain a synthesis of
EPA's analysis of existing data, available results from retrospective cases studies, and initial results from
scenario evaluations, laboratory studies, and toxicological assessments. Certain portions of the work
described here, including prospective case studies and laboratory studies, are long-term projects that
are not likely to be finished at that time. An additional report in 2014 will synthesize the results of those
long-term projects along with the information released in 2012. Figures 10 and 11 summarize the
x
-------
EPA Hydraulic Fracturing Study Plan
November 2011
estimated timelines of the research projects outlined in this study plan. EPA is committed to ensuring
that the results presented in these reports undergo thorough quality assurance and peer review.
EPA recognizes that the public has raised concerns about hydraulic fracturing that extend beyond the
potential impacts on drinking water resources. This includes, for example, air impacts, ecological effects,
seismic risks, public safety, and occupational risks. These topics are currently outside the scope of this
study plan, but should be examined in the future.
xi
-------
EPA Hydraulic Fracturing Study Plan
November 2011
1 Introduction and Purpose of Study
Hydraulic fracturing is an important means of accessing one of the nation's most vital energy resources,
natural gas. Advances in technology, along with economic and energy policy developments, have
spurred a dramatic growth in the use of hydraulic fracturing across a wide range of geographic regions
and geologic formations in the US for both oil and gas production. As the use of hydraulic fracturing has
increased, so have concerns about its potential impact on human health and the environment, especially
with regard to possible effects on drinking water resources. These concerns have intensified as hydraulic
fracturing has spread from the southern and western regions of the US to other settings, such as the
Marcellus Shale, which extends from the southern tier of New York through parts of Pennsylvania, West
Virginia, eastern Ohio, and western Maryland. Based on the increasing importance of shale gas as a
source of natural gas in the US, and the comments received by EPA from stakeholders, this study plan
emphasizes hydraulic fracturing in shale formations containing natural gas. Portions of the research,
however, may provide information on hydraulic fracturing in other types of oil and gas reservoirs, such
as coalbeds and tight sands.
In response to escalating public concerns and the anticipated growth in oil and natural gas exploration
and production, the US Congress directed EPA in fiscal year 2010 to conduct research to examine the
relationship between hydraulic fracturing and drinking water resources (US House, 2009):
The conferees urge the Agency to carry out a study on the relationship between
hydraulic fracturing and drinking water, using a credible approach that relies on the best
available science, as well as independent sources of information. The conferees expect
the study to be conducted through a transparent, peer-reviewed process that will ensure
the validity and accuracy of the data. The Agency shall consult with other federal
agencies as well as appropriate state and interstate regulatory agencies in carrying out
the study, which should be prepared in accordance with the Agency's quality assurance
principles.
This document presents the final study plan for EPA's research on hydraulic fracturing and drinking
water resources, responding to both the direction from Congress and concerns expressed by the public.
For this study, EPA defines "drinking water resources" to be any body of water, ground or surface, that
could currently, or in the future, serve as a source of drinking water for public or private water supplies.
The overarching goal of this research is to answer the following questions:
• Can hydraulic fracturing impact drinking water resources?
• If so, what conditions are associated with these potential impacts?
To answer these questions, EPA has identified a set of research activities associated with each stage of
the hydraulic fracturing water lifecycle (Figure 1), from water acquisition through the mixing of
chemicals and actual fracturing to post-fracturing production, including the management of hydraulic
fracturing wastewaters (commonly referred to as "flowback" and "produced water") and ultimate
1
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Water Use in Hydraulic
Fracturing Operations
Fundamental Research Question
Water Acquisition
Wastewater T reatment
and Waste Disposal
Chemical Mixing
Well Injection
Flowback and
Produced Water
What are the possible impacts of inadequate treatment of hydraulic
fracturing wastewaters on drinking water resources?
What are the possible impacts of surface spills on or near well pads of
flowback and produced water on drinking water resources?
What are the potential impacts of large volume water withdrawals from
ground and surface waters on drinking water resources?
What are the possible impacts of the injection and fracturing process
on drinking water resources?
What are the possible impacts of surface spills on or near well pads of
hydraulic fracturing fluids on drinking water resources?
FIGURE 1. FUNDAMENTAL RESEARCH QUESTIONS POSED FOR EACH IDENTIFIED STAGE
-------
EPA Hydraulic Fracturing Study Plan
November 2011
treatment and disposal. These research activities will identify potential impacts to drinking water
resources of water withdrawals as well as fate and transport of chemicals associated with hydraulic
fracturing. Information about the toxicity of contaminants of concern will also be gathered. This
information can then be used to assess the potential risks to drinking water resources from hydraulic
fracturing activities. Ultimately, the results of this study will inform the public and provide policymakers
at all levels with sound scientific knowledge that can be used in decision-making processes.
The study plan is organized as follows:
• Chapter 2 details the process for developing the study plan and the criteria for prioritizing the
research.
• Chapter 3 provides a brief overview of unconventional oil and natural gas resources and
production.
• Chapter 4 outlines the hydraulic fracturing water lifecycle and the research questions associated
with each stage of the lifecycle.
• Chapter 5 briefly describes the research approach.
• Chapter 6 provides background information on each stage of the hydraulic fracturing water
lifecycle and describes research specific to each stage.
• Chapter 7 provides background information and describes research to assess concerns
pertaining to environmental justice.
• Chapter 8 describes how EPA is collecting, evaluating, and analyzing existing data.
• Chapter 9 presents the retrospective and prospective case studies.
• Chapter 10 discusses scenario evaluations and modeling using existing data and new data
collected from case studies.
• Chapter 11 explains how EPA will characterize toxicity of constituents associated with hydraulic
fracturing fluids to human health.
• Chapter 12 summarizes how the studies will address the research questions posed for each
stage of the water lifecycle.
• Chapter 13 notes additional areas of concern relating to hydraulic fracturing that are currently
outside the scope of this study plan.
Also included at the end of this document are eight appendices and a glossary.
2 Process for Study Plan Development
2.1 Stakeholder Input
Stakeholder input played an important role in the development of the hydraulic fracturing study plan.
Many opportunities were provided for the public to comment on the study scope and case study
locations. The study plan was informed by information exchanges involving experts from the public and
private sectors on a wide range of technical issues. EPA will continue to engage stakeholders throughout
the course of the study and as results become available.
3
-------
EPA Hydraulic Fracturing Study Plan
November 2011
EPA has engaged stakeholders in the following ways:
Federalstate, and tribal partner consultations. Webinars were held with state partners in May 2010,
with federal partners in June 2010, and with Indian tribes in August 2010. The state webinar included
representatives from 21 states as well as representatives from the Association of State Drinking Water
Administrators, the Association of State and Interstate Water Pollution Control Administrators, the
Ground Water Protection Council (GWPC), and the Interstate Oil and Gas Compact Commission. Federal
partners included the Bureau of Land Management (BLM), the US Geological Survey (USGS), the US Fish
and Wildlife Service (FWS), the US Forest Service, the US Department of Energy (DOE), the US Army
Corps of Engineers (USACE), the National Park Service, and the Agency for Toxic Substances and Disease
Registry (ATSDR). There were 36 registered participants for the tribal webinar, representing 25 tribal
governments. In addition, a meeting with the Haudenosaunee Environmental Task Force in August 2010
included 20 representatives from the Onondaga, Mohawk, Tuscarora, Cayuga, and Tonawanda Seneca
Nations. The purpose of these consultations was to discuss the study scope, data gaps, opportunities for
sharing data and conducting joint studies, and current policies and practices for protecting drinking
water resources.
Sector-specific meetings. Separate webinars were held in June 2010 with representatives from industry
and non-governmental organizations (NGOs) to discuss the public engagement process, the scope of the
study, coordination of data sharing, and other key issues. Overall, 176 people representing various
natural gas production and service companies and industry associations participated in the webinars, as
well as 64 people representing NGOs.
Informational public meetings. Public information meetings were held between July and September
2010 in Fort Worth, Texas; Denver, Colorado; Canonsburg, Pennsylvania; and Binghamton, New York. At
these meetings, EPA presented information on its reasons for studying hydraulic fracturing, an overview
of what the study might include, and how stakeholders can be involved. Opportunities to present oral
and written comments were provided, and EPA specifically asked for input on the following questions:
• What should be EPA's highest priorities?
• Where are the gaps in current knowledge?
• Are there data and information EPA should know about?
• Where do you recommend EPA conduct case studies?
Total attendance for all of the informational public meetings exceeded 3,500 and more than 700 verbal
comments were heard.
Summaries of the stakeholder meetings can be found at http://www.epa.gov/hydraulicfracturing.
Technical Workshops. Technical workshops organized by EPA were in February and March 2011 to
explore the following focus areas: Chemical and Analytical Methods (February 24-25), Well Construction
and Operations (March 10-11), Fate and Transport (March 28-29), and Water Resource Management
(March 29-30). The technical workshops centered around three goals: (1) inform EPA of the current
technology and practices being used in hydraulic fracturing; (2) identify existing/current research related
4
-------
EPA Hydraulic Fracturing Study Plan
November 2011
to the potential impacts of hydraulic fracturing on drinking water resources; and (3) provide an
opportunity for EPA scientists to interact with technical experts. EPA invited technical experts from the
oil and natural gas industry, consulting firms, laboratories, state and federal agencies, and
environmental organizations to participate in the workshops. The information presented at the
workshops will inform the research outlined in this study plan.
Other opportunities to comment. In addition to conducting the meetings listed above, EPA provided
stakeholders with opportunities to submit electronic or written comments on the hydraulic fracturing
study. EPA received over 5,000 comments, which are summarized in Appendix B.
2.2 Science Advisory Board Involvement
The EPA Science Advisory Board (SAB) is a federal advisory committee that provides a balanced, expert
assessment of scientific matters relevant to EPA. An important function of the SAB is to review EPA's
technical programs and research plans. Members of the advisory board and ad hoc panels are
nominated by the public and are selected based on factors such as technical expertise, knowledge, and
experience. The panel formation process, which is designed to ensure public transparency, also includes
an assessment of potential conflicts of interest or lack of impartiality. SAB panels are composed of
individuals with a wide range of expertise to ensure that the technical advice is comprehensive and
balanced.
EPA's Office of Research and Development (ORD) has engaged the SAB through the development of this
study plan. This process is described below.
Initial SAB review of the study plan scope. During fiscal year 2010, ORD developed a document that
presented the scope and initial design of the study (USEPA, 2010a). The document was submitted to the
SAB's Environmental Engineering Committee for review in March 2010. In its response to EPA in June
2010 (USEPA, 2010c), the SAB recommended that:
• Initial research should be focused on potential impacts to drinking water resources, with later
research investigating more general impacts on water resources.
• Engagement with stakeholders should occur throughout the research process.
• Five to ten in-depth case studies at "locations selected to represent the full range of regional
variability of hydraulic fracturing across the nation" should be part of the research plan.
EPA concurred with these recommendations and developed the draft study plan accordingly.
The SAB also cautioned EPA against studying all aspects of oil and gas production, stating that the study
should "emphasize human health and environmental concerns specific to, or significantly influenced by,
hydraulic fracturing rather than on concerns common to all oil and gas production activities." Following
this advice, EPA focused the draft study plan on features of oil and gas production that are particular
to—or closely associated with—hydraulic fracturing, and their impacts on drinking water resources.
SAB review of the draft study plan. EPA developed a Draft Plan to Study the Potential Impacts of
Hydraulic Fracturing on Drinking Water Resources (USEPA, 2011a) after receiving the SAB's review of the
5
-------
EPA Hydraulic Fracturing Study Plan
November 2011
scoping document in June 2010 and presented the draft plan to the SAB for review in February 2011.
The SAB formed a panel to review the plan,1 which met in March 2011. The panel developed an initial
review of the draft study plan and subsequently held two public teleconference calls in May 2011 to
discuss this review. The review panel's report was discussed by the full SAB during a public
teleconference in July 2011. The public had the opportunity to submit oral and written comments at
each meeting and teleconference of the SAB. As part of the review process, the public submitted over
300 comments for consideration.2 The SAB considered the comments submitted by the public as they
formulated their review of the draft study plan. In their final report to the Agency, the SAB generally
supported the research approach outlined in the draft study plan and agreed with EPA's use of the
water lifecycle as a framework for the study (EPA, 2011b). EPA carefully considered and responded to
the SAB's recommendations on September 27, 2011.3
2.3 Research Prioritization
In developing this study plan, EPA considered the results of a review of the literature,4 technical
workshops, comments received from stakeholders, and input from meetings with interested parties,
including other federal agencies, Indian tribes, state agencies, industry, and NGOs. EPA also considered
recommendations from the SAB reviews of the study plan scope (USEPA, 2010c) and the draft study plan
(USEPA, 2011b).
In response to the request from Congress, EPA identified fundamental questions (see Figure 1) that
frame the scientific research to evaluate the potential for hydraulic fracturing to impact drinking water
resources. Following guidance from the SAB, EPA used a risk-based prioritization approach to identify
research that addresses the most significant potential risks at each stage of the hydraulic fracturing
water lifecycle. The risk assessment paradigm (i.e., exposure assessment, hazard identification, dose-
response relationship assessment, and risk characterization) provides a useful framework for asking
scientific questions and focusing research to accomplish the stated goals of this study, as well as to
inform full risk assessments in the future. For the current study, emphasis is placed on exposure
assessment and hazard identification. Exposure assessment will be informed by work on several tasks
including, but not limited to, modeling (i.e., water acquisition, injection/flowback/production,
wastewater management), case studies, and evaluation of existing data. Analysis of the chemicals used
in hydraulic fracturing, how they are used, and their fate will provide useful data for hazard
identification. A definitive evaluation of dose-response relationships and a comprehensive risk
characterization are beyond the scope of this study.
1 Biographies on the members of the SAB panel can be found at http://yosemite.epa.gov/sab/sabproduct.nsf/
fedrgstr_activites/HFSP!OpenDocument&TableRow=2.1#2.
2 These comments are available as part of the material from the SAB public meetings, and can be found at
http://yosemite.epa.gov/sab/SABPRODUCT.NSF/81e39f4c09954fcb85256ead006be86e/
d3483ab445ae61418525775900603e79!OpenDocument&TableRow=2.2#2.
3 See http://yosemite.epa.gov/sab/sabproduct.nsf/2BC3CD632FCC0E99852578E2006DF890/$File/EPA-SAB-ll-
012_Response_09-27-2011.pdf and http://water.epa.gov/type/groundwater/uic/class2/hydraulicfracturing/
upload/final_epa_response_to_sab_review_table_091511.pdf.
4 The literature review includes information from more than 120 articles, reports, presentations and other
materials. Information resulting from this literature review is incorporated throughout this study plan.
6
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Other criteria considered in prioritizing research activities included:
• Relevance: Only work that may directly inform an assessment of the potential impacts of
hydraulic fracturing on drinking water resources was considered.
• Precedence: Work that needs to be completed before other work can be initiated received a
higher priority.
• Uniqueness of the contribution: Relevant work already underway by others received a lower
priority for investment by EPA.
• Funding: Work that could provide EPA with relevant results given a reasonable amount of
funding received a higher priority.
• Leverage: Relevant work that EPA could leverage with outside investigators received a higher
priority.
As the research progresses, EPA may determine that modifying the research approach outlined in this
study plan or conducting additional research within the overall scope of the plan is prudent in order to
better answer the research questions. In that case, modifications to the activities that are currently
planned may be necessary.
2.4 Next Steps
EPA is committed to continuing our extensive outreach efforts to stakeholder as the study progresses.
This will include:
• Periodic updates will be provided to the public on the progress of the research.
• A peer-reviewed study report providing up-to-date research results will be released to the public
in 2012.
• A second, peer-reviewed study report will be released to the public in 2014. This report will
include information from the entire body of research described in this study plan.
2.5 Interagency Cooperation
In a series of meetings, EPA consulted with several federal agencies regarding research related to
hydraulic fracturing. EPA met with representatives from DOE5 and DOE's National Energy Technology
Laboratory, USGS, and USACE to learn about research that those agencies are involved in and to identify
opportunities for collaboration and leverage. As a result of those meetings, EPA has identified work
being done by others that can inform its own study on hydraulic fracturing. EPA and other agencies are
collaborating on information gathering and research efforts. In particular, the Agency is coordinating
with DOE and USGS on existing and future research projects relating to hydraulic fracturing. Meetings
between EPA and DOE have enabled the sharing of each agency's research on hydraulic fracturing and
the exchange of information among experts.
5 DOE's efforts are briefly summarized in Appendix C.
7
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Specifically, DOE, USGS, USACE, and the Pennsylvania Geological Survey have committed to collaborate
with EPA on this study. All four are working with EPA on one of the prospective case studies
(Washington County, Pennsylvania). USGS is performing stable isotope analysis of strontium for all
retrospective and prospective case studies. USGS is also sharing data on their studies in Colorado and
New Mexico.
Federal agencies also had an opportunity to provide comments on EPA's Draft Plan to Study the
Potential Impacts of Hydraulic Fracturing on Drinking Water Resources through an interagency review.
EPA received comments from the ATSDR, DOE, BLM, USGS, FWS, the Office of Management and Budget,
the US Energy Information Administration (EIA), the Occupational Safety and Health Administration, and
the National Institute of Occupational Safety and Health (NIOSH). These comments were reviewed and
the study plan was appropriately modified.
2.6 Quality Assurance
All EPA-funded intramural and extramural research projects that generate or use environmental data to
make conclusions or recommendations must comply with Agency Quality Assurance (QA) Program
requirements (USEPA, 2002). EPA recognizes the value of using a graded approach such that QA
requirements are based on the importance of the work to which the program applies. Given the
significant national interest in the results of this study, the following rigorous QA approach will be used:
• Research projects will comply with Agency requirements and guidance for quality assurance
project plans (QAPPs), including the use of systematic planning.
• Technical systems audits, audits of data quality, and data usability (quality) assessments will be
conducted as described in QAPPs.
• Performance evaluations of analytical systems will be conducted.
• Products6 will undergo QA review.
• Reports will have readily identifiable QA sections.
• Research records will be managed according to EPA's record schedule 501 for Applied and
Directed Scientific Research (USEPA, 2009).
All EPA organizations involved with the generation or use of environmental data are supported by QA
professionals who oversee the implementation of the QA program for their organization. Given the
cross-organizational nature of the research, EPA has identified a Program QA Manager who will
coordinate the rigorous QA approach described above and oversee its implementation across all
participating organizations. The organizational complexity of the hydraulic fracturing research effort also
demands that a quality management plan be written to define the QA-related policies, procedures,
roles, responsibilities, and authorities for this research. The plan will document consistent QA
procedures and practices that may otherwise vary between organizations.
6 Applicable products may include reports, journal articles, symposium/conference papers, extended abstracts,
computer products/software/models/databases and scientific data.
8
-------
EPA Hydraulic Fracturing Study Plan
November 2011
3 Overview of Unconventional Oil and Natural Gas Production
Hydraulic fracturing is often used to stimulate the production of hydrocarbons from unconventional oil
and gas reservoirs, which include shales, coalbeds, and tight sands.7 "Unconventional reservoirs" refers
to oil and gas reservoirs whose porosity, permeability, or other characteristics differ from those of
conventional sandstone and carbonate reservoirs (USEIA, 2011a). Many of these formations have poor
permeability, so reservoir stimulation techniques such as hydraulic fracturing are needed to make oil
and gas production cost-effective. In contrast, conventional oil and gas reservoirs have a higher
permeability and operators generally have not used hydraulic fracturing. However, hydraulic fracturing
has become increasingly used to increase the gas flow in wells that are considered conventional
reservoirs and make them even more economically viable (Martin and Valko, 2007).
Unconventional natural gas development has become an increasingly important source of natural gas in
the US in recent years. It accounted for 28 percent of total natural gas production in 1998 (Arthur et al.,
2008). Figure 2 illustrates that this percentage rose to 50 percent in 2009, and is projected to increase to
60 percent in 2035 (USEIA, 2010).
20%,
Natural Gas Production in the US
11% 8%
14%
22%
45%
2009
(—24 trillion cubic feet per year)
Sources of Natural Gas
| Net imports ~ Coalbed methane
| Shale gas ¦ Alaska
~ Tight sands ~ Associated with oil
8%
Projected for 2035
-26 trillion cubic feet per year)
~ Non-associated onshore
~ Non-associated offshore
FIGURE 2. NATURAL GAS PRODUCTION IN THE US (DATA FROM USEIA, 2010)
7 Hydraulic fracturing has also been used for other purposes, such as removing contaminants from soil and ground
water at waste disposal sites, making geothermal wells more productive, and completing water wells (Nemat-
Nassar et al., 1983; New Hampshire Department of Environmental Services, 2010).
9
-------
EPA Hydraulic Fracturing Study Plan
November 2011
This rise in hydraulic fracturing activities to produce gas from unconventional reservoirs is also reflected
in the number of drilling rigs operating in the US. There were 603 horizontal gas rigs in June 2010, an
increase of 277 from the previous year (Baker Hughes, 2010). Horizontal rigs are commonly used when
hydraulic fracturing is used to stimulate gas production from shale formations.
Niobrara*
• Montana
i->-; Throst
Be*
Bakken
(Hot Powder River Gammon
asijT" ---Basin—_
M ch gan
Niobrara*
Fores
City Basin
linois
Basin
¦ ; X lihta Bi
Martrmg. ¦ ' *r
Derwer
Basin
Excello-
Mulky,
New
Albany
serokee. Platform
Pierre
Woodford
Raton,
Basin |
lyettevlTl
Monterey
Arkorria Basr
1 Conasauga
Valley.s& Ridge
Province
lone Sprang-.
Barnett
Ft. Worth
Basin
Permian
Basm
Barnett-"
Woodford.
Hayhesville-
Bossier
Peareall
Basins
Lower 48 states shale plays
levonian |Ohio|i
i ""TNIarcellus
3a-13 Mafia. ¦
Ventura. Los
Angeles
Bas.ns
Shale plays
Curent plays
Prospective plays
Stacked plays
. Shallowest)' youngest
- Intermediate depth/ age
¦ Deepest' oldest
* Mixed stiae &
cfialls pay
" MbcettshaieS
&nest one pay
¦"Mixed sJiaiei
&gsrt daostone-
SRstone-sandstore
^ ! I 1
100 200 300 400
Source: Energy Information Administration based on data from various pubishea studies.
Updated: May 6 2011
FIGURE 3. SHALE GAS PLAYS IN THE CONTIGUOUS US
Shale gas extraction. Shale rock formations have become an important source of natural gas in the US
and can be found in many locations across the country, as shown in Figure 3. Depths for shale gas
formations can range from 500 to 13,500 feet below the earth's surface (GWPC and ALL Consulting,
2009). At the end of 2009, the five most productive shale gas fields in the country—the Barnett,
Haynesville, Fayetteville, Woodford, and Marcellus Shales—were producing 8.3 billion cubic feet of
natural gas per day (Zoback et al., 2010). According to recent figures from EIA, shale gas constituted 14
percent of the total US natural gas supply in 2009, and will make up 45 percent of the US gas supply in
2035 if current trends and policies persist (USEIA, 2010).
Oil production has similarly increased in oil-bearing shales following the increased use of hydraulic
fracturing. Proven oil production from shales has been concentrated primarily in the Williston Basin in
North Dakota, although oil production is increasing in the Eagle Ford Shale in Texas, the Niobrara Shale
10
-------
EPA Hydraulic Fracturing Study Plan
November 2011
in Colorado, Nebraska, arid Wyoming, and the Utica Shale in Ohio (USEIA, 2010, 2011b;
OilShaleGas.com, 2010).
Production of coalbed methane. Coalbed methane is formed as part of the geological process of coai
generation and is contained in varying quantities within ail coal. Depths of coalbed methane formations
range from 450 feet to greater than 10,000 feet (Rogers et al., 2007; National Research Council, 2010).
At greater depths, however, the permeability decreases and production is lower. Below 7,000 feet,
efficient production of coalbed methane can be challenging from a cost-effectiveness perspective
(Rogers et al., 2007). Figure 4 displays coalbed methane reservoirs in the contiguous US. In 1984, there
were very few coalbed methane wells in the US; by 1990, there were almost 8,000, and in 2000, there
were almost 14,000 (USEPA, 2004). In 2009, natural gas production from coalbed methane reservoirs
made up 8 percent of the total US natural gas production; this percentage is expected to remain
relatively constant over the next 20 years if current trends and policies persist (USEIA, 2010). Production
of gas from coalbeds almost always requires hydraulic fracturing (USEPA, 2004), and many existing
coalbed methane wells that have not been fractured are now being considered for hydraulic fracturing.
&WL ¦"'¦f.'t:¥
Coalbed Methane Fields, Lower 48 States
Norm Centra
Coal Region
-Coos Bay
toM
Dwder River
Basin
V-~Horn
Wntl River BawrL. ©as
Wyoming
j. Northern
; Appalachian
Greyer Green! . -nknn ah-Carbon Basin •
, River B3s.r> ''^rV - ' I Park Basin \ForSstPty
\ . >1 V"
SW Colprado
Coal
Cherokee
: i "'i• i
Deep River
i
Black Warrior
M, Basin
ate* mm
Basin
I 1 I
0 100 200 300 400
soutnwt nei i
Coal Roaon
Gulf Coast
Coal Ren
Coalbed Methane Fields
Coal Basins, Regions & Fields
HSKe..
Source: Energy Information Administration based on data from USGS and various published studies
Updated April 8. 2009
FIGURE 4. COALBED METHANE DEPOSITS IN THE CONTIGUOUS US
Tight sands. Tight sands (gas-bearing, fine-grained sandstones or carbonates with a low permeability)
accounted for 28 percent of total gas production in the US in 2009 (USEIA, 2010), but may account for as
much as 35 percent of the nation's recoverable gas reserves (Oil and Gas Investor, 2005). Figure 5 shows
the locations of tight gas plays in the US. Typical depths of tight sand formations range from 1,200 to
20,000 feet across the US (Prouty, 2001). Almost all tight sand reservoirs require hydraulic fracturing to
release gas unless natural fractures are present.
11
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Major Tight Gas Plays, Lower 48 States
\¦ ,; ;•. Eagi.
-. S - -^-9^" 53sn b"
f Cretaceous
, / : • ^j \j t
Greater Green k Wra RlVW Basin
^ River Basto ^Cretaceous- Lower Tertiary
Mesaveitfe-
La nee-Lew is
•ma Ba*ry£ -
Waneos- Pfceanc®
Dakota Basn
/
IWsavorde • -
*fctured Cliffs
Miles
0 100 200 300 400
Davis
R Worth
Basin
I I Tight Gas Plays
Stacked Plays
Shallowest / Youngest
Bas us
Deepest / Oldest
Source: Energy Information Administration based on data from various published studies
Updated June 6, 2010
FIGURE 5. MAJOR TIGHT GAS PLAYS IN THE CONTIGUOUS US
The following sections provide an overview of how site selection and preparation, well construction and
development, hydraulic fracturing, and natural gas production apply to unconventional natural gas
production. The current regulatory framework that governs hydraulic fracturing activities is briefly
described in Section 3.5.
3,1 Site Selection and Preparation
The hydraulic fracturing process begins with exploring possible well sites, followed by selecting and
preparing an appropriate site. In general, appropriate sites are those that are considered most likely to
yield substantial quantities of natural gas at minimum cost. Other factors, however, may be considered
in the selection process. These include proximity to buildings and other infrastructure, geologic
considerations, and proximity to natural gas pipelines or the feasibility of installing new pipelines
(Chesapeake Energy, 2009). Laws and regulations may also influence site selection. For example,
applicants applying for a Marcellus Shale natural gas permit in Pennsylvania must provide information
about proximity to coal seams and distances from surface waters and water supplies (PADEP, 2010a).
During site preparation, an area is cleared to provide space to accommodate one or more wellheads;
tanks and/or pits for holding water, used drilling fluids, and other materials; and space for trucks and
other equipment. At a typical shale gas production site, a 3- to 5-acre space is needed in addition to
access roads for transporting materials to and from the well site. If not already present, both the site
and access roads need to be built or improved to support heavy equipment.
12
-------
EPA Hydraulic Fracturing Study Plan
November 2011
3.2 Well Construction and Development
3,2,1 Types of Wells
Current practices in drilling for natural gas include drilling vertical, horizontal, and directional (S-shaped)
wells. On the following pages, two different well completions are depicted with one in a typical deep
shale gas-bearing formation like the Marcellus Shale (Figure 6) and one in a shallower environment
(Figure 7), which is often encountered where coalbed methane or tight sand gas production takes place.
The figures demonstrate a significant difference in the challenges posed for protecting underground
drinking water resources. The deep shale gas environment typically has several thousand feet of rock
formation separating underground drinking water resources, while the other shows that gas production
can take place at shallow depths that also contain underground sources of drinking water (USDWs). The
water well in Figure 7 illustrates an example of the relative depths of a gas well and a water well
Water Use in Hydraulic Fracturing Operations
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 Waste Disposal - The
wastewater is then transported for treatment and/or
disposal.
Hydraulic fracturing often involves
the injection of more than a million
gallons of water, chemicals, and sand
at high pressure down the well. The
depth and length of the well varies
depending on the characteristics of
the hydrocarbon-bearing formation.
The pressurized fluid mixture causes
the formation to crack, allowing
natural gas or oil to flow up the well.
Induced Fractures
Hydrocarbon-bearing
Formation
Water
Acquisition
Well
Injection
Flowback and
Produced Water
Wastewater
Treatment and
Waste Disposal
Chemical
Mixing
Storage
tanks
Aquifer
FIGURE 6. ILLUSTRATION OF A HORIZONTAL WELL SHOWING THE WATER LIFECYCLE IN HYDRAULIC FRACTURING
Figure 6 depicts a horizontal well, which is composed of both vertical and horizontal legs. The depth and
length of the well varies with the location and properties of the gas-containing formation. In
unconventional cases, the well can extend more than a mile below the ground surface (Chesapeake
13
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Energy, 2010) while the "toe" of the
horizontal leg can be almost two miles
from the vertical leg (Zoback et al.,
2010). Horizontal drilling provides more
exposure to a formation than a vertical
well does, making gas production more
economical. It may also have the
advantage of limiting environmental
disturbances on the surface because
fewer wells are needed to access the
natural gas resources in a particular area
(GWPC and ALL Consulting, 2009).
The technique of multilateral drilling is
becoming more prevalent in gas
production in the Marcellus Shale region
(Kargbo et al., 2010) and elsewhere. In
multilateral drilling, two or more
horizontal production holes are drilled
from a single surface location (Ruszka,
2007) to create an arrangement
resembling an upside-down tree, with
the vertical portion of the well as the
"trunk," and multiple "branches"
extending out from it in different
directions and at different depths.
3.2.2 Well Design and Construction
According to American Petroleum Institute (API, 2009a), the goal of well design is to "ensure the
environmentally sound, safe production of hydrocarbons by containing them inside the well, protecting
ground water resources, isolating the production formations from other formations, and by proper
execution of hydraulic fractures and other stimulation operations." Proper well construction is essential
for isolating the production zone from drinking water resources, and includes drilling a hole, installing
steel pipe (casing), and cementing the pipe in place. These activities are repeated multiple times
throughout the drilling event until the well is completed.
Drilling. A drilling string—composed of a drill bit, drill collars, and a drill pipe—is used to drill the well.
During the drilling process, a drilling fluid such as compressed air or a water- or oil-based liquid ("mud")
is circulated down the drilling string. Water-based liquids typically contain a mixture of water, barite,
clay, and chemical additives (OilGasGlossary.com, 2010). Drilling fluid serves multiple purposes,
including cooling the drill bit, lubricating the drilling assembly, removing the formation cuttings,
13
Water Well
Gas We
Mixture of
water,
chemicals,
and
sand
open
Drinking Water Resources
Gas and Water Resources
Mostly Gas Resources
The targeted formation is
fractured by fluids injected with
a pressure that exceeds the
parting pressure of the rock.
Induced
Fractures
FIGURE 7. DIFFERENCES IN DEPTH BETWEEN GAS WELLS AND
DRINKING WATER WELLS
-------
EPA Hydraulic Fracturing Study Plan
November 2011
maintaining the pressure control of the well, and
stabilizing the hole being drilled. Once removed
from the wellbore, both drilling liquids and drill
cuttings must be treated, recycled, and/or
disposed.
Casing. Casings are steel pipes that line the
borehole and serve to isolate the geologic
formation from the materials and equipment in
the well. The casing also prevents the borehole
from caving in, confines the injected/produced
fluid to the wellbore and the intended
production zone, and provides a method of
pressure control. Thus, the casing must be
capable of withstanding the external and internal
pressures encountered during the installation,
cementing, fracturing, and operation of the well.
When fluid is confined within the casing, the
possibility of contamination of zones adjacent to
the well is greatly diminished. In situations where
the geologic formation is considered competent
and will not collapse upon itself, an operator may
choose to forego casing in what is called an open
hole completion.
Figure 8 illustrates the different types of casings
that may be used in well construction: conductor,
surface, intermediate (not shown), and
production. Each casing serves a unique purpose.
Ideally, the surface casing should extend below
the base of the deepest USDW and be cemented to the surface. This casing isolates the USDW and
provides protection from contamination during drilling, completion, and operation of the well. Note that
the shallow portions of the well may have multiple layers of casing and cement, isolating the production
area from the surrounding formation. For each casing, a hole is drilled and the casing is installed and
cemented into place.
Casings should be positioned in the center of the borehole using casing centralizers, which attach to the
outside of the casing. A centralized casing improves the likelihood that it will be completely surrounded
by cement during the cementing process, leading to the effective isolation of the well from USDWs. The
number, depth, and cementing of the casings required varies and is set by the states.
Cementing. Once the casing is inserted in the borehole, it is cemented into place by pumping cement
slurry down the casing and up the annular space between the formation and the outside of the casing.
14
Wellhead
Surface
ement
Production
Cement
Production
tubing
Hydrocarbon-bearing
formation
FIGURE 8. WELL CONSTRUCTION
-------
EPA Hydraulic Fracturing Study Plan
November 2011
The principal functions of the cement (for vertical wells or the vertical portion of a horizontal well) are to
act as a barrier to migration of fluids up the wellbore behind the casing and to mechanically support the
casing. To accomplish these functions, the proper cement must be used for the conditions encountered
in the borehole. Additionally, placement of the cement and the type of cement used in the well must be
carefully planned and executed to ensure that the cement functions effectively.
The presence of the cement sheath around each casing and the effectiveness of the cement in
preventing fluid movement are the major factors in establishing and maintaining the mechanical
integrity of the well, although even a correctly constructed well can fail over time due to downhole
stresses and corrosion (Bellabarba et al., 2008).
3.3 Hydraulic Fracturing
After the well is constructed, the targeted formation (shale, coalbed, or tight sands) is hydraulically
fractured to stimulate natural gas production. As noted in Figure 6, the hydraulic fracturing process
requires large volumes of water that must be withdrawn from the source and transported to the well
site. Once on site, the water is mixed with chemicals and a propping agent (called a proppant).
Proppants are solid materials that are used to keep the fractures open after pressure is reduced in the
well. The most common proppant is sand (Carter et al., 1996), although resin-coated sand, bauxite, and
ceramics have also been used (Arthur et al., 2008; Palisch et al., 2008). Most, if not all, water-based
fracturing techniques use proppants. There are, however, some fracturing techniques that do not use
proppants. For example, nitrogen gas is commonly used to fracture coalbeds and does not require the
use of proppants (Rowan, 2009).
After the production casing has been perforated by explosive charges introduced into the well, the rock
formation is fractured when hydraulic fracturing fluid is pumped down the well under high pressure. The
fluid is also used to carry proppant into the targeted formation and enhance the fractures. As the
injection pressure is reduced, recoverable fluid is returned to the surface, leaving the proppant behind
to keep the fractures open. The inset in Figure 7 illustrates how the resulting fractures create pathways
in otherwise impermeable gas-containing formations, resulting in gas flow to the well for production.
The fluid that returns to the surface can be referred to as either "flowback" or "produced water," and
may contain both hydraulic fracturing fluid and natural formation water. "Flowback" can be considered
a subset of "produced water." However, for this study, EPA considers "flowback" to be the fluid
returned to the surface after hydraulic fracturing has occurred, but before the well is placed into
production, while "produced water" is the fluid returned to the surface after the well has been placed
into production. In this study plan, flowback and produced water are collectively referred to as
"hydraulic fracturing wastewaters." These wastewaters are typically stored on-site in tanks or pits
before being transported for treatment, disposal, land application, and/or discharge. In some cases,
flowback and produced waters are treated to enable the recycling of these fluids for use in hydraulic
fracturing.
15
-------
EPA Hydraulic Fracturing Study Plan
November 2011
3.4 Well Production and Closure
Natural gas production rates can vary between basins as well as within a basin, depending on geologic
factors and completion techniques. For example, the average well production rates for coalbed methane
formations range from 50 to 500 thousand cubic feet per day (mcf/d) across the US, with maximum
production rates reaching 20 million cubic feet per day (mmcf/d) in the San Juan Basin and 1 mmcf/d in
the Raton Basin (Rogers et al., 2007). The New York State Revised Draft Supplemental Generic
Environmental Impact Statement (NYS rdSGEIS) for the Marcellus Shale cites industry estimates that a
typical well will initially produce 2.8 mmcf/d; the production rate will decrease to 550 mcf/d after 5
years and 225 mcf/d after 10 years, after which it will drop approximately 3 percent a year (NYSDEC,
2011). A study of actual production rates in the Barnett Shale found that the average well produces
about 800 mmcf during its lifetime, which averages about 7.5 years (Berman, 2009).
Refracturing is possible once an oil or gas well begins to approach the point where it is no longer cost-
effectively producing hydrocarbons. Zoback et al. (2010) maintain that shale gas wells are rarely
refractured. Berman (2009), however, claims that wells may be refractured once they are no longer
profitable. The NYS rdSGEIS estimates that wells may be refractured after roughly five years of service
(NYSDEC, 2011).
Once a well is no longer producing gas economically, it is plugged to prevent possible fluid migration
that could contaminate soils or waters. According to API, primary environmental concerns include
protecting freshwater aquifers and USDWs as well as isolating downhole formations that contain
hydrocarbons (API, 2009a). An improperly closed well may provide a pathway for fluid to flow up the
well toward ground or surface waters or down the wellbore, leading to contamination of ground water
(API, 2009a). A surface plug is used to prevent surface water from seeping into the wellbore and
migrating into ground water resources. API recommends setting cement plugs to isolate hydrocarbon
and injection/disposal intervals, as well as setting a plug at the base of the lowermost USDW present in
the formation (API, 2009a).
3.5 Regulatory Framework
Hydraulic fracturing for oil and gas production wells is typically addressed by state oil and gas boards or
equivalent state natural resource agencies. EPA retains authority to address many issues related to
hydraulic fracturing under its environmental statutes. The major statutes include the Clean Air Act; the
Resource Conservation and Recovery Act; the Clean Water Act; the Safe Drinking Water Act; the
Comprehensive Environmental Response, Compensation and Liability Act; the Toxic Substances Control
Act; and the National Environmental Policy Act. EPA does not expect to address the efficacy of the
regulatory framework as part of this investigation.
16
-------
EPA Hydraulic Fracturing Study Plan
November 2011
4 The Hydraulic Fracturing Water Lifecycle
The hydraulic fracturing water lifecycle—from water acquisition to wastewater treatment and
disposal—is illustrated in Figure 9. The figure also shows potential issues for drinking water resources
associated with each phase. Table 1 summarizes the primary and secondary research questions EPA has
identified for each stage of the hydraulic fracturing water lifecycle.
The next chapter outlines the research approach and activities needed to answer these questions.
TABLE 1. RESEARCH QUESTIONS IDENTIFIED TO DETERMINE THE POTENTIAL IMPACTS OF HYDRAULIC
FRACTURING ON DRINKING WATER RESOURCES
Water Lifecycle Stage
Fundamental Research Question
Secondary Research Questions
Water Acquisition
What are the potential impacts of
large volume water withdrawals
from ground and surface waters
on drinking water resources?
• How much water is used in hydraulic
fracturing operations, and what are the
sources of this water?
• How might withdrawals affect short- and
long-term water availability in an area with
hydraulic fracturing activity?
• What are the possible impacts of water
withdrawals for hydraulic fracturing
operations on local water quality?
Chemical Mixing
What are the possible impacts of
surface spills on or near well pads
of hydraulic fracturing fluids on
drinking water resources?
• What is currently known about the
frequency, severity, and causes of spills of
hydraulic fracturing fluids and additives?
• What are the identities and volumes of
chemicals used in hydraulic fracturing fluids,
and how might this composition vary at a
given site and across the country?
• What are the chemical, physical, and
toxicological properties of hydraulic
fracturing chemical additives?
• If spills occur, how might hydraulic
fracturing chemical additives contaminate
drinking water resources?
Well Injection
What are the possible impacts of
the injection and fracturing
process on drinking water
resources?
• How effective are current well construction
practices at containing gases and fluids
before, during, and after fracturing?
• Can subsurface migration of fluids or gases
to drinking water resources occur and what
local geologic or man-made features may
allow this?
• How might hydraulic fracturing fluids
change the fate and transport of substances
in the subsurface through geochemical
interactions?
• What are the chemical, physical, and
toxicological properties of substances in the
subsurface that may be released by
hydraulic fracturing operations?
Table continued on next page
17
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table continued from previous page
Water Lifecycle Stage
Fundamental Research Question
Secondary Research Questions
Flowback and
Produced Water
What are the possible impacts of
surface spills on or near well pads
of flowback and produced water
on drinking water resources?
• What is currently known about the
frequency, severity, and causes of spills of
flowback and produced water?
• What is the composition of hydraulic
fracturing wastewaters, and what factors
might influence this composition?
• What are the chemical, physical, and
toxicological properties of hydraulic
fracturing wastewater constituents?
• If spills occur, how might hydraulic
fracturing wastewaters contaminate
drinking water resources?
Wastewater T reatment
and Waste Disposal
What are the possible impacts of
inadequate treatment of
hydraulic fracturing wastewaters
on drinking water resources?
• What are the common treatment and
disposal methods for hydraulic fracturing
wastewaters, and where are these methods
practiced?
• How effective are conventional POTWs and
commercial treatment systems in removing
organic and inorganic contaminants of
concern in hydraulic fracturing
wastewaters?
• What are the potential impacts from surface
water disposal of treated hydraulic
fracturing wastewater on drinking water
treatment facilities?
18
-------
EPA Hydraulic Fracturing Study Plan November 2011
Water Use in Hydraulic ^ ....... ...
Fracturing Operations Potential Drinking Water Issues
Water Acquisition
Wastewater Treatment
and Waste Disposal
Chemical Mixing
Well Injection
Flowback and
Produced Water
Surface and/or subsurface discharge into surface and ground water
• Incomplete treatment of wastewater and solid residuals
• Wastewater transportation accidents
• Release to surface and ground water
• Leakage from on-site storage into drinking water resources
• Improper pit construction, maintenance, and/or closure
• Water availability
Impact of water withdrawal on water quality
Accidental release to ground or surface water (e.g., well malfunction)
• Fracturing fluid migration into drinking water aquifers
• Formation fluid displacement into aquifers
• Mobilization of subsurface formation materials into aquifers
• Release to surface and ground water
(e.g., on-site spills and/or leaks)
• Chemical transportation accidents
FIGURE 9. WATER USE AND POTENTIAL CONCERNS IN HYDRAULIC FRACTURING OPERATIONS
19
-------
EPA Hydraulic Fracturing Study Plan
November 2011
5 Research Approach
The highly complex nature of the problems to be studied will require a broad range of scientific
expertise in environmental and petroleum engineering, ground water hydrology, fate and transport
modeling, and toxicology, as well as many other areas. EPA will take a transdisciplinary research
approach that integrates various types of expertise from inside and outside EPA. This study uses five
main research activities to address the questions identified in Table 1. Table 2 summarizes these
activities and their objectives; each activity is then briefly described below with more detailed
information available in later chapters.
TABLE 2. RESEARCH ACTIVITIES AND OBJECTIVES
Activity
Objective
Analysis of existing data
Gather and summarize existing data from various sources to provide current
information on hydraulic fracturing activities
Case studies
Retrospective
Prospective
Perform an analysis of sites with reported contamination to understand the
underlying causes and potential impacts to drinking water resources
Develop understanding of hydraulic fracturing processes and their potential impacts
on drinking water resources
Scenario evaluations
Use computer modeling to assess the potential for hydraulic fracturing to impact
drinking water resources based on knowledge gained during existing data analysis
and case studies
Laboratory studies
Conduct targeted studies to study the fate and transport of chemical contaminants of
concern in the subsurface and during wastewater treatment processes
Toxicological studies
Summarize available toxicological information and, as necessary, conduct screening
studies for chemicals associated with hydraulic fracturing operations
5.1 Analysis of Existing Data
EPA will gather and analyze mapped data on water quality, surface water discharge data, chemical
identification data, and site data among others. These data are available from a variety of sources, such
as state regulatory agencies, federal agencies, industry, and public sources. Included among these
sources are information from the September 2010 letter requesting data from nine hydraulic fracturing
service companies and the August 2011 letter requesting data from nine randomly chosen oil and gas
well operators. Appendix D contains detailed information regarding these requests.
5.2 Case Studies
Case studies are widely used to conduct in-depth investigations of complex topics and provide a
systematic framework for investigating relationships among relevant factors. In addition to reviewing
available data associated with the study sites, EPA will conduct environmental field sampling, modeling,
and/or parallel laboratory investigations. In conjunction with other elements of the research program,
the case studies will help determine whether hydraulic fracturing can impact drinking water resources
and, if so, the extent and possible causes of any impacts. Additionally, case studies may provide
opportunities to assess the fate and transport of fluids and contaminants in different regions and
geologic settings.
20
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Retrospective case studies are focused on investigating reported instances of drinking water resource
contamination in areas where hydraulic fracturing events have already occurred. Retrospective case
studies will use a deductive logic approach to determine whether or not the reported impacts are due to
hydraulic fracturing activity and if so, evaluate potential driving factors for those impacts.
Prospective case studies involve sites where hydraulic fracturing will be implemented after the research
begins. These cases allow sampling and characterization of the site prior to, during, and after drilling,
water extraction, injection of the fracturing fluid, flowback, and production. At each step in the process,
EPA will collect data to characterize both the pre- and post-fracturing conditions at the site. This
progressive data collection will allow EPA to evaluate changes in local water availability and quality, as
well as other factors, over time to gain a better understanding of the potential impacts of hydraulic
fracturing on drinking water resources. Prospective case studies offer the opportunity to sample and
analyze flowback and produced water. These studies also provide data to run, evaluate, and improve
models of hydraulic fracturing and associated processes, such as fate and transport of chemical
contaminants.
5.3 Scenario Evaluations
The objective of this approach is to use computer modeling to explore realistic, hypothetical scenarios
across the hydraulic fracturing water cycle that may involve adverse impacts to drinking water
resources, based primarily on current knowledge and available data. The scenarios will include a
reference case involving typical management and engineering practices in representative geologic
settings. Typical management and engineering practices will be based on what EPA learns from case
studies as well as the minimum requirements imposed by state regulatory agencies. EPA will model
surface water in areas to assess impact on water availability and quality where hydraulic fracturing
operations withdraw water. EPA will also introduce and model potential modes of failure, both in terms
of engineering controls and geologic characteristics, to represent various states of system vulnerability.
The scenario evaluations will produce insights into site-specific and regional vulnerabilities.
5.4 Laboratory Studies
Laboratory studies will be used to conduct targeted research needed to better understand the ultimate
fate and transport of chemical contaminants of concern. The contaminants of concern may be
components of hydraulic fracturing fluids or may be naturally occurring substances released from the
subsurface during hydraulic fracturing. Laboratory studies may also be necessary to modify existing
analytical methods for case study field monitoring activities. Additionally, laboratory studies will assess
the potential for treated flowback or produced water to cause an impact to drinking water resources if
released.
5.5 Toxicological Studies
Throughout the hydraulic fracturing water lifecycle there are routes through which fracturing fluids
and/or naturally occurring substances could be introduced into drinking water resources. To support
future risk assessments, EPA will summarize existing data regarding toxicity and potential human health
21
-------
EPA Hydraulic Fracturing Study Plan
November 2011
effects associated with these possible drinking water contaminants. Where necessary, EPA may pursue
additional toxicological studies to screen and assess the toxicity associated with chemical contaminants
of concern.
6 Research Activities Associated with the Hydraulic Fracturing
Water Lifecycle
This chapter is organized by the hydraulic fracturing water lifecycle depicted in Figure 9 and the
associated research questions outlined in Table 1. Each section of this chapter provides relevant
background information on the water lifecycle stage and identifies a series of more specific questions
that will be researched to answer the fundamental research question. Research activities and expected
research outcomes are outlined at the end of the discussion of each stage of the water lifecycle. A
summary of the research outlined in this chapter can be found in Appendix A.
6.1 Water Acquisition: What are the potential impacts of large volume water
WITHDRAWALS FROM GROUND AND SURFACE WATERS ON DRINKING WATER RESOURCES?
6.1.1 Background
The amount of water needed in the hydraulic fracturing process depends on the type of formation
(coalbed, shale, or tight sands) and the fracturing operations (e.g., well depth and length, fracturing fluid
properties, and fracture job design). Water requirements for hydraulic fracturing in coalbed methane
range from 50,000 to 350,000 gallons per well (Holditch, 1993; Jeu et al., 1988; Palmer et al., 1991 and
1993). The water usage in shale gas plays is significantly larger: 2 to 4 million gallons of water are
typically needed per horizontal well (API, 2010a; GWPC and ALL Consulting, 2009; Satterfield et al.,
2008). Table 3 shows how the total volume of water used in fracturing varies depending on the depth
and porosity of the shale gas play.
TABLE 3. COMPARISON OF ESTIMATED WATER NEEDS FOR HYDRAULIC FRACTURING OF HORIZONTAL WELLS IN
DIFFERENT SHALE PLAYS
Shale Play
Formation
Depth (ft)
Porosity (%)
Organic
Content(%)
Freshwater
Depth (ft)
Fracturing Water
(gallons/well)
Barnett
6,500-8,500
4-5
4.5
1,200
2,300,000
Fayetteville
1,000-7,000
2-8
4-10
500
2,900,000
Haynesville
10,500-13,500
8-9
0.5-4
400
2,700,000
Marcellus
4,000-8,500
10
3-12
850
3,800,000
Data are from GWPC and ALL Consulting, 2009.
It was estimated that 35,000 wells were fractured in 2006 alone across the US (Halliburton, 2008).
Assuming that the majority of these wells are horizontal wells, the annual national water requirement
may range from 70 to 140 billion gallons. This is equivalent to the total amount of water withdrawn
from drinking water resources each year in roughly 40 to 80 cities with a population of 50,000 or about
one to two cities of 2.5 million people. In the Barnett Shale area, the annual estimates of total water
used by gas producers ranged from 2.6 to 5.3 billion gallons per year from 2005 through 2007 (Bene et
al., 2007, as cited in Galusky, 2007). During the projected peak shale gas production in 2010, the total
22
-------
EPA Hydraulic Fracturing Study Plan
November 2011
water used for gas production in the Barnett Shale was estimated to be 9.5 billion gallons. This
represents 1.7 percent of the estimated total freshwater demand by all users within the Barnett Shale
area (554 billion gallons) (Galusky, 2007).
To meet these large volume requirements, source water is typically stored in 20,000-gallon portable
steel ("frac") tanks located at the well site (GWPC and ALL Consulting, 2009; ICF International, 2009a;
Veil, 2007). Source water can also be stored in impoundment pits on site or in a centralized location that
services multiple sites. For example, in the Barnett and Fayetteville Shale plays, source water may be
stored in large, lined impoundments ranging in capacity from 8 million gallons for 4 to 20 gas wells to
163 million gallons for 1,200 to 2,000 gas wells (Satterfield et al., 2008). The water used to fill tanks or
impoundments may come from either ground or surface water, depending on the region in which the
fracturing takes place. The transportation of source water to the well site depends on site-specific
conditions. In many areas, trucks generally transport the source water to the well site. In the long term,
where topography allows, a network of pipelines may be installed to transfer source water between the
source and the impoundments or tanks.
Whether the withdrawal of this much water from local surface or ground water sources has a significant
impact and the types of possible impacts may vary from one part of the country to another and from
one time of the year to another. In arid North Dakota, the projected need of 5.5 billion gallons of water
per year to release oil and gas from the Bakken Shale has prompted serious concerns by stakeholders
(Kellman and Schneider, 2010). In less arid parts of the country, the impact of water withdrawals may be
different. In the Marcellus Shale area, stakeholder concerns have focused on large volume, high rate
water withdrawals from small streams in the headwaters of watersheds supplying drinking water
(Maclin et al., 2009; Myers, 2009).
One way to offset the large water requirements for hydraulic fracturing is to recycle the flowback
produced in the fracturing process. Estimates for the amount of fracturing fluid that is recovered during
the first two weeks after a fracture range from 25 to 75 percent of the original fluid injected and
depends on several variables, including but not limited to the formation and the specific techniques
used (Pickett, 2009; Veil, 2010; Horn, 2009). This water may be treated and reused by adding additional
chemicals as well as fresh water to compose a new fracturing solution. There are, however, challenges
associated with reusing flowback due to the high concentrations of total dissolved solids (TDS) and other
dissolved constituents found in flowback (Bryant et al., 2010). Constituents such as specific cations (e.g.,
calcium, magnesium, iron, barium, and strontium) and anions (e.g., chloride, bicarbonate, phosphate,
and sulfate) can interfere with hydraulic fracturing fluid performance by producing scale or by
interfering with chemical additives in the fluids (Godsey, 2011). Recycled water can also become so
concentrated with contaminants that it requires either disposal or reuse with considerable dilution. Acid
mine drainage, which has a lower TDS concentration, has also been suggested as possible source water
for hydraulic fracturing (Vidic, 2010) as well as non-potable ground water, including brackish water,
saline, and brine (Godsey, 2011; Hanson, 2011).
23
-------
EPA Hydraulic Fracturing Study Plan
November 2011
6.1.2 HOW MUCH WATER IS USED IN HYDRAULIC FRACTURING OPERATIONS, AND WHAT ARE THE SOURCES OF
THIS WATER?
As mentioned in the previous section, source water for hydraulic fracturing operations can come from a
variety of sources, including ground water, surface water, and recycled flowback. Water acquisition has
not been well characterized, so EPA intends to gain a better understanding of the amounts and sources
of water being used for hydraulic fracturing operations.
6.1.2.1 Research Activities - Source Water
Analysis of existing data. EPA has asked for information on hydraulic fracturing fluid source water
resources from nine hydraulic fracturing service companies and nine oil and gas operators (see Appendix
D). The data received from the service companies will inform EPA's understanding of the general water
quantity and quality requirements for hydraulic fracturing. EPA has asked the nine oil and gas operating
companies for information on the total volume, source, and quality of the base fluid8 needed for
hydraulic fracturing at 350 hydraulically fractured oil and gas production wells in the continental US.
These data will provide EPA with a nationwide perspective on the volumes and sources of water used for
hydraulic fracturing operations, including information on ground and surface water withdrawals as well
as recycling of flowback.
EPA will also study water use for hydraulic fracturing operations in two representative regions of the US:
the Susquehanna River Basin and Garfield County, Colorado. The Susquehanna River Basin is in the heart
of the Marcellus Shale play and represents a humid climate while Garfield County is located in the
Piceance Basin and represents a semi-arid climate. EPA will collect existing data from the Susquehanna
River Basin Commission and the Colorado Oil and Gas Conservation Commission to determine the
volumes of water used for hydraulic fracturing and, if available, the sources of these waters.
EPA expects the research outlined above to produce the following:
• A list of volume and water quality parameters important for hydraulic fracturing operations.
• Information on source, volume, and quality of water used for hydraulic fracturing operations.
• Location-specific data on water use for hydraulic fracturing.
Prospective case studies. EPA will conduct prospective case studies in DeSoto Parish, Louisiana, and
Washington County, Pennsylvania. As part of these studies, EPA will monitor the volumes, sources, and
quality of water needed for hydraulic fracturing operations. These two locations are representative of an
area where ground water withdrawals have been common (Haynesville Shale in Louisiana), and an area
where surface water withdrawals and recycling practices have been used (Marcellus Shale in
Pennsylvania).
8 In the case of water-based hydraulic fracturing fluids, water would be the base fluid.
24
-------
EPA Hydraulic Fracturing Study Plan
November 2011
EPA expects the research outlined above to produce the following:
• Location-specific examples of water acquisition, including data on the source, volume, and
quality of the water.
6.1.3 HOW MIGHT WATER WITHDRAWALS AFFECT SHORT- AND LONG-TERM WATER AVAILABILITY IN AN AREA
WITH HYDRAULIC FRACTURING ACTIVITY?
Large volume water withdrawals for hydraulic fracturing are different from withdrawals for other
purposes in that much of the water used for the fracturing process may not be recovered after injection.
The impact from large volume water withdrawals varies not only with geographic area, but also with the
quantity, quality, and sources of the water used. The removal of large volumes of water could stress
drinking water supplies, especially in drier regions where aquifer or surface water recharge is limited.
This could lead to lowering of water tables or dewatering of drinking water aquifers, decreased stream
flows, and reduced volumes of water in surface water reservoirs. These activities could impact the
availability of water for drinking in areas where hydraulic fracturing is occurring. The lowering of water
levels in aquifers can necessitate the lowering of pumps or the deepening or replacement of wells, as
has been reported near Shreveport, Louisiana, in the area of the Haynesville Shale (Louisiana Office of
Conservation, 2011).
As the intensity of hydraulic fracturing activities increases within individual watersheds and geologic
basins, it is important to understand the net impacts on water resources and identify opportunities to
optimize water management strategies.
6.1.3.1 Research Activities - Water Availability
Analysis of existing data. In cooperation with USACE, USGS, state environmental agencies, state oil and
gas associations, river basin commissions, and others, EPA will compile data on water use and the
hydrology of the Susquehanna River Basin in the Marcellus Shale and Garfield County, Colorado, in the
Piceance Basin. These data will include ground water levels, surface water flows, and water quality as
well as data on hydraulic fracturing operations, such as the location of wells and the volume of water
used during fracturing. These specific study areas represent both arid and humid areas of the country.
These areas were chosen based on the availability of data from the Susquehanna River Basin
Commission and the Colorado Oil and Gas Conservation Commission.
EPA will conduct simple water balance and geographic information system (GIS) analysis using the
existing data. The data collected will be compiled along with information on hydrological trends over the
same period of time. EPA will compare control areas with similar baseline water demands and no oil and
gas development to areas with intense hydraulic fracturing activity, isolating and identifying any impacts
of hydraulic fracturing on water availability. A critical analysis of trends in water flows and water usage
patterns will be conducted in areas where hydraulic fracturing activities are occurring to determine
whether water withdrawals alter ground and surface water flows. Data collection will support the
assessment of the potential impacts of hydraulic fracturing on water availability at various spatial scales
(e.g., site, watershed, basin, and play) and temporal scales (e.g., days, months, and years).
25
-------
EPA Hydraulic Fracturing Study Plan
November 2011
EPA expects the research outlined above to produce the following:
• Maps of recent hydraulic fracturing activity and water usage in a humid region (Susquehanna
River Basin) and a semi-arid region (Garfield County, Colorado).
• Information on whether water withdrawals for hydraulic fracturing activities alter ground or
surface water flows.
• Assessment of impacts of hydraulic fracturing on water availability at various spatial and
temporal scales
Prospective case studies. The prospective case studies will evaluate potential short-term impacts on
water availability due to large volume water use for hydraulic fracturing in DeSoto Parish, Louisiana, and
Washington County, Pennsylvania. The data collected during these case studies will allow EPA to
compare potential differences in effects on local water availability between an area where ground water
is typically used (DeSoto Parish) and an area where surface water withdrawals are common (Washington
County).
EPA expects the research outlined above to produce the following:
• Identification of short-term impacts on water availability from ground and surface water
withdrawals associated with hydraulic fracturing activities.
Scenario evaluation. Scenario evaluations will assess potential long-term quantity impacts as a result of
cumulative water withdrawals. The evaluations will focus on hydraulic fracturing operations at various
spatial and temporal scales in the Susquehanna River Basin and Garfield County, Colorado, using the
existing data described above. The scenarios will include at least two futures: (1) average annual
conditions in 10 years based on the full exploitation of oil and natural gas resources; and (2) average
annual conditions in 10 years based on sustainable water use in hydraulic fracturing operations. Both
scenarios will build on predictions for land use and climate (e.g., drought, average, and wet). EPA will
take advantage of the future scenario work constructed for the EPA Region 3 Chesapeake Bay Program9
and the EPAORD Future Midwestern Landscape Program.10 The spatial scales of analysis will reflect
both environmental boundaries (e.g., site, watershed, river basin, and geologic play) and political
boundaries (e.g., city/municipality, county, state, and EPA Region).
These assessments will consider typical water requirements for hydraulic fracturing activities and will
also account for estimated demands for water from other human needs (e.g., drinking water,
agriculture, and energy), adjusted for future populations. The sustainability analysis will reflect
minimum river flow requirements and aquifer drawdown for drought, average, and wet precipitation
years, and will allow a determination of the number of typical hydraulic fracturing operations that could
be sustained for the relevant formation (e.g., Marcellus Shale) and future scenario. Appropriate physics-
based watershed and ground water models will be used for representation of the water balance and
hydrologic cycle, as discussed in Chapter 10.
9 http://www.epa.gov/region3/chesapeake/.
10 http://www.epa.gov/asmdnerl/EcoExposure/FML.html.
26
-------
EPA Hydraulic Fracturing Study Plan
November 2011
EPA expects the research outlined above to produce the following:
• Identification of long-term water quantity impacts on drinking water resources due to
cumulative water withdrawals for hydraulic fracturing.
6.1.4 What are the possible impacts of water withdrawals for hydraulic fracturing
OPERATIONS ON LOCAL WATER QUALITY?
Withdrawals of large volumes of ground water can lower the water levels in aquifers. This can affect the
aquifer water quality by exposing naturally occurring minerals to an oxygen-rich environment,
potentially causing chemical changes that affect mineral solubility and mobility, leading to salination of
the water and other chemical contaminations. Additionally, lowered water tables may stimulate
bacterial growth, causing taste and odor problems. Depletion of aquifers can also cause an upwelling of
lower quality water and other substances (e.g., methane from shallow deposits) from deeper within an
aquifer and could lead to subsidence and/or destabilization of the geology.
Withdrawals of large quantities of water from surface water resources (e.g., streams, lakes, and ponds)
can significantly affect the hydrology and hydrodynamics of these resources. Such withdrawals from
streams can alter the flow regime by changing their flow depth, velocity, and temperature (Zorn et al.,
2008). Additionally, removal of significant volumes of water can reduce the dilution effect and increase
the concentration of contaminants in surface water resources (Pennsylvania State University, 2010).
Furthermore, it is important to recognize that ground and surface water are hydraulically connected
(Winter et al., 1998); any changes in the quantity and quality of the surface water can affect ground
water and vice versa.
6.1.4.1 Research Activities - Water Quality
Analysis of existing data. EPA will use the data described in Section 6.1.3.1 to analyze changes in water
quality in the Susquehanna River Basin and Garfield County, Colorado, to determine if any changes are
due to surface or ground water withdrawals for hydraulic fracturing.
EPA expects the research outlined above to produce the following:
• Maps of hydraulic fracturing activity and water quality for the Susquehanna River Basin and
Garfield County, Colorado.
• Information on whether water withdrawals for hydraulic fracturing alter local water quality.
Prospective case studies. These case studies will allow EPA to collect data on the quality of ground and
surface waters that may be used for hydraulic fracturing before and after water is removed for hydraulic
fracturing purposes. EPA will analyze these data to determine if there are any changes in local water
quality and if these changes are a result of water withdrawals associated with hydraulic fracturing.
EPA expects the research outlined above to produce the following:
• Identification of impacts on local water quality from withdrawals for hydraulic fracturing.
27
-------
EPA Hydraulic Fracturing Study Plan
November 2011
6.2 Chemical Mixing: What are the possible impacts of surface spills on or near
WELL PADS OF HYDRAULIC FRACTURING FLUIDS ON DRINKING WATER RESOURCES?
6.2.1 Background
Hydraulic fracturing fluids serve two purposes: to create pressure to propagate fractures and to carry
the proppant into the fracture. Chemical additives and proppants are typically used in the fracturing
fluid. The types and concentrations of chemical additives and proppants vary depending on the
conditions of the specific well being fractured, creating a fracturing fluid tailored to the properties of the
formation and the needs of the project. In some cases, reservoir properties are entered into modeling
programs that simulate fractures (Castle et al., 2005; Hossain and Rahman, 2008). These simulations
may then be used to reverse engineer the requirements for fluid composition, pump rates, and
proppant concentrations.
Table 4 lists the volumetric composition of a fluid used in a fracturing operation in the Fayetteville Shale
as an example of additive types and concentrations (GWPC and ALL Consulting, 2009; API, 2010b). A list
of publicly known chemical additives found in hydraulic fracturing fluids is provided in Appendix E.
In the case outlined in Table 4, the total concentration of chemical additives was 0.49 percent. Table 4
also calculates the volume of each additive based on a total fracturing fluid volume of 3 million gallons,
and shows that the total volume of chemical additives is 14,700 gallons. In general, the overall
concentration of chemical additives in fracturing fluids used in shale gas plays ranges from 0.5 to 2
percent by volume, with water and proppant making up the remainder (GWPC and ALL Consulting,
2009), indicating that 15,000 to 60,000 gallons of the total fracturing fluid consist of chemical additives
(assuming a total fluid volume of 3 million gallons).
The chemical additives are typically stored in tanks on site and blended with water and the proppant
prior to injection. Flow, pressure, density, temperature, and viscosity can be measured before and after
mixing (Pearson, 1989). High pressure pumps then send the mixture from the blender into the well
(Arthur et al., 2008). In some cases, special on-site equipment is used to measure the properties of the
mixed chemicals in situ to ensure proper quality control (Hall and Larkin, 1989).
6.2.2 What is currently known about the frequency, severity, and causes of spills of hydraulic
FRACTURING FLUIDS AND ADDITIVES?
Large hydraulic fracturing operations require extensive quantities of supplies, equipment, water, and
vehicles, which could create risks of accidental releases, such as spills or leaks. Surface spills or releases
can occur as a result of tank ruptures, equipment or surface impoundment failures, overfills, vandalism,
accidents, ground fires, or improper operations. Released fluids might flow into a nearby surface water
body or infiltrate into the soil and near-surface ground water, potentially reaching drinking water
aquifers (NYSDEC, 2011).
28
-------
EPA Hydraulic Fracturing Study Plan November 2011
TABLE 4. AN EXAMPLE OF THE VOLUMETRIC COMPOSITION OF HYDRAULIC FRACTURING FLUID
Component/
Additive Type
Example Compounds
Purpose
Percent
Composition
(by Volume)
Volume of
Chemical
(Gallons)3
Water
Deliver proppant
90
2,700,000
Proppant
Silica, quartz sand
Keep fractures open to allow
gas flow out
9.51
285,300
Acid
Hydrochloric acid
Dissolve minerals, initiate
cracks in the rock
0.123
3,690
Friction reducer
Polyacrylamide,
mineral oil
Minimize friction between
fluid and the pipe
0.088
2,640
Surfactant
Isopropanol
Increase the viscosity of the
fluid
0.085
2,550
Potassium
chloride
Create a brine carrier fluid
0.06
1,800
Gelling agent
Guar gum,
hydroxyethyl
cellulose
Thicken the fluid to suspend
the proppant
0.056
1,680
Scale inhibitor
Ethylene glycol
Prevent scale deposits in the
pipe
0.043
1,290
pH adjusting agent
Sodium or potassium
carbonate
Maintain the effectiveness of
other components
0.011
330
Breaker
Ammonium
persulfate
Allow delayed breakdown of
the gel
0.01
300
Crosslinker
Borate salts
Maintain fluid viscosity as
temperature increases
0.007
210
Iron control
Citric acid
Prevent precipitation of
metal oxides
0.004
120
Corrosion inhibitor
N,N-dimethyl
formamide
Prevent pipe corrosion
0.002
60
Biocide
Glutaraldehyde
Eliminate bacteria
0.001
30
Data are from GWPC and ALL Consulting, 2009, and API, 2010b.
a Based on 3 million gallons of fluid used.
Over the past few years there have been numerous media reports of spills of hydraulic fracturing fluids
(Lustgarten, 2009; M. Lee, 2011; Williams, 2011). While these media reports highlight specific incidences
of surface spills of hydraulic fracturing fluids, the frequency and typical causes of these spills remain
unclear. Additionally, these reports tend to highlight severe spills. EPA is interested in learning about the
range of volumes and reported impacts associated with surface spills of hydraulic fracturing fluids and
additives.
6.2.2.1 Research Activities - Surface Spills of Hydraulic Fracturing Fluids and Additives
Analysis of existing data. EPA will compile and evaluate existing information on the frequency, severity,
and causes of spills of hydraulic fracturing fluids and additives. These data will come from a variety of
sources, including information provided by nine oil and gas operators. In an August 2011 information
request sent to these operators, EPA requested spill incident reports for any fluid spilled at 350 different
randomly selected well sites in 13 states across the US. Other sources of data are expected to include
29
-------
EPA Hydraulic Fracturing Study Plan
November 2011
spills reported to the National Response Center, state departments of environmental protection (e.g.,
Pennsylvania and West Virginia), EPA's Natural Gas Drilling Tipline, and others.
EPA will assess the data provided by these sources to reflect a national perspective of reported surface
spills of hydraulic fracturing fluids and additives. The goal of this effort is to provide a representative
assessment of the frequency, severity, and causes of surface spills associated with hydraulic fracturing
fluids and additives.
EPA expects the research outlined above to produce the following:
• Nationwide data on the frequency, severity, and causes of spills of hydraulic fracturing fluids and
additives.
6.2.3 What are the identities and volumes of chemicals used in hydraulic fracturing fluids,
AND HOW MIGHT THIS COMPOSITION VARY AT A GIVEN SITE AND ACROSS THE COUNTRY?
EPA has compiled a list of chemicals that are publicly known to be used in hydraulic fracturing (Table El
in Appendix E). The chemicals identified in Table El, however, does not represent the entire set of
chemicals used in hydraulic fracturing activities. EPA also lacks information regarding the frequency,
quantity, and concentrations of the chemicals used, which is important when considering the toxic
effects of hydraulic fracturing fluid additives. Stakeholder meetings and media reports have emphasized
the public's concern regarding the identity and toxicity of chemicals used in hydraulic fracturing.
Although there has been a trend in recent years of public disclosure of hydraulic fracturing chemicals,
inspection of these databases shows that much information is still deemed to be proprietary and is not
made available to the public.
6.2.3.1 Research Activities - Hydraulic Fracturing Fluid Composition
Analysis of existing data. In September 2010, EPA issued information requests to nine hydraulic
fracturing service companies seeking information on the identity and quantity of chemicals used in
hydraulic fracturing fluid in the past five years (Appendix D). This information will provide EPA with a
better understanding of the common compositions of hydraulic fracturing fluids (i.e., identity of
components, concentrations, and frequency of use) and the factors that influence these compositions.
By asking for data from the past five years, EPA expects to obtain information on chemicals that have
been used recently. Some of these chemicals, however, may no longer be used in hydraulic fracturing
operations, but could be present in areas where retrospective case studies will be conducted. Much of
the data collected from this request have been claimed as confidential business information (CBI). In
accordance with 40 C.F.R. Part 2 Subpart B, EPA will treat it as such until a determination regarding the
claims is made.
The list of chemicals from the nine hydraulic fracturing service companies will be compared to the list of
publicly known hydraulic fracturing chemical additives to determine the accuracy and completeness of
the list of chemicals given in Table El in Appendix E. The combined list will provide EPA with an
inventory of chemicals used in hydraulic fracturing operations.
30
-------
EPA Hydraulic Fracturing Study Plan
November 2011
EPA expects the research outlined above to produce the following:
• Description of types of hydraulic fracturing fluids and their frequency of use (subject to 40 C.F.R. Part 2
Subpart B regulations).
• A list of chemicals used in hydraulic fracturing fluids, including concentrations (subject to 40 C.F.R. Part 2
Subpart B regulations).
• A list of factors that determine and alter the composition of hydraulic fracturing fluids.
Prospective case studies. These case studies will allow EPA to collect information on chemical products
used in hydraulic fracturing fluids. EPA will use these data to illustrate how hydraulic fracturing fluids are
used at specific wells in the Haynesville and Marcellus Shale plays.
EPA expects the research outlined above to produce the following:
• Illustrative examples of hydraulic fracturing fluids used in the Haynesville and Marcellus Shale
plays.
6.2.4 What are the chemical, physical, and toxicological properties of hydraulic fracturing
CHEMICAL ADDITIVES?
Chemical and physical properties of hydraulic fracturing chemical additives can help to identify potential
human health exposure pathways by describing the mobility of the chemical additives and possible
chemical reactions associated with hydraulic fracturing additives. These properties include, but are not
limited to: density, melting point, boiling point, flash point, vapor pressure, diffusion coefficients,
partition and distribution coefficients, and solubility.
Chemical characteristics can be used to assess the toxicity of hydraulic fracturing chemical additives.
Available information may include structure, water solubility, vapor pressure, partition coefficients,
toxicological studies, or other factors. There has been considerable public interest regarding the toxicity
of chemicals used in hydraulic fracturing fluids. In response to these concerns, the US House of
Representatives Committee on Energy and Commerce launched an investigation to examine the practice
of hydraulic fracturing in the US. Through this inquiry, the Committee learned that "between 2005 and
2009, the 14 [leading] oil and gas service companies used more than 2,500 hydraulic fracturing products
containing 750 chemicals and other components" (Waxman et al., 2011). This included "29 chemicals
that are: (1) known or possible human carcinogens; (2) regulated under the Safe Drinking Water Act for
their risks to human health; or (3) listed as hazardous air pollutants under the Clean Air Act" (Waxman et
al., 2011).
6.2.4.1 Research Activities - Chemical, Physical, and Toxicological Properties
Analysis of existing data. EPA will combine the chemical data collected from the nine hydraulic
fracturing service companies with the public list of chemicals given in Appendix E and other sources that
may become available to obtain an inventory of chemicals used in hydraulic fracturing fluids. EPA will
then search existing databases to obtain known chemical, physical, and toxicological properties for the
chemicals in the inventory. EPA expects to use this list to identify a short list of 10 to 20 chemical
indicators to track the fate and transport of hydraulic fracturing fluids through the environment. The
31
-------
EPA Hydraulic Fracturing Study Plan
November 2011
criteria for selecting these indicators will include, but are not limited to: (1) the frequency of occurrence
in fracturing fluids; (2) the toxicity of the chemical; (3) the expected fate and transport of the chemical
(e.g., mobility in the environment); and (4) the availability of detection methods. EPA will also use this
chemical list to identify chemicals with little or no toxicological information and may be of high concern
for human health impacts. These chemicals of concern will undergo further toxicological assessment
EPA expects the research outlined above to produce the following:
• A list of hydraulic fracturing chemicals with known chemical, physical, and toxicological
properties.
• Identification of 10-20 possible indicators to track the fate and transport of hydraulic fracturing
fluids based on known chemical, physical, and toxicological properties.
• Identification of hydraulic fracturing chemicals that may be of high concern, but have little or no
existing toxicological information.
Toxicological analysis/assessment. EPA will identify any hydraulic fracturing chemical currently
undergoing ToxCast Phase II testing to determine if chemical, physical, and toxicological properties are
being assessed. In other cases where chemical, physical, and toxicological properties are unknown, EPA
will estimate these properties using quantitative structure-activity relationships. From this effort, EPA
will identify up to six chemicals used in hydraulic fracturing fluid and without toxicity values to be
considered for ToxCast screening and provisional peer-reviewed toxicity value (PPRTV) development.
More detailed information on characterization of the toxicity and human health approach is found in
Chapter 11.
EPA expects the research outlined above to produce the following:
• Lists of high, low, and unknown priority hydraulic fracturing chemicals based on known or
predicted toxicity data.
• Toxicological properties for up to six hydraulic fracturing chemicals that have no existing
toxicological information and are of high concern.
Laboratory studies. The list of chemicals derived from the existing data analysis and toxicological studies
will inform EPA of high priority chemicals for which existing analytical methods may be inadequate for
detection in hydraulic fracturing fluids and/or in drinking water resources. EPA will modify these
methods to suit the needs of the research.
EPA expects the research outlined above to produce the following:
• Improved analytical methods for detecting hydraulic fracturing chemicals.
6.2.5 If SPILLS OCCUR, how might hydraulic fracturing chemical additives contaminate drinking
WATER RESOURCES?
Once released unintentionally into the environment, chemical additives in hydraulic fracturing fluid may
contaminate ground water or surface water resources. The pathway by which chemical additives may
32
-------
EPA Hydraulic Fracturing Study Plan
November 2011
migrate to ground and surface water depends on many factors, including site-, chemical-, or fluid-
specific factors. Site-specific factors refer to the physical characteristics of the site and the spill. These
may include the location of the spill with respect to ground and surface water resources, weather
conditions at the time of the spill, and the type of surface the spill occurred on (e.g., soil, sand, or plastic
liner). Chemical- or fluid-specific factors include the chemical and physical properties of the chemical
additives or fluid (e.g., density, solubility, diffusion, and partition coefficients). These properties govern
the mobility of the fluid or specific chemical additives through soil and other media. To understand
exposure pathways related to surface spills of hydraulic fracturing fluids, EPA must understand site-,
chemical-, or fluid-specific factors that govern surface spills.
6.2.5.1 Research Activities - Contamination Pathways
Analysis of existing data. Surface spills of chemicals, in general, are not restricted to hydraulic fracturing
operations and can occur under a variety of conditions. Because these are common problems, there
already exists a body of scientific literature that describes how a chemical solution released on the
ground can be transported into the subsurface and/or run off to a surface water body. Using the list of
hydraulic fracturing fluid chemical additives generated through the research described in Section
6.2.3.1, EPA will identify available data on the fate and transport of hydraulic fracturing fluid additives.
The relevant research will be used to assess known impacts of spills of fracturing fluid components on
drinking water resources and to identify knowledge gaps related to surface spills of hydraulic fracturing
fluid chemical additives.
EPA expects the research outlined above to produce the following:
• Summary of existing research that describes the fate and transport of hydraulic fracturing
chemical additives, similar compounds, or classes of compounds.
• Identification of knowledge gaps for future research, if necessary.
Retrospective case studies. Accidental releases from chemical tanks, supply lines or leaking valves have
been reported at some of the candidate case study sites (listed in Appendix F) have reported. EPA has
identified two locations for retrospective case studies to consider surface spills of hydraulic fracturing
fluids through field investigations and sampling: Dunn County, North Dakota, and Bradford and
Susquehanna Counties, Pennsylvania. This research will identify any potential impacts on drinking water
resources from surface spills, and if impacts were observed, what factors may have contributed to the
contamination.
EPA expects the research outlined above to produce the following:
• Identification of impacts (if any) to drinking water resources from surface spills of hydraulic
fracturing fluids.
• Identification of factors that led to impacts (if any) to drinking water resources resulting from
accidental release of hydraulic fracturing fluids.
33
-------
EPA Hydraulic Fracturing Study Plan
November 2011
6.3 Well Injection: What are the possible impacts of the injection and fracturing
PROCESS ON DRINKING WATER RESOURCES?
6.3.1 Background
In a cased well completion, the production casing is perforated prior to the injection of hydraulic
fracturing fluid. The perforations allow the injected fluid to enter, and thus fracture, the target
formation. Wells can be fractured in either a single stage or multiple stages, as determined by the total
length of the injection zone. In a multi-stage fracture, the fracturing operation typically begins with the
stage furthest from the wellhead until the entire length of the fracture zone has been fractured.
The actual fracturing process within each stage consists of a series of injections using different volumes
and compositions of fracturing fluids (GWPC and ALL Consulting, 2009). Sometimes a small amount of
fluid is pumped into the well before the actual fracturing begins. This "mini-frac" may be used to help
determine reservoir properties and to enable better fracture design (API, 2009b). In the first stage of the
fracture job, fracturing fluid (typically without proppant) is pumped down the well at high pressures to
initiate the fracture. The fracture initiation pressure will depend on the depth and the mechanical
properties of the formation. A combination of fracturing fluid and proppant is then pumped in, often in
slugs of varying sizes and concentrations. After the combination is pumped, a water flush is used to
begin flushing out the fracturing fluid (Arthur et al., 2008).
API recommends that several parameters be continuously monitored during the actual hydraulic
fracturing process, including surface injection pressure, slurry rate, proppant concentration, fluid rate,
and proppant rate (API, 2009b). Monitoring the surface injection pressure is particularly important for
two reasons: (1) it ensures that the pressure exerted on equipment does not exceed the tolerance of the
weakest components and (2) unexpected or unusual pressure changes may be indicative of a problem
that requires prompt attention (API, 2009b). It is not readily apparent how often API's recommendations
are followed.
Hydraulic fracturing models and stimulation bottomhole pressure versus time curves can be analyzed to
determine fracture height, average fracture width, and fracture half-length. Models can also be used
during the fracturing process to make real-time adjustments to the fracture design (Armstrong et al.,
1995). Additionally, microseismic monitors and tiltmeters may be used during fracturing to plot the
positions of the fractures (Warpinski et al., 1998 and 2001; Cipolla and Wright, 2000), although this is
done primarily when a new area is being developed or new techniques are being used (API, 2009b).
Comparison of microseismic data to fracture modeling predictions helps to adjust model inputs and
increase the accuracy of height, width, and half-length determinations.
6.3.1.1 Naturally Occurring Substances
Hydraulic fracturing can affect the mobility of naturally occurring substances in the subsurface,
particularly in the hydrocarbon-containing formation. These substances, described in Table 5, include
formation fluid, gases, trace elements, naturally occurring radioactive material, and organic material.
Some of these substances may be liberated from the formation via complex biogeochemical reactions
with chemical additives found in hydraulic fracturing fluid (Falk et al., 2006; Long and Angino, 1982).
34
-------
EPA Hydraulic Fracturing Study Plan
November 2011
TABLE 5. EXAMPLES OF NATURALLY OCCURRING SUBSTANCES THAT MAY BE FOUND IN HYDROCARBON-
CONTAINING FORMATIONS
Type of Contaminant
Example(s)
Formation fluid
Brine3 (e.g., sodium chloride)
Gases
Natural gasb (e.g., methane, ethane), carbon dioxide,
hydrogen sulfide, nitrogen, helium
Trace elements
Mercury, lead, arsenic0
Naturally occurring
Radium, thorium, uranium0
radioactive material
Organic material
Organic acids, polycyclic aromatic hydrocarbons,
volatile and semi-volatile organic compounds
a Piggot and Elsworth, 1996.
b Zoback et al., 2010.
c Harper, 2008; Leventhal and Hosterman, 1982; Tuttle et al., 2009;
Vejahati et al., 2010.
The ability of these substances to reach to ground or surface waters as a result of hydraulic fracturing
activities is a potential concern. For example, if fractures extend beyond the target formation and reach
aquifers, or if the casing or cement around a wellbore fails under the pressures exerted during hydraulic
fracturing, contaminants could migrate into drinking water supplies. Additionally, these naturally
occurring substances may be dissolved into or flushed to the surface with the flowback.
6.3.2 HOW EFFECTIVE ARE CURRENT WELL CONSTRUCTION PRACTICES AT CONTAINING GASES AND FLUIDS
BEFORE, DURING, AND AFTER FRACTURING?
A number of reports have indicated that that improper well construction or improperly sealed wells may
be able to provide subsurface pathways for ground water pollution by allowing contaminant migration
to sources of drinking water (PADEP, 2010b; McMahon et al., 2011; State of Colorado Oil and Gas
Conservation Commission, 2009a, 2009b, and 2009c; USEPA, 2010b). EPA will assess to what extent
proper well construction and mechanical integrity are important factors in preventing contamination of
drinking water resources from hydraulic fracturing activities.
In addition to concerns related to improper well construction and well abandonment processes, there is
a need to understand the potential impacts of the repeated fracturing of a well over its lifetime.
Hydraulic fracturing can be repeated as necessary to maintain the flow of hydrocarbons to the well. The
near- and long-term effects of repeated pressure treatments on well construction components (e.g.,
casing and cement) are not well understood. While EPA recognizes that fracturing or re-fracturing
existing wells should also be considered for potential impacts to drinking water resources, EPA has not
been able to identify potential partners for a case study; therefore, this practice is not considered in the
current study. The issues of well age, operation, and maintenance are important and warrant more
study.
6.3.2.1 Research Activities - Well Mechanical Integrity
Analysis of existing data. As part of the voluntary request for information sent by EPA to nine hydraulic
fracturing service companies (see Appendix D), EPA asked for the locations of sites where hydraulic
fracturing operations have occurred within the past year. From this list of more than 25,000 hydraulic
35
-------
EPA Hydraulic Fracturing Study Plan
November 2011
fracturing sites, EPA statistically selected a random sample of sites and requested the complete well files
for 350 sites. Well files generally contain information regarding all activities conducted at the site,
including any instances of well failure. EPA will analyze the well files to assess the typical frequency,
causes, and severity of well failures.
EPA expects the research outlined above to produce the following:
• Data on the frequency and severity of well failures.
• Identification of contributing factors that may lead to well failures during hydraulic fracturing
activities.
Retrospective case studies. While conducting retrospective case studies, EPA will assess the mechanical
integrity of existing and historical production wells near the reported area of drinking water
contamination. To do this, EPA will review existing well construction and mechanical integrity data
and/or collect new data using the tools described in Appendix G. EPA will specifically investigate
mechanical integrity issues in Dunn County, North Dakota, and Bradford and Susquehanna Counties,
Pennsylvania. By investigating well construction and mechanical integrity at sites with reported drinking
water contamination, EPA will work to determine if well failure was responsible for the reported
contamination and whether original well integrity tests were effective in identifying problems.
EPA expects the research outlined above to produce the following:
• Identification of impacts (if any) to drinking water resources resulting from well failure or
improper well construction.
• Data on the role of mechanical integrity in suspected cases of drinking water contamination due
to hydraulic fracturing.
Prospective case studies. EPA will evaluate well construction and mechanical integrity at prospective
case study sites by assessing the mechanical integrity of the well pre- and post- fracturing. This
assessment will be done by comparing results from available logging tools and pressure tests taken
before and after hydraulic fracturing. EPA will also assess the methods and tools used to protect
drinking water resources from oil and natural gas resources before and during a hydraulic fracture
event.
EPA expects the research outlined above to produce the following:
• Data on the changes (if any) in mechanical integrity due to hydraulic fracturing.
• Identification of methods and tools used to isolate drinking water resources from oil and gas
resources before and during hydraulic fracturing.
Scenario evaluation. EPA will use computer modeling to investigate the role of mechanical integrity in
creating pathways for contaminant migration to ground and surface water resources. The models will
include engineering and geological aspects, which will be informed by existing data. Models of the
engineering systems will include the design and geometry of the vertical and horizontal wells in addition
to information on the casing and cementing materials. Models of the geology will include the expected
36
-------
EPA Hydraulic Fracturing Study Plan
November 2011
geometry of aquifers and aquitards/aquicludes, the permeability of the formations, and the geometry
and nature of boundary conditions (e.g., closed and open basins, recharge/discharge).
Once built, the models will be used to explore scenarios in which well integrity is compromised before or
during hydraulic fracturing due to inadequate or inappropriate well design and construction. In these
cases, the construction of the well is considered inadequate due to improper casing and/or cement or
improper well construction. It is suspected that breakdowns in the well casing or cement may provide a
high permeability pathway between the well casing and the borehole wall, which may lead to
contamination of a drinking water aquifer. It will be informative to assess how different types of well
construction and testing practices perform during these model scenarios and whether drinking water
resources could be affected.
EPA expects the research outlined above to produce the following:
• Assessment of well failure scenarios during and after well injection that may lead to drinking
water contamination.
6.3.3 Can subsurface migration of fluids or gases to drinking water resources occur, and
WHAT LOCAL GEOLOGIC OR MAN-MADE FEATURES MAY ALLOW THIS?
Although hydraulic fracture design and control have been researched extensively, predicted and actual
fracture lengths still differ frequently (Daneshy, 2003; Warpinski et al., 1998). Hence, it is difficult to
accurately predict and control the location and length of fractures. Due to this uncertainty in fracture
location, EPA must consider whether hydraulic fracturing may lead to fractures intersecting local
geologic or man-made features, potentially creating subsurface pathways that allow fluids or gases to
contaminate drinking water resources.
Local geologic features are considered to be naturally occurring features, including pre-existing faults or
fractures that lead to or directly extend into aquifers. If the fractures created during hydraulic fracturing
were to extend into pre-existing faults or fractures, there may be an opportunity for hydraulic fracturing
fluids, natural gas, and/or naturally occurring substances (Table 5) to contaminate nearby aquifers. Any
risk posed to drinking water resources would depend on the distance to those resources and the
geochemical and transport processes that occur in the intermediate strata. A common assumption in
shale gas formations is that natural barriers in the rock strata that act as seals for the gas in the target
formation also act as barriers to the vertical migration of fracturing fluids (GWPC and ALL Consulting,
2009). Additionally, during production the flow direction is toward the wellbore because of a decreasing
pressure gradient. It is assumed that due to this gradient, gas would be unlikely to move elsewhere as
long as the well is in operation and maintains integrity. However, in contrast to shale gas, coalbed
methane reservoirs are mostly shallow and may also be co-located with drinking water resources. In this
instance, hydraulic fracturing may be occurring in or near a USDW, raising concerns about the
contamination of shallow water supplies with hydraulic fracturing fluids (Pashin, 2007).
In addition to natural faults or fractures, it is important to consider the proximity of man-made
penetrations such as drinking water wells, exploratory wells, production wells, abandoned wells
37
-------
EPA Hydraulic Fracturing Study Plan
November 2011
(plugged and unplugged), injection wells, and underground mines. If such penetrations intersect the
injection zone in the vicinity of a hydraulically fractured well, they may serve as conduits for
contaminants to reach ground water resources. Several instances of natural gas migrations have been
noted. A 2004 EPA report on coalbed methane indicated that methane migration in the San Juan Basin
was mitigated once abandoned and improperly sealed wells were plugged. The same report found that
in some cases in Colorado, poorly constructed, sealed, or cemented wells used for a variety of purposes
could provide conduits for methane migration into shallow USDWs (USEPA, 2004). More recently, a
study in the Marcellus Shale region concluded that methane gas was present in well water in areas near
hydraulic fracturing operations, but did not identify the origin of the gas (Osborne et al., 2011).
Additional studies indicate that methane migration into shallow aquifers is a common natural
phenomenon in this region and occurs in areas with and without hydraulic fracturing operations
(NYSDEC, 2011).
6.3.3.1 Research Activities - Local Geologic and Man-Made Features
Analysis of existing data. EPA is collecting information from nine oil and gas well operators regarding
operations at specific well sites. This information will be compiled and analyzed to determine whether
existing local geologic or man-made features are identified prior to hydraulic fracturing, and if so, what
types are of concern.
EPA will also review the well files for data relating to fracture location, length, and height. This includes
data gathered to measure the fracture pressure gradients in the production zone; data resulting from
fracture modeling, microseismic fracture mapping, and/or tiltmeter analysis; and other relevant data. A
critical assessment of the available data will allow EPA to determine if fractures created during hydraulic
fracturing were localized to the stimulated zone or possibly intersected pre-existing local geologic or
man-made features. EPA expects to be able to provide information on the frequency of migration
effects and the severity of impacts to drinking water resources posed by these potential contaminant
migration pathways.
EPA expects the research outlined above to produce the following:
• Information on the types of local geologic or man-made features identified prior to hydraulic
fracturing.
• Data on whether or not fractures interact with local geologic or man-made features and the
frequency of occurrence.
Retrospective case studies. In cases of suspected drinking water contamination, EPA will use geophysical
testing, field sample analysis, and modeling to investigate the role of local geologic and/or man-made
features in leading to any identified contamination. EPA will also review existing data to determine if the
induced fractures were confined to the targeted fracture zone. These investigations will determine the
role of pre-existing natural or man-made pathways in providing conduits for the migration of fracturing
fluid, natural gas, and/or naturally occurring substances to drinking water resources. In particular, EPA
will investigate the reported contamination of a USDW in Las Animas County, Colorado, where hydraulic
fracturing took place within the USDW.
38
-------
EPA Hydraulic Fracturing Study Plan
November 2011
EPA expects the research outlined above to produce the following:
• Identification of impacts (if any) to drinking water resources from hydraulic fracturing within a
drinking water aquifer.
Prospective case studies. The prospective case studies will give EPA a better understanding of the
processes and tools used to determine the location of local geologic and/or man-made features prior to
hydraulic fracturing. EPA will also evaluate the impacts of local geologic and/or man-made features on
the fate and transport of chemical contaminants to drinking water resources by measuring water quality
before, during, and after injection. EPA is exploring the possibility of using chemical tracers to track the
fate and transport of injected fracturing fluids. The tracers may be used to determine if fracturing fluid
migrates from the targeted formation to an aquifer via existing natural or man-made pathways.
EPA expects the research outlined above to produce the following:
• Identification of methods and tools used to determine existing faults, fractures, and abandoned
wells.
• Data on the potential for hydraulic fractures to interact with existing natural features.
Scenario evaluation. The modeling tools described above allow for the exploration of scenarios in which
the presence of local geologic and man-made features leads to contamination of ground or surface
water resources. EPA will explore three different scenarios:
• Induced fractures reaching compromised abandoned wells that intersect and communicate with
ground water aquifers.
• Induced fractures reaching ground or surface water resources or permeable formations that
communicate with shallower groundwater-bearing strata.
• Sealed or dormant fractures and faults being activated by hydraulic fracturing operations,
creating pathways for upward migration of fluids and gases.
In these studies, the injection pulses will be distinguished by their near-field, short-term impacts (fate
and transport of injection fluids) as well as their far-field and long-term impacts (including the
displacement of native brines or existing gas pockets). These studies will allow the exploration of the
potential impacts of fracturing on drinking water resources with regard to variations in geology and will
help to inform the retrospective and prospective case studies.
Data provided by these studies will allow EPA to identify and predict the area of evaluation (AOE)
around a hydraulic fracturing site. The AOE includes the subsurface zone that may have the potential to
be impacted by hydraulic fracturing activities and is projected as an area at the land surface. Within this
area, drinking water resources could be affected by the migration of hydraulic fracturing fluids and
liberated gases outside the injection zone, as well as the displacement of native brines within the
subsurface. Maps of the AOEs for multiple injection operations can be overlaid on regional maps to
evaluate cumulative impacts, and, when compared to regional maps of areas contributing recharge to
39
-------
EPA Hydraulic Fracturing Study Plan
November 2011
drinking water wells (source water areas), to evaluate regional vulnerability. The AOE may also be used
to support contaminant fate and transport hypothesis testing in retrospective case studies.
EPA expects the research outlined above to produce the following:
• Assessment of key conditions that may affect the interaction of hydraulic fractures with existing
man-made and natural features.
• Identification of the area of evaluation for a hydraulically fractured well.
6.3.4 How MIGHT HYDRAULIC FRACTURING FLUIDS CHANGE THE FATE AND TRANSPORT OF SUBSTANCES IN
THE SUBSURFACE THROUGH GEOCHEMICAL INTERACTIONS?
The injection of hydraulic fracturing fluid chemical additives into targeted geologic formations may alter
both the injected chemicals and chemicals naturally present in the subsurface. The chemical identity of
the injected chemicals may change because of chemical reactions in the fluid (e.g., the formation and
breakdown of gels), reactions with the target formation, or microbe-facilitated transformations. These
chemical transformation or degradation products could also pose a risk to human health if they migrate
to drinking water resources.
Reactions between hydraulic fracturing fluid chemical additives and the target formation could increase
or decrease the mobility of these substances, depending on their properties and the complex
interactions of the chemical, physical, and biological processes occurring in the subsurface.
For example, several of the chemicals used in fracturing fluid (e.g., acids and carbonates) are known to
mobilize naturally occurring substances out of rocks and soils by changing the pH or reduction-oxidation
(redox) conditions in the subsurface. Conversely, a change in the redox conditions in the subsurface may
also decrease the mobility of naturally occurring substances (Eby, 2004; Sparks, 1995; Sposito, 1989;
Stumm and Morgan, 1996; Walther, 2009).
Along with chemical mechanisms, biological processes can change the mobility of fracturing fluid
additives and naturally occurring substances. Many microbes, for example, are known to produce
siderophores, which can mobilize metals from the surrounding matrix (Gadd, 2004). Microbes may also
reduce the mobility of substances by binding to metals or organic substances, leading to the localized
sequestration of fracturing fluid additives or naturally occurring substances (Gadd, 2004; McLean and
Beveridge, 2002; Southam, 2000).
6.3.4.1 Research activities - Geochemical Interactions
Laboratory studies. Using samples obtained from retrospective and prospective case study locations,
EPA will conduct limited laboratory studies to assess reactions between hydraulic fracturing fluid
chemical additives and various environmental materials (e.g., shale or aquifer material) collected on site.
Chemical degradation, biogeochemical reactions, and weathering reactions will be studied by
pressurizing subsamples of cores, cuttings, or aquifer material in temperature-controlled reaction
vessels. Data will be collected on the chemical composition and mineralogy of these materials.
Subsamples will then be exposed to hydraulic fracturing fluids used at the case study locations using
either a batch or continuous flow system to simulate subsurface reactions. After specific exposure
40
-------
EPA Hydraulic Fracturing Study Plan
November 2011
conditions, samples will be drawn for chemical, mineralogical, and microbiological characterization. This
approach will enable the evaluation of the reaction between hydraulic fracturing fluids and
environmental media as well as observe chemicals that may be mobilized from the solid phase due to
biogeochemical reactions.
EPA expects the research outlined above to produce the following:
• Data on the chemical composition and mineralogy of environmental media.
• Data on the reactions between hydraulic fracturing fluids and environmental media.
• List of chemicals that may be mobilized during hydraulic fracturing activities.
6.3.5 What are the chemical, physical, and toxicological properties of substances in the
SUBSURFACE THAT MAY BE RELEASED BY HYDRAULIC FRACTURING OPERATIONS?
As discussed above, multiple pathways may exist that must be considered for the potential to allow
contaminants to reach drinking water resources. These contaminants may include hydraulic fracturing
fluid chemical additives and naturally occurring substances, such as those listed in Table 5. Chemical and
physical properties of naturally occurring substances can help to identify potential exposure pathways
by describing the mobility of these substances and their possible chemical reactions.
The toxic effects of naturally occurring substances can be assessed using toxicological properties
associated with the substances. Table E3 in Appendix E provides examples of naturally occurring
substances released during hydraulic fracturing operations that may contaminate drinking water
resources. The toxicity of these substances varies considerably. For example, some naturally occurring
metals, though they can be essential nutrients, exert various forms of toxicity even at low
concentrations. Natural gases can also have adverse consequences stemming from their toxicity as well
as their physical characteristics (e.g., some are very explosive).
6.3.5.1 Research Activities - Chemical, Physical, and Toxicological Properties
Analysis of existing data. Table E3 in Appendix E lists naturally occurring substances that have been
found to be mobilized by hydraulic fracturing activities. EPA will also evaluate data from the literature,
as well as from the laboratory studies described above, on the identity of substances and their
degradation products released from the subsurface due to hydraulic fracturing. Using this list, EPA will
then search existing databases to obtain known chemical, physical, and toxicological properties for these
substances. The list will also be used to identify chemicals for further toxicological analysis and analytical
method development.
EPA expects the research outlined above to produce the following:
• List of naturally occurring substances that are known to be mobilized during hydraulic fracturing
activities and their associated chemical, physical, and toxicological properties.
• Identification of chemicals that may warrant further toxicological analysis or analytical method
development.
41
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Toxicological studies. EPA will identify any potential subsurface chemical currently undergoing ToxCast
Phase II testing to determine if chemical, physical, and toxicological properties are being assessed. In
other cases where chemical, physical, and toxicological properties are unknown, EPA will estimate these
properties using quantitative structure-activity relationships. From this effort, EPA will identify up to six
chemicals without toxicity values that may be released from the subsurface during hydraulic fracturing
for ToxCast screening and PPRTV development consideration. More detailed information on
characterization of the toxicity and human health effects of chemicals of concern is found in Chapter 11.
EPA expects the research outlined above to produce the following:
• Lists of high, low, and unknown priority for naturally occurring substances based on known or
predicted toxicity data.
• Toxicological properties for up to six naturally occurring substances that have no existing
toxicological information and are of high concern.
Laboratory studies. The list of chemicals derived from the existing data analysis and toxicological studies
will inform EPA of high priority chemicals for which existing analytical methods may be inadequate for
detection in drinking water resources. EPA will modify these methods to suit the needs of the research.
EPA expects the research outlined above to produce the following:
• Analytical methods for detecting selected naturally occurring substances released by hydraulic
fracturing.
6.4 Flowback and Produced Water: What are the possible impacts of surface
SPILLS ON OR NEAR WELL PADS OF FLOWBACK AND PRODUCED WATER ON DRINKING
WATER RESOURCES?
6.4.1 Background
After the fracturing event, the pressure is decreased and the direction of fluid flow is reversed, allowing
fracturing fluid and naturally occurring substances to flow out of the wellbore to the surface before the
well is placed into production. This mixture of fluids is called "flowback," which is a subset of produced
water. The definition of flowback is not considered to be standardized. Generally, the flowback period in
shale gas reservoirs is several weeks (URS Corporation, 2009), while the flowback period in coalbed
methane reservoirs appears to be longer (Rogers et al., 2007).
Estimates of the amount of fracturing fluid recovered as flowback in shale gas operations vary from as
low as 25 percent to high as 70 to 75 percent (Pickett, 2009; Veil, 2010; Horn, 2009). Other estimates
specifically for the Marcellus Shale project a fracture fluid recovery rate of 10 to 30 percent (Arthur et
al., 2008). Less information is available for coalbed methane reservoirs. Palmer et al. (1991) estimated a
61 percent fracturing fluid recovery rate over a 19 day period based on sampling from a single well in
the Black Warrior Basin.
42
-------
EPA Hydraulic Fracturing Study Plan
November 2011
The flow rate at which the flowback exits the well can be relatively high (e.g., >100,000 gallons per day)
for the first few days. However, this flow diminishes rapidly with time, ultimately dropping to the normal
rate of produced water flow from a natural gas well (e.g., 50 gallons per day) (Chesapeake Energy, 2010;
Hayes, 2009b). While there is no clear transition between flowback and produced water, produced
water is generally considered to be the fluid that exits the well during oil or gas production (API, 2010a;
Clark and Veil, 2009). Like flowback, produced water also contains fracturing fluid and naturally
occurring materials, including oil and/or gas. Produced water, however, is generated throughout the
well's lifetime.
The physical and chemical properties of flowback and produced water vary with fracturing fluid
composition, geographic location, geological formation, and time (Veil et al., 2004). In general, analyses
of flowback from various reports show that concentrations of TDS can range from approximately 1,500
milligram per liter (mg/L) to more than 300,000 mg/L (Gaudlip and Paugh, 2008; Hayes, 2009a; Horn,
2009; Keister, 2009; Vidic, 2010; Rowan et al., 2011). The Appalachian Basin tends to produce one of the
higher TDS concentrations by region in the US, with a mean TDS concentration of 250,000 mg/L (Breit,
2002). It can take several weeks for the flowback to reach these values.
Along with high TDS values, flowback can have high concentrations of several ions (e.g., barium,
bromide, calcium, chloride, iron, magnesium, sodium, strontium, bicarbonate), with concentrations of
calcium and strontium sometimes reported to be as high as thousands of milligrams per liter (Vidic,
2010). Flowback likely contains radionuclides, with the concentration varying by formation (Zielinski and
Budahn, 2007; Zoback et al., 2010; Rowan et al., 2011). Flowback from Marcellus Shale formation
operations has been measured at concentrations up to 18,000 picocuries per liter (pCi/L; Rowan et al.,
2011) and elsewhere in the US above 10,000 pCi/L (USGS, 1999). Volatile organic compounds (VOCs),
including but not limited to benzene, toluene, xylenes, and acetone, have also been detected (URS
Corporation, 2009; NYSDEC, 2011). A list of chemicals identified in flowback and produced water is
presented in Table E2 in Appendix E. Additionally, flowback has been reported to have pH values ranging
from 5 to 8 (Hayes, 2009a). A limited time series monitoring program of post-fracturing flowback fluids
in the Marcellus Shale indicated increased concentrations over time of TDS, chloride, barium, and
calcium; water hardness; and levels of radioactivity (URS Corporation, 2009; Rowen et al., 2011).
Flowback and produced water from hydraulic fracturing operations are held in storage tanks and waste
impoundment pits prior to or during treatment, recycling, and disposal (GWPC, 2009). Impoundments
may be temporary (e.g., reserve pits for storage) or long-term (e.g., evaporation pits used for
treatment). Requirements for impoundments can vary by location. In areas of New York overlying the
Marcellus Shale, regulators are requiring water-tight tanks to hold flowback water (ICF, 2009b; NYSDEC,
2011).
6.4.2 What is currently known about the frequency, severity, and causes of spills of flowback
AND PRODUCED WATER?
Surface spills or releases of flowback and produced water (collectively referred to as "hydraulic
fracturing wastewaters") can occur as a result of tank ruptures, equipment or surface impoundment
failures, overfills, vandalism, accidents, ground fires, or improper operations. Released fluids might flow
43
-------
EPA Hydraulic Fracturing Study Plan
November 2011
into a nearby surface water body or infiltrate into the soil and near-surface ground water, potentially
reaching drinking water aquifers (NYSDEC, 2011). However, it remains unclear how often spills of this
nature occur, how severe these spills are, and what causes them. To better understand potential
impacts to drinking water resources from surface spills, EPA is interested in learning about the range of
volumes and reported impacts associated with surface spills of hydraulic fracturing wastewaters.
6.4.2.1 Research Activities - Surface Spills of Flowback and Produced Water
Analysis of existing data. EPA will available existing information on the frequency, severity, and causes
of spills of flowback and produced water. These data will come from a variety of sources, including
information provided by nine oil and gas operators received in response to EPA's August 2011
information request. In this request, EPA asked for spill incident reports for any fluid spilled at 350
different well sites across the US. Other sources of data are expected to include spills reported to the
National Response Center, state departments of environmental protection (e.g., Pennsylvania and West
Virginia), EPA's Natural Gas Drilling Tipline, and others.
EPA will assess the data provided by these sources to create a national picture of reported surface spills
of flowback and produced water. The goal of this effort is to provide a representative assessment of the
frequency, severity, and causes of surface spills associated with flowback and produced water.
EPA expects the research outlined above to produce the following:
• Data on the frequency, severity, and common causes of spills of hydraulic fracturing flowback
and produced water.
6.4.3 What is the composition of hydraulic fracturing wastewaters, and what factors might
INFLUENCE THIS COMPOSITION?
Flowback and produced water can be composed of injected fracturing fluid, naturally occurring
materials already present in the target formation, and any reaction or degradation products formed
during the hydraulic fracturing process. Much of the existing data on the composition of flowback and
produced water focuses on the detection of ions in addition to pH and TDS measurements, as described
above. There has been an increased interest in identifying and quantifying the components of flowback
and produced water since the composition of these wastewaters affects the treatment and
recycling/disposal of the waste (Blauch, 2011; Hayes, 2011; J. Lee, 2011a). However, less is known about
the composition and variability of flowback and produced water with respect to the chemical additives
found in hydraulic fracturing fluids, reaction and degradation products, or radioactive materials.
The composition of flowback and produced water has also been shown to vary with location and time.
For example, data from the USGS produced water database indicate that the distribution of major ions,
pH, and TDS levels is not only variable on a national scale (e.g., between geologic basins), but also on the
local scale (e.g., within one basin) (USGS, 2002). Studies have also shown that the composition of
flowback changes dramatically over time (Blauch, 2011; Hayes, 2011). A better understanding of the
spatial and temporal variability of flowback and produced water could lead to improved predictions of
44
-------
EPA Hydraulic Fracturing Study Plan
November 2011
the identity and toxicity of chemical additives and naturally occurring substances in hydraulic fracturing
wastewaters.
6.4.3.1 Research Activities - Composition of Flowback and Produced Water
Analysis of existing data. EPA requested data on the composition of flowback and produced water in the
information request sent to nine hydraulic fracturing service companies and nine oil and gas operators
(Appendix D). EPA will use these data, and any other suitable data it can locate, to better understand
what chemicals are likely to be found in flowback and produced water, the variation in chemical
concentrations of those chemicals, and what factors may influence their presence and abundance. In
this manner, EPA may be able to identify potential chemicals of concern (e.g., fracturing fluid additives,
metals, and radionuclides) in flowback and produced water based on their chemical, physical, and
toxicological properties.
EPA expects the research outlined above to produce the following:
• A list of chemicals found in flowback and produced water.
• Information on distribution (range, mean, median) of chemical concentrations.
• Identification of factors that may influence the composition of flowback and produced water.
• Identification of the constituents of concern present in hydraulic fracturing wastewaters.
Prospective case studies. EPA will draw samples of flowback and produced water as part of the full water
lifecycle monitoring at prospective case study sites. At these sites, flowback and produced water will be
sampled periodically following the completion of the injection of hydraulic fracturing fluids into the
formation. Samples will be analyzed for the presence of fracturing fluid chemicals and naturally
occurring substances found in formation samples analyzed prior to fracturing. This will allow EPA to
study the composition and variability of flowback and produced water over a given period of time at two
different locations in the Marcellus Shale and the Haynesville Shale.
EPA expects the research outlined above to produce the following:
• Data on composition, variability, and quantity of flowback and produced water as a function
of time.
6.4.4 What are the chemical, physical, and toxicological properties of hydraulic fracturing
WASTEWATER CONSTITUENTS?
Chemical, physical, and toxicological properties can be used to aid identification of potential exposure
pathways and chemicals of concern related to hydraulic fracturing wastewaters. For example, chemical
and physical properties—such as diffusion coefficients, partition, factors and distribution coefficients-
can help EPA understand the mobility of different chemical constituents of flowback and produced
water in various environmental media (e.g., soil and water). These and other properties will help EPA
determine which chemicals in hydraulic fracturing wastewaters may be more likely to appear in drinking
water resources. At the same time, toxicological properties can be used to determine chemical
constituents that may be harmful to human health. By identifying those chemicals that have a high
45
-------
EPA Hydraulic Fracturing Study Plan
November 2011
mobility and substantial toxicity, EPA can identify a set of chemicals of concern associated with flowback
and produced water.
6.4.4.1 Research Activities - Chemical, Physical, and Toxicological Properties
Analysis of existing data. EPA will use the data compiled as described in Sections 6.2.3 and 6.4.4 to
create a list of chemicals found in flowback and produced water. As outlined in Section 6.2.4, EPA will
then search existing databases to obtain known chemical, physical, and toxicological properties for the
chemicals in the inventory. EPA expects to identify a list of 10 to 20 chemicals of concern found in
hydraulic fracturing wastewaters. The criteria for selecting these chemicals of concern include, but are
not limited to: (1) the frequency of occurrence in hydraulic fracturing wastewater; (2) the toxicity of the
chemical; (3) the fate and transport of the chemical (e.g., mobility in the environment); and (4) the
availability of detection methods.
EPA expects the research outlined above to produce the following:
• List of flowback and produced water constituents with known chemical, physical, and
toxicological properties.
• Identification of constituents that may be of high concern, but have no existing toxicological
information.
Toxicological studies. EPA will determine if any identified chemical present in flowback or produced
water is currently undergoing ToxCast Phase II testing to determine if chemical, physical, and
toxicological properties are being assessed. In other cases where chemical, physical, and toxicological
properties are unknown, EPA will estimate these properties using quantitative structure-activity
relationships. From this effort, EPA will identify up to six chemicals without toxicity values that may be
present in hydraulic fracturing wastewaters for ToxCast screening and PPRTV development
consideration. More detailed information on characterization of the toxicity and human health effects
of chemicals of concern is found in Chapter 11.
EPA expects the research outlined above to produce the following:
• Lists of high, low, and unknown priority chemicals based on known or predicted toxicity data.
• Toxicological properties for up to six hydraulic fracturing wastewater constituents that have no
existing toxicological information and are of high concern.
Laboratory studies. The list of chemicals derived from the existing data analysis and toxicological studies
will inform EPA of high priority chemicals for which existing analytical methods may be inadequate for
detection in hydraulic fracturing wastewaters. EPA will modify these methods to suit the needs of the
research.
EPA expects the research outlined above to produce the following:
• Analytical methods for detecting hydraulic fracturing wastewater constituents.
46
-------
EPA Hydraulic Fracturing Study Plan
November 2011
6.4.5 If SPILLS OCCUR, how might hydraulic fracturing wastewaters contaminate drinking
WATER RESOURCES?
There may be opportunities for wastewater contamination of drinking water resources both below and
above ground. If the mechanical integrity of the well has been compromised, there is the potential for
flowback and produced water traveling up the wellbore to have direct access to local aquifers, leading to
the contamination of drinking water resources. Once above ground, flowback and produced water are
stored on-site in storage tanks and waste impoundment pits, and then may be transported off-site for
treatment and/or disposal. There is a potential for releases, leaks, and/or spills associated with the
storage and transportation of flowback and produced water, which could lead to contamination of
shallow drinking water aquifers and surface water bodies. Problems with the design, construction,
operation, and closure of waste impoundment pits may also provide opportunities for releases, leaks,
and/or spills. To understand exposure pathways related to surface spills of hydraulic fracturing
wastewaters, EPA must consider both site-specific factors and chemical- or fluid-specific factors that
govern surface spills (e.g., chemical and physical properties of the fluid).
6.4.5.1 Research Activities - Contamination Pathways
Analysis of existing data. This approach used here is similar to that described in Section 6.2.5.1 for
surface spills associated with the mixing of hydraulic fracturing fluids. Surface spills of chemicals, in
general, can occur under a variety of conditions. There already exists a body of scientific literature that
describes how a chemical solution released on the ground can infiltrate the subsurface and/or run off to
a surface water body. EPA will use the list of chemicals found in hydraulic fracturing wastewaters
generated through the research described in Section 6.4.3.1 to identify individual chemicals and classes
of chemicals for review in the existing scientific literature. EPA will then identify relevant research on the
fate and transport of these chemicals. The research will be summarized to determine the known impacts
of spills of fracturing fluid wastewaters on drinking water resources, and to identify existing knowledge
gaps related to surface spills of flowback and produced water.
EPA expects the research outlined above to produce the following:
• Summary of existing research that describes the fate and transport of chemicals in hydraulic
fracturing wastewaters of similar compounds.
• Identification of knowledge gaps for future research, if necessary.
Retrospective case studies. Accidental releases from wastewater pits and tanks, supply lines, or leaking
valves have been reported at some of the candidate case study sites (listed in Appendix F). EPA has
identified three retrospective case study locations to investigate surface spills of hydraulic fracturing
wastewaters: Wise and Denton Counties, Texas; Bradford and Susquehanna Counties, Pennsylvania; and
Washington County, Pennsylvania. The studies will provide an opportunity to identify any impacts to
drinking water resources from surface spills. If impacts are found to have occurred, EPA will determine
the factors that were responsible for the contamination.
47
-------
EPA Hydraulic Fracturing Study Plan
November 2011
EPA expects the research outlined above to produce the following:
• Identification of impacts (if any) to drinking water resources from surface spills of hydraulic
fracturing wastewater.
• Identification of factors that led to impacts (if any) to drinking water resources resulting from
the accidental release of hydraulic fracturing wastewaters.
6.5 Wastewater Treatment and Waste Disposal: What are the possible impacts of
INADEQUATE TREATMENT OF HYDRAULIC FRACTURING WASTEWATERS ON DRINKING
WATER RESOURCES?
6.5.1 Background
Wastewaters associated with hydraulic fracturing can be managed through disposal or treatment,
followed by discharge to surface water bodies or reuse. Regulations and practices for management and
disposal of hydraulic fracturing wastes vary by region and state, and are influenced by local and regional
infrastructure development as well as geology, climate, and formation composition. Underground
injection is the primary method for disposal in all major gas shale plays, except the Marcellus Shale
(Horn, 2009; Veil, 2007 and 2010). Underground injection can be an effective way to manage
wastewaters, although insufficient capacity and the costs of trucking wastewater to an injection site can
sometimes be problematic (Gaudlip and Paugh, 2008; Veil, 2010).
In shale gas areas near population centers (e.g., the Marcellus Shale), wastewater treatment at publicly
owned treatment works (POTWs) or commercial wastewater treatment facilities (CWTs) may be an
option for some operations. CWTs may be designed to treat the known constituents in flowback or
produced water while POTWs are generally not able to do so effectively. For example, large quantities of
sodium and chloride are detrimental to POTW digesters and can result in high TDS concentrations in the
effluent (Veil, 2010; West Virginia Water Research Institute, 2010). If the TDS becomes too great in the
effluent, it may harm drinking water treatment facilities downstream from POTWs. Additionally, POTWs
are not generally equipped to treat fluids that contain radionuclides, which may be released from the
formation during hydraulic fracturing. Elevated levels of bromide, a constituent of flowback in many
areas, can also create problems for POTWs. Wastewater plants using chlorination as a treatment
process will produce more brominated disinfection byproducts (DBPs), which have significant health
concerns at high exposure levels. Bromides discharged to drinking water sources may also form DBPs
during the treatment process. When POTWs are used, there may be strict limits on the volumes
permitted. In Pennsylvania, for example, the disposal of production waters at POTWs is limited to less
than 1 percent of the POTW's average daily flow (Pennsylvania Environmental Quality Board, 2009).
As noted earlier, recycling of flowback for use in fracturing other wells is becoming increasingly common
and is facilitated by developments in on-site treatment to prepare the flowback for reuse. Researchers
at Texas A&M, for example, are developing a mobile treatment system that is being pilot tested in the
Barnett Shale (Pickett, 2009). In addition to being used for fracturing other wells, hydraulic fracturing
wastewater may be also treated on-site to meet requirements for use in irrigation or for watering
48
-------
EPA Hydraulic Fracturing Study Plan
November 2011
livestock (Horn, 2009). Given the logistical and financial benefits to be gained from treatment of
flowback water, continued developments in on-site treatment technologies are expected.
6.5.2 What are the common treatment and disposal methods for hydraulic fracturing
WASTEWATERS, AND WHERE ARE THESE METHODS PRACTICED?
As mentioned earlier, common treatment and disposal methods for hydraulic fracturing wastewaters
include underground injection in Class II underground injection control (UIC) wells, treatment followed
by surface discharge, and treatment followed by reuse as hydraulic fracturing fluid. Treatment, disposal,
and reuse of flowback and produced water from hydraulic fracturing activities are important because of
the contaminants present in these waters and their potential for adverse human health impacts. Recent
events in West Virginia and Pennsylvania have focused public attention on the treatment and discharge
of flowback and produced water to surface waters via POTWs (Puko, 2010; Ward Jr., 2010; Hopey,
2011). The concerns raised by the public have prompted Pennsylvania to request that oil and gas
operators not send hydraulic fracturing wastewaters to 15 facilities within the state (Hopey and Hamill,
2011; Legere, 2011). While this issue has received considerable public attention, EPA is aware that many
oil and gas operators use UIC wells as their primary disposal option. Treatment and recycling of flowback
and produced water are becoming more common in areas where underground injection is not currently
feasible.
6.5.2.1 Research Activities -Treatment and Disposal Methods
Analysis of existing data. As part of the information request to nine oil and gas well operators, EPA
asked for information relating to the disposal of wastewater generated at 350 wells across the US.
Specifically, EPA asked for the volume and final disposition of flowback and produced water, as well as
information relating to recycling of hydraulic fracturing wastewaters (e.g., recycling procedure, volume
of fluid recycled, use of recycled fluid, and disposition of any waste generated during recycling). EPA will
use the information received to obtain a nationwide perspective of recycling, treatment, and disposal
methods currently being used by nine oil and gas operators.
EPA expects the research outlined above to produce the following:
• Nationwide data on recycling, treatment, and disposal methods for hydraulic fracturing
wastewaters.
Prospective case studies. While conducting prospective case studies in the Marcellus and Haynesville
Shales, EPA will collect information on the types of recycling, treatment, and disposal practices used at
the two different locations. These areas are illustrative of a region where UIC wells are a viable disposal
option (Haynesville Shale) and where recycling is becoming more common (Marcellus Shale).
EPA expects the research outlined above to produce the following:
• Information on wastewater recycling, treatment, and disposal practices at two specific locations.
49
-------
EPA Hydraulic Fracturing Study Plan
November 2011
6.5.3 HOW EFFECTIVE ARE CONVENTIONAL POTWS AND COMMERCIAL TREATMENT SYSTEMS IN REMOVING
ORGANIC AND INORGANIC CONTAMINANTS OF CONCERN IN HYDRAULIC FRACTURING WASTEWATERS?
For toxic constituents that are present in wastewater, their separation and appropriate disposal is the
most protective approach for reducing potential adverse impacts on drinking water resources. Much is
unknown, however, about the efficacy of current treatment processes for removing certain flowback
and produced water constituents, such as fracturing fluid additives and radionuclides. Additionally, the
chemical composition and concentration of solid residuals created by wastewater treatment plants that
treat hydraulic fracturing wastewater, and their subsequent disposal, warrants more study.
Recycling and reuse of flowback and produced water may not completely alleviate concerns associated
with treatment and disposal of hydraulic fracturing wastewaters. While recycling and reuse reduce the
immediate need for treatment and disposal—and also reduce water acquisition needs—there will likely
be a need to treat and properly dispose of the final concentrated volumes of wastewater from a given
area of operation.
6.5.3.1 Research Activities -Treatment Efficacy
Analysis of existing data. EPA will gather existing data on the treatment efficiency and contaminant fate
and transport through POTWs and CWTs that have treated hydraulic fracturing wastewaters. Emphasis
will be placed on inorganic and organic contaminants, the latter being an area that has the least
historical information, and hence the greatest opportunity for advancement in treatment. This
information will enable EPA to assess the efficacy of existing treatment options and will also identify
areas for further research.
EPA expects the research outlined above to produce the following:
• Collection of analytical data on the efficacy of treatment operations that treat hydraulic
fracturing wastewaters.
• Identification of areas for further research.
Laboratory studies. Section 6.4.3.1 describes research on the composition and variability of hydraulic
fracturing wastewaters, and on the identification of chemicals of concern in flowback and produced
water. This information will be coupled with available data on treatment efficacy to design laboratory
studies on the treatability, fate, and transport of chemicals of concern, including partitioning in
treatment residues. Studies will be conducted using a pilot-scale wastewater treatment system
consisting of a primary clarifier, activated sludge basin, and secondary clarifier. Commercial treatment
technologies will also be assessed in the laboratory using actual or synthetic hydraulic fracturing
wastewater.
EPA expects the research outlined above to produce the following:
• Data on the fate and transport of hydraulic fracturing water contaminants through wastewater
treatment processes, including partitioning in treatment residuals.
50
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Prospective case studies. To the extent possible, EPA will evaluate the efficacy of treatment practices
used at the prospective case study locations in Pennsylvania and Louisiana by sampling both pre- and
post-treatment wastewaters. It is expected that such studies will include on-site treatment, use of
wastewater treatment plants, recycling, and underground injection control wells. In these cases, EPA
will identify the fate and transport of hydraulic fracturing wastewater contaminants throughout the
treatment and will characterize the contaminants in treatment residuals.
EPA expects the research outlined above to produce the following:
• Data on the efficacy of treatment methods used in two locations.
6.5.4 What are the potential impacts from surface water disposal of treated hydraulic
FRACTURING WASTEWATER ON DRINKING WATER TREATMENT FACILITIES?
Drinking water treatment facilities could be negatively impacted by hydraulic fracturing wastewaters
when treatment is followed by surface discharge. For example, there is concern that POTWs may be
unable to treat the TDS concentrations potentially found in flowback and produced water, which would
lead to high concentrations of both chloride and bromide in the effluent. High TDS levels (>500 mg/L)
have been detected in the Monongahela and Youghiogheny Rivers in 2008 and 2010, respectively (J. Lee,
2011b; Ziemkiewicz, 2011). The source of these high concentrations is unknown, however, and they
could be due to acid mine drainage treatment plants, active or abandoned coal mines, or shale gas
operations. Also, it is unclear how these high TDS concentrations may affect drinking water treatment
facilities. It is believed that increased concentrations of chloride and bromide may lead to higher levels
of both chlorinated and brominated DBPs at drinking water treatment facilities. The presence of high
levels of bromide in waters used by drinking water systems that disinfect through chlorination can lead
to higher concentrations of brominated DBPs, which may be of greater concern from a human health
perspective than chlorinated DBPs (Plewa and Wagner, 2009). Also, because of their inherent higher
molecular weight, brominated DBPs will result in higher concentrations (by weight) than their
chlorinated counterparts (e.g., bromoform versus chloroform). This has the potential to cause a drinking
water utility to exceed the current DBP regulatory limits.
High chloride and bromide concentrations are not the only factors to be addressed regarding drinking
water treatment facilities. Other chemicals, such as naturally occurring radioactive material, may also
present a problem to drinking water treatment facilities that are downstream from POTWs or CWTs that
ineffectively treat hydraulic fracturing wastewaters. To identify potential impacts to drinking water
treatment facilities, it is important to be able to determine concentrations of various classes of
chemicals of concern at drinking water intakes.
6.5.4.1 Research Activities - Potential Drinking Water Treatment Impacts
Laboratory studies. EPA will conduct laboratory studies on the formation of DBPs in hydraulic fracturing-
impacted waters (e.g., effluent from a wastewater treatment facility during processing of hydraulic
fracturing wastewater), with an emphasis on the formation of brominated DBPs. These studies will
explore two sources of brominated DBP formation: hydraulic fracturing chemical additives and high
levels of bromide in flowback and produced water. In the first scenario, water samples with known
51
-------
EPA Hydraulic Fracturing Study Plan
November 2011
amounts of brominated hydraulic fracturing chemical additives will be equilibrated with chlorine,
chloramines, and ozone disinfectants. EPA will then analyze these samples for regulated
trihalomethanes (i.e., chloroform, bromoform, bromodichloromethane, and dibromochloromethane),
haloacetic acids, and nitrosamines. In the second scenario, EPA will use existing peer-reviewed models
to identify problematic concentrations of bromide in source waters.
If actual samples of hydraulic fracturing-impacted source waters can be obtained, EPA will perform
laboratory studies to establish baseline parameters for the sample (e.g., existing bromide concentration,
total organic concentrations, and pH). The samples will then be subjected to chlorination,
chloramination, and ozonation and analyzed for brominated DBPs.
If possible, EPA will identify POTWs or CWTs that are currently treating and discharging hydraulic
fracturing wastewaters to surface waters. EPA will then collect discharge and stream samples during
times when these treatment facilities are and are not processing hydraulic fracturing wastewaters. This
will improve EPA's understanding of how contaminants in the treated effluent change when treated
hydraulic fracturing wastewaters are discharged to surface water. EPA will also assess how other sources
of contamination (e.g., acid mine drainage) alter contaminant concentrations in the effluent. The goal of
this effort is to identify when hydraulic fracturing wastewaters are the cause of high levels of TDS or
other contaminants at drinking water treatment facilities.
EPA expects the research outlined above to produce the following:
• Data on the formation of brominated DBPs from chlorination, chloramination, and ozonation
treatments of water receiving treated effluent from hydraulic fracturing wastewater treatment.
• Data on the inorganic species in hydraulic fracturing wastewater and other discharge sources
that contribute similar species.
• Contribution of hydraulic fracturing wastewater to stream/river contamination.
Scenario evaluations. Scenario evaluations will be used to identify potential impacts to drinking water
treatment facilities from surface discharge of treated hydraulic fracturing wastewaters. To accomplish
this, EPA will first construct a simplified model of an idealized river section with generalized wastewater
treatment discharges and drinking water intakes. To the extent possible, the characteristics of the
discharges will be generated based on actual representative information. This model will be able to
generate a general guide to releases of treated hydraulic fracturing wastewaters that allows exploration
of a range of parameters that may affect drinking water treatment intakes (e.g., discharge rates and
concentrations, river flow rates, and distances).
In a second step, EPA will create a watershed-specific scenario that will include the location of specific
wastewater and drinking water treatment facilities. Likely candidates for this more detailed scenario
include the Monongahela, Allegheny, or Susquehanna River networks. The final choice will be based on
the availability of data on several parameters, including the geometry of the river network and flows,
and hydraulic fracturing wastewater discharges. The primary result will be an assessment of the
potential impacts from disposal practices on specific watersheds. Secondarily, the results of the
watershed-specific scenario will be compared to the simplified scenario to determine the ability of the
52
-------
EPA Hydraulic Fracturing Study Plan
November 2011
simplified model to capture specific watershed characteristics. Taken together, the two parts of this
work will allow EPA to assess the potential impacts of chemicals of concern in flowback and produced
water at drinking water treatment intakes.
EPA expects the research outlined above to produce the following:
• Identification of parameters that generate or mitigate drinking water exposure.
• Data on potential impacts in the Monongahela, Allegheny, or Susquehanna River networks.
7 Environmental Justice Assessment
Environmental justice is the fair treatment and meaningful involvement of all people regardless of race,
color, national origin, or income with respect to the development, implementation, and enforcement of
environmental laws, regulations, and policies. Achieving environmental justice is an Agency-wide
priority (USEPA, 2010d) and is therefore considered in this study plan.
Stakeholders have raised concerns about the environmental justice implications of gas drilling
operations. It has been suggested that people with a lower socioeconomic status may be more likely to
consent to drilling arrangements, due to the greater economic need of these individuals, or their more
limited ability or willingness to engage with policymakers and agencies. Additionally, since drilling
agreements are between landowners and well operators, tenants and neighbors may have little or no
input in the decision-making process.
In response to these concerns, EPA has included in the study plan a screening analysis of whether
hydraulic fracturing activities may be disproportionately occurring in communities with environmental
justice concerns. An initial screening assessment will be conducted to answer the following fundamental
research question:
• Does hydraulic fracturing disproportionately occur in or near communities with environmental
justice concerns?
Consistent with the framework of the study plan, the environmental justice assessment will focus on the
spatial locations of the activities associated with the five stages of the water lifecycle (Figure 1). Each
stage of the water lifecycle can be categorized as either occurring onsite (chemical mixing, well injection,
and flowback and produced water) or offsite (water acquisition and wastewater treatment/disposal).
Because water acquisition, onsite activities and wastewater treatment/disposal generally occur in
different locations, EPA has identified three secondary research questions:
• Are large volumes of water for hydraulic fracturing being disproportionately withdrawn from
drinking water resources that serve communities with environmental justice concerns?
• Are hydraulically fractured oil and gas wells disproportionately located near communities with
environmental justice concerns?
53
-------
EPA Hydraulic Fracturing Study Plan
November 2011
• Is wastewater from hydraulic fracturing operations being disproportionately treated or disposed
of (via POTWs or commercial treatment systems) in or near communities with environmental
justice concerns?
The following sections outline the research activities associated with each of these secondary research
questions.
7.1.1 Are large volumes of water for hydraulic fracturing being disproportionately
WITHDRAWN FROM DRINKING WATER RESOURCES THAT SERVE COMMUNITIES WITH ENVIRONMENTAL
JUSTICE CONCERNS?
7.1.1.1 Research Activities - Water Acquisition Locations
Analysis of existing data. To the extent data are available, EPA will identify locations where large volume
water withdrawals are occurring to support hydraulic fracturing activities. These data will be compared
to demographic information from the US Census Bureau on race/ethnicity, income, and age, and then
GIS mapping will be used to obtain a visual representation of the data. This will allow EPA to screen for
locations where large volume water withdrawals may be disproportionately co-located in or near
communities with environmental justice concerns. Locations for further study may be identified,
depending on the results of this study.
EPA expects the research outlined above to produce the following:
• Maps showing locations of source water withdrawals for hydraulic fracturing and demographic
data.
• Identification of areas where there may be a disproportionate co-localization of hydraulic
fracturing water withdrawals and communities with environmental justice concerns.
Prospective case studies. Using data from the US Census Bureau, EPA will also evaluate the demographic
profile of communities that may be served by water resources used for hydraulic fracturing of the
prospective case study sites.
EPA expects the research outlined above to produce the following:
• Information on the demographic characteristics of communities in or near the two case study
sites where hydraulic fracturing water withdrawals occur.
7.1.2 Are HYDRAULICALLY FRACTURED oil AND GAS WELLS DISPROPORTIONATELY LOCATED NEAR COMMUNITIES
WITH ENVIRONMENTAL JUSTICE CONCERNS?
7.1.2.1 Research Activities - Well Locations
Analysis of existing data. As a part of the information request sent by EPA to nine hydraulic fracturing
companies (see Appendix C), EPA asked for the locations of sites where hydraulic fracturing operations
occurred between 2009 and 2010. EPA will compare these data to demographic information from the
US Census Bureau on race/ethnicity, income, and age, and use GIS mapping to visualize the data. An
54
-------
EPA Hydraulic Fracturing Study Plan
November 2011
assessment of these maps will allow EPA to screen for locations where hydraulic fracturing may be
disproportionately co-located with communities that have environmental justice concerns. Depending
upon the outcome of this analysis, locations for further study may be identified.
EPA expects the research outlined above to produce the following:
• Maps showing locations of hydraulically fractured wells (subject to CBI rules) and demographic
data.
• Identification of areas where there may be a disproportionate co-localization of hydraulic
fracturing well sites and communities with environmental justice concerns.
Retrospective and prospective case studies. EPA will evaluate the demographic profiles of communities
near prospective case study sites and communities potentially affected by reported contamination on
retrospective case study sites. An analysis of these data will provide EPA with information on the specific
communities located at case study locations.
EPA expects the research outlined above to produce the following:
• Information on the demographic characteristics of the communities where hydraulic fracturing
case studies were conducted.
7.1.3 IS WASTEWATER FROM HYDRAULIC FRACTURING OPERATIONS BEING DISPROPORTIONATELY TREATED OR
DISPOSED OF (VIA POTWS OR COMMERCIAL TREATMENT SYSTEMS) IN OR NEAR COMMUNITIES WITH
ENVIRONMENTAL JUSTICE CONCERNS?
7.1.3.1 Research Activities - Wastewater Treatment/Disposal Locations
Analysis of existing data. To the extent data are available, EPA will compile a list of wastewater
treatment plants accepting wastewater from hydraulic fracturing operations. These data will be
compared to demographic information from the US Census Bureau on race/ethnicity, income, and age,
and then GIS mapping will be used to visualize the data. This will allow EPA to screen for locations where
POTWs and commercial treatment works may be disproportionately co-located near communities with
environmental justice concerns, and may identify locations for further study.
EPA expects the research outlined above to produce the following:
• Maps showing locations of hydraulic fracturing wastewater treatment facilities and
demographic data.
• Identification of areas where there may be a disproportionate co-localization of hydraulic
fracturing wastewater treatment facilities and communities with environmental justice
concerns.
Prospective case studies. Using data available from the US Census Bureau, EPA will evaluate the
demographic profile of communities near treatment and disposal operations that accept wastewater
associated with hydraulic fracturing operations.
55
-------
EPA Hydraulic Fracturing Study Plan
November 2011
EPA expects the research outlined above to produce the following:
• Information on the demographics of communities where treatment and disposal of wastewater
from hydraulic fracturing operations at the prospective case study sites has occurred.
8 Analysis of Existing Data
As outlined in Chapter 6, EPA will evaluate data provided by a variety of stakeholders to answer the
research questions posed in Table 1. This chapter describes the types of data EPA will be collecting as
well as the approach used for collecting and analyzing these data.
8.1 Data Sources and Collection
8.1.1 Public Data Sources
The data described in Chapter 6 will be obtained from a variety of sources. Table 6 provides a selection
of public data sources EPA intends to use for the current study. The list in the table is not intended to be
comprehensive. EPA will also access data from other sources, including peer-reviewed scientific
literature, state and federal reports, and other data sources shared with EPA.
8.1.2 Information Requests
In addition to publicly available data, EPA has requested information from the oil and gas industry
through two separate information requests.11 The first information request was sent to nine hydraulic
fracturing service companies in September 2010, asking for the following information:
• Data on the constituents of hydraulic fracturing fluids—including all chemicals, proppants, and
water—used in the last five years.
• All data relating to health and environmental impacts of all constituents listed.
• All standard operating procedures and information on how the composition of hydraulic
fracturing fluids may be modified on site.
• All sites where hydraulic fracturing has occurred or will occur within one year of the request
date.
The nine companies claimed much of the data they submitted to be CBI. EPA will, in accordance with 40
C.F.R. Part 2 Subpart B, treat these data as such until EPA determines whether or not they are CBI.
A second information request was sent to nine oil and gas well operators in August 2011, asking for the
complete well files for 350 oil and gas production wells. These wells were randomly selected from a list
of 25,000 oil and gas production wells hydraulically fractured during a one-year period of time. The wells
were chosen to illustrate their geographic diversity in the continental US.
11 The complete text of these information requests can be found in Appendix D.
56
-------
EPA Hydraulic Fracturing Study Plan November 2011
TABLE 6. PUBLIC DATA SOURCES EXPECTED TO BE USED AS PART OF THIS STUDY
Source
Type of Data
Applicable Secondary Research Questions
Susquehanna
Water use for hydraulic
• How much water is used in hydraulic fracturing operations, and what are the sources of this water?
River Basin
fracturing in the
• What are the possible impacts of water withdrawals for hydraulic fracturing operations on local water
Commission
Susquehanna River Basin
quality?
Colorado Oil and
Water use for hydraulic
• How much water is used in hydraulic fracturing operations, and what are the sources of this water?
Gas
fracturing in Garfield
• What are the possible impacts of water withdrawals for hydraulic fracturing operations on local water
Conservation
County, CO
quality?
Commission
USGS
Water use in US counties
• How might withdrawals affect short- and long-term water availability in an area with hydraulic fracturing
for 1995, 2000, and 2005
activity?
State
Water quality and
• How much water is used in hydraulic fracturing operations, and what are the sources of this water?
departments of
quantity
• What are the possible impacts of water withdrawals for hydraulic fracturing operations on local water
environmental
quality?
quality or
Hydraulic fracturing
• What is the composition of hydraulic fracturing wastewaters, and what factors might influence this
departments of
wastewater composition
composition?
environmental
(PA DEP)
protection
US EPA
Toxicity databases (e.g.,
• What are the chemical, physical, and toxicological properties of hydraulic fracturing chemical additives?
ACToR, DSSTox, HERO,
• What are the chemical, physical, and toxicological properties of substances in the subsurface that may be
ExpoCastDB, IRIS, HPVIS,
released by hydraulic fracturing operations?
ToxCastDB, ToxRefDB)
• What are the chemical, physical, and toxicological properties of hydraulic fracturing wastewater
constituents?
Chemical and physical
properties databases
(e.g., EPI Suite, SPARC)
National
Information on spills
• What is currently known about the frequency, severity, and causes of spills of hydraulic fracturing fluids
Response
associated with hydraulic
and additives?
Center
fracturing operations
• What is currently known about the frequency, severity, and causes of spills of flowback and produced
water?
US Census
Demographic
• Are large volumes of water for hydraulic fracturing being disproportionately withdrawn from drinking
Bureau
information from the
water resources that serve communities with environmental justice concerns?
2010 Census and the
• Are hydraulically fractured oil and gas wells disproportionately located near communities with
2005-2009 American
environmental justice concerns?
Community Survey 5-
• Is wastewater from hydraulic fracturing operations being disproportionately treated or disposed of (via
Year Estimates
POTWs or commercial treatment systems) in or near communities with environmental justice concerns?
57
-------
EPA Hydraulic Fracturing Study Plan
November 2011
8.2 Assuring Data Quality
As indicated in Section 2.6, each research project must have a QAPP, which outlines the necessary QA
procedures, quality control activities, and other technical activities that will be implemented for a
specific project. Projects using existing data are required to develop data assessment and acceptance
criteria for this secondary data. Secondary data will be assessed to determine the adequacy of the data
according to acceptance criteria described in the QAPP. All project results will include documentation of
data sources and the assumptions and uncertainties inherent within those data.
8.3 Data Analysis
EPA will use the data collected from public sources and information requests to create various outputs,
including spreadsheets, GIS maps (if possible), and tables. Data determined to be CBI will be
appropriately managed and reported. These outputs will be used to inform answers to the research
questions described in Chapter 6 and will also be used to support other research projects, including case
studies, additional toxicity assessments, and laboratory studies. A complete summary of research
questions and existing data analysis activities can be found in Appendix A.
9 Case Studies
This chapter of the study plan describes the rationale for case study selection as well as the approaches
used in both retrospective and prospective case studies.
9.1 Case Study Selection
EPA invited stakeholders nationwide to nominate potential case studies through informational public
meetings and by submitting comments electronically or by mail. Appendix F contains a list of the
nominated case study sites. Of the 48 nominations, EPA selected seven sites for inclusion in the study:
five retrospective sites and two prospective sites. The retrospective case study investigations will focus
on locations with reported drinking water contamination where hydraulic fracturing operations have
occurred. At the prospective case study sites, EPA will monitor key aspects of the hydraulic fracturing
process that cover all five stages of the water cycle.
The final location and number of case studies were chosen based on the types of information a given
case study would be able to provide. Table 7 outlines the decision criteria used to identify and prioritize
retrospective and prospective case study sites. The retrospective and prospective case study sites were
chosen to represent a wide range of conditions that reflect a spectrum of impacts that may result from
hydraulic fracturing activities. These case studies are intended to provide enough detail to determine
the extent to which conclusions can be generalized at local, regional, and national scales.
58
-------
EPA Hydraulic Fracturing Study Plan November 2011
TABLE 7. DECISION CRITERIA FOR SELECTING HYDRAULIC FRACTURING SITES FOR CASE STUDIES
Selection Step
Inputs Needed
Decision Criteria
Nomination
• Planned, active, or historical
hydraulic fracturing activities
• Local drinking water resources
• Community at risk
• Site location, description, and
history
• Site attributes (e.g., physical,
geology, hydrology)
• Operating and monitoring data,
including well construction and
surface management activities
• Proximity of population and drinking water
supplies
• Magnitude of activity (e.g., density of wells)
• Evidence of impaired water quality
(retrospective only)
• Health and environmental concerns
(retrospective only)
• Knowledge gap that could be filled by a case
study
Prioritization
• Available data on chemical use,
site operations, health, and
environmental concerns
• Site access for monitoring wells,
sampling, and geophysical
testing
• Potential to collaborate with
other groups (e.g., federal,
state, or interstate agencies;
industry; non-governmental
organizations, communities;
and citizens)
• Geographic and geologic diversity
• Diversity of suspected impacts to drinking water
resources
• Population at risk
• Site status (planned, active, or completed)
• Unique geological or hydrological features
• Characteristics of water resources (e.g.,
proximity to site, ground water levels, surface
water and ground water interactions, unique
attributes)
• Multiple nominations from diverse stakeholders
• Land use (e.g., urban, suburban, rural,
agricultural)
Table 8 lists the retrospective case study locations EPA will investigate as part of this study and
highlights the areas to be investigated and the potential outcomes expected for each site. The case
study sites listed in Table 8 are illustrative of the types of situations that may be encountered during
hydraulic fracturing activities and represent a range of locations. In some of these cases, hydraulic
fracturing occurred more than a year ago, while in others, the wells were fractured less than a year ago.
EPA expects to be able to coordinate with other federal and state agencies as well as landowners to
conduct these studies.
59
-------
EPA Hydraulic Fracturing Study Plan November 2011
TABLE 8. RETROSPECTIVE CASE STUDY LOCATIONS
Location
Areas to be Investigated
Potential Outcomes
Applicable Secondary Research Questions
Bakken Shale (oil) -
Killdeer, Dunn Co., ND
• Production well failure
during hydraulic fracturing
• Suspected drinking water
aquifer contamination
• Possible soil
contamination
• Identify sources of well
failure
• Determine if drinking water
resources are contaminated
and to what extent
• If spills occur, how might hydraulic fracturing chemical
additives contaminate drinking water resources?
• How effective are current well construction practices at
containing gases and fluids before, during, and after
fracturing?
• Are hydraulically fractured oil and gas wells
disproportionately located near communities with
environmental justice concerns?
Barnett Shale (gas) -
Wise Co., TX
• Spills and runoff leading to
suspected drinking water
well contamination
• Determine if private water
wells and /or drinking water
resources are contaminated
• Obtain information about
mechanisms of transport of
contaminants via spills, leaks,
and runoff
• If spills occur, how might hydraulic fracturing wastewaters
contaminate drinking water resources?
• Are hydraulically fractured oil and gas wells
disproportionately located near communities with
environmental justice concerns?
Marcellus Shale (gas) -
Bradford and
Susquehanna Cos., PA
• Reported Ground water
and drinking water well
contamination
• Suspected surface water
contamination from a spill
of fracturing fluids
• Reported Methane
contamination of multiple
drinking water wells
• Determine if drinking water
wells and or drinking water
resources are contaminated
and the source of any
contamination
• Determine source of methane
in private wells
• Transferable results due to
common types of impacts
• If spills occur, how might hydraulic fracturing chemical
additives contaminate drinking water resources?
• How effective are current well construction practices at
containing gases and fluids before, during, and after
fracturing?
• Are hydraulically fractured oil and gas wells
disproportionately located near communities with
environmental justice concerns?
Table continued on next page
60
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table continued from previous page
Location
Areas to be Investigated
Potential Outcomes
Applicable Secondary Research Questions
Marcellus Shale (gas) -
Washington Co., PA
• Changes in water quality
in drinking water,
suspected contamination
• Stray gas in wells
• Leaky surface pits
• Determine if drinking water
resources are impacted and if
so, what the sources of any
impacts or contamination
may be. Identify
presence/source of drinking
water well contamination
• Determine if surface waste
storage pits are properly
managed to protect surface
and ground water
• If spills occur, how might hydraulic fracturing wastewaters
contaminate drinking water resources?
• Are hydraulically fractured oil and gas wells
disproportionately located near communities with
environmental justice concerns?
Raton Basin (CBM) -
Las Animas and
Huerfano Cos., CO
• Potential drinking water
well contamination
(methane and other
contaminants) in an area
where hydraulic fracturing
is occurring within an
aquifer
• Determine source of methane
• Determine if drinking water
resources are impacted and if
so, what the sources of any
impacts or contamination
may be. Identify
presence/source/
cause of contamination in
drinking water wells
• Can subsurface migration of fluids or gases to drinking water
resources occur, and what local geological or man-made
features may allow this?
• Are hydraulically fractured oil and gas wells
disproportionately located near communities with
environmental justice concerns?
61
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Prospective case studies are made possible by partnerships with federal and state agencies, landowners,
and industry, as highlighted in Appendix A. EPA will conduct prospective case studies in the following
areas:
• The Haynesville Shale in DeSoto Parish, Louisiana.
• The Marcellus Shale in Washington County, Pennsylvania.
The prospective case studies will provide information that will help to answer secondary research
questions related to all five stages of the hydraulic fracturing water cycle, including:
• How might water withdrawals affect short- and long-term water availability in an area with
hydraulic fracturing activity?
• What are the possible impacts of water withdrawals for hydraulic fracturing options on local
water quality?
• How effective are current well construction practices at containing gases and fluids before,
during, and after fracturing?
• What local geologic or man-made factors may contribute to subsurface migration of fluids or
gases to drinking water resources?
• What is the composition of hydraulic fracturing wastewaters, and what factors might influence
this composition?
• What are the common treatment and disposal methods for hydraulic fracturing wastewaters,
and where are these methods practiced?
• Are large volumes of water being disproportionately withdrawn from drinking water resources
that serve communities with environmental justice concerns?
• Are hydraulically fractured oil and gas wells disproportionately located near communities with
environmental justice concerns?
• Is wastewater from hydraulic fracturing operations being disproportionately treated or disposed
of (via POTWs or commercial treatment systems) in or near communities with environmental
justice concerns?
For each case study (retrospective and prospective), EPA will write and approve a QAPP before starting
any new data collection, as described in Section 2.6. Upon completion of each case study, a report
summarizing key findings will be written, peer reviewed, and published. The data will also be presented
in the 2012 and 2014 reports.
The following sections describe the general approaches to be used during the retrospective and
prospective case studies. As part of the case studies, EPA will perform extensive sampling of relevant
environmental media. Appendix H provides details on field sampling, monitoring, and analytical
methods that may be used during both the retrospective and prospective case studies. General
information is provided in this study plan, as each case study location is unique.
62
-------
EPA Hydraulic Fracturing Study Plan
November 2011
9.2 Retrospective Case Studies
As described briefly in Section 5.2, retrospective case studies are focused on investigating reported
instances of drinking water contamination in areas where hydraulic fracturing events have already
occurred. Table 8 lists the five locations where EPA will conduct retrospective case studies. Each case
study will address one or more stages of the water lifecycle by providing information that will help to
answer the research questions posed in Table 1.
While the research questions addressed by each case study vary, there are two goals for all the
retrospective case studies: (1) to determine whether or not contamination of drinking water resources
has occurred and to what extent; and (2) to assess whether or not the reported contamination is due to
hydraulic fracturing activities. These case studies will use available data and may include additional
environmental field sampling, modeling, and related laboratory investigations. Additional information
on environmental field sampling can be found in Appendix H.
Each retrospective case study will begin by determining the sampling area associated with that specific
location. Bounding the scope, vertical, and areal extent of each retrospective case study site will depend
on site-specific factors, such as the unique geologic, hydrologic, and geographic characteristics of the
site as well as the extent of reported impacts. Where it is obvious that there is only one potential source
for a reported impact, the case study site will be fairly contained. Where there are numerous reported
impacts potentially involving multiple possible sources, the case study site will be more extensive in all
dimensions, making it more challenging to isolate possible sources of drinking water contamination.
The case studies will then be conducted in a tiered fashion to develop integrated data on site history
and characteristics, water resources, contaminant migration pathways, and exposure routes. This tiered
approach is described in Table 9.
63
-------
EPA Hydraulic Fracturing Study Plan November 2011
TABLE 9. GENERAL APPROACH FOR CONDUCTING RETROSPECTIVE CASE STUDIES
Tier
Goal
Critical Path
1
Verify potential issue
• Evaluate existing data and information from operators, private citizens,
and state agencies
• Conduct site visits
• Interview stakeholders and interested parties
2
Determine approach
for detailed
investigations
• Conduct initial sampling: sample wells, taps, surface water, and soils
• Identify potential evidence of drinking water contamination
• Develop conceptual site model describing possible sources and pathways
of the reported contamination
• Develop, calibrate, and test fate and transport model(s)
3
Conduct detailed
investigations to
evaluate potential
sources of
contamination
• Conduct additional sampling of soils, aquifer, surface water and surface
wastewater pits/tanks (if present)
• Conduct additional testing: stable isotope analyses, soil gas surveys,
geophysical testing, well mechanical integrity testing, and further water
testing with new monitoring points
• Refine conceptual site model and further test exposure scenarios
• Refine fate and transport model(s) based on new information
4
Determine the
source(s) of any
impacts to drinking
water resources
• Develop multiple lines of evidence to determine the source(s) of impacts
to drinking water resources
• Exclude possible sources and pathways of the reported contamination
• Assess uncertainties associated with conclusions regarding the source(s) of
impacts
Once the potential issue has been verified in Tier 1, initial sampling activities will be conducted based on
the characteristics of the complaints and the nature of the sites. Table 10 lists sample types and testing
parameters for initial sampling activities.
TABLE 10. TIER 2 INITIAL TESTING: SAMPLE TYPES AND TESTING PARAMETERS
Sample Type
Testing Parameters
Surface and ground water
• General water quality parameters (e.g., pH, redox potential,
dissolved oxygen, TDS)
• General water chemistry parameters (e.g., cations and anions,
including barium, strontium, chloride, boron)
• Metals and metalloids (e.g., arsenic, barium, selenium)
• Radionuclides (e.g., radium)
• Volatile and semi-volatile organic compounds
• Polycyclic aromatic hydrocarbons
Soil
• General water chemistry parameters
• Metals
• Volatile and semi-volatile organic compounds
• Polycyclic aromatic hydrocarbons
Produced water from waste pits or tanks
where available
• General water quality parameters
• General water chemistry parameters
• Metals and metalloids
• Radionuclides
• Volatile and semi-volatile organic compounds
• Polycyclic aromatic hydrocarbons
• Fracturing fluid additives/degradates
64
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Results from Tier 1 and initial sampling activities will be used to inform the development of a conceptual
site model. The site model will account for the hydrogeology of the location to be studied and be used
to determine likely sources and pathways of the reported contamination. The conceptual site model will
also be informed by modeling results. These models can help to predict the fate and transport of
contaminants, identify appropriate sampling locations, determine possible contamination sources, and
understand field measurement uncertainties. The conceptual site model will be continuously updated
based on new information, data, and modeling results.
If initial sampling activities indicate potential impacts to drinking water resources, additional testing will
be conducted to refine the site conceptual model and further test exposure scenarios (Tier 3). Table 11
describes the additional data to be collected during Tier 3 testing activities.
Results from the tests outlined in Table 11 can be used to further elucidate the sources and pathways of
impacts to drinking water resources. These data will be used to support multiple lines of evidence,
which will serve to identify the sources of impacts to drinking water resources. EPA expects that it will
be necessary to examine multiple lines of evidence in all case studies, since hydraulic fracturing
chemicals and contaminants can have other sources or could be naturally present contaminants in
shallow drinking water aquifers. The results from all retrospective case study investigations will include a
thorough discussion of the uncertainties associated with final conclusions related to the sources and
pathways of impacts to drinking water resources.
TABLE 11. TIER 3 ADDITIONAL TESTING: SAMPLE TYPES AND TESTING PARAMETERS
Sample Type / Testing
Testing Parameters
Surface and ground water
• Stable isotopes (e.g., strontium, radium, carbon, oxygen, hydrogen)
• Dissolved gases (e.g., methane, ethane, propane, butane)
• Fracturing fluid additives
Soil
• Soil gas (e.g., argon, helium, hydrogen, oxygen, nitrogen, carbon dioxide,
methane, ethane, propane)
Geophysical testing
• Geologic and hydrogeologic conditions (e.g., faults, fractures, abandoned
wells)
• Soil and rock properties (e.g., porous media, fractured rock)
Mechanical integrity (review
of existing data or testing)
• Casing integrity
• Cement integrity
Drill cuttings and core
samples
• Metals
• Radionuclides
• Mineralogical analysis
The data collected during retrospective case studies may be used to assess any risks that may be posed
to drinking water resources as a result of hydraulic fracturing activities. Because of this possibility, EPA
will develop information on: (1) the toxicity of chemicals associated with hydraulic fracturing; (2) the
spatial distribution of chemical concentrations and the locations of drinking water wells; (3) how many
people are served by the potentially impacted drinking water resources, including aquifers, wells and or
surface waters; and (4) how the chemical concentrations vary over time.
65
-------
EPA Hydraulic Fracturing Study Plan
November 2011
9.3 Prospective Case Studies
EPA will conduct two prospective case studies: one in the Marcellus Shale and the other in the
Haynesville Shale. In both cases, EPA will have access to the site throughout the process of building and
fracturing the well. This access will allow EPA to obtain water quality and other data before pad
construction, after pad and well construction, and immediately after fracturing. Additionally, monitoring
will continue during a follow-up period of approximately one year after hydraulic fracturing has been
completed. Data and methods will be similar to the retrospective case studies, but these studies will
allow for baseline water quality sampling, collection of flowback and produced water for analysis, and
evaluation of hydraulic fracturing wastewater disposal methods.
The prospective case studies are made possible by partnering with oil and natural gas companies and
other stakeholders. Because of the need to enlist the support and collaboration of a wide array of
stakeholders in these efforts, case studies of this type will likely be completed 16-24 months from the
start dates. However, some preliminary results may be available for the 2012 report.
As in the case of the retrospective studies, each prospective case study will begin by determining the
sampling area associated with that specific location. Bounding the scope, vertical, and areal extent of
each prospective case study site will depend on site-specific factors, such as the unique geologic,
hydrologic, and geographic characteristics of the site. The data collected at prospective case study
locations will be placed into a wider regional watershed context. Additionally, the scope of the
prospective case studies will encompass all stages of the water lifecycle illustrated in Figure 1.
After the boundaries have been established, the case studies will be conducted in a tiered fashion, as
outlined in Table 12.
TABLE 12. GENERAL APPROACH FOR CONDUCTING PROSPECTIVE CASE STUDIES
Tier
Goal
Critical Path
1
Collect existing data
• Gather existing data and information from operators, private citizens,
and state agencies
• Conduct site visits
• Interview stakeholders and interested parties
2
Construct a conceptual
site model
• Evaluate existing data
• Identify all potential sources and pathways for contamination of drinking
water resources
• Develop flow system model
3
Conduct field sampling
• Conduct sampling to characterize ground and surface water quality and
soil/sediment quality prior to pad construction, following pad and well
construction, and immediately after hydraulic fracturing
• Collect and analyze time series samples of flowback and produced water
• Collect field samples for up to one year after hydraulic fracturing
• Calibrate flow system model
4
Determine if there are or
are likely to be impacts
to drinking water
resources
• Analyze data collected during field sampling
• Assess uncertainties associated with conclusions regarding the potential
for impacts to drinking water resources
• Recalibrate flow system model
66
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Results from Tier 1 activities will inform the development of a conceptual site model, which will be used
to assess potential pathways for contamination of drinking water resources. This model will help to
determine the field sampling activities described in Tier 3. Field sampling will be conducted in a phased
approach, as described in Table 13.
The data collected during field sampling activities may also be used to test whether geochemical and
hydrologic flow models accurately simulate changes in composition, concentration and or location of
hydraulic fracturing fluids over time in different environmental media. These data will be evaluated to
determine if there were any impacts to drinking water resources as a result of hydraulic fracturing
activities during the limited period of the study. In addition, the data will be evaluated to consider the
potential for any future impacts on drinking water resources that could arise after the study period. If
impacts are found, EPA will report on the type, cause, and extent of the impacts. The results from all
prospective case study investigations will include a discussion of the uncertainties associated with final
conclusions related to the potential impacts of hydraulic fracturing on drinking water resources.
TABLE 13. TIER 3 FIELD SAMPLING PHASES
Field Sampling Phases
Critical Path
Baseline
•
Sample all available existing wells, catalogue depth to drinking water aquifers and
characterization of the
their thickness, gather well logs
production well site
•
Sample any adjoining surface water bodies
and areas of concern
•
Sample source water for hydraulic fracturing
•
Install and sample new monitoring wells
•
Perform geophysical characterization
Production well
•
Test mechanical integrity
construction
•
Resample all wells (new and existing), surface water
•
Evaluate gas shows from the initiation of surface drilling to the total depth of the
well
•
Assess geophysical logging at the surface portion of the hole
Hydraulic fracturing of
•
Sample fracturing fluids
the production well
•
Resample all wells, surface water, and soil gas
•
Sample flowback
•
Calibrate and test flow and geochemical models
Gas production
•
Resample all wells, surface water, and soil gas
•
Sample produced water
10 Scenario Evaluations and Modeling
In this study, modeling will integrate a variety of factors to enhance EPA's understanding of potential
impacts from hydraulic fracturing on drinking water resources. Modeling will be important in both
scenario evaluations and case studies. Scenario evaluations will use existing data to explore potential
impacts on drinking water resources in instances where field studies cannot be conducted. In
retrospective and prospective case studies, modeling will help identify possible contamination pathways
at site-specific locations. The results of modeling activities will provide insight into site-specific and
regional vulnerabilities as well as help to identify important factors that affect potential impacts on
drinking water resources across all stages of the hydraulic fracturing water lifecycle.
67
-------
EPA Hydraulic Fracturing Study Plan
November 2011
10.1 Scenario Evaluations
Scenario evaluations will be a useful approach for analyzing realistic hypothetical scenarios across the
hydraulic fracturing water lifecycle that may result in adverse impacts to drinking water. Specifically, EPA
will evaluate scenarios relevant to the water acquisition, well injection, and wastewater treatment and
disposal stages of the hydraulic fracturing water lifecycle. In all cases, the scenarios will use information
from case studies and minimum state regulatory requirements to define typical management and
engineering practices, which will then be used to develop reference cases for the scenarios.
Water acquisition. EPA will evaluate scenarios for two different locations in the US: the Susquehanna
River Basin and the Upper Colorado River Basin/Garfield County, Colorado. In these instances, the
reference case for the scenarios will be developed using data collected from USGS, the Susquehanna
River Basin Commission, and the Colorado Oil and Gas Conservation Commission. The reference case
will be associated with the year 2000; this year will be classified as low, median, or high flow based on
watershed simulations over the period of 1970-2000.
EPA will then project the water use needs for hydraulic fracturing in the Susquehanna River Basin and
Upper Colorado River Basin based on three futures: (1) current business and technology; (2) full natural
gas exploitation; and (3) a green technology scenario with sustainable water management practices
(e.g., full recycling of produced water), and low population growth. These futures models are described
below in more detail. Based on these predictions, EPA will assess the potential impacts of large volume
water withdrawals needed for hydraulic fracturing for the period of 2020-2040.
Well injection. EPA will investigate possible mechanisms of well failure and stimulation-induced
overburden failure that could lead to upward migration of hydrocarbons, fracturing fluids, and/or brines
to ground or surface waters. This will be done through numerical modeling using TOUGH2 with
geomechanical enhancements. The scenarios also include multiple injection and pumping wells and the
evaluations of diffuse and focused leakage (through fractures and abandoned unplugged wells) within
an area of potential influence. The reference cases will be determined from current management and
engineering practices as well as representative geologic settings. The failure scenarios are described in
greater detail in Section 6.3.2.1.
Wastewater treatment and disposal. EPA will use a staged approach to evaluate the potential for
impacts of releases of treated hydraulic fracturing wastewaters to surface waters. The first approach will
focus on basic transport processes occurring in rivers and will be based on generalized inputs and
receptor locations. This work will use scenarios representing various flow conditions, distances between
source and receptor, and available data on possible discharge concentrations. The chemicals of interest
are the likely residues in treated wastewater, specifically chloride, bromide and naturally occurring
radioactive materials. In the second stage, specific watersheds will be evaluated using the best data
available for evaluations. Similar to the first stage, scenarios will be developed to show how various
conditions in the actual river networks impact concentrations at drinking water receptors. A comparison
of both stages will help show the level of detail necessary for specific watersheds and might lead to
revision of the first, or more generic, approach.
68
-------
EPA Hydraulic Fracturing Study Plan
November 2011
10.2 Case Studies
Modeling will be used in conjunction with data from case studies to gain a better understanding of the
potential impacts of hydraulic fracturing on drinking water resources. First, models will be developed to
simulate the flow and transport of hydraulic fracturing fluids and native fluids in an oil or gas reservoir
during the hydraulic fracturing process. These models will use data from case studies—including
injection pressures, flow rates, and lithologic properties—to simulate the development of fractures and
migration of fracturing fluids in the fracture system induced by the hydraulic fracturing process. The
results of the modeling may be used to help predict the possibility of rock formation damage and the
spreading area of fracturing fluid. Expected outputs include information on the possibility that hydraulic
fracturing-related contaminants will migrate to an aquifer system.
Models can also be developed to simulate flow and transport of the contaminants once migration to an
aquifer occurs. This modeling will consider a relatively large-scale ground water aquifer system. The
modeling will consider the possible sources of fracturing fluids emerging from the oil or gas reservoir
through a damaged formation, geological faults, or an incomplete cementing zone outside the well
casing. It will also consider local hydrogeological conditions such as precipitation, water well
distribution, aquifer boundaries, and hydraulic linkage with other water bodies. The modeling will
simulate ground water flow and transport in the aquifer system, and is expected to output information
on contamination occurring near water supply facilities. This modeling may also provide the opportunity
to answer questions about potential risks associated with hypothetical scenarios, such as conditions
under which an improperly cemented wellbore might release fracturing fluid or native fluids (including
native gases).
10.3 Modeling Tools
EPA expects that a wide range of modeling tools may be used in this study. It is standard practice to
evaluate and model complex environmental systems as separate components, as can be the case with
potential impacts to drinking water resources associated with hydraulic fracturing. For example, system
components can be classified based on media type, such as water body models, ground water models,
watershed models, and waste unit models. Additionally, models can be chosen based on whether a
stochastic or deterministic representation is needed, solution types (e.g., analytical, semi-analytical, or
numerical), spatial resolution (e.g., grid, raster, or vector), or temporal resolution (e.g., steady-state or
time-variant).
The types of models to be used in this study may include:
Hydraulic fracturing models. EPA is considering using MFrac to calculate the development of fracture
systems during real-time operations. MFrac is a comprehensive design and evaluation simulator
containing a variety of options, including three-dimensional fracture geometry and integrated acid
fracturing solutions. EPA may also use MFrac to assess formation damage subject to various engineering
operations, lithostratigraphy, and depositional environment of oil and gas deposits.
69
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Multi-phase and multi-component ground water models. Members of the TOUGH family of models
developed at Lawrence Berkeley National Laboratory can be used to simulate the flow and transport
phenomena in fractured zones, where geothermal and geochemical processes are active, where
permeability changes, and where phase-change behavior is important. These codes have been adapted
for problems requiring capabilities that will be also needed for hydraulic fracturing simulation:
multiphase and multi-component transport, geothermal reservoir simulation, geologic sequestration of
carbon, geomechanical modeling of fracture activation and creation, and inverse modeling.
Single-phase and multi-component ground water models. These ground water models include:
• The finite difference solutions, such as the USGS Modular Flow and its associated transport
codes, including Modular Transport 3D-Multispecies and the related Reactive Transport 3D,
• The finite element solutions, such as the Finite Element Subsurface Flow Model and other semi-
analytical solutions (e.g., GFLOW and TTim).
Various chemical and/or biological reactions can be integrated into the advective ground water flow
models to allow the simulation of reaction flow and transport in the aquifer system. For a suitably
conceptualized system consisting of single-phase transport of water-soluble chemicals, these models
can support hydraulic fracturing assessments.
Watershed models. EPA has experience with the well-established watershed management models Soil
Water Assessment Tool (semi-empirical, vector-based, continuous in time) and Hydrologic Simulation
Program - FORTRAN (semi-physics-based, vector-based, continuous in time). The watershed models will
play an important role in modeling water acquisition and in water quantity analysis.
Waterbody models. The well-established EPA model for representing water quality in rivers and
reservoirs is the Water Quality Analysis Simulation Program. Other, simpler approaches include
analytical solutions to the transport equation and models such as a river and stream water quality model
(QUAL2K; see Chapra, 2008). Based on extensive tracer studies, USGS has developed empirical
relationships for travel time and longitudinal dispersion in rivers and streams (Jobson, 1996).
Alternative futures models. Alternative futures analysis has three basic components (Baker et al., 2004):
(1) characterize the current and historical landscapes in a geographic area and the trajectory of the
landscape to date; (2) develop two or more alternative "visions" or scenarios for the future landscape
that reflect varying assumptions about land and water use and the range of stakeholder viewpoints; and
(3) evaluate the likely effects of these landscape changes and alternative futures on things people care
about (e.g., valued endpoints). EPA has conducted alternative futures analysis for much of the landscape
of interest for this project. The Agency has created futures for 20 watersheds12 across the country,
including the Susquehanna River basin, which overlays the Marcellus Shale and the Upper Colorado
River Basin, which includes Garfield County, Colorado.
12 http://cfpub.epa.gov/ncea/global/recordisplay.cfm?deid=212763
70
-------
EPA Hydraulic Fracturing Study Plan
November 2011
10.4 Uncertainty in Model Applications
All model parameters are uncertain because of measurement approximation and error, uncharacterized
point-to-point variability, reliance on estimates and imprecise scale-up from laboratory measurements.
Model outputs are subject to uncertainty, even after model calibration (e.g., Tonkin and Dougherty,
2008; Doherty, 2011). Thus, environmental models do not possess generic validity (Oreskes et al., 1994),
and the application is critically dependent on choices of input parameters, which are subject to the
uncertainties described above. Further, a recent review by one of the founders of the field of subsurface
transport modeling (Leonard F. Konikow) outlines the difficulties with contaminant transport modeling
and concludes that "Solute transport models should be viewed more for their value in improving the
understanding of site-specific processes, hypothesis testing, feasibility assessments, and evaluating
data-collection needs and priorities; less value should be placed on expectations of predictive reliability"
(Konikow, 2010). Proper application of models requires proper expectations (i.e., Konikow, 2010) and
acknowledgement of uncertainties, which can lead to best scientific credibility for the results (see
Oreskes, 2003).
11 Characterization of Toxicity and Human Health Effects
EPA will evaluate all stages of the hydraulic fracturing water lifecycle to assess the potential for
fracturing fluids and/or naturally occurring substances to be introduced into drinking water resources.
As highlighted throughout Chapter 6, EPA will assess the toxicity and potential human health effects
associated with these possible drinking water contaminants. To do this, EPA will first obtain an inventory
of the chemicals associated with hydraulic fracturing activities (and their estimated concentrations and
frequency of occurrence). This includes chemicals used in hydraulic fracturing fluids, naturally occurring
substances that may be released from subsurface formations during the hydraulic fracturing process,
and chemicals that are present in hydraulic fracturing wastewaters. EPA will also identify the relevant
reaction and degradation products of these substances—which may have different toxicity and human
health effects than their parent compounds—in addition to the fate and transport characteristics of the
chemicals. The aggregation of these data is described in Chapter 6.
Based on the number of chemicals currently known to be used in hydraulic fracturing operations, EPA
anticipates that there could be several hundred chemicals of potential concern for drinking water
resources. Therefore, EPA will develop a prioritized list of chemicals and, where estimates of toxicity are
not otherwise available, conduct quantitative health assessments or additional testing for certain high-
priority chemicals. In the first phase of this work, EPA will conduct an initial screen for known toxicity
and human health effects information (including existing toxicity values such as reference doses and
cancer slope factors) by searching existing databases.13 At this stage, chemicals will be grouped into one
of three categories: (1) high priority for chemicals that are potentially of concern; (2) low priority for
13 These databases include the Integrated Risk Information System (IRIS), the Provisional Peer Reviewed Toxicity
Value (PPRTV) database, the ATSDR Minimal Risk Levels (MRLs), the California EPA Office of Environmental Health
Hazard Assessment (OEHHA) Toxicity Criteria Database (TCD). Other Agency databases including the Distributed
Structure Searchable Toxicity (DSSTox) database, Aggregated Computational Toxicology Resources (ACToR)
database and the Toxicity Reference Database (ToxRefDB) may be used to facilitate data searching activities.
71
-------
EPA Hydraulic Fracturing Study Plan
November 2011
chemicals that are likely to be of little concern; and (3) unknown priority for chemicals with an unknown
level of concern. These groupings will be based on known chemical, physical, and toxicological
properties; reported occurrence levels; and the potential need for metabolism information.
Chemicals with an unknown level of concern are those for which no toxicity information is available. For
these chemicals, a quantitative structure-activity relationships (QSAR) analysis may be conducted to
obtain comparative toxicity information. A QSAR analysis uses mathematical models to predict
measures of toxicity from physical/chemical characteristics of the structure of the chemicals. This
approach may provide information to assist EPA in designating these chemicals as either high or low
priority.
The second phase of this work will focus on additional testing and/or assessment of chemicals with an
unknown level of concern. These chemicals may be subjected to a battery of tests used in the ToxCast
program, a high-throughput screening tool that can identify toxic responses (Judson et al., 2010a and
2010b; Reif et al., 2010). The quantitative nature of these in vitro assays provides information on
concentration-response relationships that, tied to known modes of action, can be useful in assessing the
level of potential toxicity. EPA will identify a small set of these chemicals with unknown toxicity values
and develop ToxCast bioactivity profiles and hazard predictions for these chemicals.
EPA will use these ToxCast profiles, in addition to existing information, to develop chemical-specific
Provisional Peer Reviewed Toxicity Values (PPRTVs) for up to six of the highest-priority chemicals that
have no existing toxicity values. PPRTVs summarize the available scientific information about the
adverse effects of a chemical and the quality of the evidence, and ultimately derive toxicity values, such
as provisional reference doses and cancer slope factors, that can be used in conjunction with exposure
and other information to develop a risk assessment. Although using ToxCast is suitable for many of the
chemicals used in hydraulic fracturing, the program has excluded any chemicals that are volatile enough
to invalidate their assays.
In addition to single chemical assessments, further information may be obtained for mixtures of
chemicals based on which components occur most frequently together and their relevant proportions as
identified from exposure information. It may be possible to test actual hydraulic fracturing fluids or
wastewater samples. EPA will assess the feasibility of this research and pursue testing if possible.
EPA anticipates that the initial database search and ranking of high, low, and unknown priority chemicals
will be completed for the 2012 interim report. Additional work using QSAR analysis and high-throughput
screening tools is expected to be available in the 2014 report. The development of chemical-specific
PPRTVs for high-priority chemicals is also expected to be available in 2014.
Information developed from this effort to characterize the toxicity and health effects of chemicals will
be an important component of future efforts to understand the overall potential risk posed by hydraulic
fracturing chemicals that may be present in drinking water resources. When combined with exposure
and other relevant data, this information will help EPA characterize the potential public health impacts
of hydraulic fracturing on drinking water resources.
72
-------
EPA Hydraulic Fracturing Study Plan
November 2011
12 Summary
The objective of this study is to assess the potential impacts of hydraulic fracturing on drinking water
resources and to identify the driving factors that affect the severity and frequency of any impacts. The
research outlined in this document addresses all stages of the hydraulic fracturing water lifecycle shown
in Figure 1 and the research questions posed in Table 1. In completing this research, EPA will use
available data, supplemented with original research (e.g. case studies, generalized scenario evaluations
and modeling) where needed. As the research progresses, EPA may learn certain information that
suggests that modifying the initial approach or conducting additional research within the overall scope
of the study plan is prudent in order to better answer the research questions. In that case, EPA may
modify the current research plan. Figures 10 and 11 summarize the research activities for the study plan
and reports anticipated timelines for research results. All data, whether generated by the EPA or not,
will undergo a comprehensive quality assurance.
73
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Water Acquisition
Chemical Mixing
Well Injection
Retrospective Case Studies
I I Results expected for 2012 report
I I Results expected for 2014 report
Investigate the location, cause, and impact of
surface spills/accidental releases of
hydraulic fracturing fluids
Investigate the role of mechanical integrity,
well construction, and geologic/man-made
features in suspected cases of drinking
water contamination
Prospective Case Studies
Document the source, quality, and quantity
of water used for hydraulic fracturing
Evaluate impacts on local water quality and
availability from water withdrawals
Identify chemical products used in hydraulic
fracturing fluids at case study locations
Identify methods and tools used to protect
drinking water from oil and gas resources
before and after hydraulic fracturing
Assess potential for hydraulic fractures to
interfere with existing geologic features
Compile and analyze existing data on source
water volume and quality requirements
Collect data on water use, hydrology, and
hydraulic fracturing activities in an
arid and humid region
FIGURE 10A. SUMMARY OF RESEARCH PROJECTS
PROPOSED FOR THE FIRST THREE STAGES OF THE
HYDRAULIC FRACTURING WATER LIFECYCLE
Analysis of Existing Data
Compile information on the frequency,
severity, and causes of spills of
hydraulic fracturing fluids
Compile data on the composition of
hydraulic fracturing fluids
Identify possible chemical indicators and
existing analytical methods
Review existing scientific literature on
surface chemical spills
Analyze data obtained from 350 well files
Identify known chemical, physical, and toxicological properties of chemicals found in hydraulic
fracturing fluids and naturally occurring chemicals released during hydraulic fracturing
74
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Chemical Mixing
Water Acquisition
Well Injection
Assess impacts of cumulative water
withdrawals in a semi-arid and humid region
Scenario Evaluations
Test well failure and
existing subsurface pathway scenarios
Develop a simple AOE model for
hydraulically fractured wells
I I Results expected for 2012 report
I I Results expected for 2014 report
Laboratory Studies
Study geochemical reactions between
hydraulic fracturing fluids and
target formations
Identify or modify existing analytical methods for hydraulic fracturing fluid chemical additives and
naturally occurring chemicals released during hydraulic fracturing
Characterization of Toxicity and Human Health Effects
Prioritize chemicals of concern based on known toxicity data
Predict toxicity of unknown chemicals and develop PPRTVs for chemicals of concern
FIGURE 10B. SUMMARY OF RESEARCH PROJECTS PROPOSED FOR THE FIRST THREE STAGES OF THE HYDRAULIC FRACTURING WATER LIFECYCLE
75
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Flowback and Produced Water
Wastewater Treatment and
Waste Disposal
Retrospective Case Studies
Investigate the location, cause, and impact of
surface spills/accidental releases of
hydraulic fracturing wastewaters
Collect and analyze time series samples of
flowback and produced water
Prospective Case Studies
Evaluate efficacy of recycling, treatment,
and disposal practices
Analysis of Existing Data
Compile data on the frequency, severity, and
causes of spills of hydraulic fracturing
wastewaters
Compile a list of chemicals found in
flowback and produced water
Review existing scientific literature on
surface chemical spills
Identify known chemical, physical, and
toxicological properties of chemicals found in
hydraulic fracturing wastewater
Gather information on treatment and
disposal practices from well files
Analyze efficacy of existing treatment
operations based on existing data
FIGURE 11 A. SUMMARY OF RESEARCH PROJECTS PROPOSED FOR THE LAST TWO STAGES OF THE HYDRAULIC FRACTURING WATER LIFECYCLE
76
-------
EPA Hydraulic Fracturing Study Plan
November 2011
] Results
] Results
Flowback and Produced Water
Wastewater Treatment and
Waste Disposal
Scenario Evaluations
Create a generalized model of surface water
discharges of treated hydraulic fracturing
wastewaters
Develop watershed-specific version of the
simplified model
Laboratory Studies
Identify or modify existing analytical methods
for chemicals found in hydraulic
fracturing wastewaters
Conduct pilot-scale studies of the treatability
of hydraulic fracturing wastewaters via POTW
and commercial technologies
Conduct studies on the formation of
brominated DBPs during treatment of
hydraulic fracturing wastewaters
Determine the contribution of contamination
from hydraulic fracturing wastewaters
and other sources
Characterization of Toxicity and Human Health Effects
Prioritize chemicals of concern based
on known toxicity data
Predict toxicity of unknown chemicals and
develop PPRTVs for chemicals of concern
FIGURE 11B. SUMMARY OF RESEARCH PROJECTS PROPOSED FOR THE LAST TWO STAGES OF THE HYDRAULIC FRACTURING WATER LIFECYCLE
77
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Brief summaries of how the research activities described in Chapter 6 will answer the fundamental
research questions appear below:
Water Acquisition: What are the potential impacts of large volume water withdrawals from ground and
surface waters on drinking water resources?
The 2012 report will provide a partial answer to this question based on the analysis of existing data. This
will include data collected from two information requests and from existing data collection efforts in the
Susquehanna River Basin and Garfield County, Colorado. The requested data from hydraulic fracturing
service companies and oil and gas operators will provide EPA with general information on the source,
quality, and quantity of water used for hydraulic fracturing operations. Data gathered in the
Susquehanna River Basin and Garfield County, Colorado, will allow EPA to assess the impacts of large
volume water withdrawals in a semi-arid and humid region by comparing water quality and quantity
data in areas with no hydraulic fracturing activity to areas with intense hydraulic fracturing activities.
Additional work will be reported in the 2014 report. EPA expects to provide information on local water
quality and quantity impacts, if any, that are associated with large volume water withdrawals at the two
prospective case study locations: Washington County, Pennsylvania, and DeSoto Parish, Louisiana. These
two locations will provide information on impacts from surface (Washington County) and ground
(DeSoto Parish) water withdrawals for hydraulic fracturing. The site-specific data can then be compared
to future scenario modeling of cumulative hydraulic fracturing-related water withdrawals in the
Susquehanna River Basin and Garfield County, Colorado, which will model the long-term impacts of
multiple hydraulically fractured oil and gas wells within a single watershed. EPA will use the futures
scenarios to assess the sustainability of hydraulic fracturing activities in semi-arid and humid
environments and to determine what factors (e.g., droughts) may affect predicted impacts.
Chemical Mixing: What are the possible impacts of surface spills on or near well pads of hydraulic
fracturing fluids on drinking water resources?
In general, EPA expects to be able to provide information on the composition hydraulic fracturing fluids
and summarize the frequency, severity, and causes of spills of hydraulic fracturing fluids in the 2012
report. EPA will use the information gathered from nine hydraulic fracturing service operators to
summarize the types of hydraulic fracturing fluids, their composition, and a description of the factors
that may determine which chemicals are used. The 2012 report will also provide a list of chemicals used
in hydraulic fracturing fluids and their known or predicted chemical, physical, and toxicological
properties. Based on known or predicted properties, a small fraction of these chemicals will be
identified as chemicals of concern and will be highlighted for additional toxicological analyses or
analytical method development, if needed. EPA will use this chemical list to identify available research
on the fate and transport of hydraulic fracturing fluid chemical additives in environmental media.
The 2014 report will contain results of additional toxicological analyses of hydraulic fracturing fluid
chemical additives with little or no known toxicological data. PPRTVs may be developed for high priority
chemicals of concern. EPA will also include the results of the retrospective case study investigations.
These investigations will provide verification of whether contamination of drinking water resources has
78
-------
EPA Hydraulic Fracturing Study Plan
November 2011
occurred, and if so, if a surface spill of hydraulic fracturing fluids could be responsible for the
contamination.
Well Injection: What are the possible impacts of the injection and fracturing process on drinking water
resources?
In 2012, EPA will primarily report on the results of the well file analysis and scenario evaluations to
assess the role that the mechanical integrity of the wells and existing geologic/man-made features may
play in the contamination of drinking water resources due to hydraulic fracturing. The well file analysis
will provide nationwide background information on the frequency and severity of well failures in
hydraulically fractured oil and gas wells, and will identify any contributing factors that may have led to
these failures. Additionally, the well file analysis will provide information on the types of local geologic
or man-made features that industry seeks to characterize prior to hydraulic fracturing, and whether or
not these features were found to interact with hydraulic fractures. In a separate effort, EPA will use
computer modeling to explore various contamination pathway scenarios involving improper well
construction, mechanical integrity failure, and the presence of local geologic/man-made features.
Results presented in the 2014 report will focus primarily on retrospective and prospective case studies
and laboratory studies. The case studies will provide information on the methods and tools used to
protect and isolate drinking water from oil and gas resources before and during hydraulic fracturing. In
particular, the retrospective case studies may offer information on the impacts to drinking water
resources from failures in well construction or mechanical integrity. EPA will use samples of the shale
formations obtained at prospective case study locations to investigate geochemical reactions between
hydraulic fracturing fluids and the natural gas-containing formation. These studies will be used to
identify important biogeochemical reactions between hydraulic fracturing fluids and environmental
media and whether this interaction may lead to the mobilization of naturally occurring materials. By
evaluating chemical, physical, and toxicological characteristics of those substances, EPA will be able to
determine which naturally occurring materials may be of most concern for human health.
Flowback and Produced Water: What are the possible impacts of surface spills on or near well pads
offlowback and produced water on drinking water resources?
EPA will use existing data to summarize the composition of flowback and produced water, as well as
what is known about the frequency, severity, and causes of spills of hydraulic fracturing wastewater.
Based on information submitted by the hydraulic fracturing service companies and oil and gas
operators, EPA will compile a list of chemical constituents found in hydraulic fracturing wastewaters and
the factors that may influence this composition. EPA will then use existing databases to determine the
chemical, physical, and toxicological properties of wastewater constituents, and will identify specific
constituents that may be of particular concern due to their mobility, toxicity, or production volumes.
Properties of chemicals with little or no existing information will be estimated using QSAR methods, and
high-priority chemicals with no existing toxicological information may be flagged for further analyses.
The list of hydraulic fracturing wastewater constituents will also be used as a basis for a review of
79
-------
EPA Hydraulic Fracturing Study Plan
November 2011
existing scientific literature to determine the fate and transport of these chemicals in the environment.
These results, in combination with the above data analysis, will be presented in the 2012 report.
Results from the retrospective and prospective case studies will be presented in the 2014 report. The
retrospective case studies will involve investigations of reported drinking water contamination at
locations near reported spills of hydraulic fracturing wastewaters. EPA will first verify if contamination of
the drinking water resources has occurred, and if so, then identify the source of this contamination. This
may or may not be due to spills of hydraulic fracturing wastewaters. These case studies may provide EPA
with information on the impacts of spills of hydraulic fracturing wastewaters to nearby drinking water
resources. Prospective case studies will give EPA the opportunity to collect and analyze samples of
flowback and produced water at different times, leading to a better understanding of the variability in
the composition of these wastewaters.
Wastewater Treatment and Waste Disposal: What are the possible impacts of inadequate treatment of
hydraulic fracturing wastewaters on drinking water resources?
In the 2012 report, EPA will analyze existing data, the results from scenario evaluations and laboratory
studies to assess the treatment and disposal of hydraulic fracturing wastewaters. Data provided by oil
and gas operators will be used to better understand common treatment and disposal methods and
where these methods are practiced. This understanding will inform EPA's evaluation of the efficacy of
current treatment processes. In a separate effort, EPA researchers will create a generalized computer
model of surface water discharges of treated hydraulic fracturing wastewaters. The model will be used
to determine the potential impacts of these wastewaters on the operation of drinking water treatment
facilities.
Research presented in the 2014 report will include the results of laboratory studies of current treatment
and disposal technologies, building upon the results reported in 2012. These studies will provide
information on fate and transport processes of hydraulic fracturing wastewater contaminants during
treatment by a wastewater treatment facility. Additional laboratory studies will be used to determine
the extent of brominated DBP formation in hydraulic fracturing wastewaters, either from brominated
chemical additives or high bromide concentrations. If possible, EPA will also collect samples of
wastewater treatment plant discharges and stream/river samples to determine the contribution of
treated hydraulic fracturing wastewater discharges to stream/river contamination. The generalized
computer model described above will be expanded to develop a watershed-specific version that will
provide additional information on potential impacts to drinking water intakes and what factors may
influence these impacts.
The results for each individual research project will be made available to the public after undergoing a
comprehensive quality assurance review. Figures 10 and 11 show which parts of the research will be
completed in time for the 2012 report and which components of the study plan are expected to be
completed for the 2014 report. Both reports will use the results of the research projects to assess the
impacts, if any, of hydraulic fracturing on drinking water resources. Overall, this study will provide data
on the key factors in the potential contamination of drinking water resources as well as information
80
-------
EPA Hydraulic Fracturing Study Plan
November 2011
about the toxicity of chemicals associated with hydraulic fracturing. The results may then be used in the
future to inform a more comprehensive assessment of the potential risks associated with exposure to
contaminants associated with hydraulic fracturing activities in drinking water.
Conclusion
This study plan represents an important milestone in responding to the direction from the US Congress
in Fiscal Year 2010 to conduct research to examine the relationship between hydraulic fracturing and
drinking water resources. EPA is committed to conducting a study that uses the best available science,
independent sources of information, and a transparent, peer-reviewed process that will ensure the
validity and accuracy of the results. The Agency will work in consultation with other federal agencies,
state and interstate regulatory agencies, industry, non-governmental organizations, and others in the
private and public sector in carrying out the study. Stakeholder outreach as the study is being conducted
will continue to be a hallmark of our efforts, just as it was during the development of this study plan.
13 Additional Research Needs
Although EPA's current study focuses on potential impacts of hydraulic fracturing on drinking water
resources, stakeholders have identified additional research areas related to hydraulic fracturing
operations, as discussed below. Integrating the results of future work in these areas with the findings of
the current study would provide a comprehensive view of the potential impacts of hydraulic fracturing
on human health and the environment. If opportunities arise to address these concerns, EPA will include
them in this current study as they apply to potential impacts of hydraulic fracturing on drinking water
resources. However, the research described in this study plan will take precedence.
13.1 Use of Drilling Muds in Oil and Gas Drilling
Drilling muds are known to contain a wide variety of chemicals that might impact drinking water
resources. This concern is not unique to hydraulic fracturing and may be important for oil and gas
drilling in general. The study plan is restricted to specifically examining the hydraulic fracturing process
and will not evaluate drilling muds.
13.2 Land Application of Flowback or Produced Waters
Land application of wastewater is a fairly common practice within the oil and gas industry. EPA plans to
identify hydraulic fracturing-related chemicals that may be present in treatment residuals. However, due
to time constraints, land application of hydraulic fracturing wastes and disposal practices associated
with treatment residuals is outside the scope of the current study.
13.3 Impacts from Disposal of Solids from Wastewater Treatment Plants
In the process of treating wastewater, the solids are separated from the liquid in the mixture. The
handling and disposal of these solids can vary greatly before they are deposited in pits or undergo other
disposal techniques. These differences can greatly affect exposure scenarios and the toxicological
characteristics of the solids. For this reason, a comprehensive assessment of solids disposal is beyond
81
-------
EPA Hydraulic Fracturing Study Plan
November 2011
the current study's resources. However, EPA will use laboratory-scale studies to focus on determining
the fate and transport of hydraulic fracturing water contaminants through wastewater treatment
processes, including partitioning in treatment residuals.
13.4 Disposal of Hydraulic Fracturing Wastewaters in Class II Underground
Injection Wells
Particularly in the West, millions of gallons of produced water and flowback are transported to Class II
UIC wells for disposal. This study plan does not propose to evaluate the potential impacts of this
regulated practice or the associated potential impacts due to the transport and storage leading up to
ultimate disposal in a UIC well.
13.5 Fracturing or Re-Fracturing Existing Wells
In addition to concerns related to improper well construction and well abandonment processes, there
are concerns about the repeated fracturing of a well over its lifetime. Hydraulic fracturing can be
repeated as necessary to maintain the flow of hydrocarbons to the well. The near- and long-term effects
of repeated pressure treatments on well construction components (e.g., casing and cement) are not well
understood. While EPA recognizes that fracturing or re-fracturing existing wells should also be
considered for potential impacts to drinking water resources, EPA has not been able to identify potential
partners for a case study; therefore, this practice is not considered in the current study. The issues of
well age, operation, and maintenance are important and warrant more study.
13.6 Comprehensive Review of Compromised Waste Containment
Flowback is deposited in pits or tanks available on site. If these pits or tanks are compromised by leaks,
overflows, or flooding, flowback can potentially affect surface and ground water. This current study
partially addresses this issue. EPA will evaluate information on spills collected from incident reports
submitted by hydraulic fracturing service operators and observations from the case studies. However, a
thorough review of pit or storage tank containment failures is beyond the scope of this study.
13.7 Air Quality
There are several potential sources of air emissions from hydraulic fracturing operations, including the
off-gassing of methane from flowback before the well is put into production, emissions from truck traffic
and diesel engines used in drilling equipment, and dust from the use of dirt roads. There have been
reports of changes in air quality from natural gas drilling that have raised public concerns. Stakeholders
have also expressed concerned over the potential greenhouse gas impacts of hydraulic fracturing. This
study plan does not propose to address the potential impacts from hydraulic fracturing on air quality or
greenhouse gases because these issues fall outside the scope of assessing potential impacts on drinking
water resources.
82
-------
EPA Hydraulic Fracturing Study Plan
November 2011
13.8 Terrestrial and Aquatic Ecosystem Impacts
Stakeholders have expressed concern that hydraulic fracturing may have effects on terrestrial and
aquatic ecosystems unrelated to its effects on drinking water resources. For example, there is concern
that contamination from chemicals used in hydraulic fracturing could result either from accidents during
their use, transport, storage, or disposal; spills of untreated wastewater; or planned releases from
wastewater treatment plants. Other impacts could result from increases in vehicle traffic associated
with hydraulic fracturing activities, disturbances due to site preparation and roads, or stormwater runoff
from the drilling site. This study plan does address terrestrial and aquatic ecosystem impacts from
hydraulic fracturing because this issue is largely outside the scope of assessing potential impacts on
drinking water resources.
13.9 Seismic Risks
It has been suggested that drilling and/or hydraulically fracturing shale gas wells might cause low-
magnitude earthquakes. Public concern about this possibility has emerged due to several incidences
where weak earthquakes have occurred in several locations with recent increases in drilling, although no
conclusive link between hydraulic fracturing and these earthquakes has been found. The study plan does
not propose to address seismic risks from hydraulic fracturing, because they are outside the scope of
assessing potential impacts on drinking water resources.
13.10 Occupational Risks
Occupational risks are of concern in the oil and gas extraction industry in general. For example, NIOSH
reports that the industry has an annual occupational fatality rate eight times higher than the rate for all
US workers, and that fatality rates increase when the level of drilling activity increases (NIOSH, 2009).
Acute and chronic health effects associated with worker exposure to hydraulic fracturing fluid chemicals
could be of concern. Exposure scenarios could include activities during transport of materials, chemical
mixing, delivery, and any potential accidents. The nature of this work poses potential risks to workers
that have not been well characterized. Therefore, the recent increase in gas drilling and hydraulic
fracturing activities may be a cause for concern with regard to occupational safety. The study plan does
not propose to address occupational risks from hydraulic fracturing, because this issue is outside the
scope of assessing potential impacts on drinking water resources.
13.11 Public Safety Concerns
Emergency situations such as blowouts, chemical spills from sites with hydraulic fracturing, or spills from
the transportation of materials associated with hydraulic fracturing (either to or from the well pad)
could potentially jeopardize public safety. Stakeholders also have raised concerns about the possibility
of public safety hazards as a result of sabotage and about the need for adequate security at drilling sites.
This issue is not addressed in the study plan because it is outside the scope of assessing potential
impacts on drinking water resources.
83
-------
EPA Hydraulic Fracturing Study Plan
November 2011
13.12 Economic Impacts
Some stakeholders value the funds they receive for allowing drilling and hydraulic fracturing operations
on their properties, while others look forward to increased job availability and more prosperous
businesses. It is unclear, however, what the local economic impacts of increased drilling activities are
and how long these impacts may last. For example, questions have been raised concerning whether the
high-paying jobs associated with oil and gas extraction are available to local people, or if they are more
commonly filled by those from traditional oil and gas states who have specific skills for the drilling and
fracturing process. It is important to better understand the benefits and costs of hydraulic fracturing
operations. However, the study plan does not address this issue, because it is outside the scope of
assessing potential impacts on drinking water resources
13.13 Sand Mining
As hydraulic fracturing operations have become more prevalent, the demand for proppants has also
risen. This has created concern over increased sand mining and associated environmental effects. Some
stakeholders are worried that sand mining may lower air quality, adversely affect drinking water
resources, and disrupt ecosystems (Driver, 2011). The impact of sand mining should be studied in the
future, but is outside the scope of the current study because it falls outside the hydraulic fracturing
water lifecycle framework established for this study.
84
-------
EPA Hydraulic Fracturing Study Plan
November 2011
References
API (American Petroleum Institute). (2009a, July). Environmental protection for onshore oil and gas
production operations and leases. API Recommended Practice 51R, first edition. Washington, DC:
American Petroleum Institute. Retrieved June 24, 2011, from
http://www.api.org/plicy/exploration/hydraulicfracturing/upload/API_RP_SlR.pdf
API (American Petroleum Institute). (2009b, October). Hydraulic fracturing operations—well
construction and integrity guidelines. API Guidance Document HF1. Washington, DC: American
Petroleum Institute.
API (American Petroleum Institute). (2010a, June). Water management associated with hydraulic
fracturing. API Guidance Document HF2, first edition. Washington, DC: American Petroleum Institute.
Retrieved January 20, 2011, from http://www.api.org/Standards/new/api-hf2.cfm.
API (American Petroleum Institute). (2010b, July 19). Freeing up energy—hydraulic fracturing: Unlocking
America's natural gas resources. Washington, DC: American Petroleum Institute. Retrieved December 2,
2010, from http://www.api.org/policy/exploration/hydraulicfracturing/upload/
HYDRAULIC_FRACTURING_PRIMER.pdf.
Armstrong, K., Card, R., Navarette, R., Nelson, E., Nimerick, K., Samuelson, M., Collins, J., Dumont, G.,
Priaro, M., Wasylycia, N., & Slusher, D. (1995, Autumn). Advanced fracturing fluids improve well
economics. Oil Field Review, 34-51.
Arthur, J. D., Bohm, B., & Layne, M. (2008, September 21-24). Hydraulic fracturing considerations for
natural gas wells of the Marcellus Shale. Presented at The Ground Water Protection Council 2008
Annual Forum, Cincinnati, OH.
Baker Hughes. (2010, June 11). Baker Hughes rig count blog. Retrieved August 10, 2010, from
http://blogs.bakerhughes.com/rigcount.
Bellabarba, M., Bulte-Loyer, H., Froelich, B., Le Roy-Delage, S., Kujik, R., Zerouy, S., Guillot, D., Meroni,
N., Pastor, S., & Zanchi, A. (2008, Spring). Ensuring zonal isolation beyond the life of the well. Oil Field
Review, 18-31.
Berman, A. (2009, August 1). Lessons from the Barnett Shale suggest caution in other shale plays. World
Oil, 230(8).
Blauch, M. (2011, March 29). Shale frac sequential flowback analyses and reuse implications. Presented
at the EPA's Hydraulic Fracturing Technical Workshop 4, Washington, DC.
Breit, G.N. (2002). Produced waters database: US Geological Survey. Accessed September 20, 2011 from
http://energy.cr.usgs.gov/prov/prodwat/index.htm.
Bryant, J., Welton, T., & Haggstrom, J. (2010, September 1). Will flowback or produced water do? E&P.
Retrieved January 19, 2011, from http://www.epmag.eom/Magazine/2010/9/item65818.php.
85
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Carter, R. H., Holditch, S. A., & Wolhart, S. L. (1996, October 6-9). Results of a 1995 hydraulic fracturing
survey and a comparison of 1995 and 1990 industry practices. Presented at the Society of Petroleum
Engineers Annual Technical Conference, Denver, CO.
Castle, J. W., Falta, R. W., Bruce, D., Murdoch, L., Foley, J., Brame, S. E., & Brooks, D. (2005). Fracture
dissolution of carbonate rock: an innovative process for gas storage. Topical Report, DOE, NETL, DE-
FC26-02NT41299. Washington, DC: Department of Energy.
Chapra, S.C. (2008). Surface water quality modeling. Long Grove, IL: Waveland Press.
Chesapeake Energy. (2009). Barnett Shale—natural gas production. Retrieved August 9, 2010, from
http://www.askchesapeake.com/Barnett-Shale/Production/Pages/information.aspx.
Chesapeake Energy. (2010, July). Hydraulic fracturing fact sheet. Retrieved August 9, 2010, from
http://www.chk.com/Media/CorpMediaKits/Hydraulic_Fracturing_Fact_Sheet.pdf.
Cipolla, C. L., & Wright, C. A. (2000, April 3-5). Diagnostic techniques to understand hydraulic fracturing:
What? Why? And how? Presented at the Society of Petroleum Engineers/Canadian Energy Research
Institute Gas Technology Symposium, Calgary, Alberta, Canada.
Clark, C. E, & Veil, J. A. (2009). Produced water volumes and management practices in the US
Washington, DC: US Department of Energy, National Energy Technology Laboratory, Project No. DE-
AC02-06CH11357. Retrieved July 27, 2010, from http://www.netl.doe.gov/technologies/
coalpower/ewr/water/pdfs/anl%20produced%20water%20volumes%20sep09.pdf.
Daneshy, A. A. (2003, April). Off-balance growth: A new concept in hydraulic fracturing. No. SPE 80992.
Journal of Petroleum Technology (Distinguished Author Series), 55(4), 78-85.
Doherty, J. (2011, July-August). Modeling: Picture perfect or abstract art? Ground Water, 49(4), 455.
Driver, A. (2011, September 21). Critics of energy 'fracking' raise new concern: sand. Reuters. Retrieved
September 22, 2011, from http://www.msnbc.msn.com/id/44612454/ns/us_news-
environment/t/critics-energy-fracking-raise-new-concern-sand/.
Eby, G. N. (2004). Principles of environmental geochemistry. Pacific Grove, CA: Thompson-Brooks/Cole.
Falk, H., Lavergren, U., & Bergback, B. (2006). Metal mobility in alum shale from Oland, Sweden. Journal
of Geochemical Exploration, 90(3), 157-165.
Gadd, G. M. (2004). Microbial influences on metal mobility and application for bioremediation.
Geoderma, 122, 109-119.
Galusky, L. P., Jr. (2007, April 3). Fort Worth Basin/Barnett Shale natural gas play: An assessment of
present and projected fresh water use. Fort Worth, TX: Barnett Shale Water Conservation and
Management Committee. Retrieved July 21, 2010, from www.barnettshalewater.org/uploads/
Barnett_Water_Availability_Assessment Apr_3 2007.pdf.
86
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Gaudlip, A. W., & Paugh, L. O. (2008, November 18). Marcellus Shale water management challenges in
Pennsylvania (No. SPE 119898). Presented at the Society of Petroleum Engineers Shale Gas Production
Conference, Irving, TX.
Godsey, W.E. (2011, March 29). Fresh, brackish, or saline water for hydraulic fracs: What are the
options? Presented at the EPA's Hydraulic Fracturing Technical Workshop 4, Washington, DC.
GWPC (Ground Water Protection Council). (2009). State oil and natural gas regulations designed to
protect water resources. Washington, DC: US Department of Energy, National Energy Technology
Laboratory. Retrieved July 23, 2010, from http://data.memberclicks.com/site/coga/GWPC.pdf.
GWPC (Ground Water Protection Council) & ALL Consulting. (2009). Modern shale gas development in
the US: A primer. Contract DE-FG26-04NT15455. Washington, DC: US Department of Energy, Office of
Fossil Energy and National Energy Technology Laboratory. Retrieved August 2, 2010, from
http://www.netl.doe.gov/technologies/oil-gas/publications/EPreports/
Shale_Gas_Primer_2009.pdf.
Halliburton. (2008). US shale gas - an unconventional resource, unconventional challenge. Retrieved
September 7, 2011, from
http://www.halliburton.com/public/solutions/contents/Shale/related_docs/H063771.pdf.
Hall, B. E., & Larkin, S. D. (1989). On-site quality control of fracture treatments. Journal of Petroleum
Technology, 41(5), 526-532.
Hanson, G. (2011, March 29). How are appropriate water sources for hydraulic fracturing determined?
Pre-development conditions and management of development phase water usage. Presented at the
EPA's Hydraulic Fracturing Technical Workshop 4, Washington, DC.
Harper, J. A. (2008). The Marcellus Shale—An old "new" gas reservoir in Pennsylvania. Pennsylvania
Geology, 38(1), 2-13.
Hayes, T. (2009a, June 4). Gas shale produced water. Presented at the Research Partnership to Secure
Energy for America/Gas Technology Institute Gas Shales Forum, Des Plaines, IL. Retrieved August 11,
2010, from http://www.rpsea.org/attachments/contentmanagers/429/Gas_Shale_Produced_Water_-
_Dr._Tom_Hayes_GTI.pdf.
Hayes, T. (2009b, December 31). Sampling and analysis of water streams associated with the
development of Marcellus Shale gas, final report. Canonsburg, PA: Marcellus Shale Coalition, Gas
Technology Institute.
Hayes, T. (2011, March 29). Characterization of Marcellus shale and Barnett shale flowback waters and
technology development for water reuse. Presented at the EPA's Hydraulic Fracturing Technical
Workshop 4, Washington, DC.
87
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Holditch, S. A. (1993, March). Completion methods in coal-seam reservoirs. Journal of Petroleum
Technology; 45(3), 270-276.
Hopey, D. (2011, March 5). Radiation-fracking link sparks swift reactions. Pittsburgh Post-Gazette.
Retrieved August 31, 2011, from http://www.post-gazette.com/pg/11064/1129908-113.stm.
Hopey, D., & Hamill, S.D. (2011, April 19). Pa.: Marcelus wastewater shouldn't go to treatment plants.
Pittsburgh Post-Gazette. Retrieved August 31, 2011, from http://www.post-
gazette.eom/pg/11109/1140412-100-0.stm.
Horn, A. D. (2009, March 24). Breakthrough mobile water treatment converts 75% of fracturing flowback
fluid to fresh water and lowers C02 emissions (No. SPE 121104). Presented at the Society of Petroleum
Engineers E&P Environmental and Safety Conference, San Antonio, TX.
Hossain, Md. M., & Rahman, M. K. (2008). Numerical simulation of complex fracture growth during tight
reservoir stimulation by hydraulic fracturing. Journal of Petroleum Science and Engineering, 60, 86-104.
ICF International. (2009a, August 5). Technical assistance for the draft supplemental generic EIS: oil, gas
and solution mining regulatory program. Well permit issuance for horizontal drilling and high-volume
hydraulic fracturing to develop the Marcellus Shale and other low permeability gas reservoirs—Task 2.
Albany, NY: ICF Incorporated, LLC, New York State Energy Research and Development Authority Contract
PO Number 9679. Retrieved July 25, 2010, from http://www.nyserda.org/publications/
ICF%20Task%202%20Report_Final.pdf.
ICF International. (2009b, August 7). Technical assistance for the draft supplemental generic EIS: oil, gas
and solution mining regulatory program. Well permit issuance for horizontal drilling and high-volume
hydraulic fracturing to develop the Marcellus Shale and other low permeability gas reservoirs—Task 1.
Albany, NY: ICF Incorporated, LLC, New York State Energy Research and Development Authority
Contract PO Number 9679. Retrieved July 25, 2010, from http://www.nyserda.com/
publications/ICF%20Task%201%20Report_Final.pdf.
Jeu, S. J., Logan, T. L., & McBane, R. A. (1988, October 2-5). Exploitation of deeply buried coalbed
methane using different hydraulic fracturing techniques in the Piceance Basin, Colorado, and San Juan
Basin, New Mexico. Presented at the Society of Petroleum Engineers Annual Technical Conference and
Exhibition, Houston, TX.
Jobson, H.E. (1996). Prediction oftraveltime and longitudinal dispersion in rivers and streams. ISGS
Water-Resources Investigations, Report 96-4013.
Judson, R. S., Martin, M. T., Reif, D. M., Houck, K. A., Knudsen, T. B., Rotroff, D. M., Xia, M., Sakamuru, S.,
Huang, R., Shinn, P., Austin, C. P., Kavlock, R. J., & Dix, D. J. (2010a). Analysis of eight oil spill dispersants
using rapid, in vitro tests for endocrine and other biological activity. Environmental Science &
Technology, 44, 5979-5985.
88
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Judson, R. S., Houck, K. A., Kavlock, R. J., Knudsen, T. B., Martin, M. T., Mortensen, H. M., Reif, D. M.,
Rotroff, D. M., Shah, I., Richard, A. M., & Dix, D. J. (2010b). In vitro screening of environmental chemicals
for targeted testing prioritization: The ToxCast project. Environmental Health Perspectives, 118, 485-
492.
Kargbo, D. M., Wilhelm, R. G., & Campbell, D. J. (2010). Natural gas plays in the Marcellus Shale:
challenges and potential opportunities. Environmental Science & Technology, 44(15), 5679-5684.
Keister, T. (2009, January 12). Marcellus gas well water supply and wastewater disposaltreatment, and
recycle technology. Brockway, PA: ProChemTech International, Inc. Retrieved July 29, 2010, from
http://www.prochemtech.com/Literature/TAB/PDF_TAB_Marcellus_Gas_Well_Water_Recycle.pdf.
Kellman, S., & Schneider, K. (2010, September 15). Water demand is flash point in Dakota oil boom.
Circle of Blue Waternews. Retrieved September 18, 2010, from http://www.circleofblue.org/
waternews/2010/world/scarce-water-is-no-limit-yet-to-north-dakota-oil-shale-boom/.
Konikow, L.F. (2010). The secret to successful solute-transport modeling. Groundwater, 49(2), 144-159.
Lee, J.J. (2011a, March 29). Water quality in the development area of the Marcellus shale gas in
Pennsylvania and the implications on discerning impacts from hydraulic fracturing. Presented at the
EPA's Hydraulic Fracturing Technical Workshop 4, Washington, DC.
Lee, J.J. (2011b, March 30). Hydraulic fracturing and safe drinking water. Presented at the EPA's
Hydraulic Fracturing Technical Workshop 4, Washington, DC.
Lee, M. (2011, April 20). Chesapeake battles out-of-control Marcellus gas well. Bloomberg. Retrieved
August 31, 2011, from http://www.bloomberg.com/news/2011-04-20/chesapeake-battles-out-of-
control-gas-well-spill-in-pennsylvania.html.
Legere, L. (2011, August 13). State pushes for legal end to shale wastewater discharges. The Times
Tribune. Retrieved August 31, 2011, from http://thetimes-tribune.com/news/state-pushes-for-legal-
end-to-shale-wastewater-discharges-1.1188211#axzzlVDXItBdl.
Leventhal, J. S., & Hosterman, J. W. (1982). Chemical and mineralogical analysis of Devonian black shale
samples from Martin County, Kentucky; Caroll and Washington Counties, Ohio; Wise County, Virginia;
and Overton County, Tennessee. Chemical Geology, 37, 239-264.
Long, D. T., & Angino, E. E. (1982). The mobilization of selected trace metals from shales by aqueous
solutions: Effects of temperature and ionic strength. Economic Geology, 77(3), 646-652.
Louisiana Office of Conservation. (2011, August 19). Order No. ENV2011-GW014. Retrieved October 19,
2011, from http://dnr.louisiana.gov/assets/news_releases/OrderENV2011-GW0140001.pdf.
Lustgarten, A. (2009, September 21). Frack fluid spill in Dimock contaminates stream, killing fish.
ProPublica. Retrieved August 31, 2011, from http://www.propublica.org/article/frack-fluid-spill-in-
dimock-contaminates-stream-killing-fish-921.
89
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Maclin, E., Urban, R., & Haak, A. (2009, December 31). Re: New York State Department of Environmental
Conservation's draft supplemental generic environmental impact statement on the oil, gas, and solution
mining regulatory program. Arlington, VA: Trout Unlimited. Retrieved July 26, 2010, from
http://www.tcgasmap.org/media/
Trout%20Unlimited%20NY%20Comments%20on%20Draft%20SGEIS.pdf.
Martin, T., & Valko, P. (2007). Hydraulic fracture design for production enahancement. In M.J.
Economides & T. Martin (Eds.), Modern Fracturing: Enhancing Natural Gas Production (p95) ET
Publishing, Houston, TX.
McLean, J. S., & Beveridge, T. J. (2002). Interactions of bacteria and environmental metals, fine-grained
mineral development, and bioremediation strategies. In P. M. Haung, et al. (Eds.), Interactions between
soil particles and microrganisms (pp. 67-86). New York, NY: Wiley.
McMahon, P. B., Thomas, J. C., & Hunt, A. G. (2011). Use of diverse geochemical data sets to determine
sources and sinks of nitrate and methane in groundwater, Garfield County, Colorado, 2009. US
Geological Survey Scientific Investigations Report 2010-5215. Reston, VA: US Department of the
Interior, US Geological Survey.
Myers, T. (2009). Technical memorandum: Review and analysis of draft supplemental generic
environmental impact statement on the oil, gas and solution mining regulatory program. Well permit
issuance for horizontal drilling and high-volume hydraulic fracturing to develop the Marcellus Shale and
other low-permeability gas reservoirs. New York, NY: Natural Resources Defense Council. Retrieved July
26, 2010, from http://www.tcgasmap.org/media/NRDCMyers%20Comments%20on%20Draft%
20SGEIS.pdf.
National Research Council. (2010). Management and effects of coalbed methane produced water in the
western US. Washington, DC: National Academies Press.
Nemat-Nassar, S., Abe, H., & Hirakawa, S. (1983). Hydraulic fracturing and geothermal energy. The
Hague, The Netherlands: Kluwer Academic Publishers.
New Hampshire Department of Environmental Services. (2010). Environmental fact sheet. Well
development by hydro-fracking. Concord, NH: New Hampshire Department of Environmental Services.
Retrieved January 11, 2011, from
http://des.nh.gov/organization/commissioner/pip/factsheets/dwgb/documents/dwgb-l-3.pdf.
NIOSH (National Institute for Occupational Safety and Health). (2009, February). Oil and gas extraction.
Inputs: Occupational safety and health risks. Atlanta, GA: Centers for Disease Control and Prevention.
Retrieved September 17, 2010, from http://www.cdc.gov/niosh/programs/oilgas/risks.html.
NYSDEC (New York State Department of Environmental Conservation). (2011, September). Supplemental
generic environmental impact statement on the oil, gas and solution mining regulatory program (revised
draft). Well permit issuance for horizontal drilling and high-volume hydraulic fracturing to develop the
Marcellus Shale and other low-permeability gas reservoirs. Albany, NY: New York State Department of
90
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Environmental Conservation. Retrieved January 20, 2010, from
ftp://ftp.dec.state.ny.us/dmn/download/OGdSGEISFull.pdf.
Oil and Gas Investor. (2005, March). Tight Gas (special supplement). Houston, TX: Oil and Gas
Investor/Hart Energy Publishing LP. Retrieved August 9, 2010, from http://www.oilandgasinvestor.com/
pdf/Tight%20Gas.pdf.
OilGasGlossary.com. (2010). Drilling fluid definition. Retrieved February 3, 2011, from http://
oilgasglossary.com/drilling-fluid.html.
OilShaleGas.com. (2010). OilShaleGas.com—oil & shale gas discovery news. Retrieved January 17, 2011,
from http://oilshalegas.com.
Oreskes, N. K., Shrader-Frechette, K., & Belitz, K. (1994, February 4). Verification, validation, and
confirmation of numerical models in the earth sciences. Science, 263(5147), 641-646.
Oreskes, N. K. (2003). The role of quantitative models in science. In C. D. Canham, J. J. Cole, & W. K.
Lauenroth (Eds.), Models in ecosystem science (pp. 13-31). Princeton, NJ: Princeton University Press.
Osborn, S.G., Vengosh, A., Warner, N.R., Jackson, R.B. (2011). Methane contamination of drinking water
accompanying gas-well drilling and hydraulic fracturing. Proceedings of the National Academy of
Sciences, 108(20), 8172-8176.
PADEP (Pennsylvania Department of Environmental Protection). (2010a). Marcellus Shale. Harrisburg,
PA: Pennsylvania Department of Environmental Protection. Retrieved August 9, 2010, from
http://www.elibrary.dep.state.pa.us/dsweb/Get/Document-77964/0100-FS-DEP4217.pdf.
PADEP (Pennsylvania Department of Environmental Protection). (2010b, December 15). Consent order
and settlement agreement (Commonwealth of Pennsylvania Department of Environmental Protection
and Cabot Oil & Gas Corporation). PA: Pennsylvania Department of Environmental Protection.
Palisch, T. T., Vincent, M. C., & Handren, P. J. (2008, September 21-24). Slickwater fracturing—food for
thought. No. 115766-MS. Paper presented at the Society of Petroleum Engineers Annual Technical
Conference, Denver, CO.
Palmer, I. D., Fryan, R. T., Tumino, K. A., & Puri, R. (1991, August 12). Water fracs outperform gel fracs in
coalbed pilot. Oil and Gas Journal, 71-76.
Palmer, I. D., Lambert, S. W., & Spitler, J. L. (1993). Coalbed methane well completions and stimulations.
AAPG Studies in Geology, 38, 303-341.
Pashin, J. C. (2007). Hydrodynamics of coalbed methane reservoirs in the Black Warrior Basin: Key to
understanding reservoir performance and environmental Issues. Applied Geochemistry, 22, 2257-2272.
Pearson, C. M. (1989). US Patent No. 4,845,981,1989. System for monitoring fluids during well
stimulation processes. Washington, DC: US Patent and Trademark Office.
91
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Pennsylvania Environmental Quality Board. (2009, November 7). Proposed Rulemaking [25 PA. CODE CH.
95] wastewater treatment requirements [39 Pa.B. 6467] [Saturday, November 7, 2009], The
Pennsylvania Bulletin, 39(45), Doc. No. 09-2065. Retrieved January 21, 2011, from http://
www.pabulletin.com/secure/data/vol39/39-45/2065.html.
Pennsylvania State University. (2010). Marcellus education fact sheet Water withdrawals for
development of Marcellus Shale gas in Pennsylvania: Introduction to Pennsylvania's water resources.
University Park, PA: College of Agricultural Sciences, Pennsylvania State University. Retrieved November
26, 2010, from http://pubs.cas.psu.edu/freepubs/pdfs/ua460.pdf.
Pickett, A. (2009, March). New solutions emerging to treat and recycle water used in hydraulic fracs.
American Oil & Gas Reporter. Retrieved July 29, 2010, from http://www.aogr.com/index.php/
magazine/cover_story_archives/march_2009_cover_story/.
Piggot, A. R., Elsworth, D. (1996). Displacement of formation fluids by hydraulic fracturing.
Geotechnique, 46(4), 671-681.
Plewa, M.J., Wagner, E.D. (2009). Quantitative Comparative Mammalian Cell Cytotoxicity and
Genotoxicity of Selected Classes of Drinking Water Disinfection By-Products. Water Research
Foundation, Denver, CO.
Prouty, J. L. (2001). Tight gas in the spotlight. Gas Technology Institute GasTIPS, 7(2), 4-10.
Puko, T. (2010, August 7). Drinking water from Mon deemed safe. The Pittsburgh Tribune-Review.
Retrieved August 31, 2011, from http://www.pittsburghlive.eom/x/pittsburghtrib/news/s_693882.html.
Reif, D. M., Martin, M. T., Tan, S. W., Houck, K. A., Judson, R. S., Richard, A. M., Knudsen, T. B., Dix, D. J.,
& Kavlock, R. J. (2010). Endocrine profiling and prioritization of environmental chemicals using ToxCast
data. Environmental Health Perspectives, 118, 1714-1720.
Rogers, R. E., Ramurthy, M., Rodvelt, G., & Mullen, M. (2007). Coalbed methane: Principles and
practices. Third edition. Starkville, MS: Oktibbeha Publishing Co. Retrieved August 2, 2010, from
http://www.halliburton.com/public/pe/contents/Books_and_Catalogs/web/CBM/CBM_Book_lntro.pdf.
Rowan, T. M. (2009, September 23-25). Spurring the Devonian: Methods of fracturing the lower Huron in
southern West Virginia and eastern Kentucky. Presented at the Society for Petroleum Engineers Eastern
Regional Meeting, Charleston, WV.
Rowan, E. L., Engle, M. A., Kirby, C. S., & Kraemer, T. F. (2011, September 7). Radium content of oil- and
gas-field produced waters in the northern Appalachian Basin - Summary and discussion of data. US
Geological Survey Scientific Investigations Report 2011-5135.
Ruszka, J. (2007, August 1). Global challenges drive multilateral drilling. E&P. Retrieved August 13, 2010,
from http://www.epmag.com/archives/features/583.htm.
92
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Satterfield, J., Kathol, D., Mantell, M., Hiebert, F., Lee, R., & Patterson, K. (2008, September 20-24).
Managing water resource challenges in select natural gas shale plays. GWPC Annual Forum. Oklahoma
City, OK: Chesapeake Energy Corporation. Retrieved July 21, 2010, from http://www.gwpc.org/
meetings/forum/2008/proceedings/Ground%20Water%20&%20Energy/SatterfieldWaterEnergy.pdf.
Southam, G. (2000). Bacterial surface-mediated mineral formation. In D. R. Lovely (Ed.), Environmental
Microbe-Metal Interactions (pp. 257-276). Washington, DC: American Society of Microbiology.
Sparks, D. L. (1995). Environmental soil chemistry. San Diego, CA: Academic Press.
Sposito, G. (1989). The chemistry of soils. New York, NY: Oxford University Press.
State of Colorado Oil and Gas Conservation Commission. (2009a, October 5). Bradenhead test report.
OGCC Operator Number 26420, API Number 123-11848. Denver, CO: State of Colorado Oil and Gas
Conservation Commission.
State of Colorado Oil and Gas Conservation Commission. (2009b, December 7). Sundry notice. OGCC
Operator Number 26420, API Number 05-123-11848. Denver, CO: State of Colorado Oil and Gas
Conservation Commission.
State of Colorado Oil and Gas Conservation Commission. (2009c, December 17). Colorado Oil and Gas
Conservation Commission approved Wattenberg Bradenhead testing and staff policy. Letter sent to all
oil and gas operators active in the Denver Basin. Denver, CO: State of Colorado Oil and Gas Conservation
Commission.
Stumm, W., & Morgan, J. J. (1996). Chemical equilibria and rates in natural waters. Third edition. New
York, NY: John Wiley & Sons, Inc.
Tonkin, M., & Dougherty, J. (2009). Efficient nonlinear predictive error variance for highly
parameterized models. Water Resources Research, 45.
Tuttle, M. L. W., Briet, G. N., & Goldhaber, M. B. (2009). Weathering of the New Albany Shale, Kentucky:
II. Redistribution of minor and trace elements. Applied Geochemistry, 24, 1565-1578.
URS Corporation. (2009, September 16). Water-related issues associated with gas production in the
Marcellus Shale: Additives use, flowback quality and quantities, regulations, on-site treatment, green
technologies, alternate water sources, water well-testing. Prepared for New York State Energy Research
and Development Authority, Contract PO No. 10666. Fort Washington, PA: URS Corporation. Retrieved
August 2, 2010, from http://www.nyserda.org/publications/02%20Chapter%202%20-%20URS%202009-
9-16.pdf.
US House. (2009). Department of the Interior, Environment, and related agencies Appropriations Act,
2010. Washington, DC: Conference of Committee, US House. Retrieved September 23, 2011 from
http://frwebgate.access.gpo.gov/cgi-
bin/getdoc.cgi?dbname=lll_cong_reports&docid=f:hr316.111.pdf.
93
-------
EPA Hydraulic Fracturing Study Plan
November 2011
USEIA (US Energy Information Administration). (2010, December). Annual energy outlook 2011: Early
release overview. Washington, DC: US Department of Energy. Retrieved January 17, 2011, from
http://www.eia.gov/forecasts/aeo/.
USEIA (US Energy Information Administration). (2011a). Glossary. Retrieved September 20, 2011, from
http://205.254.135.24/tools/glossary/.
USEIA (US Energy Information Administration). (2011b, October 11). Oil and natural gas drilling on the
rise. Today in Energy. Retrieved October 15, 2011 from
http://www.eia.gov/todayinenergy/detail.cfm?id=3430.
USEPA (US Environmental Protection Agency). (2002, November). Overview of the EPA quality system for
environmental data and technology. No. EPA/240/R-02/003. Washington, DC: US Environmental
Protection Agency, Office of Environmental Information. Retrieved January 20, 2011, from
http://www.epa.gov/QUALITY/qs-docs/overview-final.pdf.
USEPA (US Environmental Protection Agency). (2004, June). Evaluation of impacts to underground
sources of drinking water by hydraulic fracturing ofcoalbed methane reservoirs. No. EPA/816/R-04/003.
Washington, DC: US Environmental Protection Agency, Office of Water. Retrieved January 21, 2011,
from http://water.epa.gov/type/groundwater/uic/class2/hydraulicfracturing/
wells_coalbedmethanestudy.cfm.
USEPA (US Environmental Protection Agency). (2009). EPA Records Schedule 501, Applied and Directed
Scientific Research. Retrieved September 7, 2011, from
http://www.epa.gov/records/policy/schedule/sched/501.htm.
USEPA (US Environmental Protection Agency). (2010a, March). Scoping materials for initial design of EPA
research study on potential relationships between hydraulic fracturing and drinking water resources.
Washington, DC: US Environmental Protection Agency, Office of Research and Development. Retrieved
September 16, 2010, from http://yosemite.epa.gOv/sab/sabproduct.nsf/0/
3B745430D624ED3B852576D400514B76/$File/Hydraulic+Frac+Scoping+Doc+for+SAB-3-22-
10+Final.pdf.
USEPA (US Environmental Protection Agency). (2010b, April 23). Trip report (EXCO Resources' gas well
drilling site, Norris Ferry Road, southern Caddo Parish (Shreveport), LA). Dallas, TX: US Environmental
Protection Agency Region 6.
USEPA (US Environmental Protection Agency). (2010c, June). Advisory on EPA's research scoping
document related to hydraulic fracturing. Washington, DC: US Environmental Protection Agency, Office
of the Administrator, Science Advisory Board. Retrieved September 16, 2010, from
http://yosemite.epa.gov/sab/sabproduct. nsf/0/CC09DE2B8B4755718525774D0044F929/$File/
EPA-SAB-10-009-unsigned.pdf.
USEPA (US Environmental Protection Agency). (2010d, July). EPA's action development process: Interim
guidance on considering environmental justice during the development of an action. OPEI Regulatory
94
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Development Series. Washington, DC: US Environmental Protection Agency. Retrieved January 17, 2011,
from http://www.epa.gov/environmentaljustice/resources/policy/
considering-ej-in-rulemaking-guide-07-2010.pdf.
USEPA (US Environmental Protection Agency). (2011a, February). Draft plan to study the potential
impacts of hydraulic fracturing on drinking water resources. Washington, DC: US Environmental
Protection Agency, Office of Research and Development.
USEPA (US Environmental Protection Agency). (2011b, August). SAB review ofEPA's Draft Hydraulic
Fracturing Study Plan. Washington, DC: US Environmental Protection Agency, Office of the
Administrator, Science Advisory Board. Retrieved September 7, 2011, from
http://yosemite.epa.gov/sab/sabproduct.nsf/0/2BC3CD632FCC0E99852578E2006DF890/$File/EPA-SAB-
ll-012-unsigned.pdf.
USGS (US Geological Survey). (1999, September). Naturally occurring radioactive materials (NORM) in
produced water and oil field equipment - an issue for the energy industry. USGS Fact Sheet FS-142-99.
Retrieved September 14, 2011, from http://pubs.usgs.gov/fs/fs-0142-99/fs-0142-99.pdf.
USGS (US Geological Survey). (2002, May 29). Produced waters database. Reston, VA: US Geological
Survey National Center. Retrieved January 17, 2011, from
http://energy.cr.usgs.gov/prov/prodwat/data2.htm.
Veil, J. A., Puder, M. G., Elcock, D., & Redweik, R. J. (2004). A white paper describing produced water
from production of crude oil, natural gas, and coal bed methane. Prepared for the US Department of
Energy, National Energy Technology Laboratory. Argonne, IL: Argonne National Laboratory. Retrieved
January 20, 2011, from http://www.evs.anl.gov/pub/doc/
ProducedWatersWP0401.pdf.
Veil, J. A. (2007, August). Trip report for field visit to Fayetteville Shale gas wells. No. ANL/EVS/R-07/4.
Prepared for the US Department of Energy, National Energy Technology Laboratory, project no. DE-
FC26-06NT42930. Argonne, IL: Argonne National Laboratory. Retrieved July 27, 2010, from
http://www.evs.anl.gov/pub/doc/ANL-EVS_R07-4TripReport.pdf.
Veil, J. A. (2010, July). Final report: Water management technologies used by Marcellus Shale gas
producers. Prepared for the US Department of Energy, National Energy Technology Laboratory,
Department of Energy award no. FWP 49462. Argonne, IL: Argonne National Laboratory. Retrieved on
January 20, 2011, from http://www.evs.anl.gov/pub/doc/Water%20Mgmt%20in%20Marcellus-final-
jull0.pdf.
Vejahati, F., Xu, Z., & Gupta, R. (2010). Trace elements in coal: Associations with coal and minerals and
their behavior during coal utilization—a review. Fuel, 89, 904-911.
Vidic, R. D. (2010, March 18). Sustainable water management for Marcellus Shale development.
Presented at Marcellus Shale natural gas stewardship: Understanding the environmental impact,
Marcellus Shale Summit, Temple University, Philadelphia, PA. Retrieved July 29, 2010, from
95
-------
EPA Hydraulic Fracturing Study Plan
November 2011
http://www.temple.edu/environment/NRDP_pics/shale/presentations_TUsummit/Vidic-Temple-
2010.pdf.
Walther, J. V. (2009). Essentials of geochemistry. Second edition. Boston, MA: Jones and Bartlett
Publishers.
Ward Jr., K. (2010, July 19). Environmentalists urge tougher water standards. The Charleston Gazette.
Retrieved August 31, 2011, from http://sundaygazettemail.com/News/201007190845.
Warpinski, N. R., Branagan, P. T., Peterson, R. E., & Wolhart, S. L. (1998, March 15-18). Mapping
hydraulic fracture growth and geometry using microseismic events detected by a wireline retrievable
accelerometer array. Presented at the Society of Petroleum Engineers Gas Technology Symposium,
Calgary, Alberta, Canada.
Warpinski, N. R., Walhart, S. L., & Wright, C. A. (2001, September 30-October 3). Analysis and prediction
of microseismicity induced by hydraulic fracturing. Presented at the Society of Petroleum Engineers
Annual Technical Conference, New Orleans, LA.
Waxman, H.A., Markey, E.J., & DeGette, D. (2011, April). Chemicals used in hydraulic fracturing.
Retrieved August 31, 2011, from
http://democrats.energycommerce.house.gov/sites/default/files/documents/Hydraulic%20Fracturing%
20Report%204.18.ll.pdf.
West Virginia Water Research Institute. (2010). Zero discharge water management for horizontal shale
gas well development: Technology status assessment. Prepared for the US Department of Energy,
National Energy Technology Laboratory, Department of Energy award no. DE-FE0001466. Morgantown,
WV: West Virginia Water Research Institute, West Virginia University. Retrieved July 29, 2010, from
http://prod75-interl.netl.doe.gov/technologies/oil-gas/publications/ENVreports/FE0001466_TSA.pdf.
Williams, D.O. (2011, June 21). Fines for Garden Gulch drilling spills finally to be imposed after more
than three years. The Colorado Independent. Retrieved August 31, 2011, from
http://coloradoindependent.com/91659/fines-for-garden-gulch-drilling-spills-finally-to-be-imposed-
after-more-than-three-years.
Winter, T. C., Harvey, J. W., Franke, O. L., & Alley, W. M. (1998). Ground water and surface water: A
single resource. US Geological Survey Circular, 1139, 1-78.
Zielinski, R.A., & Budahn, J. R. Mode of occurrence and environmental mobility of oil-field radioactive
material at US Geological Survey research site B, Osage-Skiatook Project, northeastern Oklahoma.
Applied Geochemistry, 22, 2125-2137.
Ziemkiewicz, P. (2011, March 30). Wastewater from gas development: chemical signatures in the
Monongahela River Basin. Presented at the EPA's Hydraulic Fracturing Technical Workshop 4,
Washington, DC.
96
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Zoback, M., Kitasei, S., & Copithorne, B. (2010, July). Addressing the environmental risks from shale gas
development. Briefing paper 1. Washington, DC: Worldwatch Institute. Retrieved January 20, 2011, from
http://www.worldwatch.org/files/pdf/Hydraulic%20Fracturing%20Paper.pdf.
Zorn, T. G., Seelbach, P. W., Rutherford, E. S., Wills, T. C., Cheng, S., & Wiley, M. J. (2008, November). A
regional-scale habitat suitability model to assess the effects of flow reduction on fish assemblages in
Michigan streams. Fisheries Division Research Report 2089. Lansing, Ml: State of Michigan Department
of Natural Resources. Retrieved January 20, 2011, from http://www.michigandnr.com/PUBLICATIONS/
PDFS/ifr/ifrlibra/Research/reports/2089/RR2089.pdf.
97
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Appendix A: Research Summary
TABLE Al. RESEARCH TASKS IDENTIFIED FOR WATER ACQUISITION
Water Acquisition: What are the potential impacts of large volume water withdrawals from ground and surface waters on drinking water resources?
Secondary Question
Research Tasks
Potential Product(s)
Report
How much water is used in hydraulic
Analysis of Existing Data
fracturing operations, and what are
• Compile and analyze data submitted by nine
• List of volume and water quality parameters
2012
the sources of this water?
hydraulic fracturing service companies for
information on source water volume and
quality requirements
that are important for hydraulic fracturing
operations
• Compile and analyze data from nine oil and gas
• Information on source, volume, and quality of
2012
operators on the acquisition of source water
water used for hydraulic fracturing operations
for hydraulic fracturing operations
• Compile data on water use and hydraulic
• Location-specific data on water use for
2012
fracturing activity for the Susquehanna River
hydraulic fraction
Basin and Garfield County, CO
Prospective Case Studies
• Document the source of the water used for
• Location-specific examples of water
2014
hydraulic fracturing activities
acquisition, including data on the source,
• Measure the quantity and quality of the water
volume, and quality of the water
used at each case study location
How might water withdrawals affect
Analysis of Existing Data
short- and long-term water
• Compile data on water use, hydrology, and
• Maps of recent hydraulic fracturing activity and
2012
availability in an area with hydraulic
hydraulic fracturing activity for the
water usage in a humid region (Susquehanna
fracturing activity?
Susquehanna River Basin and Garfield County,
CO
River Basin) and a semi-arid region (Garfield
County, CO)
• Compare control areas to areas with hydraulic
• Information on whether water withdrawals for
2012
fracturing activity
hydraulic fracturing activities alter ground and
surface water flows
• Assessment of impacts of hydraulic fracturing
on water availability at various spatial and
temporal scales
2012
Prospective Case Studies
• Compile information on water availability
• Identification of short-term impacts on water
2014
impacts due to water withdrawals from ground
availability from ground and surface water
Continued on next page
(DeSoto Parish, LA) and surface (Washington
County, PA) waters
withdrawals associated with hydraulic
fracturing activities
98
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Water Acquisition: What are the potential impacts of large volume water withdrawals from ground and surface waters on drinking water resources?
Secondary Question
Research Tasks
Potential Product(s)
Report
Continued from previous page
How might water withdrawals affect
short- and long-term water
availability in an area with hydraulic
fracturing activity?
Scenario Evaluations
• Conduct future scenario modeling of
cumulative hydraulic fracturing-related water
withdrawals in the Susquehanna River Basin
and Garfield County, CO
• Identification of long-term water quantity
impacts on drinking water resources due to
cumulative water withdrawals for hydraulic
fracturing
2014
What are the possible impacts of
water withdrawals for hydraulic
fracturing operations on local water
quality?
Analysis of Existing Data
• Compile data on water quality and hydraulic
fracturing activity for the Susquehanna River
Basin and Garfield County, CO
• Analyze trends in water quality
• Compare control areas to areas with intense
hydraulic fracturing activity
• Maps of hydraulic fracturing activity and water
quality for the Susquehanna River Basin and
Garfield County, CO
• Information on whether water withdrawals for
hydraulic fracturing activities alter local water
quality
2012
2012
Prospective Case Studies
• Measure local water quality before and after
water withdrawals for hydraulic fracturing
• Identification of impacts on local water quality
from water withdrawals for hydraulic
fracturing
2014
99
-------
EPA Hydraulic Fracturing Study Plan November 2011
TABLE A2. RESEARCH TASKS IDENTIFIED FOR CHEMICAL MIXING
Chemical Mixing: What are the possible impacts of surface spills on or near well pads of hydraulic fracturing fluids on drinking water resources?
Secondary Question
Research Tasks
Potential Product(s)
Report
What is currently known about the
Analysis of Existing Data
frequency, severity, and causes of
• Compile information regarding surface spills
• Nationwide data on the frequency, severity,
2012
spills of hydraulic fracturing fluids
obtained from nine oil and gas operators
and causes of spills of hydraulic fracturing
and additives?
• Compile information on frequency, severity,
and causes of spills of hydraulic fracturing
fluids and additives from existing data sources
fluids and additives
What are the identities and volumes
Analysis of Existing Data
of chemicals used in hydraulic
• Compile information on hydraulic fracturing
• Description of types of hydraulic fracturing
2012
fracturing fluids, and how might this
fluids and chemicals from publically available
fluids and their frequency of use (subject to
composition vary at a given site and
data and data provided by nine hydraulic
CBI rules)
across the country?
fracturing service companies
• Identify factors that may alter hydraulic
fracturing fluid composition
• List of chemicals used in hydraulic fracturing
fluids, including concentrations (subject to CBI
rules)
• List of factors that determine and alter the
composition of hydraulic fracturing fluids
2012
2012
Prospective Case Studies
• Collect information on the chemical products
• Illustrative examples of hydraulic fracturing
2014
used in the hydraulic fracturing fluids at the
fluids used in the Haynesville and Marcellus
case study locations
Shale plays
What are the chemical, physical, and
Analysis of Existing Data
toxicological properties of hydraulic
• Search existing databases for chemical,
• List of hydraulic fracturing chemicals with
2012
fracturing chemical additives?
physical, and toxicological properties
• Prioritize list of chemicals based on their
known chemical, physical, and toxicological
properties
known properties for (1) further toxicological
• Identification of 10-20 possible indicators to
2012
analysis or (2) to identify/modify existing
track the fate and transport of hydraulic
analytical methods
fracturing fluids based on known chemical,
physical, and toxicological properties
• Identification of hydraulic fracturing chemicals
that may be of high concern, but have no or
2012
Continued on next page
little existing toxicological information
100
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Chemical Mixing: What are the possible impacts of surface spills on or near well pads of hydraulic fracturing fluids on drinking water resources?
Secondary Question
Research Tasks
Potential Product(s)
Report
Continued from previous page
What are the chemical, physical, and
toxicological properties of hydraulic
fracturing chemical additives?
Toxicological Analysis
• Identify chemicals currently undergoing
ToxCast Phase II testing
• Predict chemical, physical, and toxicological
properties based on chemical structure for
chemicals with unknown properties
• Identify up to six hydraulic fracturing chemicals
with unknown toxicity values for ToxCast
screening and PPRTV development
• Lists of high, low, and unknown priority
hydraulic fracturing chemicals based on known
or predicted toxicity data
• Toxicological properties for up to six hydraulic
fracturing chemicals that have no existing
toxicological information and are of high
concern
2012
2014
Laboratory Studies
• Identify or modify existing analytical methods
for selected hydraulic fracturing chemicals
• Analytical methods for detecting hydraulic
fracturing chemicals
2012/14
If spills occur, how might hydraulic
fracturing chemical additives
contaminate drinking water
resources?
Analysis of Existing Data
• Review existing scientific literature on surface
chemical spills with respect to hydraulic
fracturing chemical additives or similar
compounds
• Summary of existing research that describes
the fate and transport of hydraulic fracturing
chemical additives, similar compounds, or
classes of compounds
• Identification of knowledge gaps for future
research, if necessary
2012
2012
Retrospective Case Studies
• Investigate hydraulic fracturing sites where
surface spills of hydraulic fracturing fluids have
occurred (Dunn County, ND; Bradford and
Susquehanna Counties, PA)
• Identification of impacts (if any) to drinking
water resources from surface spills of hydraulic
fracturing fluids
• Identification of factors that led to impacts (if
any) to drinking water resources resulting from
the accidental release of hydraulic fracturing
fluids
2014
2014
101
-------
EPA Hydraulic Fracturing Study Plan November 2011
TABLE A3. RESEARCH TASKS IDENTIFIED FOR WELL INJECTION
Well Injection: What are the possible impacts of the injection and fracturing process on drinking water resources?
Secondary Question
Research Tasks
Potential Product(s)
Report
How effective are current well
Analysis of Existing Data
construction practices at containing
• Compile and analyze data from nine oil and gas
• Data on the frequency and severity of well
2014
gases and fluids before, during, and
operators on well construction practices
failures
after hydraulic fracturing?
• Identification of contributing factors that may
lead to well failures during hydraulic fracturing
activities
2014
Retrospective Case Studies
• Investigate the cause(s) of reported drinking
• Identification of impacts (if any) to drinking
2014
water contamination—including testing well
water resources resulting from well failure or
mechanical integrity—in Dunn County, ND, and
improper well construction
Bradford and Susquehanna Counties, PA
• Data on the role of mechanical integrity in
suspected cases of drinking water
contamination due to hydraulic fracturing
2014
Prospective Case Studies
• Conduct tests to assess well mechanical
• Data on changes (if any) in mechanical
2014
integrity before and after fracturing
integrity due to hydraulic fracturing
• Assess methods and tools used to isolate and
• Identification of methods and tools used to
2014
protect drinking water resources from oil and
isolate and protect drinking water resources
gas resources before and during hydraulic
from oil and gas resources before and during
fracturing
hydraulic fracturing
Scenario Evaluations
• Test scenarios involving hydraulic fracturing of
• Assessment of well failure scenarios during
2012
inadequately or inappropriately constructed or
and after well injection that may lead to
designed wells
drinking water contamination
Can subsurface migration of fluids or
Analysis of Existing Data
gases to drinking water resources
• Compile and analyze information from nine oil
• Information on the types of local geologic or
2012
occur, and what local geologic or
and gas operators on data relating to the
man-made features that are searched for prior
man-made features may allow this?
location of local geologic and man-made
to hydraulic fracturing
features and the location of hydraulically
• Data on whether or not fractures interact with
2012
created fractures
local geologic or man-made features and the
Continued on next page
frequency of occurrence
102
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Well Injection: What are the possible impacts of the injection and fracturing process on drinking water resources?
Secondary Question
Research Tasks
Potential Product(s)
Report
Continued from previous page
Can subsurface migration of fluids or
gases to drinking water resources
occur, and what local geologic or
man-made features may allow this?
Retrospective Case Studies
• Investigate the cause(s) of reported drinking
water contamination in an area where
hydraulic fracturing is occurring within a USDW
where the fractures may directly extend into
an aquifer (Las Animas Co., CO)
• Identification of impacts (if any) to drinking
water resources from hydraulic fracturing
within a drinking water aquifer
2014
Prospective Case Studies
• Gather information on the location of known
faults, fractures, and abandoned wells
• Identification of methods and tools used to
determine existing faults, fractures, and
abandoned wells
• Data on the potential for hydraulic fractures to
interact with existing natural features
2014
2014
Scenario Evaluations
• Test scenarios involving hydraulic fractures (1)
interacting with nearby man-made features
including abandoned or production wells, (2)
reaching drinking water resources or
permeable formations, and (3) interacting with
existing faults and fractures
• Develop a simple model to determine the area
of evaluation associated with a hydraulically
fractured well
• Assessment of key conditions that may affect
the interaction of hydraulic fractures with
existing man-made and natural features
• Identification of the area of evaluation for a
hydraulically fractured well
2012
2012
How might hydraulic fracturing fluids
change the fate and transport of
substances in the subsurface
through geochemical interactions?
Laboratory Studies
• Identify hydraulic fracturing fluid chemical
additives to be studied and relevant
environmental media (e.g., soil, aquifer
material, gas-bearing formation material)
• Characterize the chemical and mineralogical
properties of the environmental media
• Determine the products of reactions between
chosen hydraulic fracturing fluid chemical
additives and relevant environmental media
• Data on the chemical composition and
mineralogy of environmental media
• Data on reactions between hydraulic fracturing
fluids and environmental media
• List of chemicals that may be mobilized during
hydraulic fracturing activities
2014
2014
2014
103
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Well Injection: What are the possible impacts of the injection and fracturing process on drinking water resources?
Secondary Question
Research Tasks
Potential Product(s)
Report
What are the chemical, physical, and
Analysis of Existing Data
toxicological properties of
• Compile information from existing literature
• List of naturally occurring substances that are
2012
substances in the subsurface that
on the identity of chemicals released from the
known to be mobilized during hydraulic
may be released by hydraulic
subsurface
fracturing activities and their associated
fracturing operations?
• Search existing databases for chemical,
chemical, physical, and toxicological properties
physical, and toxicological properties
• Identification of chemicals that may warrant
further toxicological analysis or analytical
method development
2012
Toxicological Analysis
• Identify chemicals currently undergoing
• Lists of high, low, and unknown priority for
2012
ToxCast Phase II testing
naturally occurring substances based on
• Predict chemical, physical, and toxicological
known or predicted toxicity data
properties based on chemical structure for
• Toxicological properties for up to six naturally
2014
chemicals with unknown properties (if any)
occurring substances that have no existing
• Identify up to six chemicals with unknown
toxicological information and are of high
toxicity values for ToxCast screening and
concern
PPRTV development (if any)
Laboratory Studies
• Identify or modify existing analytical methods
• Analytical methods for detecting selected
2012/14
for selected naturally occurring substances
naturally occurring substances released by
released by hydraulic fracturing
hydraulic fracturing
104
-------
EPA Hydraulic Fracturing Study Plan November 2011
TABLE A4. RESEARCH TASKS IDENTIFIED FOR FLOWBACK AND PRODUCED WATER
Flowback and Produced Water:
What are the possible impacts of surface spills on or near well pads of flowback and produced water on drinking water resources?
Secondary Question
Research Tasks
Potential Product(s)
Report
What is currently known about the
frequency, severity, and causes of
spills of flowback and produced
water?
Analysis of Existing Data
• Compile information on frequency, severity,
and causes of spills of flowback and produced
waters from existing data sources
• Data on the frequency, severity, and causes of
spills of flowback and produced waters
2012
What is the composition of hydraulic
fracturing wastewaters, and what
factors might influence this
composition?
Analysis of Existing Data
• Compile and analyze data submitted by nine
hydraulic fracturing service companies for
information on flowback and produced water
• Compile and analyze data submitted by nine
operators on the characterization of flowback
and produced waters
• Compile data from other sources, including
existing literature and state reports
• List of chemicals found in flowback and
produced water
• Information on distribution (range, mean,
median) of chemical concentrations
• Identification of factors that may influence the
composition of flowback and produced water
• Identification of constituents of concern
present in hydraulic fracturing wastewaters
2012
2012
2012
2012
Prospective Case Studies
• Collect time series samples of flowback and
produced water at locations in the Haynesville
and Marcellus shale plays
• Data on composition, variability, and quantity
of flowback and produced water as a function
of time
2014
What are the chemical, physical, and
toxicological properties of hydraulic
fracturing wastewater constituents?
Continued on next page
Analysis of Existing Data
• Search existing databases for chemical,
physical, and toxicological properties of
chemicals found in flowback and produced
water
• Prioritize list of chemicals based on their
known properties for (1) further toxicological
analysis or (2) to identify/modify existing
analytical methods
• List of flowback and produced water
constituents with known chemical, physical,
and toxicological properties
• Identification of 10-20 possible indicators to
track the fate and transport of hydraulic
fracturing wastewaters based on known
chemical, physical, and toxicological properties
• Identification of constituents that may be of
high concern, but have no or little existing
toxicological information
2012
2012
2012
105
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Flowback and Produced Water:
What are the possible impacts of surface spills on or near well pads offlowback and produced water on drinking water resources?
Secondary Question
Research Tasks
Potential Product(s)
Report
Continued from previous page
Toxicological Analysis
• Predict chemical, physical, and toxicological
• Lists of high, low, and unknown-priority
2012
What are the chemical, physical, and
properties based on chemical structure for
hydraulic fracturing chemicals based on known
toxicological properties of hydraulic
chemicals with unknown properties
or predicted toxicity data
fracturing wastewater constituents?
• Identify up to six hydraulic fracturing
wastewater constituents with unknown
toxicity values for ToxCast screening and
PPRTV development
• Toxicological properties for up to six hydraulic
fracturing wastewater constituents that have
no existing toxicological information and are of
high concern
2014
Laboratory Studies
• Identify or modify existing analytical methods
• Analytical methods for detecting hydraulic
2014
for selected hydraulic fracturing wastewater
fracturing wastewater constituents
constituents
If spills occur, how might hydraulic
Analysis of Existing Data
fracturing wastewaters contaminate
• Review existing scientific literature on surface
• Summary of existing research that describes
2012
drinking water resources?
chemical spills with respect to chemicals found
in hydraulic fracturing wastewaters or similar
compounds
the fate and transport of chemicals in
hydraulic fracturing wastewaters or similar
compounds
• Identification of knowledge gaps for future
research, if necessary
2012
Retrospective Case Studies
• Investigate hydraulic fracturing sites where
• Identification of impacts (if any) to drinking
2014
surface spills of hydraulic fracturing
water resources from surface spills of hydraulic
wastewaters have occurred (Wise and Denton
fracturing wastewaters
Counties, TX; Bradford and Susquehanna
• Identification of factors that led to impacts (if
2014
Counties, PA; Washington County, PA)
any) to drinking water resources resulting from
the accidental release of hydraulic fracturing
wastewaters
106
-------
EPA Hydraulic Fracturing Study Plan November 2011
TABLE A5. RESEARCH TASKS IDENTIFIED FOR WASTEWATER TREATMENT AND WASTE DISPOSAL
Wastewater Treatment and Waste Disposal:
What are the possible impacts of inadequate treatment of hydraulic fracturing wastewaters on drinking water resources?
Secondary Question
Research Tasks
Potential Product(s)
Report
What are the common treatment
and disposal methods for hydraulic
fracturing wastewaters, and where
are these methods practiced?
Analysis of Existing Data
• Gather information from well files requested
from nine well owners and operators on
treatment and disposal practices
• Nationwide data on recycling, treatment, and
disposal methods for hydraulic fracturing
wastewaters
2012
Prospective Case Studies
• Gather information on recycling, treatment, and
disposal practices in two different locations
(Haynesville and Marcellus Shale)
• Information on wastewater recycling,
treatment, and disposal practices at two
specific locations
2014
How effective are conventional
POTWs and commercial treatment
systems in removing organic and
inorganic contaminants of concern in
hydraulic fracturing wastewaters?
Analysis of Existing Data
• Gather existing data on the treatment
efficiency and contaminant fate and transport
through treatment trains applied to hydraulic
fracturing wastewaters
• Collection of analytical data on the efficacy of
existing treatment operations that treat
hydraulic fracturing wastewaters
• Identification of areas for further research
2014
2014
Laboratory Studies
• Pilot-scale studies on synthesized and actual
hydraulic fracturing wastewater treatability via
conventional POTW technology (e.g.
settling/activated sludge processes) and
commercial technologies (e.g. filtration, RO)
• Data on the fate and transport of hydraulic
fracturing water contaminants through
wastewater treatment processes, including
partitioning in treatment residuals
2014
Prospective Case Studies
• Collect data on the efficacy of any treatment
methods used in the case study
• Data on the efficacy of treatment methods used
in two locations
2014
107
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Wastewater Treatment and Waste Disposal:
What are the possible impacts of inadequate treatment of hydraulic fracturing wastewaters on drinking water resources?
Secondary Question
Research Tasks
Potential Product(s)
Report
What are the potential impacts from
surface water disposal of treated
hydraulic fracturing wastewater on
drinking water treatment facilities?
Laboratory Studies
• Conduct studies on the formation of
brominated DBPs during treatment of hydraulic
fracturing wastewaters
• Collect discharge and stream/river samples in
locations potentially impacted by hydraulic
fracturing wastewater discharge
• Data on the formation of brominated DBPs
from chlorination, chloramination, and
ozonation treatments
• Data on the inorganic species in hydraulic
fracturing wastewater and other discharge
sources that contribute similar species
• Contribution of hydraulic fracturing wastewater
to stream/river contamination
2012/14
2014
2014
Scenario Evaluation
• Develop a simplified generic scenario of an
idealized river with generalized inputs and
receptors
• Develop watershed-specific versions of the
simplified scenario using location-specific data
and constraints
• Identification of parameters that generate or
mitigate drinking water exposure
• Data on potential impacts in the Monongahela,
Allegheny, or Susquehanna River networks
2012
2014
108
-------
EPA Hydraulic Fracturing Study Plan November 2011
TABLE A6. RESEARCH TASKS IDENTIFIED FOR ENVIRONMENTAL JUSTICE
Environmental Justice: Does hydraulic fracturing disproportionately occur in or near communities with environmental justice concerns?
Secondary Question
Research Tasks
Potential Product(s)
Report
Are large volumes of water being
Analysis of Existing Data
disproportionately withdrawn from
• Compare data on locations of source water
• Maps showing locations of source water
2012
drinking water resources that serve
withdrawals to demographic information (e.g.,
withdrawals and demographic data
communities with environmental
race/ethnicity, income, and age)
• Identification of areas where there may be a
2012
justice concerns?
disproportionate co-localization of large
volume water withdrawals for hydraulic
fracturing and communities with
environmental justice concerns
Prospective Case Studies
• Analyze demographic profiles of communities
• Illustrative information on the types of
2014
located near the case study locations
communities where hydraulic fracturing occurs
Are hydraulically fractured oil and
Analysis of Existing Data
gas wells disproportionately located
• Compare data on locations of hydraulically
• Maps showing locations of hydraulically
2012
near communities with
fractured oil and gas wells to demographic
fractured wells (subject to CBI rules) and
environmental justice concerns?
information (e.g., race/ethnicity, income, and
demographic data
age)
• Identification of areas where there may be a
disproportionate co-localization of hydraulic
fracturing well sites and communities with
environmental justice concerns
2012
Retrospective and Prospective Case Studies
• Analyze demographic profiles of communities
• Illustrative information on the types of
2014
located near the case study locations
communities where hydraulic fracturing occurs
Is wastewater from hydraulic
Analysis of Existing Data
fracturing operations being
• Compare data on locations of hydraulic
• Maps showing locations of wastewater
2012
disproportionately treated or
fracturing wastewater disposal to demographic
disposal and demographic data
disposed of (via POTWs or
information (e.g., race/ethnicity, income, and
• Identification of areas where there may be a
2012
commercial treatment systems) in or
age)
disproportionate co-localization of wastewater
near communities with
disposal and communities with environmental
environmental justice concerns?
justice concerns
Prospective Case Studies
• Analyze demographic profiles of communities
• Illustrative information on the types of
2014
located near the case study locations
communities where hydraulic fracturing occurs
109
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Appendix B: Stakeholder Comments
In total, EPA received 5,521 comments that were submitted electronically to
hydraulic.fracturing@epa.gov or mailed to EPA. This appendix provides a summary of those comments.
More than half of the electronic comments received consisted of a form letter written by
Energycitizens.org14 and sent by citizens. This letter states that "Hydraulic fracturing has been used
safely and successfully for more than six decades to extract natural gas from shale and coal deposits. In
this time, there have been no confirmed incidents of groundwater contamination caused by the
hydraulic fracturing process." Additionally, the letter states that protecting the environment "should not
lead to the creation of regulatory burdens or restrictions that have no valid scientific basis." EPA has
interpreted this letter to mean that the sender supports hydraulic fracturing and does not support the
need for additional study.
Table B1 provides an overall summary of the 5,521 comments received15.
TABLE Bl. SUMMARY OF STAKEHOLDER COMMENTS
Percentage of
Percentage of
Stakeholder Comments
Comments
Comments
(w/ Form Letter)
(w/o Form Letter)
Position on Study Plan
For
18.2
63.2
Opposed
72.1
3.0
No Position
9.7
33.8
Expand Study
8.8
30.5
Limit Study
0.7
2.5
Position on Hydraulic Fracturing
For
75.7
15.7
Opposed
11.6
40.3
No Position
12.7
44.1
Table B2 further provides the affiliations (i.e., citizens, government, industry) associated with the
stakeholders, and indicates that the majority of comments EPA received came from citizens.
14 Energy Citizens is financially sponsored by API, as noted at http://energycitizens.org/ec/advocacy/content-
rail.aspx?ContentPage=About.
15 Comments may be found at
http://yosemite.epa.gov/sab/SABPRODUCT.NSF/81e39f4c09954fcb85256ead006be86e/d3483ab445ae614185257
75900603e79!OpenDocument&TableRow=2.2#2
110
-------
EPA Hydraulic Fracturing Study Plan November 2011
TABLE B2. SUMMARY OF COMMENTS ON HYDRAULIC FRACTURING AND RELATED STUDY PLAN
Category
Percentage of
Comments
(w/ Form Letter)
Percentage of
Comments
(w/o Form Letter)
Association
0.24
0.82
Business association
0.69
2.39
Citizen
23.47
81.56
Citizen (form letter Energycitizens.org)
71.22
NA
Elected official
0.18
0.63
Environmental
1.10
3.84
Federal government
0.07
0.25
Lobbying organization
0.04
0.13
Local government
0.62
2.14
Oil and gas association
0.09
0.31
Oil and gas company
0.38
1.32
Political group
0.16
0.57
Private company
0.78
2.71
Scientific organization
0.02
0.06
State government
0.13
0.44
University
0.24
0.82
Water utility
0.02
0.06
Unknown
0.56
1.95
Table B3 provides a summary of the frequent research areas requested in the stakeholder comments.
TABLE B3. FREQUENT RESEARCH AREAS REQUESTED IN STAKEHOLDER COMMENTS
Research Area
Number of
Requests*
Ground water
292
Surface water
281
Air pollution
220
Water use (source of water used)
182
Flowback treatment/disposal
170
Public health
165
Ecosystem effects
160
Toxicity and chemical identification
157
Chemical fate and transport
107
Radioactivity issues
74
Seismic issues
36
Noise pollution
26
* Out of 485 total requests to expand the hydraulic fracturing study.
Ill
-------
EPA Hydraulic Fracturing Study Plan
November 2011
In addition to the frequently requested research areas, there were a variety of other comments and
recommendations related to potential research areas. These comments and recommendations are listed
below:
• Abandoned and undocumented wells
• Auto-immune diseases related to hydraulic fracturing chemicals
• Bioaccumulation of hydraulic fracturing chemicals in the food chain
• Biodegradable/nontoxic fracturing liquids
• Carbon footprint of entire hydraulic fracturing process
• Comparison of accident rates to coal/oil mining accident rates
• Disposal of drill cuttings
• Effects of aging on well integrity
• Effects of hydraulic fracturing on existing public and private wells
• Effects of truck/tanker traffic
• Effects on local infrastructure (e.g., roads, water treatment plants)
• Effects on tourism
• Hydraulic fracturing model
• Economic impacts on landowners
• Land farming on fracturing sludge
• Light pollution
• Long-term corrosive effects of brine and microbes on well pipes
• Natural flooding near hydraulic fracturing operations
• Radioactive proppants
• Recovery time and persistence of hydraulic fracturing chemicals in contaminated aquifers
• Recycling of flowback and produced water
• Removal of radium and other radionuclides from flowback and produced water
• Restoration of drill sites
• Review current studies of hydraulic fracturing with microseismic testing
• Sociological effects (e.g., community changes with influx of workers)
• Soil contamination at drill sites
• Volatile organic compound emissions from hydraulic fracturing operations and impoundments
• Wildlife habitat fragmentation
• Worker occupational health
112
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Appendix C: Department of Energy's Efforts on Hydraulic Fracturing
DOE has invested in research on safer hydraulic fracturing techniques, including research related to well
integrity, greener additives, risks from abandoned wells, possible seismic impacts, water treatment and
recycling, and fugitive methane emissions.
DOE's experience includes quantifying and evaluating potential risks resulting from the production and
development of shale gas resources, including multi-phase flow in wells and reservoirs, well control,
casing, cementing, drilling fluids, and abandonment operations associated with drilling, completion,
stimulation, and production operations. DOE also has experience in evaluating seal-integrity and
wellbore-integrity characteristics in the context of the protection of groundwater.
DOE has developed a wide range of new technologies and processes, including innovations that reduce
the environmental impact of exploration and production, such as greener chemicals or additives used in
shale gas development, flowback water treatment processes and water filtration technologies. Data
from these research activities may assist decision-makers.
DOE has developed and evaluated novel imaging technologies for areal magnetic surveys for the
detection of unmarked abandoned wells, and for detecting and measuring fugitive methane emissions
from exploration, production, and transportation facilities. DOE also conducts research in produced
water characterization, development of shale formation fracture models, development of microseismic
and isotope-based comprehensive monitoring tools, and development of integrated assessment models
to predict geologic behavior during the evolution of shale gas plays. DOE's experience in engineered
underground containment systems for C02 storage and enhanced geothermal systems also brings
capabilities that are relevant to the challenges of safe shale gas production.
As part of these efforts, EPA and DOE are working together on a prospective case study located in the
Marcellus Shale region that leverages DOE's capabilities in field-based monitoring of environmental
signals. DOE is conducting soil gas surveys, hydraulic fracturing tracer studies, and electromagnetic
induction surveys to identify possible migration of natural gas, completion fluids, or production fluids.
Monitoring activities will continue throughout the development of the well pad, and during hydraulic
fracturing and production of shale gas at the site. The Marcellus Test Site is undergoing a comprehensive
monitoring plan, including potential impacts to drinking water resources.
More information can be found on the following websites:
• http://www.fe.doe.gov/programs/oilgas/index.html
• http://www.netl.doe.gov/technologies/oil-gas/index.html
• http://www.netl.doe.gov/kmd/Forms/Search.aspx
• http://ead.anl.gov/index.cfm
• http://wwwl.eere.energy.gov/geothermal/
113
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Appendix D: Information Requests
Request to hydraulic fracturing service companies. In September 2010, EPA issued information requests
to nine hydraulic fracturing service companies to collect data that will inform this study. The requests
were sent to the following companies: BJ Services, Complete Well Services, Halliburton, Key Energy
Services, Patterson-UTI, RPC, Schlumberger, Superior Well Services, and Weatherford. These companies
are a subset of those from which the House Committee on Energy and Commerce requested comment.
Halliburton, Schlumberger, and BJ Services are the three largest companies operating in the US; the
others are companies of varying size that operate in the major US shale plays. EPA sought information
on the chemical composition of fluids used in the hydraulic fracturing process, data on the impacts of
the chemicals on human health and the environment, standard operating procedures at hydraulic
fracturing sites and the locations of sites where fracturing has been conducted. EPA sent a mandatory
request to Halliburton on November 9, 2010, to compel Halliburton to provide the requested
information. All companies have submitted the information.
The questions asked in the voluntary information request are stated below.
QUESTIONS
Your response to the following questions is requested within thirty (30) days of receipt of this
information request:
1. Provide the name of each hydraulic fracturing fluid formulation/mixture distributed or utilized
by the Company within the past five years from the date of this letter. For each
formulation/mixture, provide the following information for each constituent of such product.
"Constituent" includes each and every component of the product, including chemical
substances, pesticides, radioactive materials and any other components.
a. Chemical name (e.g., benzene—use IUPAC nomenclature);
b. Chemical formula (e.g., C6H6);
c. Chemical Abstract System number (e.g., 71-43-2);
d. Material Safety Data Sheet;
e. Concentration (e.g., ng/g or ng/L) of each constituent in each hydraulic fracturing fluid
product. Indicate whether the concentration was calculated or determined analytically.
This refers to the actual concentration injected during the fracturing process following
mixing with source water, and the delivered concentration of the constituents to the
site. Also indicate the analytical method which may be used to determine the
concentration (e.g., SW-846 Method 8260, in-house SOP), and include the analytical
preparation method (e.g., SW-846 Method 5035), where applicable;
f. Identify the persons who manufactured each product and constituent and the persons
114
-------
EPA Hydraulic Fracturing Study Plan
November 2011
who sold them to the Company, including address and telephone numbers for any such
persons;
g. Identify the purpose and use of each constituent in each hydraulic fracturing fluid
product (e.g., solvent, gelling agent, carrier);
h. For proppants, identify the proppant, whether or not it was resin coated, and the
materials used in the resin coating;
i. For the water used, identify the quantity, quality and the specifications of water needed
to meet site requirements, and the rationale for the requirements;
j. Total quantities of each constituent used in hydraulic fracturing and the related quantity
of water in which the chemicals were mixed to create the fracturing fluids to support
calculated and/or measured composition and properties of the hydraulic fracturing
fluids; and
k. Chemical and physical properties of all chemicals used, such as Henry's law coefficients,
partitioning coefficients (e.g., Kow K0c, Kd), aqueous solubility, degradation products and
constants and others.
2. Provide all data and studies in the Company's possession relating to the human health and
environmental impacts and effects of all products and constituents identified in Question 1.
3. For all hydraulic fracturing operations for natural gas extraction involving any of the products
and constituents identified in the response to Question 1, describe the process including the
following:
a. Please provide any policies, practices and procedures you employ, including any
Standard Operating Procedures (SOPs) concerning hydraulic fracturing sites, for all
operations including but not limited to: drilling in preparation for hydraulic fracturing
including calculations or other indications for choice and composition of drilling
fluids/muds; water quality characteristics needed to prepare fracturing fluids-
relationships among depth, pressure, temperature, formation geology, geophysics and
chemistry and fracturing fluid composition and projected volume; determination of
estimated volumes of flowback and produced waters; procedures for managing
flowback and produced waters; procedures to address unexpected circumstances such
as loss of drilling fluid/mud, spills, leaks or any emergency conditions (e.g., blow outs),
less than fully effective well completion; modeling and actual choice of fracturing
conditions such as pressures, temperatures, and fracturing material choices;
determination of exact concentration of constituents in hydraulic fracturing fluid
formulations/mixtures; determination of dilution ratios for hydraulic fracturing fluids,
and
b. Describe how fracturing fluid products and constituents are modified at a site during the
115
-------
EPA Hydraulic Fracturing Study Plan
November 2011
fluid injection process.
a. Identify all sites where, and all persons to whom, the Company:
i. provided hydraulic fracturing fluid services that involve the use of hydraulic
fracturing fluids for the year prior to the date of this letter, and
ii. plans to provide hydraulic fracturing fluid services that involve the use of
hydraulic fracturing fluids during one year after the date of this letter.
b. Describe the specific hydraulic fracturing fluid services provided or to be provided for
each of the sites in Question 4.a.i. and ii., including the identity of any contractor that
the Company has hired or will hire to provide any portion of such services.
For each site identified in response to Question 4, please provide all information specified in the
enclosed electronic spreadsheet.
Request to Oil and Gas Operators. On August 11, 2011, EPA sent letters to nine companies that own or
operate oil and gas wells requesting their voluntary participation in EPA's hydraulic fracturing study.
Clayton Williams Energy, Conoco Phillips, EQT Production, Hogback Exploration, Laramie Energy II, MDS
Energy, Noble Energy, Sand Ridge Operating, and Williams Production were randomly selected from a
list of operators derived from the information gathered from the September 2010 letter to hydraulic
fracturing service companies. The companies were asked to provide data on well construction, design,
and well operation practices for 350 oil and gas wells that were hydraulically fractured from 2009 to
2010. EPA made this request as part of its national study to examine the potential impacts of hydraulic
fracturing on drinking water resources. As of October 31, 2011, all nine companies have agreed to assist
EPA and are currently sending or have completed sending their information.
The wells were selected using a stratified random method and reflect diversity in both geography and
size of the oil and gas operator. To identify the wells for this request, the list of operators was sort in
order by those with the most wells to those with the fewest wells. EPA defined operators to be "large" if
their combined number of wells accounted for the top 50 percent of wells on the list, "medium" if their
combined number of wells accounted for the next 25 percent of wells on the list and "small" if their
number of wells were among the last 25 percent of wells on the list. To minimize potential burden on
the smallest operators, all operators with nine wells or less were removed from consideration for
selection. Then, using a map from the U.S. Energy Information Administration showing all shale gas plays
(Figure 3), EPA classified four different areas of the nation: East, South, Rocky Mountain (including
California) and Other. To choose the nine companies that received the request, EPA randomly selected
one "large" operator from each geographic area, for a total of four "large" operators, and then
randomly, and without geographic consideration, selected two "medium" and three "small" operators.
Once the nine companies were identified, we used a computer algorithm that balanced geographic
diversity and random selection within an operator's list to select 350 wells.
116
-------
EPA Hydraulic Fracturing Study Plan
The questions asked in the letters were as follows:
November 2011
Your response to the following questions is requested within thirty (30) days of receipt of this
information request:
For each well listed in Enclosure 5 of this letter, provide any and all of the following information:
Geologic Maps and Cross Sections
1. Prospect geologic maps of the field or area where the well is located. The map should
depict, to the extent known, the general field area, including the existing production wells
within the field, preferably showing surface and bottom-hole locations, names of
production wells, faults within the area, locations of delineated source water protection
areas, and geologic structure.
2. Geologic cross section(s) developed for the field in order to understand the geologic
conditions present at the wellbore, including the directional orientation of each cross
section such as north, south, east, and west.
Drilling and Completion Information
3. Daily drilling and completion records describing the day-by-day account and detail of drilling
and completion activities.
4. Mud logs displaying shows of gas or oil, losses of circulation, drilling breaks, gas kicks, mud
weights, and chemical additives used.
5. Caliper, density, resistivity, sonic, spontaneous potential, and gamma logs.
6. Casing tallies, including the number, grade, and weight of casing joints installed.
7. Cementing records for each casing string, which are expected to include the type of cement
used, cement yield, and wait-on-cement times.
8. Cement bond logs, including the surface pressure during each logging run, and cement
evaluation logs, radioactive tracer logs or temperature logs, if available.
9. Pressure testing results of installed casing.
10. Up-to-date wellbore diagram.
Water Quality, Volume, and Disposition
11. Results from any baseline water quality sampling and analyses of nearby surface or
groundwater prior to drilling.
12. Results from any post-drilling and post-completion water quality sampling and analyses of
nearby surface or groundwater.
13. Results from any formation water sampling and analyses, including data on composition,
depth sampled, and date collected.
14. Results from chemical, biological, and radiological analyses of "flowback," including date
sampled and cumulative volume of "flowback" produced since fracture stimulation.
117
-------
EPA Hydraulic Fracturing Study Plan
November 2011
15. Results from chemical, biological, and radiological analyses of "produced water," including
date sampled and cumulative volume of "produced water" produced since fracture
stimulation.
16. Volume and final disposition of "flowback."
17. Volume and final disposition of "produced water."
18. If any of the produced water or flowback fluids were recycled, provide information,
including, but not limited to, recycling procedure, volume of fluid recycled, disposition of
any recycling waste stream generated, and what the recycled fluids were used for.
Hydraulic Fracturing
19. Information about the acquisition of the base fluid used for fracture stimulation, including,
but not limited to, its total volume, source, and quality necessary for successful stimulation.
If the base fluid is not water, provide the chemical name(s) and CAS number(s) of the base
fluid.
20. Estimate of fracture growth and propagation prior to hydraulic fracturing. This estimate
should include modeling inputs (e.g., permeability, Young's modulus, Poisson's ratio) and
outputs (e.g., fracture length, height, and width).
21. Fracture stimulation pumping schedule or plan, which would include the number, length,
and location of stages; perforation cluster spacings; and the stimulation fluid to be used,
including the type and respective amounts of base fluid, chemical additives and proppants
planned.
22. Post-fracture stimulation report containing, but not limited to, a chart showing all pressures
and rates monitored during the stimulation; depths stimulated; number of stages employed
during stimulation; calculated average width, height, and half-length of fractures; and
fracture stimulation fluid actually used, including the type and respective amounts of base
fluid, chemical additives and proppants used.
23. Micro-seismic monitoring data associated with the well(s) listed in Enclosure 5, or
conducted in a nearby well and used to set parameters for hydraulic fracturing design.
Environmental Releases
24. Spill incident reports for any fluid spill associated with this well, including spills by vendors
and service companies. This information should include, but not be limited to, the volume
spilled, volume recovered, disposition of any recovered volume, and the identification of
any waterways or groundwater that was impacted from the spill and how this is known.
118
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Appendix E: Chemicals Identified in Hydraulic Fracturing Fluid and
Flowback/Produced Water
NOTE: In all tables in Appendix E, the chemicals are primarily listed as identified in the cited reference.
Due to varying naming conventions or errors in reporting, there may be some duplicates or inaccurate
names. Some effort has been made to eliminate errors, but further evaluation will be conducted as part
of the study analysis.
TABLE El. CHEMICALS FOUND IN HYDRAULIC FRACTURING FLUIDS
Chemical Name Use Ref.
l-(l-naphthylmethyl)quinolinium chloride
12
l-(phenylmethyl)-ethyl pyridinium, methyl derive.
Acid corrosion inhibitor
1,6,13
1,1,1-Trifluorotoluene
7
l,l':3',l"-Terphenyl
8
l,l':4',l"-Terphenyl
8
1,1-Dichloroethylene
7
1,2,3-Propanetricarboxylic acid, 2-hydroxy-, trisodium
12,14
salt, dihydrate
1,2,3-Trimethylbenzene
12, 14
1,2,4-Butanetricarboxylic acid, 2-phosphono-
12,14
1,2,4-Trimethylbenzene
Non-ionic surfactant
5,10,12,13,14
l,2-Benzisothiazolin-3-one
7,12,14
l,2-Dibromo-2,4-dicyanobutane
12,14
1,2-Ethanediaminium, N, N'-bis[2-[bis(2-
12
hydroxyethyl)methylammonio]ethyl]-N,N'bis(2-
hydroxyethyl)-N,N'-dimethyl-,tetrachloride
1,2-Propylene glycol
8,12,14
1,2-Propylene oxide
12
l,3,5-Triazine-l,3,5(2H,4H,6H)-triethanol
12,14
1,3,5-Trimethylbenzene
12,14
1,4-Dichlorobutane
7
1,4-Dioxane
7,14
1,6 Hexanediamine
Clay control
13
1,6-Hexanediamine
8,12
1,6-Hexanediamine dihydrochloride
12
l-[2-(2-Methoxy-l-methylethoxy)-l-methylethoxy]-2-
13
propanol
1-3-Dimethyladamantane
8
1-Benzylquinolinium chloride
Corrosion inhibitor
7,12,14
1-Butanol
7,12,14
1-Decanol
12
1-Eicosene
7,14
1-Hexadecene
7,14
1-Hexanol
12
l-Methoxy-2-propanol
7,12,14
1-Methylnaphthalene
1
Table continued on next page
119
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
1-Octadecanamine, N,N-dimethyl-
12
1-Octadecene
7,14
1-Octanol
12
1-Propanaminium, 3-amino-N-(carboxymethyl)-N,N-
12
dimethyl-, N-coco acyl derivs., chlorides, sodium salts
1-Propanaminium, 3-amino-N-(carboxymethyl)-N,N-
7,12,14
dimethyl-, N-coco acyl derivs., inner salts
1-Propanaminium, N-(3-aminopropyl)-2-hydroxy-N,N-
7,12,14
dimethyl-3-sulfo-, N-coco acyl derivs., inner salts
1-Propanesulfonic acid, 2-methyl-2-[(l-oxo-2-
7,14
propenyl)amino]-
1-Propanol
Crosslinker
10,12,14
1-Propene
13
1-Tetradecene
7,14
1-Tridecanol
12
1-Undecanol
Surfactant
13
2-(2-Butoxyethoxy)ethanol
Foaming agent
1
2-(2-Ethoxyethoxy)ethyl acetate
12,14
2-(Hydroxymethylamino)ethanol
12
2-(Thiocyanomethylthio)benzothiazole
Biocide
13
2,2'-(Octadecylimino)diethanol
12
2,2,2-Nitrilotriethanol
8
2,2'-[Ethane-l,2-diylbis(oxy)]diethanamine
12
2,2'-Azobis-{2-(imidazlin-2-yl)propane dihydrochloride
7,14
2,2-Dibromo-3-nitrilopropionamide
Biocide
1,6,7,9,10,12,14
2,2-Dibromopropanediamide
7,14
2,4,6-Tribromophenol
7
2,4-Dimethylphenol
4
2,4-Hexadienoic acid, potassium salt, (2E,4E)-
7,14
2,5 Dibromotoluene
7
2-[2-(2-Methoxyethoxy)ethoxy]ethanol
8
2-acrylamido-2-methylpropanesulphonic acid sodium
12
salt polymer
2-acrylethyl(benzyl)dimethylammonium Chloride
7,14
2-bromo-3-nitrilopropionamide
Biocide
1,6
2-Butanone oxime
12
2-Butoxyacetic acid
8
2-Butoxyethanol
Foaming agent, breaker
fluid
1,6,9,12,14
2-Butoxyethanol phosphate
8
2-Di-n-butylaminoethanol
12,14
2-Ethoxyethanol
Foaming agent
1,6
2-Ethoxyethyl acetate
Foaming agent
1
2-Ethoxynaphthalene
7,14
2-Ethyl-l-hexanol
5,12,14
2-Ethyl-2-hexenal
Defoamer
13
2-Ethylhexanol
9
2-Fluorobiphenyl
7
Table continued on next page
120
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
2-Fluorophenol
7
2-Hydroxyethyl acrylate
12,14
2-Mercaptoethanol
12
2-Methoxyethanol
Foaming agent
1
2-Methoxyethyl acetate
Foaming agent
1
2-Methyl-l-propanol
Fracturing fluid
12,13,14
2-Methyl-2,4-pentanediol
12,14
2-Methyl-3(2H)-isothiazolone
Biocide
12,13
2-Methyl-3-butyn-2-ol
7,14
2-Methylnaphthalene
1
2-Methylquinoline hydrochloride
7,14
2-Monobromo-3-nitrilopropionamide
Biocide
10,12,14
2-Phosphonobutane-l,2,4-tricarboxylic acid, potassium
12
salt
2-Propanol, aluminum salt
12
2-Propen-l-aminium, N,N-dimethyl-N-2-propenyl-,
7,14
chloride
2-Propen-l-aminium, N,N-dimethyl-N-2-propenyl-,
7,14
chloride, homopolymer
2-Propenoic acid, polymer with sodium phosphinate
7,14
2-Propenoic acid, telomer with sodium hydrogen sulfite
7,14
2-Propoxyethanol
Foaming agent
1
2-Substituted aromatic amine salt
12,14
3,5,7-Triazatricyclo(3.3.1.1(superscript 3,7))decane, 1-
7,14
(3-chloro-2-propenyl)-, chloride, (Z)-
3-Bromo-l-propanol
Microbiocide
1
4-(l,l-Dimethylethyl)phenol, methyloxirane,
7,14
formaldehyde polymer
4-Chloro-3-methylphenol
4
4-Dodecylbenzenesulfonic acid
7,12,14
4-Ethyloct-l-yn-3-ol
Acid inhibitor
5,12,14
4-Methyl-2-pentanol
12
4-Methyl-2-pentanone
5
4-Nitroquinoline-l-oxide
7
4-Terphenyl-dl4
7
(4R)-l-methyl-4-(prop-l-en-2-yl)cyclohexene
5,12,14
5-Chloro-2-methyl-3(2H)-isothiazolone
Biocide
12,13,14
6-Methylquinoline
8
Acetaldehyde
12,14
Acetic acid
Acid treatment, buffer
5,6,9,10,12,14
Acetic acid, cobalt(2+) salt
12,14
Acetic acid, hydroxy-, reaction products with
14
triethanolamine
Acetic anhydride
5,9,12,14
Acetone
Corrosion Inhibitor
5,6,12,14
Acetonitrile, 2,2',2"-nitrilotris-
12
Acetophenone
12
Table continued on next page
121
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Acetylene
9
Acetylenic alcohol
12
Acetyltriethyl citrate
12
Acrolein
Biocide
13
Acrylamide
7,12,14
Acrylamide copolymer
12
Acrylamide-sodium acrylate copolymer
7,14
Acrylamide-sodium-2-acrylamido-2-methlypropane
sulfonate copolymer
Gelling agent
7,12,14
Acrylate copolymer
12
Acrylic acid/2-acrylamido-methylpropylsulfonic acid
copolymer
12
Acrylic copolymer
12
Acrylic polymers
12,14
Acrylic resin
14
Acyclic hydrocarbon blend
12
Adamantane
8
Adipic acid
Linear gel polymer
6,12,14
Alcohol alkoxylate
12
Alcohols
12,14
Alcohols, Cll-14-iso-, C13-rich
7,14
Alcohols, C9-C22
12
Alcohols; C12-14-secondary
12,14
Aldehyde
Corrosion inhibitor
10,12,14
Aldol
12,14
Alfa-alumina
12,14
Aliphatic acids
7,12,14
Aliphatic alcohol glycol ether
14
Aliphatic alcohol polyglycol ether
12
Aliphatic amine derivative
12
Aliphatic hydrocarbon (naphthalenesulfonic acide,
sodium salt, isopropylated)
Surfactant
13
Alkaline bromide salts
12
Alkalinity
13
Alkanes, CIO-14
12
Alkanes, Cl-2
4
Alkanes, C12-14-iso-
14
Alkanes, C13-16-iso-
12
Alkanes, C2-3
4
Alkanes, C3-4
4
Alkanes, C4-5
4
Alkanolamine/aldehyde condensate
12
Alkenes
12
Alkenes, C>10 .alpha.-
7,12,14
Alkenes, C>8
12
Alkoxylated alcohols
12
Alkoxylated amines
12
Alkoxylated phenol formaldehyde resin
12,14
Table continued on next page
122
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Alkyaryl sulfonate
12
Alkyl alkoxylate
12,14
Alkyl amine
12
Alkyl amine blend in a metal salt solution
12,14
Alkyl aryl amine sulfonate
12
Alkyl aryl polyethoxy ethanol
7,14
Alkyl esters
12,14
Alkyl hexanol
12,14
Alkyl ortho phosphate ester
12
Alkyl phosphate ester
12
Alkyl quaternary ammonium chlorides
12
Alkyl* dimethyl benzyl ammonium chloride
*(61% C12, 23% C14, 11% C16, 2.5% C18 2.5% CIO and trace of C8)
Corrosion inhibitor
7
Alkylaryl sulfonate
7,12,14
Alkylaryl sulphonic acid
12
Alkylated quaternary chloride
12,14
Alkylbenzenesulfonate, linear
Foaming agent
5,6,12
Alkylbenzenesulfonic acid
9,12,14
Alkylethoammonium sulfates
12
Alkylphenol ethoxylates
12
Almandite and pyrope garnet
12,14
Alpha-Cll-15-sec-alkyl-omega-hydroxypoly(oxy-l,2-
ethanediyl)
12
Alpha-Terpineol
8
Alumina
Proppant
12,13,14
Aluminium chloride
7,12,14
Aluminum
Crosslinker
4,6,12,14
Aluminum oxide
12,14
Aluminum oxide silicate
12
Aluminum silicate
Proppant
13,14
Aluminum sulfate
12,14
Amides, coco, N-[3-(dimethylamino)propyl]
12,14
Amides, coco, N-[3-(dimethylamino)propyl], alkylation
products with chloroacetic acid, sodium salts
12
Amides, coco, N-[3-(dimethylamino)propyl], N-oxides
7,12,14
Amides, tall-oil fatty, N,N-bis(hydroxyethyl)
7,14
Amides, tallow, n-[3-(dimethylamino)propyl],n-oxides
12
Amidoamine
12
Amine
12,14
Amine bisulfite
12
Amine oxides
12
Amine phosphonate
12
Amine salt
12
Amines, C14-18; C16-18-unsaturated, alkyl, ethoxylated
12
Amines, C8-18 and C18-unsatd. alkyl
Foaming agent
5
Amines, coco alkyl, acetate
12
Amines, coco alkyl, ethoxylated
14
Table continued on next page
123
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Amines, polyethylenepoly-, ethoxylated,
phosphonomethylated
12
Amines, tallow alkyl, ethoxylated, acetates (salts)
12,14
Amino compounds
12
Amino methylene phosphonic acid salt
12
Aminotrimethylene phosphonic acid
12
Ammonia
9,11,12,14
Ammonium acetate
Buffer
5,10,12,14
Ammonium alcohol ether sulfate
7,12,14
Ammonium bifluoride
9
Ammonium bisulfite
Oxygen scavenger
3,9,12,14
Ammonium C6-C10 alcohol ethoxysulfate
12
Ammonium C8-C10 alkyl ether sulfate
12
Ammonium chloride
Crosslinker
1,6,10,12,14
Ammonium citrate
7,14
Ammonium fluoride
12,14
Ammonium hydrogen carbonate
12,14
Ammonium hydrogen difluoride
12,14
Ammonium hydrogen phosphonate
14
Ammonium hydroxide
7,12,14
Ammonium nitrate
7,12,14
Ammonium persulfate
Breaker fluid
1,6,9
Ammonium salt
12,14
Ammonium salt of ethoxylated alcohol sulfate
12,14
Ammonium sulfate
Breaker fluid
5,6,12,14
Amorphous silica
9,12,14
Anionic copolymer
12,14
Anionic polyacrylamide
12,14
Anionic polyacrylamide copolymer
Friction reducer
5,6,12
Anionic polymer
12,14
Anionic polymer in solution
12
Anionic surfactants
Friction reducer
5,6
Anionic water-soluble polymer
12
Anthracene
4
Antifoulant
12
Antimonate salt
12,14
Antimony
7
Antimony pentoxide
12
Antimony potassium oxide
12,14
Antimony trichloride
12
Aromatic alcohol glycol ether
12
Aromatic aldehyde
12
Aromatic hydrocarbons
13,14
Aromatic ketones
12,14
Aromatic polyglycol ether
12
Aromatics
1
Arsenic
4
Arsenic compounds
14
Table continued on next page
124
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Ashes, residues
14
Atrazine
8
Attapulgite
Gelling agent
13
Barium
4
Barium sulfate
5,12,14
Bauxite
Proppant
12,13,14
Bentazone
8
Bentone clay
14
Bentonite
Fluid additives
5,6,12,14
Bentonite, benzyl(hydrogenated tallow alkyl)
14
dimethylammonium stearate complex
Benzalkonium chloride
14
Benzene
Gelling agent
1,12,14
Benzene, l,l'-oxybis-, tetrapropylene derivs.,
14
sulfonated, sodium salts
Benzene, C10-16-alkyl derivs.
12
Benzenesulfonic acid, (1-methylethyl)-, ammonium salt
7,14
Benzenesulfonic acid, C10-16-alkyl derivs.
12,14
Benzenesulfonic acid, C10-16-alkyl derivs., potassium
12,14
salts
Benzo(a)pyrene
4
Benzoic acid
9,12,14
Benzyl chloride
12
Benzyl-dimethyl-(2-prop-2-enoyloxyethyl)ammonium
8
chloride
Benzylsuccinic acid
8
Beryllium
11
Bicarbonate
7
Bicine
12
Biocide component
12
Bis(l-methylethyl)naphthalenesulfonic acid,
12
cyclohexylamine salt
Bis(2-methoxyethyl) ether
Foaming Agent
1
Bishexamethylenetriamine penta methylene
12
phosphonic acid
Bisphenol A
8
Bisphenol A/Epichlorohydrin resin
12,14
Bisphenol A/Novolac epoxy resin
12,14
Blast furnace slag
Viscosifier
13,14
Borate salts
Crosslinker
3,12,14
Borax
Crosslinker
1,6,12,14
Boric acid
Crosslinker
1,6,9,12,14
Boric acid, potassium salt
12,14
Boric acid, sodium salt
9,12
Boric oxide
7,12,14
Boron
4
Boron sodium oxide
12,14
Boron sodium oxide tetrahydrate
12,14
Table continued on next page
125
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Bromide (-1)
7
Bromodichloromethane
7
Bromoform
7
Bronopol
Microbiocide
5,6,12,14
Butane
5
Butanedioic acid, sulfa-, l,4-bis(l,3-dimethylbutyl)
ester, sodium salt
12
Butyl glycidyl ether
12,14
Butyl lactate
12,14
C.I. Pigment orange 5
14
C10-C16 ethoxylated alcohol
Surfactant
12,13,14
C-ll to C-14 n-alkanes, mixed
12
C12-14-tert-alkyl ethoxylated amines
7,14
Cadmium
4
Cadmium compounds
13,14
Calcium
4
Calcium bromide
14
Calcium carbonate
12,14
Calcium chloride
7,9,12,14
Calcium dichloride dihydrate
12,14
Calcium fluoride
12
Calcium hydroxide
pH control
12,13,14
Calcium hypochlorite
12,14
Calcium oxide
Proppant
9,12,13,14
Calcium peroxide
12
Calcium sulfate
Gellant
13,14
Carbohydrates
5,12,14
Carbon
14
Carbon black
Resin
13,14
Carbon dioxide
Foaming agent
5,6,12,14
Carbonate alkalinity
7
Carbonic acid calcium salt (1:1)
pH control
12,13
Carbonic acid, dipotassium salt
12,14
Carboxymethyl cellulose
8
Carboxymethyl guar gum, sodium salt
12
Carboxymethyl hydroxypropyl guar
9,12,14
Carboxymethylguar
Linear gel polymer
6
Carboxymethylhydroxypropylguar
Linear gel polymer
6
Cationic polymer
Friction reducer
5,6
Caustic soda
13,14
Caustic soda beads
13,14
Cellophane
12,14
Cellulase enzyme
12
Cellulose
7,12,14
Cellulose derivative
12,14
Ceramic
13,14
Cetyl trimethyl ammonium bromide
12
CFR-3
14
Table continued on next page
126
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Chloride
4
Chloride (-1)
14
Chlorine
Lubricant
13
Chlorine dioxide
7,12,14
Chlorobenzene
4
Chlorodibromomethane
7
Chloromethane
7
Chlorous ion solution
12
Choline chloride
9,12,14
Chromates
12,14
Chromium
Crosslinker
11
Chromium (III) acetate
12
Chromium (III), insoluble salts
6
Chromium (VI)
6
Chromium acetate, basic
13
Cinnamaldehyde (3-phenyl-2-propenal)
9,12,14
Citric acid
Iron control
3,9,12,14
Citrus terpenes
7,12,14
Coal, granular
12,14
Cobalt
7
Coco-betaine
7,14
Coconut oil acid/diethanolamine condensate (2:1)
12
Collagen (gelatin)
12,14
Common White
14
Complex alkylaryl polyo-ester
12
Complex aluminum salt
12
Complex organometallic salt
12
Complex polyamine salt
9
Complex substituted keto-amine
12
Complex substituted keto-amine hydrochloride
12
Copolymer of acrylamide and sodium acrylate
12,14
Copper
5,12
Copper compounds
Breaker fluid
1,6
Copper sulfate
7,12,14
Copper(l) iodide
Breaker fluid
5,6,12,14
Copper(ll) chloride
7,12,14
Coric oxide
14
Corn sugar gum
Corrosion inhibitor
12,13,14
Corundum
14
Cottonseed flour
13,14
Cremophor(R) EL
7,12,14
Crissanol A-55
7,14
Cristobalite
12,14
Crotonaldehyde
12,14
Crystalline silica, tridymite
12,14
Cumene
7,12,14
Cupric chloride dihydrate
7,9,12
Cuprous chloride
12,14
Table continued on next page
127
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Cured acrylic resin
12,14
Cured resin
9,12,14
Cured silicone rubber-polydimethylsiloxane
12
Cured urethane resin
12,14
Cyanide
11
Cyanide, free
7
Cyclic alkanes
12
Cyclohexane
9,12
Cyclohexanone
12,14
D-(-)-Lactic acid
12,14
Dapsone
12,14
Dazomet
Biocide
9,12,13,14
Decyldimethyl amine
7,14
D-Glucitol
7,12,14
D-Gluconic acid
12
D-Glucose
12
D-Limonene
5,7,9
Di(2-ethylhexyl) phthalate
7,12
Diatomaceous earth, calcined
12
Diatomaceus earth
Proppant
13,14
Dibromoacetonitrile
7,12,14
Dibutyl phthalate
4
Dicalcium silicate
12,14
Dicarboxylic acid
12
Didecyl dimethyl ammonium chloride
Biocide
12,13
Diesel
1,6,12
Diethanolamine
Foaming agent
1,6,12,14
Diethylbenzene
7,12,14
Diethylene glycol
5,9,12,14
Diethylene glycol monobutyl ether
8
Diethylene glycol monoethyl ether
Foaming agent
1
Diethylene glycol monomethyl ether
Foaming agent
1,12,14
Diethylenetriamine
Activator
10,12,14
Diisopropylnaphthalene
7,14
Diisopropylnaphthalenesulfonic acid
7,12,14
Dimethyl glutarate
12,14
Dimethyl silicone
12,14
Dinonylphenyl polyoxyethylene
14
Dipotassium monohydrogen phosphate
5
Dipropylene glycol
7,12,14
Di-secondary-butylphenol
12
Disodium
12
dodecyl(sulphonatophenoxy)benzenesulphonate
Disodium ethylenediaminediacetate
12
Disodium ethylenediaminetetraacetate dihydrate
12
Dispersing agent
12
Distillates, petroleum, catalytic reformer fractionator
12
residue, low-boiling
Table continued on next page
128
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Distillates, petroleum, hydrodesulfurized light catalytic
12
cracked
Dist
Nates, petroleum, hydrodesulfurized middle
12
Dist
Nates, petroleum, hydrotreated heavy naphthenic
5,12,14
Dist
Nates, petroleum, hydrotreated heavy paraffinic
12,14
Dist
Nates, petroleum, hydrotreated light
Friction reducer
5,9,10,12,14
Dist
Nates, petroleum, hydrotreated light naphthenic
12
Dist
Nates, petroleum, hydrotreated middle
12
Dist
Nates, petroleum, light catalytic cracked
12
Dist
Nates, petroleum, solvent-dewaxed heavy paraffinic
12,14
Dist
Nates, petroleum, solvent-refined heavy naphthenic
12
Dist
Nates, petroleum, steam-cracked
12
Dist
Nates, petroleum, straight-run middle
12,14
Dist
Nates, petroleum, sweetened middle
12,14
Ditallow alkyl ethoxylated amines
7,14
Docusate sodium
12
Dodecyl alcohol ammonium sulfate
12
Dodecylbenzene
7,14
Dodecylbenzene sulfonic acid salts
12,14
Dodecylbenzenesulfonate isopropanolamine
7,12,14
Dodecylbenzene sulfonic acid, monoethanolamine salt
12
Dodecylbenzene sulphonic acid, morpholine salt
12,14
Econolite Additive
14
Edifas B
Fluid additives
5,14
EDTA copper chelate
Breaker fluid, activator
5,6,10,12,14
Endo- 1,4-beta-mannanase, or Hemicellulase
14
EO-C7-9-iso; C8 rich alcohols
14
EO-C9-ll-iso; CIO rich alcohols
12,14
Epichlorohydrin
12,14
Epoxy resin
12
Erucic amidopropyl dimethyl detaine
7,12,14
Essential oils
12
Ester salt
Foaming agent
1
Ethanaminium, N,N,N-trimethyl-2-[(l-oxo-2-
14
propenyl)oxy]-, chloride
Ethanaminium, N,N,N-trimethyl-2-[(l-oxo-2-
12,14
propenyl)oxy]-,chloride, polymer with 2-propenamide
Ethane
5
Ethanol
Foaming agent, non-
1,6,10,12,14
ionic surfactant
Ethanol, 2,2'-iminobis-, N-coco alkyl derivs., N-oxides
12
Ethanol, 2,2'-iminobis-, N-tallow alkyl derivs.
12
Ethanol, 2-[2-[2-(tridecyloxy)ethoxy]ethoxy]-, hydrogen
12
sulfate, sodium salt
Ethanolamine
Crosslinker
1,6,12,14
Ethoxylated 4-nonylphenol
13
Table continued on next page
129
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Ethoxylated alcohol/ester mixture
14
Ethoxylated alcohols
5,9,12,13,14
Ethoxylated alkyl amines
12,14
Ethoxylated amine
12,14
Ethoxylated fatty acid ester
12,14
Ethoxylated fatty acid, coco
14
Ethoxylated fatty acid, coco, reaction product with
14
ethanolamine
Ethoxylated nonionic surfactant
12
Ethoxylated nonylphenol
8,12,14
Ethoxylated propoxylated C12-14 alcohols
12,14
Ethoxylated sorbitan trioleate
7,14
Ethoxylated sorbitol esters
12,14
Ethoxylated undecyl alcohol
12
Ethoxylated, propoxylated trimethylolpropane
7,14
Ethylacetate
9,12,14
Ethylacetoacetate
12
Ethyllactate
7,14
Ethylbenzene
Gelling Agent
1,9,12,14
Ethylcellulose
Fluid Additives
13
Ethylene glycol
Crosslinker/ Breaker
Fluids/ Scale Inhibitor
1,6,9,12,14
Ethylene glycol diethyl ether
Foaming Agent
1
Ethylene glycol dimethyl ether
Foaming Agent
1
Ethylene oxide
7,12,14
Ethylene oxide-nonylphenol polymer
12
Ethylenediaminetetraacetic acid
12,14
Ethylenediaminetetraacetic acid tetrasodium salt
7,12,14
hydrate
Ethylenediaminetetraacetic acid, diammonium copper
14
salt
Ethylene-vinyl acetate copolymer
12
Ethylhexanol
14
Fatty acid ester
12
Fatty acid, tall oil, hexa esters with sorbitol, ethoxylated
12,14
Fatty acids
12
Fatty acids, tall oil reaction products w/acetophenone,
14
formaldehyde & thiourea
Fatty acids, tall-oil
7,12,14
Fatty acids, tall-oil, reaction products with
12
diethylenetriamine
Fatty acids, tallow, sodium salts
7,14
Fatty alcohol alkoxylate
12,14
Fatty alkyl amine salt
12
Table continued on next page
16 Multiple categories of ethoxylated alcohols were listed in various references. Due to different naming
conventions, there is some uncertainty as to whether some are duplicates or some incorrect. Therefore,
"ethoxylated alcohols" is included here as a single item with further evaluation to follow.
130
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Fatty amine carboxylates
12
Fatty quaternary ammonium chloride
12
FD & C blue no. 1
12
Ferric chloride
7,12,14
Ferric sulfate
12,14
Fluorene
1
Fluoride
7
Fluoroaliphatic polymeric esters
12,14
Formaldehyde polymer
12
Formaldehyde, polymer with 4-(l,l-dimethyl)phenol,
12
methyloxirane and oxirane
Formaldehyde, polymer with 4-nonylphenol and
12
oxirane
Formaldehyde, polymer with ammonia and phenol
12
Formaldehyde, polymers with branched 4-nonylphenol,
14
ethylene oxide and propylene oxide
Formalin
7,12,14
Formamide
7,12,14
Formic acid
Acid Treatment
1,6,9,12,14
Formic acid, potassium salt
7,12,14
Fuel oil, no. 2
12,14
Fuller's earth
Gelling agent
13
Fumaric acid
Water gelling agent/
linear gel polymer
1,6,12,14
Furfural
12,14
Furfuryl alcohol
12,14
Galactomannan
Gelling agent
13
Gas oils, petroleum, straight-run
12
Gilsonite
Viscosifier
12,14
Glass fiber
7,12,14
Gluconic acid
9
Glutaraldehyde
Biocide
3,9,12,14
Glycerin, natural
Crosslinker
7,10,12,14
Glycine, N-(carboxymethyl)-N-(2-hydroxyethyl)-,
12
disodium salt
Glycine, N,N'-l,2-ethanediylbis[N-(carboxymethyl)-,
7,12,14
disodium salt
Glycine, N,N-bis(carboxymethyl)-, trisodium salt
7,12,14
Glycine, N-[2-[bis(carboxymethyl)amino]ethyl]-N-(2-
12
hydroxyethyl)-, trisodium salt
Glycol ethers
9,12
Glycolic acid
7,12,14
Glycolic acid sodium salt
7,12,14
Glyoxal
12
Glyoxylic acid
12
Graphite
Fluid additives
13
Guar gum
9,12,14
Guar gum derivative
12
Table continued on next page
131
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Gypsum
13,14
Haloalkyl heteropolycycle salt
12
Heavy aromatic distillate
12
Heavy aromatic petroleum naphtha
13,14
Hematite
12,14
Hemicellulase
5,12,14
Heptane
5,12
Heptene, hydroformylation products, high-boiling
12
Hexane
5
Hexanes
12
Hydrated aluminum silicate
12,14
Hydrocarbons
12
Hydrocarbons, terpene processing by-products
7,12,14
Hydrochloric acid
Acid treatment, solvent
1,6,9,10,12,14
Hydrogen fluoride (Hydrofluoric acid)
Acid treatment
12
Hydrogen peroxide
7,12,14
Hydrogen sulfide
7,12
Hydrotreated and hydrocracked base oil
12
Hydrotreated heavy naphthalene
5
Hydrotreated light distillate
14
Hydrotreated light petroleum distillate
14
Hydroxyacetic acid ammonium salt
7,14
Hydroxycellulose
Linear gel polymer
6
Hydroxyethylcellulose
Gel
3,12,14
Hydroxylamine hydrochloride
7,12,14
Hydroxyproplyguar
Linear gel polymer
6
Hydroxypropyl cellulose
8
Hydroxypropyl guar gum
Linear gel delivery,
water gelling agent
1,6,10,12,14
Hydroxysultaine
12
Igepal CO-210
7,12,14
Inner salt of alkyl amines
12,14
Inorganic borate
12,14
Inorganic particulate
12,14
Inorganic salt
12
Instant coffee purchased off the shelf
12
Inulin, carboxymethyl ether, sodium salt
12
Iron
Emulsifier/surfactant
13
Iron oxide
Proppant
12,13,14
Iron(ll) sulfate heptahydrate
7,12,14
Iso-alkanes/n-alkanes
12,14
Isoascorbic acid
7,12,14
Isomeric aromatic ammonium salt
7,12,14
Isooctanol
5,12,14
Isooctyl alcohol
12
Isopentyl alcohol
12
Table continued on next page
132
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Isopropanol
Foaming agent/
surfactant, acid
corrosion inhibitor
1,6,9,12,14
Isopropylamine
12
Isoquinoline, reaction products with benzyl chloride and
quinoline
14
Isotridecanol, ethoxylated
7,12,14
Kerosine, petroleum, hydrodesulfurized
7,12,14
Kyanite
Proppant
12,13,14
Lactic acid
12
Lactose
7,14
Latex 2000
13,14
L-Dilactide
12,14
Lead
4,12
Lead compounds
14
Lignite
Fluid additives
13
Lime
14
Lithium
7
L-Lactic acid
12
Low toxicity base oils
12
Lubra-Beads coarse
14
Maghemite
12,14
Magnesium
4
Magnesium aluminum silicate
Gellant
13
Magnesium carbonate
12
Magnesium chloride
Biocide
12,13
Magnesium chloride hexahydrate
14
Magnesium hydroxide
12
Magnesium iron silicate
12,14
Magnesium nitrate
Biocide
12,13,14
Magnesium oxide
12,14
Magnesium peroxide
12
Magnesium phosphide
12
Magnesium silicate
12,14
Magnetite
12,14
Manganese
4
Mercury
11
Metal salt
12
Metal salt solution
12
Methanamine, N,N-dimethyl-, hydrochloride
5,12,14
Methane
5
Methanol
Acid corrosion inhibitor
1,6,9,10,12,14
Methenamine
12,14
Methyl bromide
7
Methyl ethyl ketone
4
Methyl salicylate
9
Methyl tert-butyl ether
Gelling agent
1
Methyl vinyl ketone
12
Table continued on next page
133
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Methylcyclohexane
12
Methylene bis(thiocyanate)
Biocide
13
Methyloxirane polymer with oxirane, mono
(nonylphenol) ether, branched
14
Mica
Fluid additives
5,6,12,14
Microbond expanding additive
14
Mineral
12,14
Mineral filler
12
Mineral oil
Friction reducer
3,14
Mixed titanium ortho ester complexes
12
Modified lignosulfonate
14
Modified alkane
12,14
Modified cycloaliphatic amine adduct
12,14
Modified lignosulfonate
12
Modified polysaccharide or pregelatinized cornstarch or
starch
8
Molybdenum
7
Monoethanolamine
14
Monoethanolamine borate
12,14
Morpholine
12,14
Muconic acid
8
Mullite
12,14
N,N,N-Trimethyl-2[l-oxo-2-propenyl]oxy
ethanaminimum chloride
7,14
N,N,N-Trimethyloctadecan-l-aminium chloride
12
N,N'-Dibutylthiourea
12
N,N-Dimethyl formamide
Breaker
3,14
N,N-Dimethyl-l-octadecanamine-HCI
12
N,N-Dimethyldecylamine oxide
7,12,14
N,N-Dimethyldodecylamine-N-oxide
8
N,N-Dimethylformamide
5,12,14
N,N-Dimethyl-methanamine-n-oxide
7,14
N,N-Dimethyl-N-[2-[(l-oxo-2-propenyl)oxy]ethyl]-
benzenemethanaminium chloride
7,14
N,N-Dimethyloctadecylamine hydrochloride
12
N,N'-Methylenebisacrylamide
12,14
n-Alkanes,C10-C18
4
n-Alkanes,C18-C70
4
n-Alkanes,C5-C8
4
n-Butanol
9
Naphtha, petroleum, heavy catalytic reformed
5,12,14
Naphtha, petroleum, hydrotreated heavy
7,12,14
Naphthalene
Gelling agent, non-ionic
surfactant
1,9,10,12,14
Naphthalene derivatives
12
Naphthalenesulphonic acid, bis (l-methylethyl)-methyl
derivatives
12
Naphthenic acid ethoxylate
14
Table continued on next page
134
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Navy fuels JP-5
7,12,14
Nickel
4
Nickel sulfate
Corrosion inhibitor
13
Nickel(ll) sulfate hexahydrate
12
Nitrazepam
8
Nitrilotriacetamide
scale inhibiter
9,12
Nitrilotriacetic acid
12,14
Nitrilotriacetic acid trisodium monohydrate
12
Nitrobenzene
8
Nitrobenzene-d5
7
Nitrogen, liquid
Foaming agent
5,6,12,14
N-Lauryl-2-pyrrolidone
12
N-Methyl-2-pyrrolidone
12,14
N-Methyldiethanolamine
8
N-Oleyl diethanolamide
12
Nonane, all isomers
12
Non-hazardous salt
12
Nonionic surfactant
12
Nonylphenol (mixed)
12
Nonylphenol ethoxylate
8,12,14
Nonylphenol, ethoxylated and sulfated
12
N-Propyl zirconate
12
N-Tallowalkyltrimethylenedia mines
12,14
Nuisance particulates
12
Nylon fibers
12,14
Oil and grease
4
Oil of wintergreen
12,14
Oils, pine
12,14
Olefinic sulfonate
12
Olefins
12
Organic acid salt
12,14
Organic acids
12
Organic phosphonate
12
Organic phosphonate salts
12
Organic phosphonic acid salts
12
Organic salt
12,14
Organic sulfur compound
12
Organic surfactants
12
Organic titanate
12,14
Organo-metallic ammonium complex
12
Organophilic clays
7,12,14
O-Terphenyl
7,14
Other inorganic compounds
12
Oxirane, methyl-, polymer with oxirane, mono-C10-16-
12
alkyl ethers, phosphates
Oxiranemethanaminium, N,N,N-trimethyl-, chloride,
7,14
homopolymer
Oxyalkylated alcohol
12,14
Table continued on next page
135
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Oxyalkylated alkyl alcohol
12
Oxyalkylated alkylphenol
7,12,14
Oxyalkylated fatty acid
12
Oxyalkylated phenol
12
Oxyalkylated polyamine
12
Oxylated alcohol
5,12,14
P/F resin
14
Paraffin waxes and hydrocarbon waxes
12
Paraffinic naphthenic solvent
12
Paraffinic solvent
12,14
Paraffins
12
Pentaerythritol
8
Pentane
5
Perlite
14
Peroxydisulfuric acid, diammonium salt
Breaker fluid
1,6,12,14
Petroleum
12
Petroleum distillates
12,14
Petroleum gas oils
12
Petroleum hydrocarbons
7
Phenanthrene
Biocide
1,6
Phenol
4,12,14
Phenolic resin
Proppant
9,12,13,14
Phosphate ester
12,14
Phosphate esters of alkyl phenyl ethoxylate
12
Phosphine
12,14
Phosphonic acid
12
Phosphonic acid (dimethlamino(methylene))
12
Phosphonic acid, (l-hydroxyethylidene)bis-,
12,14
tetrasodium salt
Phosphonic acid, [[(phosphonomethyl)imino]bis[2,l-
Scale inhibitor
12,13
ethanediylnitrilobis(methylene)]]tetrakis-
Phosphonic acid, [[(phosphonomethyl)imino]bis[2,l-
7,14
ethanediylnitrilobis(methylene)]]tetrakis-, sodium salt
Phosphonic acid, [nitrilotris(methylene)]tris-,
12
pentasodium salt
[[(Phosphonomethyl)imino]bis[2,l-
7,14
ethanediylnitrilobis(methylene)]]tetrakis phosphonic
acid ammonium salt
Phosphoric acid ammonium salt
12
Phosphoric acid Divosan X-Tend formulation
12
Phosphoric acid, aluminium sodium salt
Fluid additives
12,13
Phosphoric acid, diammonium salt
Corrosion inhibitor
13
Phosphoric acid, mixed decyl and Et and octyl esters
12
Phosphoric acid, monoammonium salt
14
Phosphorous acid
12
Phosphorus
7
Phthalic anhydride
12
Plasticizer
12
Table continued on next page
136
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Pluronic F-127
12,14
Poly (acrylamide-co-acrylic acid), partial sodium salt
14
Poly(oxy-l,2-ethanediyl), .alpha.-(nonylphenyl)-omega-
12,14
hydroxy-, phosphate
Poly(oxy-l,2-ethanediyl), .alpha.-(octylphenyl)-omega-
12
hydroxy-, branched
Poly(oxy-l,2-ethanediyl), alpha,alpha'-[[(9Z)-9-
12,14
octadecenylimino]di-2,1-ethanediyl] bis[. omega. -
hydroxy-
Poly(oxy-l,2-ethanediyl), alpha-sulfo-.omega.-hydroxy-,
12,14
C12-14-alkyl ethers, sodium salts
Poly(oxy-l,2-ethanediyl), alpha-hydro-omega-hydroxy
12
Poly(oxy-l,2-ethanediyl), alpha-sulfo-omega-(hexyloxy)-
12,14
ammonium salt
Poly(oxy-l,2-ethanediyl), alpha-tridecyl-omega-
12,14
hydroxy-
Poly-(oxy-l,2-ethanediyl)-alpha-undecyl-omega-
12,14
hydroxy
Poly(oxy-l,2-ethanediyl)-nonylphenyl-hydroxy
Acid corrosion
inhibitor, non-ionic
surfactant
7,12,13,14
Poly(sodium-p-styrenesulfonate)
12
Polyvinyl alcohol)
12
Poly[imino(l,6-dioxo-l,6-hexanediyl)imino-l,6-
Resin
13
hexanediyl]
Polyacrylamide
Friction reducer
3,6,12,13,14
Polyacrylamides
12
Polyacrylate
12,14
Polyamine
12,14
Polyamine polymer
14
Polyanionic cellulose
12
Polyaromatic hydrocarbons
Gelling agent/
bactericides
1,6,13
Polycyclic organic matter
Gelling agent/
bactericides
1,6,13
Polyethene glycol oleate ester
7,14
Polyetheramine
12
Polyethoxylated alkanol
7,14
Polyethylene glycol
5,9,12,14
Polyethylene glycol ester with tall oil fatty acid
12
Polyethylene glycol mono(l,1,3,3-
7,12,14
tetramethylbutyl)phenyl ether
Polyethylene glycol monobutyl ether
12,14
Polyethylene glycol nonylphenyl ether
7,12,14
Polyethylene glycol tridecyl ether phosphate
12
Polyethylene polyammonium salt
12
Polyethyleneimine
14
Polyglycol ether
Foaming agent
1,6,13
Table continued on next page
137
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Polyhexamethylene adipamide
Resin
13
Polylactide resin
12,14
Polymer
14
Polymeric hydrocarbons
14
Polyoxyalkylenes
9,12
Polyoxylated fatty amine salt
7,12,14
Polyphosphoric acids, esters with triethanolamine,
12
sodium salts
Polyphosphoric acids, sodium salts
12,14
Polypropylene glycol
Lubricant
12,13
Polysaccharide
9,12,14
Polysaccharide blend
14
Polysorbate 60
14
Polysorbate 80
7,14
Polyvinyl alcohol
Fluid additives
12,13,14
Polyvinyl alcohol/polyvinylacetate copolymer
12
Portland cement clinker
14
Potassium
7
Potassium acetate
7,12,14
Potassium aluminum silicate
5
Potassium borate
7,14
Potassium carbonate
pH control
3,10,13
Potassium chloride
Brine carrier fluid
1,6,9,12,13,14
Potassium hydroxide
Crosslinker
1,6,12,13,14
Potassium iodide
12,14
Potassium metaborate
5,12,14
Potassium oxide
12
Potassium pentaborate
12
Potassium persulfate
Fluid additives
12,13
Propane
5
Propanimidamide, 2,2"-azobis[2-methyl-,
12,14
dihydrochloride
Propanol, l(or 2)-(2-methoxymethylethoxy)-
8,12,14
Propargyl alcohol
Acid corrosion inhibitor
1,6,9,12,13,14
Propylene carbonate
12
Propylene glycol
14
Propylene pentamer
12
p-Xylene
12,14
Pyridine, alkyl derivs.
12
Pyridinium, l-(phenylmethyl)-, Et Me derivs., chlorides
Acid corrosion
inhibitor, corrosion
inhibitor
1,6,12,13,14
Pyrogenic colloidal silica
12,14
Quartz
Proppant
5,6,12,13,14
Quartz sand
Proppant
3,13
Quaternary amine
8
Quaternary amine compounds
12
Quaternary ammonium compound
8,12
Table continued on next page
138
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Quaternary ammonium compounds, (oxydi-2,1-
7,14
ethanediyl)bis[coco alkyldimethyl, dichlorides
Quaternary ammonium compounds,
Fluid additives
5,6,13
benzylbis(hydrogenated tallow alkyl)methyl, salts with
bentonite
Quaternary ammonium compounds, benzyl-C12-16-
12
alkyldimethyl, chlorides
Quaternary ammonium compounds, bis(hydrogenated
14
tallow alkyl)dimethyl, salts with bentonite
Quaternary ammonium compounds, bis(hydrogenated
Viscosifier
13
tallow alkyl)dimethyl, salts with hectorite
Quaternary ammonium compounds, dicoco
12
alkyldimethyl, chlorides
Quaternary ammonium compounds, trimethyltallow
12
alkyl, chlorides
Quaternary ammonium salts
8,12,14
Quaternary compound
12
Quaternary salt
12,14
Radium (228)
4
Raffinates (petroleum)
5
Raffinates, petroleum, sorption process
12
Residual oils, petroleum, solvent-refined
5
Residues, petroleum, catalytic reformer fractionator
12,14
Resin
14
Rosin
12
Rutile
12
Saline
Brine carrier fluid,
breaker
5,10,12,13,14
Salt
14
Salt of amine-carbonyl condensate
14
Salt of fatty acid/polyamine reaction product
14
Salt of phosphate ester
12
Salt of phosphono-methylated diamine
12
Salts of alkyl amines
Foaming agent
1,6,13
Sand
14
Saturated sucrose
7,12,14
Secondary alcohol
12
Selenium
7
Sepiolite
14
Silane, dichlorodimethyl-, reaction products with silica
14
Silica
Proppant
3,12,13,14
Silica gel, cryst.-free
14
Silica, amorphous
12
Silica, amorphous precipitated
12,14
Silica, microcrystalline
13
Silica, quartz sand
14
Silicic acid (H4Si04), tetramethyl ester
12
Silicon dioxide (fused silica)
12,14
Table continued on next page
139
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Silicone emulsion
12
Silicone ester
14
Silver
7
Silwet L77
12
Soda ash
14
Sod
um
4
Sod
um 1-octanesulfonate
7,14
Sod
um 2-mercaptobenzothiolate
Corrosion inhibitor
13
Sod
um acetate
7,12,14
Sod
um alpha-olefin Sulfonate
14
Sod
um aluminum oxide
12
Sod
um benzoate
7,14
Sod
um bicarbonate
5,9,12,14
Sod
um bisulfite, mixture of NaHS03 and Na2S205
7,12,14
Sod
um bromate
Breaker
12,13,14
Sod
um bromide
7,9,12,14
Sod
um carbonate
pH control
3,12,13,14
Sod
um chlorate
12,14
Sod
um chlorite
Breaker
7,10,12,13,14
Sod
um chloroacetate
7,14
Sod
um cocaminopropionate
12
Sod
um decyl sulfate
12
Sod
um diacetate
12
Sod
um dichloroisocyanurate
Biocide
13
Sod
um erythorbate
7,12,14
Sod
um ethasulfate
12
Sod
um formate
14
Sod
um hydroxide
Gelling agent
1,9,12,13,14
Sod
um hypochlorite
7,12,14
Sod
um iodide
14
Sod
um ligninsulfonate
Surfactant
13
Sod
um metabisulfite
12
Sod
um metaborate
7,12,14
Sod
um metaborate tetrahydrate
12
Sod
um metasilicate
12,14
Sod
um nitrate
Fluid additives
13
Sod
um nitrite
Corrosion inhibitor
12,13,14
Sod
um octyl sulfate
12
Sod
um oxide (Na20)
12
Sod
um perborate
12
Sod
um perborate tetrahydrate
Concentrate
7,10,12,13,14
Sod
um persulfate
5,9,12,14
Sod
um phosphate
12,14
Sod
um polyacrylate
7,12,14
Sod
um pyrophosphate
5,12,14
Sod
um salicylate
12
Sod
um silicate
12,14
Sod
um sulfate
7,12,14
Table continued on next page
140
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Sodium sulfite
14
Sodium tetraborate decahydrate
Crosslinker
1,6,13
Sodium thiocyanate
12
Sodium thiosulfate
7,12,14
Sodium thiosulfate, pentahydrate
12
Sodium trichloroacetate
12
Sodium xylenesulfonate
9,12
Sodium zirconium lactate
12
Sodium a-olefin sulfonate
7
Solvent naphtha, petroleum, heavy aliph.
14
Solvent naphtha, petroleum, heavy arom.
Non-ionic surfactant
5,10,12,13,14
Solvent naphtha, petroleum, light arom.
Surfactant
12,13,14
Sorbitan, mono-(9Z)-9-octadecenoate
7,12,14
Stannous chloride dihydrate
12,14
Starch
Proppant
12,14
Starch blends
Fluid additives
6
Steam cracked distillate, cyclodiene dimer,
12
dicyclopentadiene polymer
Steranes
4
Stoddard solvent
7,12,14
Stoddard solvent IIC
7,12,14
Strontium
7
Strontium (89&90)
13
Styrene
Proppant
13
Substituted alcohol
12
Substituted alkene
12
Substituted alkylamine
12
Sugar
14
Sulfamic acid
7,12,14
Sulfate
4,7,12,14
Sulfite
7
Sulfomethylated tannin
5
Sulfonate acids
12
Sulfonate surfactants
12
Sulfonic acid salts
12
Sulfonic acids, C14-16-alkane hydroxy and C14-16-
7,12,14
alkene, sodium salts
Sulfonic acids, petroleum
12
Sulfur compound
12
Sulfuric acid
9,12,14
Surfactant blend
14
Surfactants
9,12
Symclosene
8
Synthetic organic polymer
12,14
Talc
Fluid additives
5,6,9,12,13,14
Tall oil, compound with diethanolamine
12
Tallow soap
12,14
Table continued on next page
141
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Table El continued from previous page
Chemical Name Use Ref.
Tar bases, quinoline derivatives, benzyl chloride-
7,12,14
quaternized
Tebuthiuron
8
Terpenes
12
Terpenes and terpenoids, sweet orange-oil
7,12,14
Terpineol, mixture of isomers
7,12,14
tert-Butyl hydroperoxide (70% solution in water)
12,14
tert-Butyl perbenzoate
12
Tetra-calcium-alumino-ferrite
12,14
Tetrachloroethylene
7
Tetradecyl dimethyl benzyl ammonium chloride
12
Tetraethylene glycol
12
Tetraethylenepentamine
12,14
Tetrakis(hydroxymethyl)phosphonium sulfate
7,9,12,14
Tetramethylammonium chloride
7,9,12,14
Thallium and compounds
7
Thiocyanic acid, ammonium salt
7,14
Thioglycolic acid
Iron Control
12,13,14
Thiourea
Acid corrosion inhibitor
1,6,12,13,14
Thiourea polymer
12,14
Thorium
2
Tin
1
Tin(ll) chloride
12
Titanium
Crosslinker
4
Titanium complex
12,14
Titanium dioxide
Proppant
12,13,14
Titanium(4+) 2-[bis(2-hydroxyethyl)amino]ethanolate
12
propan-2-olate (1:2:2)
Titanium, isopropoxy (triethanolaminate)
12
TOC
7
Toluene
Gelling agent
1,12,14
trans-Squalene
8
Tr
butyl phosphate
Defoamer
13
Tr
calcium phosphate
12
Tr
calcium silicate
12,14
Tr
ethanolamine
5,12,14
Tr
ethanolamine hydroxyacetate
7,14
Tr
ethanolamine polyphosphate ester
12
Tr
ethanolamine zirconium chelate
12
Tr
ethyl citrate
12
Tr
ethyl phosphate
12,14
Tr
ethylene glycol
5,12,14
Tr
isopropanolamine
12,14
Tr
methyl ammonium chloride
9,14
Tr
methylamine quaternized polyepichlorohydrin
5,12,14
Tr
methylbenzene
Fracturing fluid
12,13
Tr
-n-butyl tetradecyl phosphonium chloride
7,12,14
Tr
phosphoric acid, pentasodium salt
12,14
Table continued on next page
142
-------
EPA Hydraulic Fracturing Study Plan
Table El continued from previous page
Chemical Name
November 2011
Use Ref.
Tripropylene glycol monomethyl ether
Viscosifier
13
Tris(hydroxymethyl)amine
7
Trisodium citrate
7,14
Trisodium ethylenediaminetetraacetate
12,14
Trisodium ethylenediaminetriacetate
12
Trisodium phosphate
7,12,14
Trisodium phosphate dodecahydrate
12
Triterpanes
4
Triton X-100
7,12,14
Ulexite
12,14
Ulexite, calcined
14
Ultraprop
14
Undecane
7,14
Uranium-238
2
Urea
7,12,14
Vanadium
1
Vanadium compounds
14
Vermiculite
Lubricant
13
Versaprop
14
Vinylidene chloride/methylacrylate copolymer
14
Wall material
12
Walnut hulls
12,14
Water
Water gelling agent/
foaming agent
1,14
White mineral oil, petroleum
12,14
Xylenes
Gelling agent
1,12,14
Yttrium
1
Zinc
Lubricant
13
Zinc carbonate
Corrosion inhibitor
13
Zinc chloride
12
Zinc oxide
12
Zirconium
7
Zirconium complex
Crosslinker
5,10,12,14
Zirconium nitrate
Crosslinker
1,6
Zirconium oxide sulfate
12
Zirconium oxychloride
Crosslinker
12,13
Zirconium sodium hydroxy lactate complex (sodium
12
zirconium lactate)
Zirconium sulfate
Crosslinker
1,6
Zirconium, acetate lactate oxo ammonium complexes
14
Zirconium,tetrakis[2-[bis(2-hydroxyethyl)amino-
Crosslinker
10,12,14
kN]ethanolato-kO]-
a-[3.5-Dimethyl-l-(2-methylpropyl)hexyl]-w-hydroxy-
7,14
poly(oxy-l,2-ethandiyl)
143
-------
EPA Hydraulic Fracturing Study Plan
November 2011
References
1. Sumi, L. (2005). Our drinking water at risk. What EPA and the oil and gas industry don't want us
to know about hydraulic fracturing. Durango, CO: Oil and Gas Accountability Project/Earthworks.
Retrieved January 21, 2011, from http://www.earthworksaction.org/pubs/
DrinkingWaterAtRisk.pdf.
2. Sumi, L. (2008). Shale gas: Focus on the Marcellus Shale. Oil and Gas Accountability Project.
Durango, CO.
3. Ground Water Protection Council & ALL Consulting. (2009). Modern shale gas development in
the US: A primer. Washington, DC: US Department of Energy, Office of Fossil Energy and
National Energy Technology Laboratory. Retrieved January 19, 2011, from
http://www.netl.doe.gov/technologies/oil-gas/publications/
EPreports/Shale_Gas_Primer_2009.pdf.
4. Veil, J. A., Puder, M. G., Elcock, D., & Redweik, R. J. (2004). A white paper describing produced
water from production of crude oil, natural gas, and coal bed methane. Argonne National
Laboratory Report for U.S. Department of Energy, National Energy Technology Laboratory.
5. Material Safety Data Sheets; EnCana Oil & Gas (USA), Inc.: Denver, CO. Provided by EnCana upon
US EPA Region 8 request as part of the Pavillion, WY, ground water investigation.
6. US Environmental Protection Agency. (2004). Evaluation of impacts to underground sources of
drinking water by hydraulic fracturing of coalbed methane reservoirs. No. EPA/816/R-04/003.
Washington, DC: US Environmental Protection Agency, Office of Water.
7. New York State Department of Environmental Conservation. (2009, September). Supplemental
generic environmental impact statement on the oil, gas and solution mining regulatory program
(draft). Well permit issuance for horizontal drilling and high-volume hydraulic fracturing to
develop the Marcellus Shale and other low-permeability gas reservoirs. Albany, NY: New York
State Department of Environmental Conservation. Retrieved January 20, 2010, from
ftp://ftp.dec.state.ny.us/dmn/download/OGdSGEISFull.pdf.
8. US Environmental Protection Agency.(2010). Region 8 analytical lab analysis.
9. Bureau of Oil and Gas Management. (2010). Chemicals used in the hydraulic fracturing process in
Pennsylvania. Pennsylvania Department of Environmental Protection. Retrieved September 12,
2011, from
http://assets.bizjournals.com/cms_media/pittsburgh/datacenter/DEP_Frac_Chemical_List_6-
30-10.pdf.
10. Material Safety Data Sheets; Halliburton Energy Services, Inc.: Duncan, OK. Provided by
Halliburton Energy Services during an on-site visit by EPA on May 10, 2010.
11. Alpha Environmental Consultants, Inc., Alpha Geoscience, NTS Consultants, Inc. (2009). Issues
related to developing the Marcellus Shale and other low-permeability gas reservoirs. Report for
the New York State Energy Research and Development Authority. NYSERDA Contract No. 11169,
NYSERDA Contract No. 10666, and NYSERDA Contract No. 11170. Albany, NY.
12. US House of Representatives Committee on Energy and Commerce Minority Staff (2011).
Chemicals used in hydraulic fracturing.
144
-------
EPA Hydraulic Fracturing Study Plan
November 2011
13. US Environmental Protection Agency. (2010). Expanded site investigation analytical report:
Pavillion Area groundwater investigation. Contract No. EP-W-05-050. Retrieved September 7,
2011, from
http://www.epa.gov/region8/superfund/wy/pavillion/PavillionAnalyticalResultsReport.pdf.
14. Submitted non-Confidential Business Information by Halliburton, Patterson and Superior.
Available on the Federal Docket, EPA-HQ-ORD-2010-0674.
145
-------
EPA Hydraulic Fracturing Study Plan November 2011
TABLE E2. CHEMICALS IDENTIFIED IN FLOWBACK/PRODUCED WATER
Chemical Ref. Chemical Ref.
1,1,1-Trifluorotoluene
1
l,2-Bromo-2-nitropropane-l,3-
3
diol (2-bromo-2-nitro-l,3-
propanediol or bronopol)
1,-3-Dimethyladamantane
3
1,4-Dichlorobutane
1
1,6-Hexanediamine
3
l-Methoxy-2-propanol
3
2-(2-Methoxyethoxy)ethanol
3
2-(Thiocyanomethylthio)
3
benzothiazole
2,2,2-Nitrilotriethanol
3
2,2-Dibromo-3-
3
nitrilopropionamide
2,2-Dibromoacetonitrile
3
2,2-Dibromopropanediamide
3
2,4,6-Tribromophenol
1
2,4-Dimethylphenol
2
2,5-Dibromotoluene
1
2-Butanone
2
2-Butoxyacetic acid
3
2-Butoxyethanol
3
2-Butoxyethanol phosphate
3
2-Ethyl-3-propylacrolein
3
2-Ethylhexanol
3
2-Fluorobiphenyl
1
2-Fluorophenol
1
3,5-Dimethyl-l,3,5-thiadiazinane-
3
2-thione
4-Nitroquinoline-l-oxide
1
4-Terphenyl-dl4
1
5-Chloro-2-methyl-4-isothiazolin-
3
3-one
6-Methylquinoline
3
Acetic acid
3
Acetic anhydride
3
Acrolein
3
Acrylamide (2-propenamide)
3
Adamantane
3
Adipic acid
3
Aluminum
2
Ammonia
4
Ammonium nitrate
3
Ammonium persulfate
3
Anthracene
2
Antimony
1
Arsenic
2
Atrazine
3
Barium
2
Bentazon
3
Benzene
2
Benzo(a)pyrene
2
Benzyldimethyl-(2-prop-2-
enoyloxyethyl)ammonium
chloride
3
Benzylsuccinic acid
3
Beryllium
4
Bicarbonate
1
Bis(2-ethylhexyl)phthalate
1
Bis(2-ethylhexyl)phthalate
4
Bisphenol a
3
Boric acid
3
Boric oxide
3
Boron
1,2
Bromide
1
Bromoform
1
Butanol
3
Cadmium
2
Calcium
2
Carbonate alkalinity
1
Cellulose
3
Chloride
2
Chlorobenzene
2
Chlorodibromomethane
1
Chloromethane
4
Chrome acetate
3
Chromium
4
Chromium hexavalent
Citric acid
3
Cobalt
1
Copper
2
Cyanide
1
Cyanide
4
Decyldimethyl amine
3
Decyldimethyl amine oxide
3
Diammonium phosphate
3
Dichlorobromomethane
1
Didecyl dimethyl ammonium
chloride
3
Diethylene glycol
3
Diethylene glycol monobutyl
ether
3
Dimethyl formamide
3
Table continued on next page
146
-------
EPA Hydraulic Fracturing Study Plan
Table E2 continued from previous page
Chemical Ref.
Dimethyldiallylammonium
3
chloride
Di-n-butylphthalate
2
Dipropylene glycol monomethyl
3
ether
Dodecylbenzene sulfonic acid
3
Eo-C7-9-iso-,C8 rich-alcohols
3
Eo-C9-ll-iso, ClO-rich alcohols
3
Ethoxylated 4-nonylphenol
3
Ethoxylated nonylphenol
3
Ethoxylated nonylphenol
3
(branched)
Ethoxylated octylphenol
3
Ethyl octynol
3
Ethylbenzene
2
Ethylbenzene
3
Ethylcellulose
3
Ethylene glycol
3
Ethylene glycol monobutyl ether
3
Ethylene oxide
3
Ferrous sulfate heptahydrate
3
Fluoride
1
Formamide
3
Formic acid
3
Fumaric acid
3
Glutaraldehyde
3
Glycerol
3
Hydroxyethylcellulose
3
Hydroxypropylcellulose
3
Iron
2
Isobutyl alcohol (2-methyl-l-
3
propanol)
Isopropanol (propan-2-ol)
3
Lead
2
Limonene
3
Lithium
1
Magnesium
2
Manganese
2
Mercaptoacidic acid
3
Mercury
4
Methanamine,N,N-dimethyl-,N-
3
oxide
Methanol
3
Methyl bromide
1
Methyl chloride
1
Methyl-4-isothiazolin
3
Methylene bis(thiocyanate)
3
November 2011
Chemical
Ref.
Methylene phosphonic acid
3
(diethylenetriaminepenta [methyl
enephosphonic] acid)
Modified polysaccharide or
3
pregelatinized cornstarch or
starch
Molybdenum
1
Monoethanolamine
3
Monopentaerythritol
3
m-Terphenyl
3
Muconic acid
3
N,N,N-trimethyl-2[l-oxo-2-
3
propenyl]oxy ethanaminium
chloride
n-Alkanes, C10-C18
2
n-Alkanes, C18-C70
2
n-Alkanes, C1-C2
2
n-Alkanes, C2-C3
2
n-Alkanes, C3-C4
2
n-Alkanes, C4-C5
2
n-Alkanes, C5-C8
2
Naphthalene
2
Nickel
2
Nitrazepam
3
Nitrobenzene
3
Nitrobenzene-d5
1
n-Methyldiethanolamine
3
Oil and grease
2
o-Terphenyl
1
o-Terphenyl
3
Oxiranemethanaminium, N,N,N-
3
trimethyl-, chloride,
homopolymer
p-Chloro-m-cresol
2
Petroleum hydrocarbons
1
Phenol
2
Phosphonium,
3
tetrakis(hydroxymethly)-sulfate
Phosphorus
1
Polyacrylamide
3
Polyacrylate
3
Polyethylene glycol
3
Polyhexamethylene adipamide
3
Polypropylene glycol
3
Polyvinyl alcohol [alcotex 17f-h]
3
Potassium
1
Propane-1,2-diol
3
Table continued on next page
147
-------
EPA Hydraulic Fracturing Study Plan November 2011
Table E2 continued from previous page
Chemical Ref.
Propargyl alcohol
3
Pryidinium, l-(phenylmethyl)-,
3
ethyl methyl derivatives, chlorides
p-Terphenyl
3
Quaternary amine
3
Quaternary ammonium
3
compound
Quaternary ammonium salts
3
Radium (226)
2
Radium (228)
2
Selenium
1
Silver
1
Sodium
2
Sodium carboxymethylcellulose
3
Sodium dichloro-s-triazinetrione
3
Sodium mercaptobenzothiazole
3
Squalene
3
Steranes
2
Strontium
1
Sucrose
3
Sulfate
1,2
Sulfide
1
Sulfite
1
Tebuthiuron
3
Terpineol
3
Tetrachloroethene
4
Tetramethyl ammonium chloride
3
Tetra sodium
3
ethylenediaminetetraacetate
Thallium
1
Thiourea
3
Titanium
2
Toluene
2
Total organic carbon
1
Tributyl phosphate
3
Trichloroisocyanuric acid
3
Trimethylbenzene
3
Tripropylene glycol methyl ether
3
Trisodium nitrilotriacetate
3
Triterpanes
2
Urea
3
Xylene (total)
2
Zinc
2
Zirconium
1
148
-------
EPA Hydraulic Fracturing Study Plan
November 2011
References
1. New York State Department of Environmental Conservation. (2011, September/ Supplemental
generic environmental impact statement on the oil, gas and solution mining regulatory program
(draft). Well permit issuance for horizontal drilling and high-volume hydraulic fracturing to
develop the Marcellus Shale and other low-permeability gas reservoirs. Albany, NY: New York
State Department of Environmental Conservation. Retrieved January 20, 2010, from
ftp://ftp.dec.state.ny.us/dmn/download/OGdSGEISFull.pdf.
2. Veil, J. A., Puder, M. G., Elcock, D., & Redweik, R. J. (2004). A white paper describing produced
water from production of crude oil, natural gas, and coal bed methane. Prepared for the US
Department of Energy, National Energy Technology Laboratory. Argonne, IL: Argonne National
Laboratory. Retrieved January 20, 2011, from http://www.evs.anl.gov/pub/doc/
ProducedWatersWP0401.pdf.
3. URS Operating Services, Inc. (2010, August 20). Expanded site investigation—Analytical results
report. Pavillion area groundwater investigation. Prepared for US Environmental Protection
Agency. Denver, CO: URS Operating Services, Inc. Retrieved January 27, 2011, from
http://www.epa.gov/region8/superfund/wy/pavillion/
PavillionAnalyticalResultsReport.pdf.
4. Alpha Environmental Consultants, Inc., Alpha Geoscience, & NTS Consultants, Inc. (2009). Issues
related to developing the Marcellus Shale and other low-permeability gas reservoirs. Albany, NY:
New York State Energy Research and Development Authority.
149
-------
EPA Hydraulic Fracturing Study Plan November 2011
TABLE E3. NATURALLY OCCURRING SUBSTANCES MOBILIZED BY FRACTURING ACTIVITIES
• i Common _ ,
Chemical ,, , „ Ref.
Valence States
Aluminum
III
1
Antimony
V,III,-III
1
Arsenic
V, III, 0,-III
1
Barium
II
1
Beryllium
II
1
Boron
III
1
Cadmium
II
1
Calcium
II
1
Chromium
VI, III
1
Cobalt
III, II
1
Copper
11,1
1
Hydrogen sulfide
N/A
Iron
III, II
1
Lead
IV, II
1
Magnesium
II
1
Molybdenum
VI, III
1
Nickel
II
1
Radium (226)
II
Radium (228)
II
Selenium
VI, IV, II, 0, -II
1
Silver
1
1
Sodium
1
1
Thallium
III, 1
1
Thorium
IV
Tin
IV, II, -IV
1
Titanium
IV
1
Uranium
VI, IV
Vanadium
V
1
Yttrium
III
1
Zinc
II
1
References
1. Sumi, L. (2005). Our drinking water at risk: What EPA and the oil and gas industry don't want us
to know about hydraulic fracturing. Durango, CO: Oil and Gas Accountability Project/Earthworks.
Retrieved January 21, 2011, from http://www.earthworksaction.org/pubs/
DrinkingWaterAtRisk.pdf.
2. Sumi, L. (2008). Shale gas: Focus on the Marcellus Shale. Durango, CO: Oil and Gas
Accountability Project/Earthworks. Retrieved January 21, 2011, from
http://www.earthworksaction.org/pubs/OGAPMarcellusShaleReport-6-12-08.pdf.
150
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Appendix F: Stakeholder-Nominated Case Studies
This appendix lists the stakeholder-nominated case studies. Potential retrospective case study sites can be found in Table Fl, while potential
prospective case study sites are listed in Table F2.
TABLE Fl. POTENTIAL RETROSPECTIVE CASE STUDY SITES
Formation
Location
Key Areas to Be Addressed
Key Activities
Potential Outcomes
Partners
Bakken Shale
Killdeer and
Dunn Co., ND
Production well failure during
hydraulic fracturing; suspected
drinking water aquifer
contamination; surface waters
nearby; soil contamination;
more than 2,000 barrels of oil
and fracturing fluids leaked
from the well
Monitoring wells to evaluate
extent of contamination of
aquifer; soil and surface water
monitoring
Determine extent of
contamination of drinking water
resources; identify sources of
well failure
NDDMR-
Industrial
Commission, EPA
Region 8,
Berthold Indian
Reservation
Barnett Shale
Alvord, TX
Benzene in water well
RRCTX,
landowners,
USGS, EPA
Region 6
Barnett Shale
Azle, TX
Skin rash complaints from
contaminated water
RRCTX,
landowners,
USGS, EPA
Region 6
Barnett Shale
Decatur, TX
Skin rash complaints from
drilling mud applications to
land
RRCTX,
landowners,
USGS, EPA
Region 6
Table continued on next page
151
-------
EPA Hydraulic Fracturing Study Plan
Table F1 continued from previous page
November 2011
Formation
Location
Key Areas to Be Addressed
Key Activities
Potential Outcomes
Partners
Barnett Shale
Wise/Denton
Potential drinking water well
Monitor other wells in area and
Determine sources of
RRCTX, TCEQ,
Cos. (including
contamination; surface spills;
install monitoring wells to
contamination of private well
landowners, City
Dish), TX
waste pond overflow;
documented air contamination
evaluate source(s)
of Dish, USGS,
EPA Region 6,
DFW Regional
Concerned
Citizens Group,
North Central
Community
Alliance, Sierra
Club
Barnett Shale
South Parker
Hydrocarbon contamination in
Monitor other wells in area;
Determine source of methane
RRCTX,
Co. and
multiple drinking water wells;
install monitoring wells to
and other contaminants in
landowners,
Weatherford,
may be from faults/fractures
evaluate source(s)
private water well; information
USGS, EPA
TX
from production well beneath
properties
on role of fracture/fault
pathway from hydraulic
fracturing zone
Region 6
Barnett Shale
Tarrant Co., TX
Drinking water well
contamination; report of
leaking pit
Monitoring well
Determine if pit leak impacted
underlying ground water
RRCTX,
landowners,
USGS, EPA
Region 6
Barnett Shale
Wise Co. and
Spills; runoff; suspect drinking
Sample wells, soils
Determine sources of
RRCTX,
Decatur, TX
water well contamination; air
quality impacts
contamination of private well
landowners,
USGS, EPA
Region 6,
Earthworks Oil &
Gas
Accountability
Project
Clinton
Bainbridge,
Methane buildup leading to
OHDNR, EPA
Sandstone
OH
home explosion
Region 5
Fayetteville
Arkana Basin,
General water quality concerns
AROGC, ARDEQ,
Shale
AR
EPA Region 6
Fayetteville
Conway Co.,
Gray, smelly water
AROGC, ARDEQ,
Shale
AR
EPA Region 6
Table continued on next page
152
-------
EPA Hydraulic Fracturing Study Plan
Table F1 continued from previous page
November 2011
Formation
Location
Key Areas to Be Addressed
Key Activities
Potential Outcomes
Partners
Fayetteville
Van Buren or
Stray gas (methane) in wells;
AROGC, ARDEQ,
Shale
Logan Cos., AR
other water quality
impairments
EPA Region 6
Haynesville
Caddo Parish,
Drinking water impacts
Monitoring wells to evaluate
Evaluate extent of water well
LGS, USGS, EPA
Shale
LA
(methane in water)
source(s)
contamination and if source is
from hydraulic fracturing
operations
Region 6
Haynesville
DeSoto Parish,
Drinking water reductions
Monitoring wells to evaluate
Determine source of drinking
LGS, USGS, EPA
Shale
LA
water availability; evaluate
existing data
water reductions
Region 6
Haynesville
Harrison Co.,
Stray gas in water wells
RRCTX,
Shale
TX
landowners,
USGS, EPA
Region 6
Marcellus
Bradford Co.,
Drinking water well
Soil, ground water, and surface
Determine source of methane in
PADEP,
Shale
PA
contamination; surface spill of
hydraulic fracturing fluids
water sampling
private wells
landowners, EPA
Region 3,
Damascus
Citizens Group,
Friends of the
Upper Delaware
Marcellus
Clearfield Co.,
Well blowout
PADEP, EPA
Shale
PA
Region 3
Marcellus
Dimock,
Contamination in multiple
Soil, ground water, and surface
Determine source of methane in
PADEP, EPA
Shale
Susquehanna
Co., PA
drinking water wells; surface
water quality impairment from
spills
water sampling
private wells
Region 3,
landowners,
Damascus
Citizens Group,
Friends of the
Upper Delaware
Marcellus
Gibbs Hill, PA
On-site spills; impacts to
Evaluate existing data;
Evaluate extent of large surface
PADEP,
Shale
drinking water; changes in
determine need for additional
spill's impact on soils, surface
landowner, EPA
water quality
data
water, and ground water
Region 3
Table continued on next page
153
-------
EPA Hydraulic Fracturing Study Plan
Table F1 continued from previous page
November 2011
Formation
Location
Key Areas to Be Addressed
Key Activities
Potential Outcomes
Partners
Marcellus
Shale
Hamlin
Township and
McKean Co.,
PA
Drinking water contamination
from methane; changes in
water quality
Soil, ground water, and surface
water sampling
Determine source of methane in
community and private wells
PADEP, EPA
Region 3,
SchreinerOil &
Gas
Marcellus
Shale
Hickory, PA
On-site spill; impacts to
drinking water; changes in
water quality; methane in
wells; contaminants in drinking
water (acrylonitrile, VOCs)
PADEP,
landowner, EPA
Region 3
Marcellus
Shale
Hopewell
Township, PA
Surface spill of hydraulic
fracturing fluids; waste pit
overflow
Sample pit and underlying soils;
sample nearby soil, ground
water, and surface water
Evaluate extent of large surface
spill's impact on soils, surface
water, and ground water
PADEP,
landowners, EPA
Region 3
Marcellus
Shale
Indian Creek
Watershed,
WV
Concerns related to wells in
karst formation
WVOGCC, EPA
Region 3
Marcellus
Shale
Lycoming Co.,
PA
Surface spill of hydraulic
fracturing fluids
PADEP sampled soils, nearby
surface water, and two nearby
private wells; evaluate need for
additional data collection to
determine source of impact
Evaluate extent of large surface
spill's impact on soils, surface
water, and ground water
Marcellus
Shale
Monongahela
River Basin, PA
Surface water impairment
(high TDS, water availability)
Data exists on water quality
over time for Monongahela
River during ramp up of
hydraulic fracturing activity;
review existing data
Assess intensity of hydraulic
fracturing activity
Marcellus
Shale
Susquehanna
River Basin, PA
and NY
Water availability; water
quality
Assess water use and water
quality overtime; review
existing data
Determine if water withdrawals
for hydraulic fracturing are
related to changes in water
quality and availability
Marcellus
Shale
Tioga Co., NY
General water quality concerns
Marcellus
Shale
Upshur Co.,
WV
General water quality concerns
WVOGCC, EPA
Region 3
Table continued on next page
154
-------
EPA Hydraulic Fracturing Study Plan
Table F1 continued from previous page
November 2011
Formation
Location
Key Areas to Be Addressed
Key Activities
Potential Outcomes
Partners
Marcellus
Wetzel Co.,
Stray gas; spills; changes in
Soil, ground water, and surface
Determine extent of impact
WVDEP,
Shale
WV, and
water quality; several
water sampling
from spill of hydraulic fracturing
WVOGCC,
Washington/
landowners concerned about
fluids associated with well
PADEP, EPA
Green Cos., PA
methane in wells
blowout and other potential
impacts to drinking water
resources
Region 3,
landowners,
Damascus
Citizens Group
Piceance
Battlement
Water quality and quantity
COGCC,
Basin
Mesa, CO
concerns
landowners, EPA
Region 8
Piceance
Garfield Co.,
Drinking water well
Soil, ground water, and surface
Evaluate source of methane and
COGCC,
Basin (tight
CO (Mamm
contamination; changes in
water sampling; review existing
degradation in water quality
landowners, EPA
gas sand)
Creek area)
water quality; water levels
data
basin-wide
Region 8,
Colorado League
of Women
Voters
Piceance
Rifle, CO
Water quality and quantity
COGCC,
Basin
concerns
landowners, EPA
Region 8
Piceance
Silt, CO
Water quality and quantity
COGCC,
Basin
concerns
landowners, EPA
Region 8
Powder River
Clark, WY
Drinking water well
Monitoring wells to evaluate
Evaluate extent of water well
WOOGC, EPA
Basin (CBM)
contamination
source(s)
contamination and if source is
from hydraulic fracturing
operations
Region 8,
landowners
San Juan
LaPlata Co.,
Drinking water well
Large amounts of data have
Evaluate extent of water well
COGCC, EPA
Basin
CO
contamination, primarily with
been collected through various
contamination and determine if
Region 8, BLM,
(shallow CBM
methane (area along the edge
studies of methane seepage; gas
hydraulic fracturing operations
San Juan Citizens
and tight
of the basin has large methane
wells at the margin of the basin
are the source
Alliance
sand)
seepage)
can be very shallow
Table continued on next page
155
-------
EPA Hydraulic Fracturing Study Plan
Table F1 continued from previous page
November 2011
Formation
Location
Key Areas to Be Addressed
Key Activities
Potential Outcomes
Partners
Raton Basin
Huerfano Co.,
Drinking water well
Monitoring wells to evaluate
Evaluate extent of water well
COGCC, EPA
(CBM)
CO
contamination; methane in
well water; well house
explosion
source of methane and
degradation in water quality
contamination and determine if
hydraulic fracturing operations
are the source
Region 8
Raton Basin
Las Animas
Concerns about methane in
COGCC,
(CBM)
Co., CO
water wells
landowners, EPA
Region 8
Raton Basin
North Fork
Drinking water well
Monitoring wells to evaluate
Evaluate extent of water well
COGCC,
(CBM)
Ranch, Las
contamination; changes in
source of methane and
contamination and determine if
landowners, EPA
Animas Co.,
water quality and quantity
degradation in water quality
hydraulic fracturing operations
Region 8
CO
are the source
Tight gas
Garfield Co.,
Drinking water and surface
Monitoring to assess source of
Determine if contamination is
COGCC, EPA
sand
CO
water contamination;
documented benzene
contamination
contamination
from hydraulic fracturing
operations in area
Region 8,
Battlement
Mesa Citizens
Group
Tight gas
Pavillion, WY
Drinking water well
Monitoring wells to evaluate
Determine if contamination is
WOGCC, EPA
sand
contamination
source(s) (ongoing studies by
ORD and EPA Region 8)
from hydraulic fracturing
operations in area
Region 8,
landowners
Tight gas
Sublette Co.,
Drinking water well
Monitoring wells to evaluate
Evaluate extent of water well
WOGCC, EPA
sand
WY (Pinedale
Anticline)
contamination (benzene)
source(s)
contamination and determine if
hydraulic fracturing operations
are the source
Region 8,
Earthworks
156
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Within the scope of this study, prospective case studies will focus on key areas such as the full lifecycle and environmental monitoring. To
address these issues, key research activities will include water and soil monitoring before, during, and after hydraulic fracturing activities.
TABLE F2. PROSPECTIVE CASE STUDIES
Formation
Location
Potential Outcomes
Partners
Bakken Shale
Berthold Indian
Reservation, ND
Baseline water quality data, comprehensive monitoring
and modeling of water resources during all stages of the
hydraulic fracturing process
NDDMR-lndustrial Commission, University
of North Dakota, EPA Region 8, Berthold
Indian Reservation
Barnett Shale
Flower Mound/
Bartonville, TX
Baseline water quality data, comprehensive monitoring
and modeling of water resources during all stages of the
hydraulic fracturing process
NDDMR-lndustrial Commission, EPA Region
8, Mayor of Flower Mound
Marcellus
Shale
Otsego Co., NY
Baseline water quality data, comprehensive monitoring
and modeling of water resources during all stages of the
hydraulic fracturing process
NYSDEC; Gastem, USA; others TBD
Marcellus
Shale
TBD, PA
Baseline water quality data, comprehensive monitoring
and modeling of water resources during all stages of the
hydraulic fracturing process in a region of the country
experiencing intensive hydraulic fracturing activity
Chesapeake Energy, PADEP, others TBD
Marcellus
Shale
Wyoming Co, PA
Baseline water quality data, comprehensive monitoring
and modeling of water resources during all stages of the
hydraulic fracturing process
DOE, PADEP, University of Pittsburgh,
Range Resources, USGS, landowners, EPA
Region 3
Niobrara
Shale
Laramie Co., WY
Baseline water quality data, comprehensive monitoring
and modeling of water resources during all stages of the
hydraulic fracturing process, potential epidemiology study
by Wyoming Health Department
WOGCC, Wyoming Health Department,
landowners, USGS, EPA Region 8
Woodford
Shale or
Barnett Shale
OKorTX
Baseline water quality data, comprehensive monitoring
and modeling of water resources during all stages of the
hydraulic fracturing process
OKCC, landowners, USGS, EPA Region 6
157
-------
EPA Hydraulic Fracturing Study Plan
Appendix F Acronym List
ARDEQ Arkansas Department of Environmental Quality
AROGC Arkansas Oil and Gas Commission
BLM Bureau of Land Management
CBM coalbed methane
Co. county
COGCC Colorado Oil and Gas Conservation Commission
DFW Dallas-Fort Worth
DOE US Department of Energy
EPA US Environmental Protection Agency
LGS Louisiana Geological Survey
NDDMR North Dakota Department of Mineral Resources
NYSDEC New York Department of Environmental Conservation
OHDNR Ohio Department of Natural Resources
OKCC Oklahoma Corporation Commission
PADEP Pennsylvania Department of Environmental Protection
RRCTX Railroad Commission of Texas
TBD to be determined
TCEQ Texas Commission on Environmental Quality
USACE US Army Corps of Engineers
USGS US Geological Survey
VOC volatile organic compound
WOGCC Wyoming Oil and Gas Conservation Commission
WVDEP West Virginia Department of Environmental Protection
WVOGCC West Virginia Oil and Gas Conservation Commission
158
November 2011
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Appendix G: Assessing Mechanical Integrity
In relation to hydrocarbon production, it is useful to distinguish between the internal and external
mechanical integrity of wells. Internal mechanical integrity is concerned with the containment of fluids
within the confines of the well. External mechanical integrity is related to the potential movement of
fluids along the wellbore outside the well casing.
A well's mechanical integrity can be determined most accurately through a combination of data and
tests that individually provide information, which can then be compiled and evaluated. This appendix
provides a brief overview of the tools used to assess mechanical well integrity.
Cement Bond Tools
The effectiveness of the cementing process is determined using cement bond tools and/or cement
evaluation tools. Cement bond tools are acoustic devices that produce data (cement bond logs) used to
evaluate the presence of cement behind the casing. Cement bond logs generally include a gamma-ray
curve and casing collar locator; transit time, which measures the time it takes for a specific sound wave
to travel from the transmitter to the receiver; amplitude curve, which measures the strength of the first
compressional cycle of the returning sound wave; and a graphic representation of the waveform, which
displays the manner in which the received sound wave varies with time. This latter presentation, the
variable density log, reflects the material through which the signal is transmitted. To obtain meaningful
data, the tool must properly calibrated and be centralized in the casing to obtain data that is meaningful
for proper evaluation of the cement behind the casing.
Other tools available for evaluating cement bonding use ultrasonic transducers arranged in a spiral
around the tool or in a single rotating hub to survey the circumference of the casing. The transducers
emit ultrasonic pulses and measure the received ultrasonic waveforms reflected from the internal and
external casing interfaces. The resulting logs produce circumferential visualizations of the cement bonds
with the pipe and borehole wall. Cement bonding to the casing can be measured quantitatively, while
bonding to the formation can only be measured qualitatively. Even though cement bond/evaluation
tools do not directly measure hydraulic seal, the measured bonding qualities do provide inferences of
sealing.
The cement sheath can fail during well construction if the cement fails to adequately encase the well
casing or becomes contaminated with drilling fluid or formation material. After a well has been
constructed, cement sheath failure is most often related to temperature- and pressure-induced stresses
resulting from operation of the well (Ravi et al., 2002). Such stresses can result in the formation of a
microannulus, which can provide a pathway for the migration of fluids from high-pressure zones.
Temperature Logging
Temperature logging can be used to determine changes that have taken place in and adjacent to
injection/production wells. The temperature log is a continuous recording of temperature versus depth.
159
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Under certain conditions the tool can be used to conduct a flow survey, locating points of inflow or
outflow in a well; locate the top of the cement in wells during the cement curing process (using the heat
of hydration of the cement); and detect the flow of fluid and gas behind the casing. The temperature
logging tool is the oldest of the production tools and one of the most versatile, but a highly qualified
expert must use it and interpret its results.
Noise Logging
The noise logging tool may have application in certain conditions to detect fluid movement within
channels in cement in the casing/borehole annulus. It came into widespread application as a way to
detect the movement of gas through liquid. For other flows, for example water through a channel, the
tool relies on the turbulence created as the water flows through a constriction that creates turbulent
flow. Two advantages of using the tool are its sensitivity and lateral depth of investigation. It can detect
sound through multiple casings, and an expert in the interpretation of noise logs can distinguish flow
behind pipe from flow inside pipe.
Pressure Testing
A number of pressure tests are available to assist in determining the internal mechanical integrity of
production wells. For example, while the well is being constructed, before the cement plug is drilled out
for each casing, the casing should be pressure-tested to find any leaks. The principle of such a "standard
pressure test" is that pressure applied to a fixed-volume enclosed vessel, closed at the bottom and the
top, should remain constant if there are no leaks. The same concept applies to the "standard annulus
pressure test," which is used when tubing and packers are a part of the well completion.
The "Ada" pressure test is used in some cases where the well is constructed with tubing without a
packer, in wells with only casing and open perforations, and in dual injection/production wells.
The tools discussed above are summarized below in Table Gl.
160
-------
EPA Hydraulic Fracturing Study Plan November 2011
TABLE Gl. COMPARISON OF TOOLS USED TO EVALUATE WELL INTEGRITY
Type of Tool
Description and Application
Types of Data
Acoustic cement
bond tools
Acoustic devices to evaluate the
presence of cement behind the
casing
• Gamma-ray curve
• Casing collar locator: depth control
• Transit time: time it takes for a specific sound wave
to travel from the transmitter to the receiver
• Amplitude curve: strength of the first
compressional cycle of the returning sound wave
• Waveform: variation of received sound wave over
time
• Variable density log: reflects the material through
which the signal is transmitted
Ultrasonic
transducers
Transmit ultrasonic pulses and
measure the received ultrasonic
waveforms reflected from the
internal and external casing
interfaces to survey well casing
• Circumferential visualizations of the cement bonds
with the pipe and borehole wall
• Quantitative measures of cement bonding to the
casing
• Qualitative measure of bonding to the formation
• Inferred sealing integrity
Temperature
logging
Continuous recording of
temperature versus depth to
detect changes in and adjacent
to injection/production wells
• Flow survey
• Points of inflow or outflow in a well
• Top of cement in wells during the cement curing
process (using the heat of hydration of the
cement)
• Flow of fluid and gas behind casing
Noise logging
tool
Recording of sound patterns
that can be correlated to fluid
movement; sound can be
detected through multiple
casings
• Fluid movement within channels in cement in the
casing/borehole annulus
Pressure tests
Check for leaks in casing
• Changes in pressure within a fixed-volume
enclosed vessel, implying that leaks are present
References
Ravi, K., Bosma, M., & Gastebled, O. (2002, April 30-May 2). Safe and economic gas wells through
cement design for life of the well. No. SPE 75700. Presented at the Society of Petroleum Engineers Gas
Technology Symposium, Calgary, Alberta, Canada.
161
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Appendix H: Field Sampling and Analytical Methods
Field samples and monitoring data associated with hydraulic fracturing activities are collected for a
variety of reasons, including to:
• Develop baseline data prior to fracturing.
• Monitor any changes in drinking water resources during and after hydraulic fracturing.
• Identify and quantify environmental contamination that may be associated with hydraulic
fracturing.
• Evaluate well mechanical integrity.
• Evaluate the performance of treatment systems.
Field sampling is important for both the prospective and retrospective case studies discussed in Chapter
9. In retrospective case studies, EPA will take field samples to determine the cause of reported drinking
water contamination. In prospective case studies, field sampling and monitoring provides for the
identification of baseline conditions of the site prior to drilling and fracturing. Additionally, data will be
collected during each step in the oil or natural gas drilling operation, including hydraulic fracturing of the
formation and oil or gas production, which will allow EPA to monitor changes in drinking water
resources as a result of hydraulic fracturing.
The case study site investigations will use monitoring wells and other available monitoring points to
identify (and determine the quantity of) chemical compounds relevant to hydraulic fracturing activities
in the subsurface environment. These compounds may include the chemical additives found in hydraulic
fracturing fluid and their reaction/degradation products, as well as naturally occurring materials (e.g.,
formation fluid, gases, trace elements, radionuclides, and organic material) released during fracturing
events.
This appendix first describes types of samples (and analytes associated with those samples) that may be
collected throughout the oil and natural gas production process and the development and refinement of
laboratory-based analytical methods. It then discusses the potential challenges associated with
analyzing the collected field samples. The appendix ends with a summary of the data analysis process as
well as a discussion of the evaluation of potential indicators associated with hydraulic fracturing
activities.
Field Sampling: Sample Types and Analytical Focus
Table HI lists monitoring and measurement parameters for both retrospective and prospective case
studies. Note that samples taken in retrospective case studies will be collected after hydraulic fracturing
has occurred and will focus on collecting evidence of contamination of drinking water resources.
Samples taken for prospective case studies, however, will be taken during all phases of oil and gas
production and will focus on improving EPA's understanding of hydraulic fracturing activities.
162
-------
EPA Hydraulic Fracturing Study Plan November 2011
TABLE HI. MONITORING AND MEASUREMENT PARAMETERS AT CASE STUDY SITES
Sample Type
Case Study Site
Parameters
Surface and ground
water (e.g., existing
wells, new wells)
Soil/sediments, soil
gas
Prospective and
retrospective (collect as
much historical data as
available)
• General water quality (e.g., pH, redox, dissolved oxygen)
and water chemistry parameters (e.g., cations and anions)
• Dissolved gases (e.g., methane)
• Stable isotopes (e.g., Sr, Ra, C, H)
• Metals
• Radionuclides
• Volatile and semi-volatile organic compounds, polycyclic
aromatic hydrocarbons
• Soil gas sampling in vicinity of proposed/actual hydraulic
fracturing well location (e.g., Ar, He, H2, 02, N2, C02, CH4,
C2H6, C2H4, C3H6, C3Hs, iC4Hio, nC4Hio, iC5H12)
Flowback and
produced water
Prospective
• General water quality (e.g., pH, redox, dissolved oxygen,
total dissolved solids) and water chemistry parameters
(e.g., cations and anions)
• Metals
• Radionuclides
• Volatile and semi-volatile organic compounds, polycyclic
aromatic hydrocarbons
• Sample fracturing fluids (time series sampling)
o Chemical concentrations
o Volumes injected
o Volumes recovered
Drill cuttings, core
samples
Prospective
• Metals
• Radionuclides
• Mineralogic analyses
Table HI indicates that field sampling will focus primarily on water and soil samples, which will be
analyzed for naturally occurring materials and chemical additives used in hydraulic fracturing fluid,
including their reaction products and/or degradates. Drill cuttings and core samples will be used in
laboratory experiments to analyze the chemical composition of the formation and to explore chemical
reactions between hydraulic fracturing fluid additives and the hydrocarbon-containing formation.
Data collected during the case studies are not restricted to the collection of field samples. Other data
include results from mechanical integrity tests and surface geophysical testing. Mechanical well integrity
can be assessed using a variety of tools, including acoustic cement bond tools, ultrasonic transducers,
temperature and noise logging tools, and pressure tests. Geophysical testing can assess geologic and
hydrogeologic conditions, detect and map underground structures, and evaluate soil and rock
properties.
Field Sampling Considerations
Samples collected from drinking water taps or treatment systems will reflect the temperature, pressure,
and redox conditions associated with the sampling site and may not reflect the true conditions in the
subsurface, particularly in dissolved gas concentrations. In cases where dissolved gases are to be
analyzed, special sampling precautions are needed. Because the depths of hydraulic fracturing wells can
exceed 1,000 feet, ground water samples will be collected from settings where the temperature and
163
-------
EPA Hydraulic Fracturing Study Plan
November 2011
1-L
bomb sampler
Duplicate |
150 mL vessels
for dissolved gas
analysis
pressure are significantly higher than at the surface.
When liquid samples are brought to the surface,
decreasing pressure can lead to off-gassing of dissolved
gases (such as methane) and to changes in redox
potential and pH that can lead to changes in the
speciation and solubility of minerals and metals.
Therefore, the sampling of water from these depths will
require specialized sampling equipment that maintains
FIGURE HI BOMB SAMPLER the pressure of the formation until the sample is
analyzed. One possible approach for this type of sampling
is to employ a bomb sampler (shown in Figure Gl) with a double-valve configuration that activates a
series of stainless steel sampling vessels to collect pressurized ground water in one sampling pass.
Use of Pressure Transducers
Pressure transducers are a commonly used tool to measure water pressure changes correlated with
changes in water levels within wells. The transducers are coupled with data loggers to electronically
record the water level and time the measurement was obtained. They are generally used as an
alternative to the frequent manual measurement of water levels. The devices used in this study consist
of a small, self-contained pressure sensor, temperature sensor, battery, and non-volatile memory. The
measurement frequency is programmable. Such data are often used to help predict groundwater flow
directions and to evaluate possible relationships between hydraulic stresses (e.g., pumping, injection,
natural recharge, etc.) and changes in water levels in wells, if sufficient data regarding the timing of the
hydraulic stresses are available. These data may aid in evaluations of hydrostratigraphy and hydraulic
communication within the aquifer.
Development and Refinement of Laboratory-Based Analytical Methods
The ability to characterize chemical compounds related to hydraulic fracturing activities depends on the
ability to detect and quantify individual constituents using appropriate analytical methods. As discussed
in Chapter 6, EPA will identify the chemical additives used in hydraulic fracturing fluids as well as those
found in flowback and produced water, which may include naturally occurring substances and
reaction/degradation products of fracturing fluid additives. The resulting list of chemicals will be
evaluated for existing analytical methods. Where analytical methods exist, detailed information will be
compiled on detection limits, interferences, accuracy, and precision. In other instances, standardized
analytical methods may not be readily available for use on the types of samples generated by hydraulic
fracturing activities. In these situations, a prioritization strategy informed by risk, case studies, and
experimental and modeling investigations will be used to develop analytical methods for high-priority
chemicals in relevant environmental matrices (e.g., brines).
The sampling and analytical chemistry requirements depend on the specific goals of the field
investigation (e.g., detection, quantification, toxicity, fate and transport). Sample types may include
formulations of hydraulic fracturing fluid systems, water samples (e.g., ambient water, flowback, and
164
-------
EPA Hydraulic Fracturing Study Plan
November 2011
produced water), drilling fluids, soil, and solid residues. In many cases, samples may reflect the presence
of multiple phases (gas-liquid-solid) that impact chemical partitioning in the environment. Table H2
briefly discusses the types of analytical instrumentation that can be applied to samples collected during
field investigations (both retrospective and prospective case studies).
TABLE H2. OVERVIEW OF ANALYTICAL INSTRUMENTS THAT CAN BE USED TO IDENTIFY AND QUANTIFY
CONSTITUENTS ASSOCIATED WITH HYDRAULIC FRACTURING ACTIVITIES
Type of Analyte
Analytical Instrument(s)
MDL Range*
Volatile organics
GC/MS: gas chromatograph/mass spectrometer
GC/MS/MS: gas chromatograph/mass spectrometer/
mass spectrometer
0.25-10 ng/L
Water-soluble organics
LC/MS/MS: liquid chromatograph/mass
spectrometer/mass spectrometer
0.01-0.025 ng/L
Unknown organic compounds
LC/TOF: liquid chromatograph/time-of-flight mass
spectrometer
5 Mg/L
Metals, minerals
ICP: inductively coupled plasma
1-100 ng/L
GFAA: graphite furnace atomic absorption
0.5-1 ng/L
Transition metals, isotopes
ICP/MS: inductively coupled plasma/mass spectrometer
0.5-10 ng/L
Redox-sensitive metal species,
LC/ICP/MS: liquid chromatograph/inductively coupled
0.5-10 ng/L
oxyanion speciation, thioarsenic
plasma/mass spectrometer
speciation, etc.
Ions (charged elements or
IC: ion chromatograph
0.1-1 mg/L
compounds)
The minimum detection limit, which depends on the targeted analyte.
Potential Challenges
The analysis of field samples collected during case studies is not without challenges. Two anticipated
challenges are discussed below: matrix interference and the analysis of unknown chemical compounds.
Matrix Interference
The sample matrix can affect the performance of the analytical methods being used to identify and
quantify target analytes; typical problems include interference with the detector signal (suppression or
amplification) and reactions with the target analyte, which can reduce the apparent concentration or
complicate the extraction process. Some potential matrix interferences are listed in Table H3.
165
-------
EPA Hydraulic Fracturing Study Plan
November 2011
TABLE H3. EXAMPLES OF MATRIX INTERFERENCES THAT CAN COMPLICATE ANALYTICAL APPROACHES USED TO
CHARACTERIZE SAMPLES ASSOCIATED WITH HYDRAULIC FRACTURING
Type of Matrix
Interference
Example Interferences
Potential Impacts on Chemical Analysis
Chemical
• Inorganics: metals, minerals, ions
• Organics: coal, shale,
hydrocarbons
• Dissolved gases: methane,
hydrogen sulfide, carbon dioxide
• pH
• Oxidation potential
• Complexation or co-precipitation with analyte,
impacting extraction efficiency, detection, and
recovery
• Reaction with analyte changing apparent
concentration
• Impact on pH, oxidation potential, microbial growth
• Impact on solubility, microbial growth
Biological
• Bacterial growth
• Biodegradation of organic compounds, which can
change redox potential, or convert electron acceptors
(iron, sulfur, nitrogen, metalloids)
Physical
• Pressure and temperature
• Dissolved and suspended solids
• Geologic matrix
• Changes in chemical equilibria, solubility, and
microbial growth
• Release of dissolved minerals, sequestration of
constituents, and mobilization of minerals, metals
Some gases and organic compounds can partition out of the aqueous phase into a non-aqueous phase
(already present or newly formed), depending on their chemical and physical properties. With the
numbers and complex nature of additives used in hydraulic fracturing fluids, the chemical composition
of each phase depends on partitioning relationships and may depend on the overall composition of the
mixture. The unknown partitioning of chemicals to different phases makes it difficult to accurately
determine the quantities of target analytes. In order to address this issue, EPA has asked for chemical
and physical properties of hydraulic fracturing fluid additives in the request for information sent to the
nine hydraulic fracturing service providers.
Analysis of Unknown Chemical Compounds
Once injected, hydraulic fracturing fluid additives may maintain their chemical structure, partially or
completely decompose, or participate in reactions with the surrounding strata, fluids, gases, or
microbes. These reactions may result in the presence of degradates, metabolites, or other
transformation products, which may be more or less toxic than the parent compound and consequently
increase or decrease the risks associated with hydraulic fracturing formulations. The identification and
quantification of these products may be difficult, and can be highly resource intensive and time-
consuming. Therefore, the purpose of each chemical analysis will be clearly articulated to ensure that
the analyses are planned and performed in a cost-effective manner.
Data Analysis
The data collected by EPA during retrospective case studies will be used to determine the source and
extent of reported drinking water contamination. In these cases, EPA will use different methods to
investigate the sources of contamination and the extent to which the contamination has occurred. One
important method to determine the source and migration pathways of natural gas is isotopic
fingerprinting, which compares both the chemical composition and the isotopic compositions of natural
gas. Although natural gas is composed primarily of methane, it can also include ethane, propane,
166
-------
EPA Hydraulic Fracturing Study Plan
November 2011
butane, and pentane, depending on how it is formed. Table H4 illustrates different types of gas, the
constituents, and the formation process of the natural gas.
TABLE H4. TYPES OF NATURAL GASES, CONSTITUENTS, AND PROCESS OF FORMATION
Type of Natural Gas
Constituents
Process of Formation
Thermogenic gas
Methane, ethane, propane,
butane, and pentane
Geologic formation of fossil fuel
Biogenic gas
Methane and ethane
Methane-producing
microorganisms chemically break
down organic material
Thermogenic light hydrocarbons detected in soil gas typically have a well-defined composition indicative
of reservoir composition. Above natural gas reservoirs, methane dominates the light hydrocarbon
fraction; above petroleum reservoirs, significant concentrations of ethane, propane, and butane are
found (Jones et al., 2000). Also, ethane, propane, and butane are not produced by biological processes
in near-surface sediments; only methane and ethylene are products of biodegradation. Thus, elevated
levels of methane, ethane, propane, and butane in soil gas indicate thermogenic origin and could serve
as tracers for natural gas migration from a reservoir.
The isotopic signature of methane can also be used to delineate the source of natural gas migration in
retrospective case studies because it varies with the formation process. Isotopic fingerprinting uses two
parameters—613C and 6D—to identify thermogenic and biogenic methane. These two parameters are
equal to the ratio of the isotopes 13C/12C and D/H, respectively. Baldassare and Laughrey (1997), Schoell
(1980 and 1983), Kaplan et al. (1997), Rowe and Muehlenbachs (1999), and others have summarized
values of 613C and 6D for methane, and their data show that it is often possible to distinguish methane
formed from biogenic and thermogenic processes by plotting 613C versus 6D. Thus, the isotopic
signature of methane recovered from retrospective case study sites can be compared to the isotopic
signature of potential sources of methane near the contaminated site. Isotopic fingerprinting of
methane, therefore, could be particularly useful for determining if the methane is of thermogenic origin
and in situations where multiple methane sources are present.
In prospective case studies, EPA will use the data collected from field samples to (1) provide a
comprehensive picture of drinking water resources during all stages in the hydraulic fracturing water
lifecycle and (2) inform hydraulic fracturing models, which may then be used to predict impacts of
hydraulic fracturing on drinking water resources.
Evaluation of Potential Indicators of Contamination
Natural gas is not the only potential chemical indicator for gas migration due to hydraulic fracturing
activities: Hydrogen sulfide, hydrogen, and helium may also be used as potential tracers. Hydrogen
sulfide is produced during the anaerobic decomposition of organic matter by sulfur bacteria, and can be
found in varying amounts in sulfur deposits, volcanic gases, sulfur springs, and unrefined natural gas and
petroleum, making it a potential indicator of natural gas migration. Hydrogen gas (H2) and helium (He)
are widely recognized as good fault and fracture indicators because they are chemically inert, physically
stable, and highly insoluble in water (Klusman, 1993; Ciotoli et al., 1999 and 2004). For example, H2 and
167
-------
EPA Hydraulic Fracturing Study Plan
November 2011
He have been observed in soil gas at values up to 430 and 50 parts per million by volume (ppmv)
respectively over the San Andreas Fault in California (Jones and Pirkle, 1981), and Wakita et al. (1978)
has observed He at a maximum concentration of 350 ppmv along a nitrogen vent in Japan. The presence
of He in soil gas is often independent of the oil and gas deposits. However, since He is more soluble in oil
than water, it is frequently found at elevated concentrations in soil gas above natural gas and petroleum
reservoirs and hence may serve as a natural tracer for gas migration.
EPA will use the data collected from field samples to identify and evaluate other potential indicators of
hydraulic fracturing fluid migration into drinking water supplies. For example, flowback and produced
water have higher ionic strengths (due to large concentrations of potassium and chloride) than surface
waters and shallow ground water and may also have different isotopic compositions of strontium and
radium. Although potassium and chloride are often used as indicators of flowback or produced water,
they are not considered definitive. However, if the isotopic composition of the flowback or produced
water differs significantly from those of nearby drinking water resources, then isotopic ratios could be
sensitive indicators of contamination. Recent research by Peterman et al. (2010) lends support for
incorporating such analyses into this study. Additionally, DOE NETL is working to determine if stable
isotopes can be used to identify Marcellus flowback and produced water when commingled with surface
waters or shallow ground water. EPA also plans to use this technique to evaluate contamination
scenarios in the retrospective case studies and will coordinate with DOE on this aspect of the research.
References
Baldassare, F. J., & Laughrey, C. D. (1997). Identifying the sources of stray methane by using geochemical
and isotopic fingerprinting. Environmental Geosciences, 4, 85-94.
Ciotoli, G., Etiope, G., Guerra, M., & Lombardi, S. (1999). The detection of concealed faults in the Ofanto
basin using the correlation between soil-gas fracture surveys. Tectonophysics, 299, 321-332.
Ciotoli, G., Lombardi, S., Morandi, S., & Zarlenga, F. (2004). A multidisciplinary statistical approach to
study the relationships between helium leakage and neotectonic activity in a gas province: The Vasto
basin, Abruzzo-Molise (central Italy). The American Association of Petroleum Geologists Bulletin, 88, 355-
372.
Jones, V. T., & Pirkle, R. J. (1981, March 29-April 3). Helium and hydrogen soil gas anomalies associated
with deep or active faults. Presented at the American Chemical Society Annual Conference, Atlanta, GA.
Jones, V. T., Matthews, M. D., & Richers, D. M. (2000). Light hydrocarbons for petroleum and gas
prospecting. In M. Hale (Ed.), Handbook of Exploration Geochemistry (pp. 133-212). Elsevier Science B.V.
Kaplan, I. R., Galperin, Y., Lu, S., & Lee, R. (1997). Forensic environmental geochemistry—Differential of
fuel-types, their sources, and release time. Organic Geochemistry, 27, 289-317.
Klusman, R. W. (1993). Soil gas and related methods for natural resource exploration. New York, NY:
John Wiley & Sons.
168
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Peterman, Z. E., Thamke, J., & Futa, K. (2010, May 14). Strontium isotope detection of brine
contamination of surface water and groundwater in the Williston Basin, northeastern Montana.
Presented at the GeoCanada Annual Conference, Calgary, Alberta, Canada.
Rowe, D., & Muehlenbachs, K. (1999). Isotopic fingerprinting of shallow gases in the western Canadian
sedimentary basin—Tools for remediation of leaking heavy oil wells. Organic Geochemistry, 30, 861-871.
Schoell, M. (1980). The hydrogen and carbon isotopic composition of methane from natural gases of
various origin. Geochimica et Cosmochimica Acta, 44, 649-661.
Schoell, M. (1983). Genetic characteristics of natural gases. American Association of Petroleum
Geologists Bulletin, 67, 2225-2238.
Wakita, H., Fujii, N., Matsuo, S., Notsu, K., Nagao, K., & Takaoka, N. (1978, April 28). Helium spots:
Caused by diapiric magma from the upper mantle. Science, 200(4340), 430-432.
169
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Glossary
Abandoned well: A well that is no longer in use, whether dry, inoperable, or no longer productive.1
ACToR: EPA's online warehouse of all publicly available chemical toxicity data, which can be used to find
all publicly available data about potential chemical risks to human health and the environment. ACToR
aggregates data from over 500 public sources on over 500,000 environmental chemicals searchable by
chemical name, other identifiers, and chemical structure.15
Aerobic: Life or processes that require, or are not destroyed by, the presence of oxygen.2
Anaerobic: A life or process that occurs in, or is not destroyed by, the absence of oxygen.2
Analyte: A substance or chemical constituent being analyzed.3
Aquiclude: An impermeable body of rock that may absorb water slowly, but does not transmit it.4
Aquifer: An underground geological formation, or group of formations, containing water. A source of
ground water for wells and springs.2
Aquitard: A geological formation that may contain ground water but is not capable of transmitting
significant quantities of it under normal hydraulic gradients.2
Assay: A test for a specific chemical, microbe, or effect.2
Biocide: Any substance the kills or retards the growth of microorganisms.5
Biodegradation: The chemical breakdown of materials under natural conditions.2
Casing: Pipe cemented in the well to seal off formation fluids and to keep the hole from caving in.1
Coalbed: A geological layer or stratum of coal parallel to the rock stratification.
DSSTox: A public forum for publishing downloadable, structure-searchable, standardized chemical
structure files associated with toxicity data.2
ExpoCastDB: A database that consolidates observational human exposure data and links with toxicity
data, environmental fate data, and chemical manufacture information.13
HERO: Database that includes more than 300,000 scientific articles from the peer-reviewed literature
used by EPA to develop its Integrated Science Assessments (ISA) that feed into the NAAQS review. It also
includes references and data from the Integrated Risk Information System (IRIS), a database that
supports critical agency policymaking for chemical regulation. Risk assessments characterize the nature
and magnitude of health risks to humans and the ecosystem from pollutants and chemicals in the
environment.14
HPVIS: Database that provides access to health and environmental effects information obtained through
the High Production Volume (HPV) Challenge.
170
-------
EPA Hydraulic Fracturing Study Plan
November 2011
IRIS: A human health assessment program that evaluates risk information on effects that may result
from exposure to environmental contaminants.2
Flowback water: After the hydraulic fracturing procedure is completed and pressure is released, the
direction of fluid flow reverses, and water and excess proppant flow up through the wellbore to the
surface. The water that returns to the surface is commonly referred to as "flowback."6
Fluid leakoff: The process by which injected fracturing fluid migrates from the created fractures to other
areas within the hydrocarbon-containing formation.
Formation: A geological formation is a body of earth material with distinctive and characteristic
properties and a degree of homogeneity in its physical properties.2
Ground water: The supply of fresh water found beneath the Earth's surface, usually in aquifers, which
supply wells and springs. It provides a major source of drinking water.2
Horizontal drilling: Drilling a portion of a well horizontally to expose more of the formation surface area
to the wellbore.1
Hydraulic fracturing: The process of using high pressure to pump fluid, often carrying proppants into
subsurface rock formations in order to improve flow into a wellbore.1
Hydraulic fracturing water lifecycle: The lifecycle of water in the hydraulic fracturing process,
encompassing the acquisition of water, chemical mixing of the fracturing fluid, injection of the fluid into
the formation, the production and management of flowback and produced water, and the ultimate
treatment and disposal of hydraulic fracturing wastewaters.
Impoundment: A body of water or sludge confined by a dam, dike, floodgate, or other barrier.2
Mechanical integrity: An injection well has mechanical integrity if: (1) there is no significant leak in the
casing, tubing, or packer (internal mechanical integrity) and (2) there is no significant fluid movement
into an underground source of drinking water through vertical channels adjacent to the injection
wellbore (external mechanical integrity).7
Natural gas or gas: A naturally occurring mixture of hydrocarbon and non-hydrocarbon gases in porous
formations beneath the Earth's surface, often in association with petroleum. The principal constituent is
methane.1
Naturally occurring radioactive materials: All radioactive elements found in the environment, including
long-lived radioactive elements such as uranium, thorium, and potassium and any of their decay
products, such as radium and radon.
Play: A set of oil or gas accumulations sharing similar geologic and geographic properties, such as source
rock, hydrocarbon type, and migration pathways.1
171
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Produced water: After the drilling and fracturing of the well are completed, water is produced along
with the natural gas. Some of this water is returned fracturing fluid and some is natural formation water.
These produced waters move back through the wellhead with the gas.8
Proppant/propping agent: A granular substance (sand grains, aluminum pellets, or other material) that
is carried in suspension by the fracturing fluid and that serves to keep the cracks open when fracturing
fluid is withdrawn after a fracture treatment.9
Prospective case study: Sites where hydraulic fracturing will occur after the research is initiated. These
case studies allow sampling and characterization of the site prior to, and after, water extraction, drilling,
hydraulic fracturing fluid injection, flowback, and gas production. The data collected during prospective
case studies will allow EPA to evaluate changes in water quality over time and to assess the fate and
transport of chemical contaminants.
Public water system: A system for providing the public with water for human consumption (through
pipes or other constructed conveyances) that has at least 15 service connections or regularly serves at
least 25 individuals.10
Redox (reduction-oxidation) reaction: A chemical reaction involving transfer or electrons from one
element to another.3
Residential well: A pumping well that serves one home or is maintained by a private owner.5
Retrospective case study: A study of sites that have had active hydraulic fracturing practices, with a
focus on sites with reported instances of drinking water resource contamination or other impacts in
areas where hydraulic fracturing has already occurred. These studies will use existing data and possibly
field sampling, modeling, and/or parallel laboratory investigations to determine whether reported
impacts are due to hydraulic fracturing activities.
Shale: A fine-grained sedimentary rock composed mostly of consolidated clay or mud. Shale is the most
frequently occurring sedimentary rock.9
Source water: Operators may withdraw water from surface or ground water sources themselves or may
purchase it from suppliers.6
Subsurface: Earth material (as rock) near but not exposed at the surface of the ground.11
Surface water: All water naturally open to the atmosphere (rivers, lakes, reservoirs, ponds, streams,
impoundments, seas, estuaries, etc.).2
Tight sands: A geological formation consisting of a matrix of typically impermeable, non-porous tight
sands.
Toe: The far end of the section that is horizontally drilled.12
172
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Total dissolved solids (TDS): All material that passes the standard glass river filter; also called total
filterable residue. Term is used to reflect salinity.2
ToxCastDB: A database that links biological, metabolic, and cellular pathway data to gene and in vitro
assay data for the chemicals screened in the ToxCast HTS assays. Also included in ToxCastDB are human
disease and species homology information, which correlate with ToxCast assays that affect specific
genetic loci. This information is designed to make it possible to infer the types of human disease
associated with exposure to these chemicals.16
ToxRefDB: A database that collects in vivo animal studies on chemical exposures.17
Turbidity: A cloudy condition in water due to suspended silt or organic matter.2
Underground injection well (UIC): A steel- and concrete-encased shaft into which hazardous waste is
deposited by force and under pressure.2
Underground source of drinking water (USDW): An aquifers currently being used as a source of drinking
water or capable of supplying a public water system. USDWs have a TDS content of 10,000 milligrams
per liter or less, and are not "exempted aquifers."2
Vadose zone: The zone between land surface and the water table within which the moisture content is
less than saturation (except in the capillary fringe) and pressure is less than atmospheric. Soil pore space
also typically contains air or other gases. The capillary fringe is included in the vadose zone.2
Water table: The level of ground water.2
References
1. Oil and Gas Mineral Services. (2010). Oil and gas terminology. Retrieved January 20, 2011, from
http://www.mineralweb.com/library/oil-and-gas-terms.
2. US Environmental Protection Agency. (2006). Terms of environment: Glossary, abbreviations and
acronyms. Retrieved January 20, 2011, from http://www.epa.gov/OCEPAterms/
aterms.html.
3. Harris, D. C. (2003). Quantitative chemical analysis. Sixth edition. New York, NY: W. H. Freeman
and Company.
4. Geology Dictionary. (2006). Aquiclude. Retrieved January 30, 2011, from http://
www.alcwin.org/Dictionary_Of_Geology_Description-136-A.htm.
5. Webster's New World College Dictionary. (1999). Fourth edition. Cleveland, OH: Macmillan USA.
6. New York State Department of Environmental Conservation. (2011, September). Supplemental
generic environmental impact statement on the oil, gas and solution mining regulatory program
(revised draft). Well permit issuance for horizontal drilling and high-volume hydraulic fracturing
to develop the Marcellus Shale and other low-permeability gas reservoirs. Albany, NY: New York
State Department of Environmental Conservation, Division of Mineral Resources, Bureau of Oil
& Gas Regulation. Retrieved January 20, 2011, from ftp://ftp.dec.state.ny.us/dmn/download/
OGdSGEISFull.pdf.
173
-------
EPA Hydraulic Fracturing Study Plan
November 2011
7. U. S. Environmental Protection Agency. (2010). Glossary of underground injection control terms.
Retrieved January 19, 2011, from http://www.epa.gOv/r5water/uic/glossary.htm#ltds.
8. Ground Water Protection Council & ALL Consulting. (2009, April). Modern shale gas
development in the US: A primer. Prepared for the US Department of Energy, Office of Fossil
Energy and National Energy Technology Laboratory. Retrieved January 20, 2011, from
http://www.netl.doe.gov/technologies/oil-gas/publications/EPreports/
Shale_Gas_Primer_2009.pdf.
9. US Department of the Interior. Bureau of Ocean Energy Management, Regulation and
Enforcement: Offshore minerals management glossary. Retrieved January 20, 2011, from
http://www.mms.gOv/glossary/d.htm.
10. U. S. Environmental Protection Agency. (2010.) Definition of a public water system. Retrieved
January 30, 2011, from http://water.epa.gov/infrastructure/drinkingwater/pws/pwsdef2.cfm.
11. Merriam-Webster's Dictionary. (2011). Subsurface. Retrieved January 20, 2011, from
http://www.merriam-webster.com/dictionary/subsurface.
12. Society of Petroleum Engineers. (2011). SPE E&P Glossary. Retrieved September 14, 2011, from
http://www.spe.Org/glossary/wiki/doku.php/welcome#terms_of_use.
13. U.S. Environmental Protection Agency. (2011, September 21). Expocast. Retrieved October 5,
2011, from http://www.epa.gov/ncct/expocast/.
14. U.S. Environmental Protection Agency. (2011, October 31). The HERO Database. Retrieved
October 31, 2011, from http://hero.epa.gov/.
15. Judson, R., Richard, A., Dix, D., Houck, K., Elloumi, F., Martin, M., Cathey, T., Transue, T.R.,
Spencer, R., Wolf, M. (2008) ACTOR - Aggregated Computational Toxicology Resource.
Toxicology and Applied Pharmacology, 233: 7-13.
16. Martin, M.T., Judson, R.S., Reif, D.M., Kavlock, R.J., Dix, D.J. (2009) Profiling Chemicals Based on
Chronic Toxicity Results from the U.S. EPAToxRef Database. Environmental Health Perspectives,
117(3):392-9.
17. U.S. Environmental Protection Agency. (2011, October 31). The HERO Database. Retrieved
October 31, 2011, from http://actor.epa.gov/actor/faces/ToxCastDB/Home.jsp.
174
-------
EPA Hydraulic Fracturing Study Plan
November 2011
Total dissolved solids (TDS): All material that passes the standard glass river filter; also called total
filterable residue. Term is used to reflect salinity.2
ToxCastDB: A database that links biological, metabolic, and cellular pathway data to gene and in vitro
assay data for the chemicals screened in the ToxCast HTS assays. Also included in ToxCastDB are human
disease and species homology information, which correlate with ToxCast assays that affect specific
genetic loci. This information is designed to make it possible to infer the types of human disease
associated with exposure to these chemicals.16
ToxRefDB: A database that collects in vivo animal studies on chemical exposures.17
Turbidity: A cloudy condition in water due to suspended silt or organic matter.2
Underground injection well (UIC): A steel- and concrete-encased shaft into which hazardous waste is
deposited by force and under pressure.2
Underground source of drinking water (USDW): An aquifers currently being used as a source of drinking
water or capable of supplying a public water system. USDWs have a TDS content of 10,000 milligrams
per liter or less, and are not "exempted aquifers."2
Vadose zone: The zone between land surface and the water table within which the moisture content is
less than saturation (except in the capillary fringe) and pressure is less than atmospheric. Soil pore space
also typically contains air or other gases. The capillary fringe is included in the vadose zone.2
Water table: The level of ground water.2
References
1. Oil and Gas Mineral Services. (2010). Oil and gas terminology. Retrieved January 20, 2011, from
http://www.mineralweb.com/library/oil-and-gas-terms.
2. US Environmental Protection Agency. (2006). Terms of environment: Glossary, abbreviations and
acronyms. Retrieved January 20, 2011, from http://www.epa.gov/OCEPAterms/
aterms.html.
3. Harris, D. C. (2003). Quantitative chemical analysis. Sixth edition. New York, NY: W. H. Freeman
and Company.
4. Geology Dictionary. (2006). Aquiclude. Retrieved January 30, 2011, from http://
www.alcwin.org/Dictionary_Of_Geology_Description-136-A.htm.
5. Webster's New World College Dictionary. (1999). Fourth edition. Cleveland, OH: Macmillan USA.
6. New York State Department of Environmental Conservation. (2011, September). Supplemental
generic environmental impact statement on the oil, gas and solution mining regulatory program
(revised draft). Well permit issuance for horizontal drilling and high-volume hydraulic fracturing
to develop the Marcellus Shale and other low-permeability gas reservoirs. Albany, NY: New York
State Department of Environmental Conservation, Division of Mineral Resources, Bureau of Oil
& Gas Regulation. Retrieved January 20, 2011, from ftp://ftp.dec.state.ny.us/dmn/download/
OGdSGEISFull.pdf.
173
-------
EPA Hydraulic Fracturing Study Plan
November 2011
7. U. S. Environmental Protection Agency. (2010). Glossary of underground injection control terms.
Retrieved January 19, 2011, from http://www.epa.gOv/r5water/uic/glossary.htm#ltds.
8. Ground Water Protection Council & ALL Consulting. (2009, April). Modern shale gas
development in the US: A primer. Prepared for the US Department of Energy, Office of Fossil
Energy and National Energy Technology Laboratory. Retrieved January 20, 2011, from
http://www.netl.doe.gov/technologies/oil-gas/publications/EPreports/
Shale_Gas_Primer_2009.pdf.
9. US Department of the Interior. Bureau of Ocean Energy Management, Regulation and
Enforcement: Offshore minerals management glossary. Retrieved January 20, 2011, from
http://www.mms.gOv/glossary/d.htm.
10. U. S. Environmental Protection Agency. (2010.) Definition of a public water system. Retrieved
January 30, 2011, from http://water.epa.gov/infrastructure/drinkingwater/pws/pwsdef2.cfm.
11. Merriam-Webster's Dictionary. (2011). Subsurface. Retrieved January 20, 2011, from
http://www.merriam-webster.com/dictionary/subsurface.
12. Society of Petroleum Engineers. (2011). SPE E&P Glossary. Retrieved September 14, 2011, from
http://www.spe.Org/glossary/wiki/doku.php/welcome#terms_of_use.
13. U.S. Environmental Protection Agency. (2011, September 21). Expocast. Retrieved October 5,
2011, from http://www.epa.gov/ncct/expocast/.
14. U.S. Environmental Protection Agency. (2011, October 31). The HERO Database. Retrieved
October 31, 2011, from http://hero.epa.gov/.
15. Judson, R., Richard, A., Dix, D., Houck, K., Elloumi, F., Martin, M., Cathey, T., Transue, T.R.,
Spencer, R., Wolf, M. (2008) ACTOR - Aggregated Computational Toxicology Resource.
Toxicology and Applied Pharmacology, 233: 7-13.
16. Martin, M.T., Judson, R.S., Reif, D.M., Kavlock, R.J., Dix, D.J. (2009) Profiling Chemicals Based on
Chronic Toxicity Results from the U.S. EPAToxRef Database. Environmental Health Perspectives,
117(3):392-9.
17. U.S. Environmental Protection Agency. (2011, October 31). The HERO Database. Retrieved
October 31, 2011, from http://actor.epa.gov/actor/faces/ToxCastDB/Home.jsp.
174
------- |