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An Evaluation of the Hydraulic Fracturing Literature for the Determination of Cause–Effect Relationships and the Analysis of Environmental Risk and Sustainability


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As hydraulic fracturing has increased in recent years, debate has arisen as to its sustainability. In the chapter, we analyzed recent peer-reviewed and nonpeer-reviewed literature involving the environmental effects of hydraulic fracturing. The analysis was based on several factors. The first was for the establishment of cause-effect relationships for meeting the requirements for a probabilistic risk assessment. To accomplish this goal a generic conceptual model was proposed to describe potential cause-effect relationships. Second, we examined the technical literature for potential systemic bias. We then conducted a search for human health and ecological risk assessments. An evaluation of the current data points pointed to several areas of uncertainty in describing a cause-effect pathway suitable for a risk assessment. The results also indicated that while bending science was not widespread in the literature, signs of it were visible from every funding category, on every side of the debate, and by every bending strategy looked for. Finally, although hydraulic fracturing is a widely used technique, the search for risk assessments revealed that while there is much discussion of the need for risk assessments, only three have been done to date.
Content may be subject to copyright.
Environmental and Health Issues in Unconventional Oil and Gas Development.
Copyright © 2016 Elsevier Inc. All rights reserved.
MariAnna K. Lane, Wayne G. Landis
Institute of Environmental Toxicology, Huxley College of the Environment,
Western Washington University, Bellingham Washington USA
Hydraulic fracturing (HF) is a gas extraction technique in which high-pressure wa-
ter, sand, and chemicals are injected into natural gas wells to dislodge otherwise
difficult-to-extract gas, such as that trapped in shale and tight sand deposits. The
An Evaluation of the
Hydraulic Fracturing
Literature for the
Determination of Cause–
Effect Relationships
and the Analysis of
Environmental Risk
and Sustainability
Chapter Outline
Introduction 151
Sustainability 152
Conceptual Model and Risk
Assessment 152
Normative Science and Bending
Science 154
Evaluation Methods 155
Literature Search 155
Results 156
Characterization of Literature
Surveyed 156
Cause–Effect Pathways 161
Bending Science Criteria
Analysis 162
Relationship between Conclusion
and Sector 162
Qualitative Analysis: Specific
Examples of Bending 163
Discussion and Conclusions 166
Search Term Box 168
References 171
Environmental and Health Issues of Unconventional Oil and Gas
techniques and applications are summarized in the companion chapters. There
are 20 shale plays in the continental United States (Brittingham et al., 2014) (see
Chapter 1, fig 1.4).
HF is seen as a means of producing domestic energy and a transition fuel from
dirtier fuels like coal to renewable resources. While proponents of HF empha-
size the potential economic benefits of unconventional shale gas extraction, a
variety of associated human and environmental hazards have been identified
(see eg., Chapter 8). These hazards include concerns of ground and surface water
contamination, air quality, climate change impacts, seismic stability, toxicity of
HF chemicals, increased noise and traffic, habitat fragmentation and degrada-
tion, and human health concerns. The lack of data is a common refrain in the
assessment of these hazards. The environmental effects are the main focus of
this study, although the overlap of many of these issues and general lack of in-
formation in many cases warrants the inclusion of other related issues.
The original purpose of this chapter was to examine the sustainability of HF.
However, it soon became apparent that a systematic evaluation of the cause–
effect relationships between the potential sources of stressors and impacts to
typical endpoints had not been completed. In a recent review, Burton et al.
(2014) concluded that data were not yet sufficient to conduct an ecological risk
assessment although no risk assessment was attempted.
Our literature search and the conclusion of Burton et al. (2014) points to the
lack of a research program organized around describing causal relationships. We
propose a preliminary cause–effect conceptual model to act as a starting point
around which to organize future research on the impact and eventual sustain-
ability of HF. The next sections outline this effort.
Conceptual Model and Risk Assessment
Problem formulation is the initial step in an ecological risk assessment
(USEPA, 1998). Perhaps the most important piece in this step is the conceptual
model. The conceptual model links the stressors or action of interest in a risk
assessment by a causal network to the endpoints that drive the decision-making
process. The creation of a conceptual model and the evaluation of cause–effect
for ecological risk assessment has been a powerful tool in sorting information
and in producing an ecological risk assessment to support decision making. This
review uses the cause–effect pathway as an organizing principle in collating and
integrating the many types of publications generated describing the potential
effects of HF. For our purposes we are using the fundamental structure of the
relative risk model (Landis and Wiegers, 2005), diagrammed in Figure 10.1.
The initial point is the listing of all the potential sources of stressors for the
particular activity being investigated. In this instance we will be taking the entire
activity of the process of an HF site, from exploration, drilling, extraction, logis-
tics, and eventual closure. The stressors box represents all the potential stressors
An Evaluation of the Hydraulic Fracturing Literature
resulting from the process. This item will include not only the drilling materials
and chemicals, but also the alteration of the landscape due to having numer-
ous well pads in close proximity to the roads required for support. The habitat
box represents both the spatial location of the sources and the exposure of the
stressors as well as the types of environments. The habitat segment describes the
exposure of the stressors to the endpoints under consideration. Although HF is a
land-based operation, it can border a variety of aquatic environments. Ground-
water may also become part of the surface water in some locations. Atmospheric
releases have the potential for long-range transport, broadening the types of en-
vironments under consideration. The effects box can be toxicological in nature,
but it can also include fragmentation of the landscape, diversion of water, and
increase in total suspended solids or destruction of habitat for a threatened or
endangered species. At the end the impact box lists the endpoints being used for
the decision-making process and the potential change due to the HF operation.
In general, the entire process works best when tied to a specific operation and
location and a specific set of regulatory requirements.
Causality and the preliminary conceptual model for hydraulic fracturing.
(a) The basic structure of a cause–effect pathway as developed for the relative risk model.
(b) list of candidates for each category based on the literature search. Uncertainties exist for
many of these factors and these are listed in Table 10.2.
Environmental and Health Issues of Unconventional Oil and Gas
The cause–effect model is next populated using data from a number of sources.
Site-specific data are preferred for a number of reasons, including reliability and
relevance. However, this broader review is not tied to a site and must rely on
the published literature. We have made the decision to focus on reviews done
during the last few years as the set from which to summarize the state of knowl-
edge regarding risk to HF. Our cutoff date was June 1, 2015. As usual we have
screened the literature using criteria such as relevance of the study, quality of the
data, tools used during the analysis, and where the study sits in our cause–effect
model. However, it has also been demonstrated for a number of controversial
issues that another type of analysis is required.
Normative Science and Bending Science
Science becomes normative science when there is an embedded policy pref-
erence or goal. Examples of this include concepts like “ecosystem health”
and “sustainability,” which can be thought of as “stealth policy advocacy”
(Lackey, 2004). Taken a step further, science becomes bent science when it is
willfully manipulated to serve a predefined policy goal. This bending can take
a number of forms, from funding research that already has a specified policy
outcome to attacking scientists who publish undesirable results (McGarity and
Wagner, 2008). The concepts of bending and normative science have become well
established in the realm of science–policy interaction. These issues have been
documented extensively in everything from tobacco smoke to climate change.
In a discussion on climate change, Oreskes (2013) notes in response to contrarian
positions of denial “the cultural and intellectual question becomes, why exactly
would someone want to do that?”
In a 2003 paper on the manipulation of science, McGarity (2003) notes that
bending is frequently employed by what he calls “risk producing industries”
in order to deflect blame and liability. The driving factor in these cases is
economic interests. Adding evidence to this idea, in a psychological study Le-
wandowsky et al. (2013) found a correlation between belief in free markets,
conspiratorial thinking, and the rejection of climate change and to a lesser
extent other sciences. However, McGarity and Wagner (2008) show bending
is not restricted to industry and political conservatives but can also be seen in
government agencies, public and environmental interest groups, and trial at-
torneys. According to McGarity and Wagner (2008), bending is likely to occur
if the advocate believes costs of adverse scientific findings are higher than costs
spent undermining research and if the advocate has sufficient resources to
mount the desired attacks. Given this analysis, one would expect to find in-
stances of science bending on both sides of a contentious policy issue assum-
ing both sides have sufficient resources at their disposal.
Bending science is an obvious issue for scientists because it has the capacity to
distort the scientific literature and decrease public trust of science (McGarity and
Wagner, 2008). HF makes a good case study to assess the prevalence of bending
based on its increasing importance, public visibility, and the number of potential
An Evaluation of the Hydraulic Fracturing Literature
interest groups. To this end, we conducted a literature search of peer-reviewed and
nonpeer-reviewed literature on the environmental effects of HF, as well as a spe-
cific search for risk assessments to assess the use of decision-making tools.
Literature Search
We conducted a literature search, tied the outcomes to the cause–effect pathway
and performed an assessment of the prevalence of bending in the peer-reviewed
and nonpeer-reviewed literature. Search terms and databases used to find rel-
evant literature are included in Section “Search Term Box.” We selected papers
based on their relevance to the environmental effects of HF and currency to
provide the most current information.
The literature was then sorted as to which part of the causal pathway could be
informed by the investigation. Potential endpoints were also derived from this
survey and compiled. Many of the papers discussed uncertainties in the datasets
and in our understanding of cause–effect relationships and these were also eval-
uated. The information from these reviews was finally sorted using the bins es-
tablished from our initial causal diagram.
Criteria for analyzing data were based on the strategies for bending science de-
veloped by McGarity and Wagner (2008) and indications of tampering with
science based on Oreskes and Conway (2010). The use of literature searches
as a methodology for assessing scientific consensus and research was based on
Oreskes (2004b). McGarity and Wagner (2008) detail six strategies for bending
science summarized later.
1. Shaping science – research commissioned to produce a desired outcome
by an outside party with vested interests.
2. Hiding science – preventing undesirable scientific findings from becoming
3. Attacking science – illegitimate attacks on undesirable research.
4. Harassing scientists – false allegations of misconduct, subpoenas or
depositions, and data sharing requests on researchers with undesirable
5. Packaging science – commissioning review articles or hand-picked panels
to generate the image of consensus or communicate findings in the most
favorable light.
6. Spinning science – portraying science in a particular way to advance eco-
nomic or ideological goals rather than to communicate the science accu-
With the exception of (4), in which a literature search alone was inadequate to
assess, we used these strategies to qualitatively analyze each piece of literature
surveyed. Unlike Oreskes (2004b), which relied on abstracts, the entire body of
text of each piece of literature was closely read, funding sources investigated, and
conclusions noted to fully search for signs of bending. Literature that exhibited
Environmental and Health Issues of Unconventional Oil and Gas
any of these bending strategies is discussed in Section “Specific Examples of
Bending” in the Section “Results.”
The narrative of Oreskes and Conway (2010) detailing indications that the
science may have been tampered with or bent was summarized as seven discrete
criteria and applied to a frame of binary logic to result in a score for each piece
of literature, which could be used to compare the literature and assess the likeli-
hood of bending. These criteria are given later phrased as questions with a yes
or no answer:
1. Is it peer reviewed? Yes (1), No (0)
2. Is there original research? Yes (1), No (0)
3. Do the funding sources have vested interests? Yes (0), No (1)
4. Does the article have no misleading, or distracting facts, or terminology?
Yes (0), No (1)
5. Is there an attack on “undesirable” research or researchers? Yes (0), No (1)
6. Is only one’s own research or commentary cited? Yes (0), No (1)
7. Is the author(s) an expert in an unrelated field? Yes (0), No (1)
We assigned a score of either 1 or 0 to the answer to these questions, which
is shown next to each question mentioned previously – a score of 1 if the
answer did not indicate bending, and 0 if it did. For example, a peer-reviewed
article is theoretically less likely to be bent because the peer-review process is
designed to prevent poorly designed or corrupt research from being published.
So, if an article was peer reviewed it was assigned a score of 1, and if it was not
peer reviewed it was assigned a score of 0. It is not guaranteed, however, that
a peer-reviewed article will not be bent, so these scores should be viewed as
an initial screening of the likelihood of bending and a convenient metric for
comparing trends in the literature, not a definitive measure of the amount of
bending. An article with a lower total score would be more expected to contain
bending than an article with a higher total score. The McGarity and Wagner
(2008) bending strategies as described earlier were used to analyze and look
for specific examples of bending.
Characterization of Literature Surveyed
A total of 19 peer-reviewed and 10 nonpeer-reviewed articles were included in
this study (see Table 10.1). Funding for peer-reviewed articles came from a vari-
ety of academic, governmental, industry, and nongovernmental organizational
(NGO) sectors.
Endpoints of concern in the literature surveyed included groundwater con-
tamination, surface water contamination, air quality, climate change, ecological
impacts, toxicity, seismic stability, and social impacts (Table 10.1). Uncertainties
listed included the lack of baseline data, composition of fracturing fluid, toxicity
of specific chemicals in the fracturing fluid, chemical fate and transport, mecha-
nisms of groundwater contamination, chronic effects, risks or magnitude of risks,
An Evaluation of the Hydraulic Fracturing Literature
Table 10.1 Papers Sorted by Relevance to the Cause–Effect
Pathway and Then by Endpoint
Cause-Effect Pathway
Source Stressor Exposure Effects
Molofsky et al.
Farag and Harper
Osborn et al.
Farag and Harper
Molofsky et al.
Orem et al. (2014) Gordalla et al.
Medical Health
Experts (2014)
Darrah et al.
Barbot et al.
Barbot et al.
Vengosh et al.
Vengosh et al.
Burton et al.
Fontenot et al.
Stringfellow et al.
Goldstein et al.
Goldstein et al.
Farag et al. (2014)
Stringfellow et al.
Gordalla et al.
Fontenot et al.
Adams (2011)
Papoulias and
Velasco (2013)
Kassotis et al.
General Endpoint Papers Specific Focus
Groundwater Barbot et al. (2013) Water quality parameters
Bever (2014) Surfactant toxicity
Darrah et al. (2014) Methane contamination
Fontenot et al. (2013) Trace metals and total
dissolved solids
Fountain (2014) Methane contamination
Goldstein et al. (2014) Toxicity and contamination
McHugh et al. (2014) Comment on Fontenot et al.
Concerned Health
Professionals of NY
Drinking water contamination
Molofsky et al. (2013) Methane contamination
Mufson (2014) Methane contamination
Environmental and Health Issues of Unconventional Oil and Gas
General Endpoint Papers Specific Focus
Orem et al. (2013) Chemistry of organics
Osborn et al. (2011) Methane contamination
Stokstad (2014) Methane contamination
Vengosh et al. (2014) Methane and salt
Verango (2013) Methane contamination
Surface water Adams (2011) Trees and soil
Burton et al. (2014) Hazarads of HFHV operations
Farag et al. (2014) Salinity
Goldstein et al. (2014) Toxicity and contamination
Concerned Health
Professionals of NY
Radioactive contamination
Vengosh et al. (2014) Organics, salts, metals
Air quality Goldstein et al. (2014) Toxicity and contamination
Concerned Health
Professionals of NY
Direct and indirect pollution
Rice (2014) Human health effects
Small et al. (2014) Risk and risk governance
Climate change Small et al. (2014) Risk and risk governance
Barbot et al. (2013) HF as alternative to coal
Ecological Adams (2011) Trees and soil
Burton et al. (2014) Hazards of HVHF operations
Papoulias and Velasco
Fish histopathology
Small et al. (2014) Risk and risk governance
Toxicity Farag and Harper (2014) Salinity
Farag et al. (2014) Salinity
Goldstein et al. (2014) Toxicity and contamination
Table 10.1 Papers Sorted by Relevance to the Cause–Effect
Pathway and Then by Endpoint (cont.)
An Evaluation of the Hydraulic Fracturing Literature
impact of chemicals released into the environment, and public health impacts
(Table 10.2). The synthesis of these results is summarized in Figure 10.1b along
the lines of the cause–effect model.
The additional risk assessment searches yielded many articles discussing the
need to conduct risk assessments and several characterizations of hazards, but
were not risk assessments. The exceptions to this were risk assessments conduct-
ed by the Maryland Department of the Environment and Department of Natural
Resources (2014), a human health risk assessment of air emissions in Colorado
(McKenzie et al., 2013), a master’s thesis involving groundwater contamination
in Pennsylvania (Fletcher, 2012), and water pollution risk in the Marcellus Shale
(Rozell and Reaven, 2012). All of these risk assessments were heavily focused
on human health and could not be classified as ecological risk assessment, al-
though the Maryland (2014) assessment did have some consideration of risk to
the environment and natural resources.
General Endpoint Papers Specific Focus
Gordalla et al. (2013) HF chemicals in Germany
Kassotis et al. (2014) Endocrine disruption in human
cell lines
Stringfellow et al. (2014) Chemical, physical, and
toxicity data
Seismic stability Concerned Health
Professionals of NY
Deep-well injection as trigger
Small et al. (2014) Risk and risk governance
Vengosh et al. (2014) Injection of large water
Social Horn (2013) Delay of EPA reports
Concerned Health
Professionals of NY
Boom–bust social dynamics
Mooney (2014) NY ban versus MD policies
Robbins (2013) HF and the Endangered
Species Act
Small et al. (2014) Risk and risk governance
Soraghan (2011) Use of term “fracking”
Blank, review; gray, nonpeer-reviewed work.
Table 10.1 Papers Sorted by Relevance to the Cause–Effect
Pathway and Then by Endpoint (cont.)
Environmental and Health Issues of Unconventional Oil and Gas
Given the lack of probabilistic ecological risk assessments and even human
health risk assessments to a large degree, we conducted additional research to
determine types of analytical tools decision makers were using if not risk assess-
ments. Three specific states were singled out as examples: New York, Maryland,
and Michigan. In New York, the recent ban on HF enacted by Governor Cuomo
was based in part by a review by the New York State Department of Health,
which concluded that the current state of scientific information was insufficient
Table 10.2 Uncertainties Discussed in the Peer-Reviewed and
Nonpeer-Reviewed Literature
Uncertainty Peer-Reviewed Literature
Baseline data Adams (2011), Burton et al. (2014),
Fontenot et al. (2013), Goldstein
et al. (2014), Gordalla et al. (2013),
Molofsky et al. (2013), Osborn et al.
(2011), Vengosh et al. (2014)
Mufson (2014)
Composition of
HF fluid
Adams (2011), Barbot et al. (2013),
Goldstein et al. (2014), Stringfellow
et al. (2014)
Toxicity of
chemicals in
Burton et al. (2014), Goldstein et al.
(2014), Gordalla et al. (2013), Orem
et al. (2014), Stringfellow et al. (2014)
Bever (2014)
Chemical fate
and transport
Burton et al. (2014), Goldstein
et al. (2014), Gordalla et al. (2013),
Stringfellow et al. (2014)
Mechanism of
Darrah et al. (2014), Fontenot et al.
(2013), Goldstein et al. (2014),
McHugh et al. (2014), Molofsky et al.
(2013), Orem et al. (2014), Osborn
et al. (2011), Stockstad (2014),
Vengosh et al. (2014)
Bever (2014),
Mufson (2014),
Verango (2013)
Chronic effects Farag and Harper (2014) Mooney (2014)
of risks
Burton et al. (2014) Concerned Health
Professionals of
NY (2014), Mooney
Impact of
released into
Adams (2011), Orem et al. (2014),
Small et al. (2014)
Concerned Health
Professionals of NY
Public health
Small et al. (2014) Concerned Health
Professionals of NY
(2014), Rice (2014)
An Evaluation of the Hydraulic Fracturing Literature
to understand the public health risks associated with HF (New York State De-
partment of Health, 2014). In contrast, Maryland is a state that allows HF.
Although Maryland has a much smaller area of potential HF sites, which may
have influenced the state’s decision (Mooney, 2014), a key difference was also
that the decision was based largely on an assessment conducted by the Mary-
land Department of the Environment and the Maryland Department of Natural
Resources. Unlike the New York Department of Health review, this document
qualitatively estimates some of the hazards associated with HF.
Michigan is also a state that allows HF. A question and answer for the public on
their state website is very firm on the position to not regulate HF, suggesting that
the state has been studying HF for decades with no indication of human or en-
vironmental impacts (Michigan Department of Environmental Quality, 2015).
Recently, the state has commissioned an extensive report on the impact of HF to
a wide range of human and environmental issues from the University of Michi-
gan (see Graham Sustainability Institute, 2015).
Cause–Effect Pathways
We were able to find information on a number of factors that would compose
a cause–effect pathway for the construction of a suitable conceptual model for
performing a risk assessment (Figure 10.1b). The Maryland (2014) assessment
was particularly helpful in listing the sources.
There are a large number of potential uncertainties in quantifying the cause–ef-
fect pathway in order to produce a quantitative risk assessment. Table 10.2 lists
a number of issues regarding the uncertainties for many of these parameters.
Some can be eliminated by careful study of fracking sites, their construction, op-
eration, the infrastructure used to build the sites, measurements of downstream
emissions, the composition of the stormwater, and the composition of the drill-
ing muds, to name a few examples.
However, many of the stressors that are released, the types of receiving habitats,
and the organisms potentially exposed can be reasonably quantified for a spe-
cific site. Appropriate geographic information system analysis and a properly de-
signed monitoring program can answer the questions of stressors, habitats, and
effects as has been done for a number of contaminated sites. As for chemical-
induced effects, many of the chemicals or close analogs found in HF have been
tested in the laboratory or there is experience from other contaminated sites.
The particular differences in HF are the depths of the drilling and contamination
of deep aquifers. However, once those materials find their way to the surface the
result is that of a classic contaminated site.
The environmental endpoints are typical of any contaminated or impacted
sites. Under that column are the endpoints that comprise evaluations under the
Toxic Substance Control Act (TSCA), Resource Conservation and Recovery Act
(RCRA), Oil Pollution Act (OPA), or the Clean Water and Clean Air Acts. Specific
species, numeric water quality standards, and other site-specific numeric values
can be derived depending upon the location of the HF site.
Environmental and Health Issues of Unconventional Oil and Gas
Bending Science Criteria Analysis
Although some general trends are visible in average criteria scores, none of these
trends are significant due to the high standard deviations. Nonpeer-reviewed
papers tended to have lower scores than peer-reviewed papers (Figure 10.2a).
Peer-reviewed papers with government, academic, or NGOs all had the same
average criteria score while papers with industry funding had lower average cri-
teria scores but high standard deviation (Figure 10.2b). There was no discernible
trend in the average criteria scores for papers categorized by placement on the
cause–effect pathway (Figure 10.2c) or whether the conclusions of the papers
leaned pro, anti, or neutral toward HF (Figure 10.2d). The papers dealing with
exposure had the highest criteria score and lowest standard deviation, while the
papers regarding effects had the highest standard deviation (Figure 10.2c). This
is logical considering it is difficult to argue with exposure data – it is typically
a yes or no question. Effects, however, are much more up to interpretation and
subject to the definition of what constitutes an effect.
In each of the funding categories (government, academic, NGO, and industry) at
least 50% of the literature had conclusions that were neutral toward HF. In the
Results of the bending science analysis showing average criteria scores with error bars
showing standard deviation.
The literature is sorted by peer-reviewed and nonpeer-reviewed (a), funding source (b),
placement on the cause–effect pathway (c), and position on HF (d) categories.
An Evaluation of the Hydraulic Fracturing Literature
government and academic funding categories, the same proportion of papers had
pro and anti-HF conclusions. More NGO-funded papers had pro-HF conclusions,
although at this sample size this was only a difference of one paper. Similarly, half
of industry-funded papers had pro-HF conclusions and none had anti-HF conclu-
sions, but this may be due to a sampling error rather than to an actual trend.
Shaping. Shaping is when outside interests fund research with a particular goal
in mind. Within this set of papers, one potential instance of shaping science
was identified. In 2011 and 2013, Molofsky et al. published research aimed at
determining the mechanism of methane contamination in groundwater in the
Marcellus Shale. Both the researchers and funding for these papers were from
GSI Environmental, Inc., an environmental consulting firm, and Cabot Oil &
Gas Corporation, which has a stake in HF research as a gas extraction corpora-
tion. Interestingly, this research involves the same general location and subject
as a group of papers published by a group of researchers at Duke University
(Darrah et al., 2014; Osborn et al., 2011). While both sets of researchers ul-
timately reach the same basic conclusion that gas contamination by upward
migration triggered by HF is not occurring, they disagree about whether HF is
at all to blame for the methane contamination of groundwater in the region.
The GSI Environmental/Cabot Oil & Gas Corporation researchers conclude that
methane concentrations are best correlated with topographic and geologic fea-
tures and therefore natural and unrelated to HF activities. The Duke University
research team concluded that where instances of contamination do occur, they
are most likely to be the result of well casing failure and so related to the broader
gas extraction process but not HF directly.
It is possible that these groups of researchers came to slightly different conclu-
sions simply due to their different expertise and methods. The fact that the GSI
Environmental/Cabot Oil & Gas Corporation researchers found conclusions
that absolve HF of any responsibility for the methane contamination, howev-
er, is increasingly suspect given the additional activities of this research group,
which will be explained in Section “Attacking.”
Hiding. As McGarity and Wagner (2008) state, hiding is often the most difficult-
to-identify science-bending technique because it is only an option for those with
something to hide, and by definition it avoids being discovered. With regard to
HF, the only indication that hiding was occurring came from a Huffington Post Ar-
ticle (Horn, 2013), which details a mismatch in United States (US) Environmental
Protection Agency (EPA) internal documents and reports on a Pennsylvania study,
a similar Texas study, and the delay of a report on a Wyoming study. The article
suggests industry lobbying is a likely culprit behind the EPA’s alleged misdeeds.
Attacking. We identified two potential instances of attacks on HF research in
the literature surveyed, both centered on the issue of groundwater contamina-
tion and the GSI Environmental/Cabot Oil & Gas Corporation research group.
The first instance regards the differences between the aforementioned research
Environmental and Health Issues of Unconventional Oil and Gas
group and the Duke University research group introduced in section “Shaping.”
In an announcement on the website of GSI Environmental about the release of
the Molofsky et al. (2011) study, they advertise that “gas development activities
in the Marcellus Shale have not caused widespread methane impacts on water
wells in northeastern Pennsylvania. This directly counters allegations made in
a recent study by Duke University (Osborne et al., 2011) [sic].” They further
emphasize the “apparent misinterpretation by the Duke study [which] under-
scores the need for a multiple lines-of-evidence approach for proper character-
ization” (GSI Environmental Inc, 2013). The tone of this announcement and
use of words like “allegations” and “apparent misinterpretation” directly attacks
the Osborn et al. (2011) study and Duke researchers.
Disagreements and frank critiques of others’ work is a normal part of the sci-
entific and peer-review process. It is often difficult to determine whether such
disagreements are simply just that or if they are carefully planned attacks on
research whose only real fault is having undesirable conclusions. This point
is further illustrated by the second potential attack instance, involving a study
of water quality in drinking water wells overlying the Barnett Shale (Fontenot
et al., 2013) and a subsequent comment published in the journal regarding
that study (McHugh et al., 2014). Fontenot et al. (2013) found levels of arsenic,
strontium, selenium, and total dissolved solids exceeding maximum contami-
nant levels in some wells surveyed. They are careful to note that the source of
elevated contaminants is beyond the scope of the study and impossible to deter-
mine without measurements from before, after, and during gas extraction activi-
ties in the region, but they suggest that mechanical disturbance from drilling is
most consistent with their data.
McHugh et al. (2014) attack the conclusions of Fontenot et al. (2013). Their
complaints are that (1) Fontenot et al.’s comparison of active and nonactive
datasets is not statistically valid or meaningful to establishing causation, (2)
the comparison against historical data is flawed because of the increase in de-
tection limits of metals, and (3) the patterns in their data are not consistent
with natural gas extraction and they failed to consider mechanisms other than
natural gas extraction. On their own, these critiques seem valid. Points (1) and
(3) directly attack Fontenot et al.’s conclusion about the mechanism of contami-
nation. However, as stated earlier, Fontenot et al. (2013) were careful to note
that they were not able to definitively establish the mechanism or source of
contamination. The McHugh et al. (2014) comment makes no mention of this,
instead making it seem as if it was the main purpose of Fontenot et al. (2013)
to establish the mechanism of the contamination they found. McGarity and
Wagner (2008) note that attacks on undesirable scientific research need not be
valid to produce the desired damage; simply the presence of a critique and hint
of controversy surrounding a piece of research can be enough to dissuade deci-
sion makers from seriously considering that research. Given this, it is question-
able as to whether the goal of the McHugh et al. (2014) comment was to simply
discourage any research that connects gas extraction in any way to groundwater
An Evaluation of the Hydraulic Fracturing Literature
Packaging. Packaging involves the use of review articles to create the semblance
of scientific consensus surrounding an issue, or present research that best sup-
ports the viewpoints of the orchestrator of the review. Two review articles sur-
veyed showed some signs of packaging. The first, Small et al. (2014), was the
result of a National Research Council project, which had support from both the
Park Foundation and Shell Upstream America. The Park Foundation is an NGO,
which has contributed significantly to groups opposing HF (Soraghan, 2012).
Shell Upstream America is the US branch of Royal Dutch Shell, a global petro-
chemical corporation. The resultant text relied heavily on the use of normative
language when presenting the issues surrounding HF, noting the potential for
“widespread economic benefits” and ability to “considerably” mitigate opera-
tional risks. However, despite such instances of normative language, the overall
tone of the review remained neither pro nor anti-HF.
The second review Burton et al. (2014) received funding from the Graham
Sustainability Institute, Arkansas Game & Fish Commission, National Science
Foundation, and the Michigan Society of Fellows. Although the overall portrayal
of the issue was neither pro nor anti-HF as in Small et al. (2014), there was a lack
of citations for claims and the rather distracting claim that agriculture likely has
a larger impact on water resources than HF. Despite these shortcomings, it was
not clear in either of these review articles that the packaging had taken place to
willfully skew the perception of HF.
Spinning. Spinning is perhaps the easiest of the bending strategies to perform,
considering all it requires is that the scientific findings be cast in a light that
makes them seem most supportive of the interest group’s goals. Spinning
was also the most frequently identified category of bending in both the peer-
reviewed and nonpeer-reviewed literature. In the peer-reviewed literature the
spinning primarily occurred in Section “Discussion and Conclusions,” which
is logical as this section is typically the most qualitative and open to interpreta-
tions by the authors.
The first example of spinning in the peer-reviewed literature occurred in Orem
et al. (2014), an article analyzing the chemical components of formation and
produced water. In the conclusion, the authors stated “[t]he environmental and
human health impacts (if any) of the release of these compounds into surface
and groundwater are unclear.” This statement implies a familiarity with the lit-
erature on the subject of impacts from HF. However, the statement had no cita-
tions and there was almost no discussion of toxicity data for those chemicals.
Environmental and health impacts would indeed be unclear if you had done
little research on the subject. While it could be the case that the authors were
familiar with the topic and simply failed to include a citation, the parentheti-
cal “if any” included in the author’s claim implies a high probability that there
are no impacts. This is quite the claim to make, given the volume of research
suggesting the opposite conclusion (see Adams, 2011; Farag and Harper, 2014;
Gordalla et al., 2013; Kassotis et al., 2014). Orem et al. (2014) was funded by the
US Geological Survey Energy Resources Program and US Department of Energy.
Environmental and Health Issues of Unconventional Oil and Gas
Spinning is also observable in the discrepancies between the research and
conclusions of the GSI Environmental/Cabot Oil & Gas Corporation research
group and the Duke University research group. As mentioned before, both
groups came to the same general conclusion that gas contamination by up-
ward migration triggered by HF is not occurring. In an editorial Stockstad
(2014) notes the criticism by Molofsky that the Duke University researchers
put too heavy a focus on the few contamination events that have occurred. In
their 2013 paper, Molofsky et al. concede that there have in fact been instances
of gas well casing malfunctions resulting in stray gas migration but they em-
phasize that these are isolated, localized issues which do not result in regional
scale impacts to water quality. The mainstream media also picked up on this
debate, and their reports highlighted either the relatively small number of con-
tamination instances, the fact that contamination is occurring at all, or the
possibility of a technological fix – all of which frame the issue very differently
(see Fountain, 2014; Mufson, 2014).
In the previous cases the overall conclusion of the mainstream media ultimately
remained fairly true to the study they were reporting on, but this was not al-
ways true. This is reflected particularly well in the coverage of a Colorado study
on the surfactants added to HF fluid. The news media latched onto a claim that
these chemicals were no more toxic than household products. One particular
Washington Post article (Bever, 2014) boasted “Study: Fracking chemicals found
in toothpaste and ice cream” as the title. The study also reiterates the findings
of Darrah et al. (2014) that water contamination is from well leaks rather than
HF directly with an overall effect downplaying the hazards associated with HF.
The final example of spinning comes from a letter by public health profession-
als to Governor Cuomo and Health Commissioner Zucker of New York (Con-
cerned Health Professionals of New York 2014). As a persuasive piece intended
to convince the readers to adopt a moratorium on HF, it serves as a not-so-subtle
example of strategies for spinning science. Throughout the document, strong de-
scriptive words like “indisputable” and “unavoidable” emphasize the certainty
of science favorable to their goal while pointing out the uncertainties that re-
main and the need for more research to reduce these uncertainties. Pointing
out uncertainties in science is a classic strategy for those hoping to delay action
and is facilitated by the standards of proof required by science and the judicial
system. As Oreskes (2004a) points out, however, definitive proof has never truly
been a requirement for political action.
The findings of this study suggest that while bending may not be pervasive in
the sense that every piece of literature is likely to be bent, it is pervasive in the
sense that bending does occur in every category of funding, every side of
the debate, and by every bending strategy. This finding is significant because
while much literature has focused on the dishonest activities of industry
(Oreskes and Conway, 2010) or government under the influence of industry
An Evaluation of the Hydraulic Fracturing Literature
(Vallianatos and Jenkins, 2014), this review identified bending in peer-reviewed
literature of all funding sources and on both sides of the HF debate. This is
consistent with the claim by McGarity and Wagner (2008) that an interest
group will participate in bending if they have sufficient resources and perceive
the cost of adverse findings to be greater than the costs spent undermining
research. Additionally, signs of all strategies of bending (with the exclusion of
harassing scientists, which was beyond the scope of this study) were found in
the literature surveyed.
This finding has a number of implications for the perceived integrity of the peer-
reviewed and nonpeer-reviewed literature as well as its ease of identification.
While the criteria score rankings were a useful analytical tool, there is no simple
checklist that can be used to definitively determine whether or not a piece of lit-
erature is bent. Only careful analysis of the text can identify potential instances
of bending, and even that alone is often not enough to demonstrate that the
science was intentionally bent to further a particular goal. It is difficult to prove
bending because that specific crime can only occur with intent, and without
some knowledge of internal dynamics it is difficult to know if the potential
bending was in fact carefully calculated or simply the result of carelessness, or
unintentional bias, on the part of the individual authors.
The differences between New York’s and Maryland’s decision-making outcomes
and supporting reports highlight the impact of the subtle biases of different
disciplines. While there is a substantial amount of literature discussing the need
for risk assessments on HF and detailing the hazards, only three risk assessments
have actually been done. Several of the studies discussing risk assessments have
claimed that there is not adequate information to conduct a risk assessment
(Adgate et al., 2014; New York State Department of Health, 2014). Burton et al.
(2014) also claim that uncertainty is too high for risk assessment. However, the
ability to incorporate estimates, expert elicitation, and similar techniques into
risk assessments means that a risk assessment can be conducted even when sig-
nificant data gaps exist. Until a risk assessment is conducted, it is not possible
to conclude that the uncertainty would be too high to inform decision making.
The New York State Department of Health study (2014) alludes to the fact that
a degree of certainty is desirable for decision making, but this is no reason that
risk assessments cannot be done. Tools such as sensitivity analysis can point to
the variables critical to the outcome of the risk assessment. Given this, the wide-
spread absence of risk assessments (particularly, ecological risk assessments)
and the lack of risk assessments in this field may be due to factors other than
the uncertainties.
There are a number of reasons to conduct quantitative risk assessments for HF.
First, research and monitoring programs need to be based on specific research
questions. One of the major outcomes of a risk assessment is the identification of
specific hypotheses regarding endpoints at risk and the identification of specific
uncertainties. It may be that even with high uncertainty the estimated risk is use-
ful to decision makers in setting at least preliminary policy choices until those
Environmental and Health Issues of Unconventional Oil and Gas
uncertainties are resolved. Finally a strong conceptual model can be a framework
describing in detail what is known, the uncertainties around each, and provide
a quantitative description of the science regarding the risk due to HF. Perhaps
the end result would be in making it more difficult to bend the science using the
techniques described in this manuscript.
Table A1.1 List of Search Terms and Locations, or Other Means of
Location Where Appropriate for Literature Analyzed
Search Term or Other
Means of Location Search Engine Date
Adams (2011) Vengosh et al. (2014)
N/A 11/15/2014
Barbot et al. (2013) Hydraulic fracturing and
environmental effects
Google Scholar 10/16/2014
Bever (2014) Fracking Washington Post 1/26/2015
Burton et al. (2014) Hydraulic fracturing and
Web of Science 10/23/2014
Concerned Health
Professionals of
NY (2014)
Listed as citing
Vengosh et al. (2014)
Google Scholar 11/15/2014
Farag and Harper
Hydraulic fracturing and
Web of Science 10/23/2014
Farag et al. (2014) Author search: Farag
Web of Science 11/11/2014
Fontenot et al.
McHugh et al. (2014)
Goldstein et al.
Hydraulic fracturing and
Web of Science 10/23/2014
Gordalla et al.
Hydraulic fracturing and
Web of Science 10/23/2014
Jackson et al.
Darrah et al. (2014)
Kassotis et al.
USGS hydraulic
Google 11/15/2014
McHugh et al.
Author search:
Molofsky LJ
Web of Science 10/19/2014
Mooney (2014) Fracking Washington Post 1/26/2015
Molofsky et al.
Citation in Darrah et al.
An Evaluation of the Hydraulic Fracturing Literature
Search Term or Other
Means of Location Search Engine Date
Orem et al. (2014) Hydraulic fracturing and
Web of Science 10/23/2014
Osborn et al.
Darrah et al. (2014)
Papoulias and
Velasco (2013)
Vengosh et al. (2014)
Rice (2014) Fracking USA Today 1/26/2015
Robbins (2013) USFWS hydraulic
Google Scholar 11/15/2014
Small et al. (2014) Jackson et al. (2014)
Google Scholar 10/19/2014
Stockstad (2014) Science article N/A 10/14/2014
Stringfellow et al.
Hydraulic fracturing and
Web of Science 10/23/2014
Vengosh et al.
Hydraulic fracturing
and environmental
Web of Science 10/16/2014
Table A1.2 Results of Risk Assessment Searches, Including
Summaries of the Most Relevant Results. Searches all Conducted
2/2/2015, Except Those With Asterisks, Which Were Conducted
on 2/4/2015
Location Search Term # Results
# Risk
science and
Risk assessment
and hydraulic
43 0
toxicology and
chemistry (via
Wiley Online
2 0 Burton et al.
Table A1.1 List of Search Terms and Locations, or Other Means of
Location Where Appropriate for Literature Analyzed (cont.)
Environmental and Health Issues of Unconventional Oil and Gas
Location Search Term # Results
# Risk
(via Wiley
Online Library)
3 0
Human and
ecological risk
(via Taylor &
Francis Online
6 0
Risk analysis
(via Wiley
Online Library)
21 1 Rozell and
Science 8 0 Vidic et al.
Nature 27 0
Journal of
(via Springer
18 0 Racicot et al.
PA department
of environmen-
tal protection
10 0
WV depart-
ment of en-
31 0
Google Maryland and
hydraulic frac-
turing and risk
Department of
the Environment
and Department
of Natural
Table A1.2 Results of Risk Assessment Searches, Including
Summaries of the Most Relevant Results. Searches all Conducted
2/2/2015, Except Those With Asterisks, Which Were Conducted
on 2/4/2015 (cont.)
An Evaluation of the Hydraulic Fracturing Literature
Location Search Term # Results
# Risk
*Michigan and
hydraulic frac-
turing and risk
0University of
Michigan (2013)
*Indiana and hy-
draulic fracturing
and risk assess-
1Fletcher (2012)
*Colorado and
hydraulic frac-
turing and risk
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... Bending science is the processes by which the culture of science, regulation, and other segments of society can interact to suppress unfavorable or enhance favorable scientific results, in many cases to advance economic, political, or ideological ends (McGarity and Wagner 2008). McGarity and Wagner (2008) describe 6 major tools for bending science, which I will highlight throughout my documentation of the history of atrazine (see Lane and Landis 2016 for similar example on fracking). The first tool is shaping science, which is the art of creating research to produce a desired outcome, often referred to as outcome-oriented research. ...
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The development of unconventional oil and gas shales using hydraulic fracturing and directional drilling is currently a focal point of energy and climate change discussions. While this technology has provided access to substantial reserves of oil and gas, the need for large quantities of water, emissions, and infrastructure raises concerns over the environmental impacts. Written by an international consortium of experts, this book provides a comprehensive overview of the extraction from unconventional reservoirs, providing clear explanations of the technology and processes involved. Each chapter is devoted to different aspects including global reserves, the status of their development and regulatory framework, water management and contamination, air quality, earthquakes, radioactivity, isotope geochemistry, microbiology, and climate change. Case studies present baseline studies, water monitoring efforts and habitat destruction. This book is accessible to a wide audience, from academics to industry professionals and policy makers interested in environmental pollution and petroleum exploration.
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Fast-paced growth in natural gas production in the Marcellus Shale has fueled intense debate over the risk of groundwater contamination from hydraulic fracturing and the shale gas extraction process at large. While several notable incidents of groundwater contamination near shale gas wells have been investigated, the exact causes are uncertain and widely disputed. One of the most frequently occurring and widely reported environmental incidents from shale gas development is that of surface spills. Several million gallons of fluid are managed on each well site; significant risk for spill exists at several stages in the extraction process. While surface spills have been primarily analyzed from the perspective of surface water contamination, spills also have the potential to infiltrate groundwater aquifers. This thesis develops a risk assessment framework to analyze the risk of groundwater resource contamination in Pennsylvania from surface spills of hydraulic fracturing fluid. It first identifies the major sources of spills and characterizes the expected frequency and volume distribution of spills from these sources using results from a preliminary expert elicitation. It then develops a stochastic groundwater contaminant transport model to analyze the worst-case potential for groundwater contamination in local water wells. Finally, it discusses the range of risk perception and incentives from a wide-ranging stakeholder base, including industry, communities, environmentalists, and government. This thesis concludes that while the vast majority of shale gas operations do not result in large spills, the worst-case potential for groundwater contamination is high enough to warrant further attention; it also recommends increased inclusion of community stakeholders in both industry and government risk management strategies.
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Results from more than 1,700 water wells sampled and tested prior to proposed gas drilling in Susquehanna County, Pa., show methane to be ubiquitous in shallow groundwater, with a clear correlation of methane concentrations with surface topography. From 2010 to the present, the sampling program was extended to include all water wells within 2,500 ft of proposed gas well drilling sites in anticipation of revised Pennsylvania DEP guidelines. The Catskill formation, consisting of sandstone, shale, siltstone and conglomerate, underlies the surficial deposits. The Catskill formation outcrops on ridgetops in the majority of Susquehanna County and is roughly 1,800 ft thick. The Marcellus shale is currently the target of shale gas extraction throughout the Appalachian basin and has been estimated to contain as much as 84 tcf of gas. Vertical fracture planes are primarily oriented north-south, with penetrative planar fractures cutting through both the sandstone and shale beds of the Catskill formation.
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Significance Hydrocarbon production from unconventional sources is growing rapidly, accompanied by concerns about drinking-water contamination and other environmental risks. Using noble gas and hydrocarbon tracers, we distinguish natural sources of methane from anthropogenic contamination and evaluate the mechanisms that cause elevated hydrocarbon concentrations in drinking water near natural-gas wells. We document fugitive gases in eight clusters of domestic water wells overlying the Marcellus and Barnett Shales, including declining water quality through time over the Barnett. Gas geochemistry data implicate leaks through annulus cement (four cases), production casings (three cases), and underground well failure (one case) rather than gas migration induced by hydraulic fracturing deep underground. Determining the mechanisms of contamination will improve the safety and economics of shale-gas extraction.
Unconventional oil and natural gas extraction enabled by horizontal drilling and hydraulic fracturing (fracking) is driving an economic boom, with consequences described from "revolutionary" to "disastrous." Reality lies somewhere in between. Unconventional energy generates income and, done well, can reduce air pollution and even water use compared with other fossil fuels. Alternatively, it could slow the adoption of renewables and, done poorly, release toxic chemicals into water and air. Primary threats to water resources include surface spills, wastewater disposal, and drinking-water contamination through poor well integrity. An increase in volatile organic compounds and air toxics locally are potential health threats, but the switch from coal to natural gas for electricity generation will reduce sulfur, nitrogen, mercury, and particulate air pollution. Data gaps are particularly evident for human health studies, for the question of whether natural gas will displace coal compared with renewables, and for decadal-scale legacy issues of well leakage and plugging and abandonment practices. Critical topics for future research include data for (a) estimated ultimate recovery (EUR) of unconventional hydrocarbons, (b) the potential for further reductions of water requirements and chemical toxicity, (c) whether unconventional resource development alters the frequency of well integrity failures, (d) potential contamination of surface and ground waters from drilling and spills, (e) factors that could cause wastewater injection to generate large earthquakes, and (f) the consequences of greenhouse gases and air pollution on ecosystems and human health.
This paper deals with the possible impact of hydraulic fracturing (fracking), employed in the exploitation of unconventional shale gas and tight gas reservoirs, on groundwater, which is the most important source of drinking-water in Germany and many other European countries. This assessment, which is part of an interdisciplinary study by a panel of neutral experts on the risks and environmental impact of hydraulic fracturing, is based mainly on data obtained from three ExxonMobil drilling sites in northern Germany. First, the basic technical aspects of fracking and its relevant water fluxes are explained. The type, purpose and fate of the constituents of the fracking fluids are discussed. The chemicals used in the fracking fluids are assessed with regard to their hazardous properties according to the Regulation (EC) No. 1272/2008 of the European Parliament and of the Council on the classification, labelling and packaging of substances and mixtures (CLP regulation) and the German “Water Hazard Classes”. Contamination of groundwater by ingredients of fracking fluids may occur from under ground or may result from above-ground accidents associated with the transport, storage and handling of hazardous substances used as additives in fracking fluids. The degree of groundwater contamination cannot be predicted in a general way. Therefore, different dilutions of the fracking fluid in groundwater are considered. It is shown that the concentrations of most ingredients resulting from a 1:10,000 up to 1:100,000 dilution of the fracking fluid in groundwater are below health-based reference values such as the limit values of the European Drinking Water Directive, the WHO Guideline Values for Drinking-water Quality, and other health-based guide values for drinking-water. Regarding the salinity of fracking fluids, a dilution of 1:1,000 is sufficient to reach concentrations which are acceptable for drinking-water. From the human-toxicological point of view, the constituents of flowback water are more problematic with respect to drinking-water produced from groundwater than those of the fracking fluids. The few reliable data which have become available, as well as hydrogeological considerations, point in the direction of considerable salt concentrations and toxic constituents, e.g., Hg, As, Pb, Zn, Cd, BTX, PAHs, or even radioactive elements. The identification and assessment of reaction products and metabolites, which are produced as a result of the fracking operation and the metabolic activity of microorganisms, are important topics for further research. The recommendations include the need for a better understanding of the environmental impact of fracking operations, especially with regard to the development of sustainable rules for planning, permission, performance and management of fracking, and for the monitoring of groundwater quality around fracked drilling sites.
Technological advances in hydraulic fracturing and horizontal drilling have led to the exploration and exploitation of shale oil and gas both nationally and internationally. Extensive development of shale resources has occurred within the United States over the past decade, yet full build out is not expected to occur for years. Moreover, countries across the globe have large shale resources and are beginning to explore extraction of these resources. Extraction of shale resources is a multistep process that includes site identification, well pad and infrastructure development, well drilling, high-volume hydraulic fracturing and production; each with its own propensity to affect associated ecosystems. Some potential effects, for example from well pad, road and pipeline development, will likely be similar to other anthropogenic activities like conventional gas drilling, land clearing, exurban and agricultural development and surface mining (e.g., habitat fragmentation and sedimentation). Therefore, we can use the large body of literature available on the ecological effects of these activities to estimate potential effects from shale development on nearby ecosystems. However, other effects, such as accidental release of wastewaters, are novel to the shale gas extraction process making it harder to predict potential outcomes. Here, we review current knowledge of the effects of high-volume hydraulic fracturing coupled with horizontal drilling on terrestrial and aquatic ecosystems in the contiguous United States, an area that includes 20 shale plays many of which have experienced extensive development over the past decade. We conclude that species and habitats most at risk are ones where there is an extensive overlap between a species range or habitat type and one of the shale plays (leading to high vulnerability) coupled with intrinsic characteristics such as limited range, small population size, specialized habitat requirements, and high sensitivity to disturbance. Examples include core forest habitat and forest specialists, sagebrush habitat and specialists, vernal pond inhabitants and stream biota. We suggest five general areas of research and monitoring that will aid in development of effective guidelines and policies to minimize negative impacts and protect vulnerable species and ecosystems: 1) spatial analyses, 2) species-based modeling, 3) vulnerability assessments, 4) ecoregional assessments, and 5) threshold and toxicity evaluations.