Repository for Oil and Gas Energy Research (ROGER)

Abstract:
Mitigating hydraulic fracturing-induced seismicity (HF-IS) poses a challenge for shale gas companies and regulators alike. The use of Traffic Light Schemes (TLSs) is the most common way by which the hazards associated with HF-IS are mitigated. In this study, we discuss the implicit risk mitigation objectives of TLSs and explain the advantages of magnitude as the fundamental parameter to characterise induced seismic hazard. We go on to investigate some of the key assumptions on which TLSs are based, namely that magnitudes evolve relatively gradually from green to yellow to red thresholds (as opposed to larger events occurring “out-of-the-blue”), and that trailing event magnitudes do not increase substantially after injection stops. We compile HF-IS datasets from around the world, including the USA, Canada, the UK, and China, and track the temporal evolution of magnitudes in order to evaluate the extent to which magnitude jumps (i.e. sharp increases in magnitude from preceding events within a sequence) and trailing events occur. We find in the majority of cases magnitude jumps are less than 2 units. One quarter of cases experienced a post-injection magnitude increase, with the largest being 1.6. Trailing event increases generally occurred soon after injection, with most cases showing no increase in magnitude more than a few days after then end of injection. Hence, the effective operation of TLSs may require red-light thresholds to be set as much as two magnitude units below the threshold that the scheme is intended to avoid.

Abstract:
Unconventional oil and gas (UOG) production requires intensive freshwater consumption, but whether hydroclimate variation, which alters regional water availability, affects its activity and water footprint is still unknown. In this study, we investigate the temporal and spatial correlations of drought intensity with UOG activity and water consumption in Colorado over a 13-year period. We found that hydroclimate variation has a negligible or weak impact on the well number and water footprint of UOG production, and that monthly UOG water consumption in areas already under drought conditions could sustain up to >110% of municipal water usage at the county scale. By defining a new metric of drought-escaping distance, we show that drought climate could cover areas more than 500 miles from the well sites, preventing UOG producers from acquiring water from areas without water stress. This results in local water withdrawal that intensifies water scarcity and competition. Our study also quantifies the potential of UOG wastewater reuse to reduce regional water stress. Our findings underscore the importance of UOG production in water resource allocation in particular under drought conditions. Our research could provide new insights into understanding the effects of UOG production on regional water sustainability during drought periods in Colorado.

Abstract:
Hydraulic fracturing (“fracking”) is used in unconventional gas drilling to allow for the free flow of natural gas from rock. Sand in fracking fluid is pumped into the well bore under high pressure to enter and stabilize fissures in the rock. In the process of manipulating the sand on site, respirable dust (fracking sand dust, FSD) is generated. Inhalation of FSD is a potential hazard to workers inasmuch as respirable crystalline silica causes silicosis, and levels of FSD at drilling work sites have exceeded occupational exposure limits set by OSHA. In the absence of any information about its potential toxicity, a comprehensive rat animal model was designed to investigate the bioactivities of several FSDs in comparison to MIN-U-SIL® 5, a respirable α-quartz reference dust used in previous animal models of silicosis, in several organ systems (Fedan, J.S., Toxicol Appl Pharmacol. 00, 000–000, 2020). The present report, part of the larger investigation, describes: 1) a comparison of the physico-chemical properties of nine FSDs, collected at drilling sites, and MIN-U-SIL® 5, a reference silica dust, and 2) a comparison of the pulmonary inflammatory responses to intratracheal instillation of the nine FSDs and MIN-U-SIL® 5. Our findings indicate that, in many respects, the physico-chemical characteristics, and the biological effects of the FSDs and MIN-U-SIL® 5 after intratracheal instillation, have distinct differences.

Abstract:
Hydraulic fracturing creates fissures in subterranean rock to increase the flow and retrieval of natural gas. Sand (“proppant”) in fracking fluid injected into the well bore maintains fissure patency. Fracking sand dust (FSD) is generated during manipulation of sand to prepare the fracking fluid. Containing respirable crystalline silica, FSD could pose hazards similar to those found in work sites where silica inhalation induces lung disease such as silicosis. This study was performed to evaluate the possible toxic effects following inhalation of a FSD (FSD 8) in the lung and airways. Rats were exposed (6 h/d × 4 d) to 10 or 30 mg/m3 of a FSD, i.e., FSD 8, collected at a gas well, and measurements were performed 1, 7, 27 and, in one series of experiments, 90 d post-exposure. The following ventilatory and non-ventilatory parameters were measured in vivo and/or in vitro: 1) lung mechanics (respiratory system resistance and elastance, tissue damping, tissue elastance, Newtonian resistance and hysteresivity); 2) airway reactivity to inhaled methacholine (MCh); airway epithelium integrity (isolated, pefused trachea); airway efferent motor nerve activity (electric field stimulation in vitro); airway smooth muscle contractility; ion transport in intact and cultured epithelium; airway effector and sensory nerves; tracheal particle deposition; and neurogenic inflammation/vascular permeability. FSD 8 was without large effect on most parameters, and was not pro-inflammatory, as judged histologically and in cultured epithelial cells, but increased reactivity to inhaled MCh at some post-exposure time points and affected Na+ transport in airway epithelial cells.

Abstract:
Methane emission fluxes were estimated for 71 oil and gas well pads in the western Permian Basin (Delaware Basin), using a mobile laboratory and an inverse Gaussian dispersion method (OTM 33A). Sites with emissions that were below detection limit (BDL) for OTM 33A were recorded and included in the sample. Average emission rate per site was estimated by bootstrapping and by maximum likelihood best log-normal fit. Sites had to be split into “complex” (sites with liquid storage tanks and/or compressors) and “simple” (sites with only wellheads/pump jacks/separators) categories to achieve acceptable log-normal fits. For complex sites, the log-normal fit depends heavily on the number of BDL sites included. As more BDL sites are included, the log-normal distribution fit to the data is falsely widened, overestimating the mean, highlighting the importance of correctly characterizing low end emissions when using log-normal fits. Basin-wide methane emission rates were estimated for the production sector of the New Mexico portion of the Permian and range from ∼520 000 tons per year, TPY (bootstrapping, 95% CI: 300 000–790 000) to ∼610 000 TPY (log-normal fit method, 95% CI: 330 000–1 000 000). These estimates are a factor of 5.5–9.0 times greater than EPA National Emission Inventory (NEI) estimates for the region.

Abstract:
Releases of oil and gas (OG) wastewaters can have complex effects on stream-water quality and downstream organisms, due to sediment-water interactions and groundwater/surface water exchange. Previously, elevated concentrations of sodium (Na), chloride (Cl), barium (Ba), strontium (Sr), and lithium (Li), and trace hydrocarbons were determined to be key markers of OG wastewater releases when combined with Sr and radium (Ra) isotopic compositions. Here, we assessed the persistence of an OG wastewater spill in a creek in North Dakota using a combination of geochemical measurements and modeling, hydrologic analysis, and geophysical investigations. OG wastewater comprised 0.1 to 0.3% of the stream-water compositions at downstream sites in February and June 2015, but could not be quantified in 2016 and 2017. However, OG-wastewater markers persisted in sediments and pore water for 2.5 years after the spill and up to 7.2-km downstream from the spill site. Concentrations of OG wastewater constituents were highly variable depending on the hydrologic conditions. Electromagnetic measurements indicated substantially higher electrical conductivity in groundwater seeps below the streambed 7.2 km downstream from the spill site. Geomorphic investigations revealed mobilization of sediment is an important contaminant transport process. Labile Ba, Ra, Sr, and ammonium (NH4) concentrations extracted from sediments indicated sediments are a long-term reservoir of these constituents, both in the creek and on the floodplain. Using the drivers of ecological effects identified at this intensively studied site we identified 41 watersheds across the North Dakota landscape that may be subject to similar episodic inputs from OG wastewater spills. Effects of contaminants released to the environment during OG waste management activities remain poorly understood; however, analyses of Ra and Sr isotopic compositions, as well trace inorganic and organic compound concentrations at these sites in pore-water provide insights into potentials for animal and human exposures well outside source remediation zones.

Abstract:
Hydraulic fracturing flowback and produced water (FPW) is a highly complex and heterogenous wastewater by-product of hydraulic fracturing practices. To date, no research has examined how FPW exposure to freshwater biota may affect energetic homeostasis following subsequent induction of detoxification processes. Rainbow trout (Oncorhynchus mykiss) were acutely exposed for 48 h to either 2.5% or 7.5% FPW, and hepatic metabolism was assessed either immediately or following a 3-week recovery period. Induction of xenobiotic metabolism was observed with an 8.8-fold increase in ethoxyresorufin-O-deethylase (EROD) activity after 48 h exposure to 7.5% FPW, alongside a 10.3-fold increase in the mRNA abundance of cyp1a, both of which returned to basal level after three weeks. Glucose uptake capacity was elevated by 6.8- and 12.9-fold following 2.5% and 7.5% FPW exposure, respectively, while alanine uptake was variable. Activity measurements and mRNA abundance of key enzymes involved in hepatic metabolism indicated that aerobic metabolism was maintained with exposure, as was glycolysis. Gluconeogenesis, as measured by phosphoenolpyruvate carboxykinase (PEPCK) activity, decreased by ~30% 48 h following 2.5% FPW exposure and ~20% 3 weeks after 7.5% FPW exposure. The abundance of pepck mRNA activity followed similar, yet non-significant, trends. Finally, a delayed increase in amino acid catabolism was observed, as glutamate dehydrogenase (GDH) activity was increased 2-fold in 7.5% FPW exposed fish when compared to saline control fish at the 3-week time point. We provide evidence to suggest that although hepatic metabolism is altered following acute FPW exposure, metabolic homeostasis generally returns 3-weeks post-exposure.

Abstract:
Publicly available toxicological studies on wastewaters associated with unconventional oil and gas (UOG) activities in offshore regions are nonexistent. The current study investigated the impact of hydraulic fracturing-generated flowback water (HF-FW) on whole organism swimming performance/respiration and cardiomyocyte contractility dynamics in mahi-mahi (Coryphaena hippurus—hereafter referred to as “mahi”), an organism which inhabits marine ecosystems where offshore hydraulic fracturing activity is intensifying. Following exposure to 2.75% HF-FW for 24 h, mahi displayed significantly reduced critical swimming speeds (Ucrit) and aerobic scopes (reductions of ∼40 and 61%, respectively) compared to control fish. Additionally, cardiomyocyte exposures to the same HF-FW sample at 2% dilutions reduced a multitude of mahi sarcomere contraction properties at various stimulation frequencies compared to all other treatment groups, including an approximate 40% decrease in sarcomere contraction size and a nearly 50% reduction in sarcomere relaxation velocity compared to controls. An approximate 8-fold change in expression of the cardiac contractile regulatory gene cmlc2 was also seen in ventricles from 2.75% HF-FW-exposed mahi. These results collectively identify cardiac function as a target for HF-FW toxicity and provide some of the first published data on UOG toxicity in a marine species.

Abstract:
The Utica and Marcellus Shale Plays in the Appalachian Basin are the fourth and first largest natural gas producing plays in the United States, respectively. Hydrocarbon production generates large volumes of brine (“produced water”) that must be disposed of, treated, or reused. Though Marcellus brines have been studied extensively, there are few studies from the Utica Shale Play. This study presents new brine chemical analyses from 16 Utica Shale Play wells in Ohio and Pennsylvania. Results from Na–Cl–Br systematics and stable and radiogenic isotopes suggest that the Utica Shale Play brines are likely residual pore water concentrated beyond halite saturation during the formation of the Ordovician Beekmantown evaporative sequence. The narrow range of chemistry for the Utica Shale Play produced waters (e.g., total dissolved solids = 214–283 g/L) over both time and space implies a consistent composition for disposal and reuse planning. The amount of salt produced annually from the Utica Shale Play is equivalent to 3.4% of the annual U.S. halite production. Utica Shale Play brines have radium activities 580 times the EPA maximum contaminant level and are supersaturated with respect to barite, indicating the potential for surface and aqueous radium hazards if not properly disposed of.

Abstract:
Unconventional oil and natural gas development (UOGD) expanded extensively in the United States from the early 2000s. However, the influence of UOGD on the radioactivity of ambient particulate is not well understood. We collected the ambient particle radioactivity (PR) measurements of RadNet, a nationwide environmental radiation monitoring network. We obtained the information of over 1.5 million wells from the Enverus database. We investigated the association between the upwind UOGD well count and the downwind gross-beta radiation with adjustment for environmental factors governing the natural emission and transport of radioactivity. Our statistical analysis found that an additional 100 upwind UOGD wells within 20 km is associated with an increase of 0.024 mBq/m3 (95% confidence interval [CI], 0.020, 0.028 mBq/m3) in the gross-beta particle radiation downwind. Based on the published health analysis of PR, the widespread UOGD could induce adverse health effects to residents living close to UOGD by elevating PR.

Abstract:
Policies surrounding energy development are frequently implemented in response to known or perceived problems. South Africa is in a unique position to develop prospective policies that build on knowledge gained from elsewhere. This paper provides a prospective analysis of hydrogeological risk pathways and vulnerability attributes in advance of anticipated shale gas operations in the Karoo Basin of South Africa. The ‘hazard-pathways-receptors’ approach is applied to define the hydrogeologic system in the context of potential sources of water resource contamination. This case study focuses on two critical hydrogeological risk pathways: regional groundwater flow and discrete structural features. Depending on the targeted area (hydro-litho-structural domain, depth of target, presence of aquitard, intrusion ratio), the capacity of deep natural pathways to enable hydraulic fracturing fluids, chemicals, or produced water to reach shallow groundwater, will be reduced or difficult. Deep artesian water could however be intercepted at different depths and, based on past groundwater exploration in the Karoo, water could flow into horizontal fractures or openings characterising the shallow aquifers: sills-ring complexes, lithological contacts, and transgressive fractures across dolerite dykes. However, above-ground water and wastewater management safeguards are needed to protect shallow groundwater from potential water quality degradation due to a) flowback or produced water b) stray gas and/or c) spills or illicit discharges that could introduce contaminants into groundwater resources. This paper describes a systematic approach to evaluate hydrogeologic risk pathways and informs adaptive management policies to protect South African groundwater resources.

Abstract:
Observations of volatile organic compounds (VOCs) from a surface sampling network and simulation results from the EMAC (ECHAM5/MESSy for Atmospheric Chemistry) model were analyzed to assess the impact of increased emissions of VOCs and nitrogen oxides from U.S. oil and natural gas (O&NG) sources on air quality. In the first step, the VOC observations were used to optimize the magnitude and distribution of atmospheric ethane and higher-alkane VOC emissions in the model inventory for the base year 2009. Observation-based increases of the emissions of VOCs and NOx stemming from U.S. oil and natural gas (O&NG) sources during 2009–2014 were then added to the model, and a set of sensitivity runs was conducted for assessing the influence of the increased emissions on summer surface ozone levels. For the year 2014, the added O&NG emissions are predicted to affect surface ozone across a large geographical scale in the United States. These emissions are responsible for an increased number of days when the averaged 8-h ozone values exceed 70 ppb, with the highest sensitivity being in the central and midwestern United States, where most of the O&NG growth has occurred. These findings demonstrate that O&NG emissions significantly affect the air quality across most of the United States, can regionally offset reductions of ozone precursor emissions made in other sectors, and can have a determining influence on a region’s ability to meet National Ambient Air Quality Standard (NAAQS) obligations for ozone.

Abstract:
This paper puts forward an anarchist political ecology critique of extreme energy extractivism by examining corporate and state responses (or ‘political reactions from above’) to anti-fracking resistance in the UK. The planned drilling for unconventional gas and oil through hydraulic fracturing has triggered unprecedented opposition, with protest camps, direct actions, and legal challenges disrupting operations and slowing down planning and exploration development. Drawing on green anarchist thought, critiques of extractivism, statism, and industrialism, and a (corporate) counterinsurgency framework, I examine the strategies adopted by drilling companies and state actors to manage resistance and win the ‘hearts and minds’ of the population, deploying tactics from greenwashing in local schools to harsh policing of dissent. The latter has included the criminalisation and stigmatisation of land defenders, targeting campaigners as ‘domestic extremists’, physical abuse, targeting protesters with disabilities, and entering public-private security partnerships with local police forces which involve the ‘outsourcing’ of police communication to drilling companies. Such actions are complimented by the contracting of PR firms, lobbying, sponsorships of sports clubs and school competitions, ‘astroturfing’, and influencing local so-called democratic procedures. This has gone hand in hand with political efforts to classify operation sites as ‘Nationally Significant Infrastructure projects’ to facilitate the suppression of protest. These strategies are embedded in a recently well-documented history of police infiltration and corporate spying, laying bare an unapologetic commitment to sacrifice human and nonhuman wellbeing for industrial growth, commitment to extractivist ideology and centralisation of power at the cost of further eroding local autonomy and control.

Abstract:
Hydraulic fracturing (“fracking”) is a process used to enhance retrieval of gas from subterranean natural gas-laden rock by fracturing it under pressure. Sand used to stabilize fissures and facilitate gas flow creates a potential occupational hazard from respirable fracking sand dust (FSD). As studies of the immunotoxicity of FSD are lacking, the effects of whole-body inhalation (6 h/d for 4 d) of a FSD, i.e., FSD 8, was investigated at 1, 7, and 27 d post-exposure in rats. Exposure to 10 mg/m3 FSD 8 resulted in decreased lung-associated lymph node (LLN) cellularity, total B-cells, CD4+ T-cells, CD8+ T-cells and total natural killer (NK) cells at 7-d post exposure. The frequency of CD4+ T-cells decreased while the frequency of B-cells increased (7 and 27 d) in the LLN. In contrast, increases in LLN cellularity and increases in total CD4+ and CD8+ T-cells were observed in rats following 30 mg/m3 FSD 8 at 1 d post-exposure. Increases in the frequency and number of CD4+ T-cells and NK cells were observed in bronchial alveolar lavage fluid at 7-d post-exposure (10 mg/m3) along with an increase in total CD4+ T-cells, CD11b + cells, and NK cells at 1-day post-exposure (30 mg/m3). Increases in the numbers of B-cells and CD8+ T-cells were observed in the spleen at 1-day post 30 mg/m3 FSD 8 exposure. In addition, NK cell activity was suppressed at 1 d (30 mg/m3) and 27 d post-exposure (10 mg/m3). No change in the IgM response to sheep red blood cells was observed. The findings indicate that FSD 8 caused alterations in cellularity, phenotypic subsets, and impairment of immune function.

Abstract:
Attending to the role of visualizations in discourse formations allows for detecting the emergence of particular visual storylines. This article studies the emergence of visual storylines in energy policy, in particular shale gas controversies. The analysis is based on data gathered in three internet regions: the Netherlands, New York State, and South Africa. The analysis studies how visualizations may contribute to confirmation, disintegration, integration, or polarization of discourse coalitions due to similarities or differences between visual and discursive storylines. From the results, we suggest the notion of visual discourse coalitions (VDCs) to contribute to the study of visualizations and discourses in policy controversies. We define a VDC as a network of actors that share a similar discursive storyline and a similar visual storyline of the controversy. The article shows that visualizations and their graphic characteristics add another dimension to the formation of discourse coalitions and the way they develop, connect, or disconnect.

Abstract:
This paper exploits a natural experiment afforded by the fracking boom in Pennsylvania to shed light on the determinants of mortgage default. Looking only at mortgages originated before fracking became viable, and using the underlying geology as a supply shifter, we find that mortgages on homes exposed to shale drilling experience a significant reduction in default risk. This effect is more than four times greater for borrowers who are underwater on their loans. Additional evidence shows that fracking activity does not raise house prices, but significantly increases household income through higher royalty payments, wages, and salaries. Furthermore, we find that fracking directly leads to employment increases in the drilling/mining and construction sectors at the county level and reduces income from unemployment benefits at the ZIP-code level. Finally, in addition to reducing mortgage-default risk, we show that fracking lowers credit card delinquencies. These results are most consistent with the “double-trigger” theory of mortgage default, where underwater borrowers subject to an adverse income shock are much more likely to lose their homes to foreclosure.This paper was accepted by David Simchi-Levi, finance.

Abstract:
Hydraulic fracturing is often criticized due in part to the potential degradation of ground and surface water quality by high-salinity produced water generated during well stimulation and production. This preliminary study evaluated the response of the freshwater mussel, Elliptio complanata, after exposure to produced water. A limited number of adult mussels were grown over an 8-week period in tanks dosed with produced water collected from a hydraulically fractured well. The fatty tissue and carbonate shells were assessed for accumulation of both inorganic and organic pollutants. Ba, Sr, and cyclic hydrocarbons indicated the potential to accumulate in the soft tissue of freshwater mussels following exposure to diluted oil and gas produced water. Exposed mussels showed accumulation of Ba in the soft tissue several hundred times above background water concentrations and increased concentrations of Sr. Cyclic hydrocarbons were detected in dosed mussels and principle component analysis of gas chromatograph time-of-flight mass spectrometer results could be a novel tool to help identify areas where aquatic organisms are impacted by oil and gas produced water, but larger studies with greater replication are necessary to confirm these results.

Abstract:
Proponents of the US shale oil and gas industry argued that American citizens’ economic prosperity and national security were at stake if the industry was not rapidly expanded. Following copious amounts of a certain type of “patriotic” rhetoric, the industry grew rapidly. Simultaneously, foreign ownership of US shale industry infrastructure occurred in tandem with calls for new policies and laws to limit US citizens’ democratic rights with regard to the industry’s activities. As a result, we argue that the development of the US shale industry has weakened national security by creating negative security externalities and eroding democratic values. We offer implications for other democratic societies rich in natural resources.

Abstract:
This study assessed the effectiveness of mitigation measures adopted to address the environmental effects of oil and gas industries from the perspective of compliance, cost of production, and community awareness. The research applied a case study through multi-method-qualitative and quantitative approaches. The target population of 547,368 people involved people in Takoradi, Shama and Newtown communities. A sample size of 150 was selected and categorised under 36% for Shama, 30% for Newtown and 34% for Takoradi. A combination of probability (simple random) and non-probability (cluster and convenience) sampling frames were used to access the respondents for the study. Data collection tools were limited to questionnaires and interview sessions. The descriptive statistics, Relative Importance Index (RII) and significance testing using a one-sample t-test module guided the analysis. Interview sessions were compiled into transcripts and later categorized into themes that directly reflected the patterns of the questions on the questionnaire. The conclusion rated major decisions in mitigating oil and gas impacts on the environment as first for conscious effort to package fuel and other chemicals in safe storages, followed by the use of best road systems to reduce the risk of accidents, then application of strict rules and regulations to curb impacts and lastly capacity building for participants in the oil and gas production industry. While significant measures have been adopted to mitigate the effects of oil and gas exploration, there remain challenges with effectiveness as a result of weakness in community involvement efforts, lack of motivation, weak laws and regulations and loss of respect. For effectiveness in reducing the challenges to mitigate the environmental impacts of the oil and gas production activity, policymakers, as well as the practitioners in the oil production industry, are advised to motivate people into buying into their policy to reduce such impacts.

Abstract:
Recent studies have reported methane (CH4) emissions from abandoned oil and gas wells across the United States and the United Kingdom. These emissions can reach hundreds of kg CH4 per year per well and are important to include in greenhouse gas emission inventories and mitigation strategies. Emission estimates are generally based on single, short-term measurements that assume constant emission rates over both short (hours) and longer (months/years) time periods. To investigate this assumption, we measure CH4 emissions from 18 abandoned oil and gas wells in the USA and the UK continuously over 24 h and then make repeat 24 -h measurements at a single site over 12 months. While the lack of historical records for these wells makes it impossible to determine the underlying leakage-pathways, we observed that CH4 emissions at all wells varied over 24 h (range 0.2-81,000 mg CH4 hr−1) with average emissions varying by a factor of 18 and ranging from factors of 1.1–142. We did not find a statistically significant relationship between the magnitude of emissions and variability or that variability is correlated with temperature, relative humidity or atmospheric pressure. The results presented here suggest high CH4 emission events tend to be short-lived, so short-term (< 1 h) sampling is likely to miss them. Our findings present the dynamic nature of CH4 emissions from abandoned oil and gas wells which should be considered when planning measurement methodologies and developing greenhouse gas inventories/mitigation strategies. Incorporation of these temporal dynamics could improve national greenhouse gas emissions inventories.

Abstract:
As unconventional fossil fuel production expands in much of the world, so does controversy, and in many cases, public opposition. This study explores citizen perceptions, support, and opposition for several types of unconventional fossil fuel in the case study of Canada, where such production continues to grow. We use a nationally representative survey of Canadians (n = 1407) to assess citizen acceptance of oil sands development and natural gas development using hydraulic fracturing, as well as related infrastructure (specifically the Northern Gateway, TransMountain, and Energy East pipelines). We compare this acceptance to other forms of energy generation, namely conventional oil, coal, renewables, and nuclear. Across the Canadian sample, oil sands and pipelines tend to have less acceptance than renewables and conventional oil, but more acceptance than nuclear and coal power. Acceptance for unconventional fossil fuel development and infrastructure is consistently higher among respondents in Alberta (the province where most development occurs), where respondents perceive more economic benefits and less environmental and social costs. Within each region, acceptance levels are similar for oil sands and oil sands pipelines, while hydraulic fracturing has significantly lower acceptance within all regions. Regression analyses indicate consistent patterns: opposition to unconventional fossil fuel developments and infrastructure is predicted by higher biospheric-altruistic values and environmental concern, and support is predicted by higher egoistic and traditional values and higher trust in oil and gas companies. Results provide insights to policymakers and stakeholders, including regional differences in acceptance, and how citizens perceive oil sands related projects differently than hydraulic fracturing.

Abstract:
Key technological breakthroughs, such as hydraulic fracturing (HF) and horizontal drilling, have facilitated the extraction of shale gas. The boost of the shale gas industry has changed global energy markets and led to a decline in natural gas and oil price. Endowed with massive shale gas resources, China is ambitious to develop its shale gas industry, driven by growing energy demand and critical environmental conditions. However, an increasing number of pollution problems coming along with extraction has threatened our environment with atmospheric pollution, water risk, induced seismicity, occupational health, safety, and so on. Because HF needs millions of tons of water and produces a large quantity of effluents, water management becomes one of the most threatened problems. Also, wastewater treatment has become a key factor restricting the development of China’s shale gas industry. In response, international and domestic enterprises have developed a variety of management processes, which are divided into three categories: reinjection, reuse in hydraulic fracturing, and discharge after treatment. In this paper we first summarize Chinese shale gas development, then analyze the production of shale gas wastewater through major extraction techniques. Finally, a review was conducted on current wastewater treatments utilized in China, and advice is offered for future treatment techniques.

Abstract:
Recent research has shown relationships between health outcomes and residence proximity to unconventional oil and natural gas development (UOGD). The challenge of connecting health outcomes to environmental stressors requires ongoing research with new methodological approaches. We investigated UOGD density and well emissions and their association with symptom reporting by residents of southwest Pennsylvania. A retrospective analysis was conducted on 104 unique, de-identified health assessments completed from 2012–2017 by residents living in proximity to UOGD. A novel approach to comparing estimates of exposure was taken. Generalized linear modeling was used to ascertain the relationship between symptom counts and estimated UOGD exposure, while Threshold Indicator Taxa Analysis (TITAN) was used to identify associations between individual symptoms and estimated UOGD exposure. We used three estimates of exposure: cumulative well density (CWD), inverse distance weighting (IDW) of wells, and annual emission concentrations (AEC) from wells within 5 km of respondents’ homes. Taking well emissions reported to the Pennsylvania Department of Environmental Protection, an air dispersion and screening model was used to estimate an emissions concentration at residences. When controlling for age, sex, and smoker status, each exposure estimate predicted total number of reported symptoms (CWD, p<0.001; IDW, p<0.001; AEC, p<0.05). Akaike information criterion values revealed that CWD was the better predictor of adverse health symptoms in our sample. Two groups of symptoms (i.e., eyes, ears, nose, throat; neurological and muscular) constituted 50% of reported symptoms across exposures, suggesting these groupings of symptoms may be more likely reported by respondents when UOGD intensity increases. Our results do not confirm that UOGD was the direct cause of the reported symptoms but raise concern about the growing number of wells around residential areas. Our approach presents a novel method of quantifying exposures and relating them to reported health symptoms.

Abstract:
Using data drawn from random samples of residents in and around two boroughs located in Lycoming County, Pennsylvania, we examined individuals’ recollected pre-development and post-development perceptions of selected issues associated with Marcellus Shale development. Descriptive statistics revealed that the pattern of residents’ recollected pre-development and post-development perceptions was more or less the same. In general, issues that residents perceived would worsen prior to the development of natural gas (recollected pre-development perceptions) were viewed as worsening after the upstream activities began (post-development perceptions). The same pattern held for those issues that residents had perceived would improve. Paired sample t-tests were used to determine whether any statistically significant differences existed between residents’ recollected pre-development and post-development perceptions. Results revealed that the mean scores for residents’ recollected pre-development and post-development perceptions differed significantly for the overwhelming majority of issues.

Abstract:
Chemical additives used in hydraulic fracturing fluids (HFFs) are made up of various organic compounds that are potential human carcinogens. To estimate the emissions from these organic constituents in on-site liquid storage tanks, studies were performed using the AP-42 model on data collected from 72,023 wells put into production using hydraulic fracturing between 2008 and 2014 in the United States. Results show that a total of 8.11 × 105 kg volatile organic compounds (VOCs) were potentially emitted from liquid storage tanks during fracturing operations, which was relatively low compared to other sources/activities in well fracturing. The median well emission roughly increased from 0.110 to 0.786 kg per well in 2008 and 2014, respectively, and was primarily due to the increase in the volume of chemical additives for fracturing one well. Of NMVOC emissions, 95.1% was contributed by 60 compounds listed on the priority list of hazardous substances defined by the Agency for Toxic Substances & Disease Registry (ATSDR), while 16.7% was caused by 15 carcinogenic compounds. Specially, methanol, formaldehyde, 2-propanol, and ethanol accounted for 55.5%, 16.6%, 11.7%, and 8.31% of NMVOC emissions. Our study highlights methanol, formaldehyde, 2-propanol, and ethanol as the targeted compounds for reducing organic emissions and occupational inhalation exposures related to storage tank operations.

Abstract:
Oil and natural gas wells are a prominent source of the greenhouse gas methane (CH4), but most measurements are from newer, high producing wells. There are nearly 700,000 marginal “stripper” wells in the US, which produce less than 15 barrels of oil equivalent (BOE) d−1. We made direct measurements of CH4 and volatile organic carbon (VOC) emissions from marginal oil and gas wells in the Appalachian Basin of southeastern Ohio, all producing < 1 BOE d−1. Methane and VOC emissions followed a skewed distribution, with many wells having zero or low emissions and a few wells responsible for the majority of emissions. The average CH4 emission rate from marginal wells was 128 g h−1 (median: 18 g h−1; range: 0 - 907 g h−1). Follow-up measurements at five wells indicated high emissions were not episodic. Some wells were emitting all or more of the reported gas produced at each well, and many were venting gas from wells with no reported gas production. Measurements were made from wellheads only, not tanks, so our estimates may be conservative. Stochastic processes such as maintenance may be the main driver of emissions. Marginal wells are a disproportionate source of CH4 and VOCs relative to oil and gas production. We estimate that oil and gas wells in this lowest production category emit approximately 11% of total annual CH4 from oil and gas production in the EPA greenhouse gas inventory, although they produce about 0.2% of oil and 0.4% of gas in the US per year.

Abstract:
Pumping oilfield wastewater into deep injection wells causes earthquakes by effective stress change and solid elastic stressing. These processes result from fluid pressure changes in the seismogenic basement, so it is generally accepted that pressure diffusion governs spatiotemporal patterns of induced earthquake sequences. However, new evidence suggests that fluid density contrasts may also drive local-scale (near-well) pressure transients to greater depths than pressure diffusion and over much longer timescales. As a consequence, the pressure, temperature, and composition (PTX) conditions of wastewater and deep crustal (basement) fluids may be fundamental to understanding and managing injection-induced seismicity. This study develops a mechanistic framework that integrates PTX-dependent fluid properties into the generally accepted conceptual model of injection-induced seismicity. Nonisothermal variable-density numerical simulation is combined with ensemble simulation methods to isolate the parametric controls on injection-induced fluid pressure transients. Results show that local-scale, density-driven pressure transients are governed by a combination of fracture permeability and PTX-dependent fluid properties, while long-range pressure diffusion is largely governed by fracture permeability. Considering this new conceptual model in the context geochemical data from oil and gas basins in the United States identifies regions that may be susceptible to persistent density-driven pressure transients.

Abstract:
The unconventional oil and gas (UOG) boom in the United States produced a surge of social science research activity about the industry's local impacts, the vast majority of which relied on local stakeholders to contribute data. Like UOG development across the United States, research on the local impacts of UOG has been geographically dispersed and uneven and mostly uncoordinated. The primary purpose of this systematic review of peer-reviewed articles and theses and dissertations is to provide an overview of the timing, spatial distribution, and methods used in research on local impacts of UOG development since 2000. The study identifies 167 unique human subject data collection efforts in U.S. UOG locations between 2000 and 2018. This overview—along with analysis of response rates and recruitment and engagement patterns—reveals risks that the recent boom in impacts research may have contributed to research fatigue on the part of some human subject research participants. The study also demonstrates challenges in deriving generalizable observations from local impacts research. Both problems are associated with the uneven geographic distribution of research across UOG locations in the U.S., researchers’ tendency to arrive at the height of development activity, inconsistent and incomplete reporting on methods in publications, and an over-reliance on accessible research subjects. Future research and scholarly reflection should evaluate constraints and factors that influence research strategies. In the meantime, the U.S. research community faces an imperative to consider opportunities to enhance and coordinate research activities in energy communities.

Abstract:
Background:  Recent studies report an association between preterm birth and exposure to unconventional oil and gas wells. There has been limited previous study on exposure to conventional wells, which are common in California. Our objective was to determine whether exposure to well sites was associated with increased odds of spontaneous preterm birth (delivery at <37 weeks). Methods:  We conducted a case–control study using data on 27,913 preterm birth cases and 197,461 term birth controls. All births were without maternal comorbidities and were located in the San Joaquin Valley, CA, between 1998 and 2011. We obtained data for 83,559 wells in preproduction or production during the study period. We assessed exposure using inverse distance-squared weighting and, for each birth and trimester, we assigned an exposure tertile. Using logistic regression, we estimated adjusted odds ratios (ORs) for the association between exposure to well sites and preterm birth at 20–27, 28–31, and 32–36 weeks. Results:  We observed increased ORs for preterm birth with high exposure to wells in the first and second trimesters for births delivered at ≤31 weeks (adjusted ORs, 1.08–1.14). In stratified analyses, the associations were confined to births to Hispanic and non-Hispanic Black women and to women with ≤12 years of educational attainment. In a secondary analysis, we found evidence that exposure to wells in preproduction is associated with higher concentrations of particulate matter. Conclusions:  We found evidence that exposure to oil and gas well sites is associated with increased risk of spontaneous preterm birth.

Abstract:
Unconventional shale gas production in the United States has been largely improved due to the development of hydraulic fracturing technology and is projected to rapidly grow in the coming years. However, the acquisition of freshwater and management of flowback and produced (FP) water associated with hydraulic fracturing operation are two of the greatest challenges in shale gas development, especially in arid regions. For efficient and sustainable water management, a better understanding of freshwater consumption and FP water production for shale gas wells is necessary to appropriately expand and upgrade the existing water network and shale gas network. To achieve this, we first collected water-use volume and monthly FP water production volume data for shale gas wells drilled in the Eagle Ford and Marcellus shale regions. Next, after integrating the data from multiple database sources, the water recovery ratio was calculated as the ratio of cumulative FP water volume to water-use volume and used as a metric to characterize the wells in these two shale regions. Then, we analyzed the obtained water recovery ratio data according to the location and production history to study the spatiotemporal variations across multiple counties and time periods. It shows that around 30% of the collected wells drilled in the Eagle Ford region have the water recovery ratio greater than 1; however, only 1% of the collected wells drilled in the Marcellus region have the water recovery ratio greater than 1. Besides, the water recovery ratios vary significantly across the counties in each shale region. To demonstrate how different water recovery ratio may affect shale gas development, a shale gas supply chain network (SGSCN) optimization model from the literature was utilized to perform two case studies in the Marcellus region. The optimal results suggest that different configurations of SGSCN are required for economically desirable and practically feasible management of shale gas wells with different water recovery ratios.

Abstract:
Recent advances in horizontal drilling and hydraulic fracturing technologies have allowed producers to extract oil and gas from thin reservoirs that may not be economically viable through vertical drilling. While the new hydraulic fracturing technologies have resulted in substantial economic benefits for the state of Texas, they tend to generate high volumes of truck traffic that diversely affect the transportation system. Many of the affected roads were designed and built several decades ago to meet low traffic demand levels and not heavy repetitive truck loads. The goal of this study is to enhance state agencies’ ability to determine the truck traffic associated with fracking in existing and new wells based on several well characteristics. This paper explores spatio-temporal trends in hydraulic fracturing in Texas and develops a methodology that agencies can use to estimate the amount of water and the number of trucks needed to frack and fully develop a well. The analysis revealed that fracking horizontal wells generates eight times more water and, therefore, truck traffic than vertical wells. The relationship between water volume versus well length is non-linear. The length of laterals has a very strong correlation with frack water (0.818) and sand (0.763), while the vertical well depth has a weak to negligible relationship with fracking materials. The two prediction models presented in the paper produced statistically similar results with average errors of less than 20%. The paper explains how the predicted water volumes can be converted into the number of trucks needed to frack and fully develop a well.

Abstract:
Fertilizer drawn forward osmosis (FDFO) was proposed to extract fresh water from flowback and produced water (FPW) from shale gas extraction for irrigation, with fertilizer types and membrane orientations assessed. Draw solution (DS) with NH4H2PO4 displayed the best performance, while DS with (NH4)2HPO4 resulted in the most severe membrane fouling. DS with KCl and KNO3 led to substantial reverse solute fluxes. FDFO operation where the active layer of the membrane was facing the feed solution outperformed that when the active layer was facing the DS. Diluted DS and diluted FPW samples were used for irrigation of Cherry radish and Chinese cabbage. Compared to deionized water, irrigation with diluted DS (total dissolved solid (TDS) = 350 mg·L-1) promoted plant growth. In contrast, inhibited plant growth was observed when FPW with high salinity (TDS = 5000 mg·L-1) and low salinity (TDS = 1000 mg·L-1) was used for irrigation of long-term (8-week) plant cultures. Finally, upregulated genes were identified to illustrate the difference in plant growing. The results of this study provide a guide for efficient and safe use of FPW after FDFO treatment for agricultural application.

Abstract:
Wastewater discharges from cities and industries, especially megacities, and intensive livestock can be considered as main sources of pollution of our rivers and groundwater. Water pollution, therefore, constitutes a major threat to both aquatic ecosystems and human health. Here we address the influence of chemical pollution in waste- and drinking water, their associated potential toxicological effects, as well as, the available technologies for their removal. This opinion paper provides illustrative selected examples covering a broad range for both drinking water and wastewater treatment processes, for which a battery of toxicity tests is applied for their risk assessment. The examples are classified based on five hot topics: (i) Bioassays for toxicity evaluation, (ii) Toxicity of municipal wastewaters, (iii) Toxicity of pharmaceutical residues and hospital wastewaters, (iv) Toxicity of other non-urban effluent examples, and (v) Drinking water treatment processes and toxicity evaluation. 'Chemical analysis combined with batteries of bioassays covering a broad range of endpoints: cytotoxicity, endocrine disruption, genotoxicity, and other types seem to be good way to assess performance/efficiency of the water treatment processes when removing chemical contaminants.. Altogether, while recognizing that water treatment is a cornerstone for water pollution reduction, providing safe water for both human use and its return back to the aquatic environment will be undoubtedly enhanced with the use of ecotoxicity biomonitoring.

Abstract:
The increased water consumption for hydraulic fracturing and the volume of wastewater generated from shale gas and tight oil exploration are major environmental challenges associated with unconventional energy development. Recycling of the flowback and produced water for hydraulic fracturing is one of the solutions for reducing the water footprint of hydraulic fracturing and removing highly saline oil and gas wastewater. Here we investigated the implications of recycling saline wastewater for hydraulic fracturing by monitoring the natural gas production, flowback water volume, and the water quality of generated flowback water in shale gas wells from Changning gas field in Sichuan Basin, China. A comparison of two sets of shale gas wells, with six wells in each sub-group, from the same location in Changning gas field shows lower (~20%) natural gas production and higher flowback water volume (~18%) in wells that were fracked with recycled saline wastewater relative to wells that were fracked with fresh water after a year of production. Geochemical analysis suggests that hydraulic fracturing with saline wastewater increases the salinity of the wastewater and reduces the magnitude of water-shale rock interactions. In spite of the direct economic consequences in reduction in natural gas production from recycling of wastewater for hydraulic fracturing, in areas where water scarcity could become a limiting factor for future large-scale shale gas development, hydraulic fracturing with recycled flowback water can be more beneficial than utilization of limited freshwater resources, as long as the higher saline flowback water is fully recycled.

Abstract:
Hydraulic fracturing, a method used in Northeastern British Columbia (Canada) to extract natural gas, can release contaminants with potential deleterious health effects on fetal development. To date, the association between hydraulic fracturing activity and birth outcomes has not been evaluated in this region.

Abstract:
This systematic review summarizes the relationship between shale gas development and crime. A comprehensive search uncovered 25 shale–crime quantitative studies published between 2005 and 2019. These outputs suggest the study of shale gas development and crime is multidisciplinary, increasing rapidly and mainly carried out in the United States. When considered in aggregate these studies provide clear evidence that shale gas development is likely to increase crime. A majority of studies find that shale gas development increases total crime, violent crime, property crime, social disorganization crimes and violence against women. We conclude by suggesting that these findings should be considered by policymakers and planners when determining whether and how shale development should be allowed.

Abstract:
The American public is split on support for hydraulic fracturing (“fracking”). This study seeks to better understand fracking attitudes by predicting support via economic, environmental, and public health concern. We find support for fracking is intertwined with political partisanship. We show those identifying as “other” political party are significantly more likely to claim “don’t know” in response to questions of fracking support. However, fracking attitudes are not solely the product of political ideology, but also of perceived effects on the environment, the economy, and especially public health.

Abstract:
Despite the current moratorium, shale gas has been posited by the United Kingdom’s government as an important indigenous source of natural gas, a result of heightened concerns over national energy security and dwindling conventional fossil fuel reserves. Although several petroleum development licenses were awarded in the Vale of Pickering area of North Yorkshire in 2015, little research exists at the nexus of social and natural sciences on shale gas developments, particularly on potential risks to communities and the environment in the UK. This study uses the concept of energy justice and an interdisciplinary spatial assessment of potential environmental risks arising from shale gas developments, to evaluate where injustices may emerge, using the Vale of Pickering as a case study. A novel methodology was used to model a possible scenario of shale gas developments, including the spatial dimensions of air and water pollution, seismicity and traffic flows, which were combined to generate an overall environmental risk assessment. This was analysed with a metric of socio-economic vulnerability, to highlight social groups which may be disproportionately at risk from fracking. Overall, modelled proximity-based risk under this scenario did not disproportionately increase in areas with higher populations of socio-economically vulnerable groups, however potential areas for other forms of energy injustices to emerge, such as benefit-sharing injustice were found. This study offers a holistic method for identifying and understanding the local socio-environmental justice dimensions of national energy projects, such as shale gas developments, considerations which can be integrated into future planning processes.

Abstract:
This paper examines the impact of the U.S. fracking boom on local STI transmission rates and prostitution activity as measured by online prostitution review counts. We first document significant and robust positive effects on gonorrhea rates in fracking counties at the national level. But we find no evidence that fracking increases prostitution when using our national data, suggesting sex work may not be the principal mechanism linking fracking to gonorrhea growth. To explore mechanisms, we then focus on remote, high-fracking production areas that experienced large increases in sex ratios due to male in-migration. For this restricted sample we find enhanced gonorrhea transmission effects and moderate evidence of extensive margin effects on prostitution markets. This study highlights public health concerns relating to economic shocks and occupational conditions that alter the local demographic composition.

Abstract:
A linear programming (LP) model is presented to investigate optimal shale gas wastewater management strategies for Marcellus shale play in Pennsylvania (PA) focusing on membrane distillation (MD) as the treatment technology. The optimization framework established in this study incorporates (1) detailed treatment cost obtained from techno-economic assessment (TEA) of MD, (2) cost of wastewater transportation from shale gas sites to treatment or disposal facilities, and (3) cost of injection into salt water disposal (SWD) wells. The optimization model is applied to four case study areas with significant shale gas extraction: Greene and Washington counties in Southwest PA and Susquehanna and Bradford counties in Northeast PA. The results reveal that onsite treatment in combination with shale gas wastewater treatment at natural gas compressor stations (NG CS) where available waste heat can be utilized for the treatment process are the most economically advantageous management options. The optimal solution could result in over 60% benefit over direct disposal in SWD, which translates to over $16 million/year savings in the counties in Northeast PA. Furthermore, the results of sensitivity analysis indicate that transportation cost is a major contributor to the overall cost of shale gas wastewater management.

Abstract:
Memorandums of Understanding (MOUs) are a policy tool for local governments to gain more control over unconventional oil and gas development. MOUs ideally empower local governments to minimize potential risks by negotiating more stringent best management practices directly with the operators, who benefit from a more stable regulatory landscape. This study investigates the energy justice dimensions of these MOUs as they were negotiated in the midst of community conflicts in Colorado. By comparing two communities whose local governments differently managed the public meetings, our analysis points to the significance of the everyday practices of government representatives for promoting recognition and procedural justice. We track the expressions of trust and mistrust expressed by the “interested public” who actively participated in the meetings to better understand the shifting relationships among those citizens, state and local government, and industry. In the community where local government representatives facilitated recognition and procedural justice, the conflict ended with stronger expressions of trust in that government than in the other community. Expressions of trust in industry and state government remained negative or worsened in both communities.

Abstract:
Chemical spills in streams can impact ecosystem or human health. Typically, the public learns of spills from reports from industry, media, or government rather than monitoring data. For example, ∼1300 spills (76 ≥ 400 gallons or ∼1500 L) were reported from 2007 to 2014 by the regulator for natural gas wellpads in the Marcellus shale region of Pennsylvania (U.S.), a region of extensive drilling and hydraulic fracturing. Only one such incident of stream contamination in Pennsylvania has been documented with water quality data in peer-reviewed literature. This could indicate that spills (1) were small or contained on wellpads, (2) were diluted, biodegraded, or obscured by other contaminants, (3) were not detected because of sparse monitoring, or (4) were not detected because of the difficulties of inspecting data for complex stream networks. As a first step in addressing the last problem, we developed a geospatial-analysis tool, GeoNet, that analyzes stream networks to detect statistically significant changes between background and potentially impacted sites. GeoNet was used on data in the Water Quality Portal for the Pennsylvania Marcellus region. With the most stringent statistical tests, GeoNet detected 0.2% to 2% of the known contamination incidents (Na ± Cl) in streams. With denser sensor networks, tools like GeoNet could allow real-time detection of polluting events.

Abstract:
Produced water (PW) is a major waste-product of oil and gas production that some consider a viable agricultural irrigation water source. However, the presence of petroleum hydrocarbons, toxic metals and potentially high salinity of PW may be deleterious for soil health. Thus, we irrigated wheat with minimally treated PW to investigate effects on soil health, wheat growth, and the soil microbiome. Irrigation treatments included control irrigation water (IW), 1% and 5% PW dilutions (1% PW, 5% PW), and a saltwater solution with salinity equivalent to the 5% PW dilution (SW). Wheat was irrigated three times a week, for a total of 2.1 L per pot by harvest. During wheat growth, we measured plant physiological parameters, soil electrical conductivity, as well as profiled soil microbial diversity by performing 16S ribosomal ribonucleic acid (rRNA) gene analysis. Soil health parameters were measured after harvest, including chemical, biological, physical, and nutrient properties that were used to calculate an overall soil health index (SQI). SQI analysis revealed that the SW and 5% PW treatments had significantly reduced soil health as compared to the control. Furthermore, the 16S rRNA gene analysis showed that the microbial community membership and structure was significantly different between irrigation treatments, highlighting shifts in the soil microbiome which may impact soil biochemical cycling. Both the SW- and 5% PW-treated wheat had reduced yields as compared to the control. Our results indicate that irrigating wheat with minimally treated PW may result in yield decreases, as well as reducing both overall soil health and soil microbial community diversity. Future large-scale field studies are needed to determine the long-term soil health effects of PW on different soil types and crops.

Abstract:
As natural gas has grown in importance as a global energy source, leakage of methane (CH4) from wells has been noted. Leakage of this greenhouse gas is important because it affects groundwater quality and, when emitted to the atmosphere, climate. We hypothesized that streams might be most contaminated by CH4 in the northern Appalachian Basin in regions with the longest history of hydrocarbon extraction activities. To test this, we searched for CH4-contaminated streams basin. Methane concentrations ([CH4]) for 529 stream sites are reported, in New York, West Virginia and mostly Pennsylvania. Despite targeting contaminated areas, the median [CH4], 1.1 μg/L, was lower than a recently identified threshold indicating potential contamination, 4.0 μg/L. [CH4] values were higher in a few streams because they receive high-[CH4] groundwaters, often from upwelling seeps. By analogy to the more commonly observed type of groundwater seep known as abandoned mine drainage (AMD), we introduce the term, “gas leak discharge” (GLD) for these waters where they are not associated with coal mines. GLD and AMD, observed in all parts of the study area, are both CH4-rich. Surprisingly, the region of oldest and most productive oil/gas development did not show the highest median for stream [CH4]. Instead, the median was statistically highest where dense coal mining was accompanied by conventional and unconventional oil and gas development, emphasizing the importance of CH4 contamination from coal mines into streams.

Abstract:
This study models emissions quantities and neighboring exposure concentrations of six airborne pollutants, including PM10, PM2.5, crystalline silica, arsenic, uranium, and barium, that result from the disposal of Marcellus shale drill cuttings waste during the 2011-to-2017 period. Using these predicted exposures, this study evaluates current setback distances required in Pennsylvania from waste facilities. For potential residents living at the perimeter of the current setback distance, 274 m (900 ft), a waste disposal rate of 612.4 metric tons per day at landfills (the 99th percentile in record) does not result in exceedances of the exposure limits for any of the six investigated pollutants. However, the current setback distance can result in exceedance with respect to the 24-hr daily concentration standards for PM10 and PM2.5 established in the National Air Ambient Quality Standards (NAAQS), if daily waste disposal rate surpasses 900 metric tons per day. Dry depositions of barium-containing and uranium-containing particulate matter should not be a danger to public health based on these results. To investigate the air quality impacts of waste transportation and the potential for reductions, this paper describes an optimization of landfill locations in Pennsylvania indicating the potential benefits in reduced environmental health hazard level possible by decreasing the distance traveled by waste disposal trucks. This strategy could reduce annual emissions of PM10 and PM2.5 by a mean of 64% and reduce the expected number of annual fatal accidents by nearly half and should be considered a potential risk management goal in the long run. Therefore, policy to limit or encourage reduction of distances traveled by waste removal trucks and manage setback distances as a function of delivered waste quantities is merited. Implications This study shows the necessity of reviewing current setback distance required in Pennsylvania, which might not ensure 24-hr mean PM10 and PM2.5 levels below the values stated in National Ambient Air Quality Standards for the residents living at the perimeter. Furthermore, this study also reveals potential tremendous benefits from optimizing location of landfills accepting drill cuttings within Pennsylvania, with PM10 and PM2.5 emission, total distance traveled shrinking, and number of fatal accidents shrinking by nearly half.

Abstract:
The engagement of residents in hydraulic fracturing (fracking) debates within regions in which extraction occurs is critically important for shaping fracking policies. Such engagement may be less likely to occur in such regions, however, due to social factors associated with fossil fuel dependence, or what has been termed petro-statism. Alberta, Canada, is just such a place, and we use survey data (N = 226) from a sample of residents in Lethbridge, Fox Creek, and Rosebud—three Alberta communities where local residents have experienced nearby proposed or active fracking for natural gas. We found the social capital attributes of trust and self-efficacy, as well as concern for the impacts of fracking, strongly predict public engagement in fracking issues in the three study sites. Annual household income, education, and working in the energy sector also shape citizens’ participation in fracking. Furthermore, we found that trust in particular institutions can have different levels of influence on personal and collective engagement.

Abstract:
The advent of shale gas in economically and commercially viable scale has changed the dynamics of the U.S energy profile making it a net exporter of natural gas. However, despite the growing importance of shale gas, its impact on the economy of US has not been substantially investigated. This creates gaps in the empirical literature of energy economics with limited policy guides for the policy makers and other relevant stakeholders. This paper therefore contributes to the extant literature by examining the impacts of shale gas on economic expansion in the U.S in an augmented framework that includes capital stock and labour as additional variables. With quarterly dataset that covers the period, 2002Q1 to 2019Q1, we employed Cho et al. (2015) [1]'s Quantile Autoregressive Distributed Lag (QARDL) modelling technique to probe the long run relationships between the variables. The results confirm a long-run significant impact of shale gas and capital stock on economic growth of U.S while labour force is found to be a positive but not significant factor in economic growth of the U.S. Investment in capital infrastructure that can enhance the technology of natural gas extraction and fracking is recommended for full optimization of the shale gas consumption. Concerted efforts should also be made, through research and development, to improve the efficiency of labour force.

Abstract:
As global exploration of shale gas reserves increases, there is a need for accurate and efficient approach to proper water management, which is one of the vital problems related to shale gas production. This study looks at the effect of using multiple or hybrid treatment technologies in maximizing hydraulic fracturing wastewater reuse, whilst ensuring sustainability of the process in terms of energy and associated cost. The study considers ultrafiltration and membrane distillation processes as possible pre-treatment and desalination technologies for flowback water management. It also considers the possibility of supplying the electrical and thermal energy requirements of these regenerators using flared gas. Two different scenarios are considered based on flowback water composition in hydraulic fracturing in terms of salinity. Application of the proposed model to a case study leads to 24.13 % reduction in the quantity of water needed for fracturing. In terms of energy requirements, the approach yields 31.6 % reduction in the required thermal energy in membrane distillation and 8.62 % in energy requirement for ultrafiltration. For flowback water with moderate total dissolved solids concentration, 93.6 % of wastewater reuse comes from pre-treated water by ultrafiltration and 6.4 % from membrane distillation. However, as the flowback water salinity becomes higher, the percentage of pre-treated reusable water reduces to 81.1 % and the percentage supply through membrane distillation increases to 18.9 %. In all cases, the results indicate that the decision to allow the pre-treated water to pass through desalination technology strictly depends on the quantity of water required by a wellpad and the salinity of the wastewater.

Abstract:
Unconventional oil and gas (UOG) drilling has expanded rapidly across the United States, including in the Fayetteville Shale formation in north-central Arkansas where drilling began in 2004. As one of the oldest regions of UOG activity in the United States, this area has experienced significant land-use changes, specifically development of natural habitat and agricultural land for gas infrastructure. In recent years, drilling of new wells has stopped and production has declined. By 2017, 1038 wells had ceased production and been abandoned, which makes them eligible for land reclamation. However, most of these sites (80%) have not been reclaimed and continue to cause losses in ecosystem services. If reclamation was performed on lands associated with abandoned infrastructure, we estimate more than $2 million USD annually in agricultural, timber, and carbon sequestration values would be gained. These benefits far outweigh the costs of reclamation, especially since the benefits accrue over time and reclamation is a short-term cost. Our estimates indicate a 2–4 year break-even time period when cumulative ecosystem services benefits will outweigh reclamation costs. We predicted a well-abandonment rate of 155 per year until 2050 when 98% of wells will be abandoned, which indicates great potential for future ecosystem services restoration. Thus, we recommend that Arkansans at the government and citizen level work to restore lands impacted by UOG development in the Fayetteville Shale region so that their value to landowners and society can be recovered, which will enhance long-term economic and environmental benefits.

Abstract:
Oil and gas development has grown rapidly in recent years in the United States, generating substantial debate over its risks and benefits. A large body of research has surveyed individuals living in and around producing regions to evaluate their views on the industry, with somewhat mixed results. Here, we present the first detailed analysis on this topic using real-world voting data, drawing from precinct-level results of a 2018 election in Colorado that included a vote on Proposition 112, which would have set very large setback requirements on new oil and gas activity. We find partisan affiliation correlates very strongly with support for oil and gas development, that voters in precincts with higher levels of oil and gas activity are modestly more supportive of the industry, but that this support weakens in precincts where development has grown most rapidly.