Repository for Oil and Gas Energy Research (ROGER)

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We use the synthetic control method to determine the economic impact of the shale boom to Ohio, Pennsylvania, and West Virginia. Estimation results are mixed. The shale development decreased the poverty rate and increased the employment growth rate in Pennsylvania and West Virginia in the short run. Top oil and gas producing counties in West Virginia also experienced short-term personal income growth due to fracking. However, most of the positive impacts disappeared a few years after the initial boom periods. The shale development did not bring significant economic benefits to Ohio. Further, shale drilling activities exert a potential long-term negative effect on population growth in all three states.

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The widespread application of directional drilling and hydraulic fracturing technologies expanded oil and gas (OG) development to previously inaccessible resources. A single OG well can generate millions of liters of wastewater, which is a mixture of brine produced from the fractured formations and injected hydraulic fracturing fluids (HFFs). With thousands of wells completed each year, safe management of OG wastewaters has become a major challenge to the industry and regulators. OG wastewaters are commonly disposed of by underground injection, and previous research showed that surface activities at an Underground Injection Control (UIC) facility in West Virginia affected stream biogeochemistry and sediment microbial communities immediately downstream from the facility. Because microbially driven processes can control the fate and transport of organic and inorganic components of OG wastewater, we designed a series of aerobic microcosm experiments to assess the influence of high total dissolved solids (TDS) and two common HFF additives—the biocide 2,2-dibromo-3-nitrilopropionamide (DBNPA) and ethylene glycol (an anti-scaling additive)—on microbial community structure and function. Microcosms were constructed with sediment collected upstream (background) or downstream (impacted) from the UIC facility in West Virginia. Exposure to elevated TDS resulted in a significant decrease in aerobic respiration, and microbial community analysis following incubation indicated that elevated TDS could be linked to the majority of change in community structure. Over the course of the incubation, the sediment layer in the microcosms became anoxic, and addition of DBNPA was observed to inhibit iron reduction. In general, disruptions to microbial community structure and function were more pronounced in upstream and background sediment microcosms than in impacted sediment microcosms. These results suggest that the microbial community in impacted sediments had adapted following exposure to OG wastewater releases from the site. Our findings demonstrate the potential for releases from an OG wastewater disposal facility to alter microbial communities and biogeochemical processes. We anticipate that these studies will aid in the development of useful models for the potential impact of UIC disposal facilities on adjoining surface water and shallow groundwater.

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Background: Oil and natural gas extraction may produce environmental pollution at levels that affect reproductive health of nearby populations. Available studies have primarily focused on unconventional gas drilling and have not accounted for local population changes that can coincide with drilling activity. Objective: Our study sought to examine associations between residential proximity to oil and gas drilling and adverse term birth outcomes using a difference-in-differences study design. Methods: We created a retrospective population-based term birth cohort in Texas between 1996 and 2009 composed of mother–infant dyads ( n=2,598,025 n=2,598,025 ) living <10km <10km from an oil or gas site. We implemented a difference-in-differences approach to estimate associations between drilling activities and infant health: term birth weight and term small for gestational age (SGA). Using linear and logistic regression, we modeled interactions between births before (unexposed) or during (exposed) drilling activity and residential proximity near (0–1, 1–2, or 2–3km 2–3km ) or far ( 3–10km 3–10km ) from an active or future drilling site, adjusting for individual- and neighborhood-level characteristics. Results: The adjusted mean difference in term birth weight for mothers living 0–1 vs. 3–10km 3–10km from a current or future drilling site was –7.3g –7.3g [95% confidence interval (CI): –11.6 –11.6 , –3.0 –3.0 ] for births during active vs. future drilling. The corresponding adjusted odds ratio for SGA was 1.02 (95% CI: 0.98, 1.06). Negative associations with term birth weight were observed for the 1–2 and 2–3km 2–3km near groups, and no consistent differences were identified by type of drilling activity. Larger, though imprecise, adverse associations were found for infants born to Hispanic women, women with the lowest educational attainment, and women living in cities. Conclusions: Residing near oil and gas drilling sites during pregnancy was associated with a small reduction in term birth weight but not SGA, with some evidence of environmental injustices. Additional work is needed to investigate specific drilling-related exposures that might explain these associations. https://doi.org/10.1289/EHP7678

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The shale gas boom revolutionized the energy sector through hydraulic fracturing (fracking). High levels of energy production force communities, states, and nations to consider the externalities and potential risks associated with this unconventional oil and natural gas development (UOGD). In this review, we systematically outline the environmental, economic, and anthropogenic impacts of UOGD, while also considering the diverse methodological approaches to these topics. We summarize the current status and conclusions of the academic literature, in both economic and related fields, while also providing suggested avenues for future research. Causal inference will continue to be important for the evaluation of UOGD costs and benefits. We conclude that current economic, global, and health forces may require researchers to revisit outcomes in the face of a potential shale bust. Expected final online publication date for the Annual Review of Resource Economics, Volume 13 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

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We investigate the physical mechanisms governing the activation of faults during hydraulic fracturing. Recent studies have debated the varying importance of different fault reactivation mechanisms. Pore pressure increase caused by injection is generally considered to be the primary driver of induced seismicity. However, in very tight reservoir rocks, unless a fracture network exists to act as a hydraulic conduit, the rate of diffusion may be too low to explain the spatiotemporal evolution of some microseismic sequences. Thus, poroelastic stress transfer and aseismic slip have been invoked to explain observations of events occurring beyond the expected distance of a diffusive front. In this study we use the high quality microseismic data acquired during hydraulic fracturing at the Preston New Road (PNR) wells, Lancashire, UK, to examine fault triggering mechanisms. Injection through both wells generated felt induced seismicity-an ML 1.5 during PNR-1z injection in 2018 and an ML 2.9 during PNR-2 in 2019-and the microseismic observations show that each activated a different fault. Previous studies have already shown that PNR-1z seismicity was triggered by a combination of both direct hydraulic effects and elastic stress transfer generated by tensile fracture opening. Here we perform a similar analysis of the PNR-2 seismicity, finding that the PNR-2 fault triggering was mostly likely dominated by the diffusion of increased fluid pressure through a secondary zone of hydraulic fractures. However, elastic stress transfer caused by hydraulic fracture opening would have also acted to promote slip. It is significant that no microseismicity was observed on the previously activated fault during PNR-2 operations. This dataset therefore provides a unique opportunity to estimate the minimum perturbation required to activate the fault. As it appears that there was no hydraulic connection between them during each stimulation, any perturbation caused to the PNR-1z fault by PNR-2 stimulation must be through elastic or poroelastic stress transfer. As such, by computing the stress transfer created by PNR-2 stimulation onto the PNR-1z fault, we are able to approximate the minimum bound for the required stress perturbation: in excess of 0.1 MPa, an order of magnitude larger than commonly stated estimates of a generalised triggering threshold.

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Produced water (PW) generation has been increasing recently due to the expansion of fossil fuel extraction and the aging of oil wells worldwide and especially in the United States (US). The adverse health risks, seismicity, and environmental impacts associated with PW have become a challenging concern. Therefore, there is increased demand for improved PW treatment and reuse management options. There are multiple methods for treating PW; this article focuses on treatment through membrane filtration. Moreover, this mini review aims to summarize statistics on PW abundance, trends in PW generation over time, to briefly call attention to health-related issues, highlight some treatment challenges, and mention potential purposes for reuse with an emphasis on the US, the largest generator of PW worldwide.

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Arsenic (As) is a toxic trace element with many sources, including hydrocarbons such as oil, natural gas, oil sands, and oil- and gas-bearing shales. Arsenic from these hydrocarbon sources can be released to the environment through human activities of hydrocarbon production, storage, transportation and use. In addition, accidental release of hydrocarbons to aquifers with naturally occurring (geogenic) As can induce mobilization of As to groundwater through biogeochemical reactions triggered by hydrocarbon biodegradation. In this paper, we review the occurrence of As in different hydrocarbons and the release of As from these sources into the environment. We also examine the occurrence of As in wastes from hydrocarbon production, including produced water and sludge. Last, we discuss the potential for As release related to waste management, including accidental or intentional releases, and recycling and reuse of these wastes.

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Hydraulic fracturing has become widely used in recent years to access vast global unconventional sources of oil and gas. This process involves the injection of proprietary mixtures of water and chemicals to fracture shale formations and extract the hydrocarbons trapped within. These injection fluids, along with minerals, hydrocarbons, and saline waters present within the formations being drilled into, return to the surface as flowback and produced water (FPW). FPW is a highly complex mixture, containing metals, salts and clay, as well as many organic chemicals, including polycyclic aromatic hydrocarbons such as phenanthrene. The present study sought to determine the effects of temperature on the accumulation of phenanthrene in rainbow trout (Oncorhynchus mykiss). This model organism resides in rivers overlapping the Montney and Duvernay formations, both highly developed formations for hydraulic fracturing. Rainbow trout acclimated to temperatures of 4, 13 and 17°C were exposed to either 5% or 20% FPW, as well as saline mixtures representing the exact ionic content of FPW to determine the accumulation of radiolabelled 14C phenanthrene within the gill, gut, liver and gallbladder. FPW exposure reduced the overall accumulation of phenanthrene in a manner most often similar to high salinity exposure, indicating that the high ionic strength of FPW is the primary factor affecting accumulation. Accumulation was different at the temperature extremes (4 and 17°C), although no consistent relationship was observed between temperature and accumulation across the observed tissues. These results indicate that several physiological responses occur as a result of FPW exposure and water temperature change which dictate phenanthrene uptake, particularly in the gills. Temperature (and seasonality) alone cannot be used to model the potential accumulation of polycyclic aromatic hydrocarbons after FPW spills.

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Oilfield flowback and produced water (FPW) is a waste stream that may offer an alternative source of water for multiple beneficial uses. One practice gaining interest in several semi-arid states is the reuse of FPW for agricultural irrigation. However, it is unknown if the reuse of FPW on edible crops could increase health risks from ingestion of exposed food, or impact crop growth. A greenhouse experiment was conducted using wheat (Triticum aestivum) to investigate the uptake potential of select hydraulic fracturing additives known to be associated with health risks. The selected chemicals included acrylamide, didecyldimethylammonium chloride (DDAC), diethanolamine, and tetramethylammonium chloride (TMAC). Mature wheat grain was extracted and analyzed by liquid chromatography-triple quadrupole mass spectrometry (LC-QQQ) to quantify chemical uptake. Plant development observations were also documented to evaluate impacts of the chemicals on crop yield. Analytical results indicated that TMAC and diethanolamine had significantly higher uptake into both wheat grain and stems than control plants which were not exposed to the four chemicals under investigation. Acrylamide was measured in statistically higher concentrations in the stems only, while DDAC was not detected in grain or stems. Growth impacts included lodging in treated wheat plants due to increased stem height and grain weight, potentially resulting from increased nitrogen application. While analytical results show that uptake of select hydraulic fracturing chemicals in wheat grain and stems is measurable, reuse of FPW for irrigation in real world scenarios would likely result in less uptake because water would be subject to natural degradation, and often treatment and dilution practices. Nonetheless, based on the outstanding data gaps associated with this research topic, chemical specific treatment and regulatory safeguards are still recommended.

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For decades, the governance regimes of the United States and many other nations have increasingly devolved authority from central federal governments to substantially weaker state and local governments and even private industry. This trend produces uneven results for affected spaces and modes of governance. At the same time, industries have been re-regulated under neoliberalization to maximize corporate profitability. Conterminous to the trend of neoliberal deregulation is the global energy transition. The U.S. energy system has shifted away from coal toward natural gas and has become the world’s top producer of hydrocarbons due to the widespread deployment of drilling techniques that allow access to unconventional resources. We evaluate the ways that neoliberal governance structures can create uneven socio-economic impacts from oil and gas development across U.S. states using a multi-level modeling framework with random slopes and cross-level interactions. We utilize a multi-level state and county data set that covers 2000–2016 to examine different outcomes across scales and places. We find evidence that state political economies—reflected in the ideological composition of state legislatures as well as the political spending of the energy sector—condition the effects of oil and gas development on well-being. These findings are discussed in reference to theories of neoliberalism, growth machine politics, energy boomtowns, and natural resource-dependent communities.

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Shale gas has grown to become a major new source of energy in countries around the globe. While its importance for energy supply is well recognized, there has also been public concern over potential risks from hydraulic fracturing (‘fracking’). Although commercial development has not yet taken place in the UK, licenses for drilling were issued in 2008, signalling potential future development. This paper examines whether public fears about fracking affect house prices in areas that have been licensed for shale gas exploration. Our estimates suggest differentiated effects. Licensing did not affect house prices but fracking the first well in 2011, which caused two minor earthquakes, did. We find a 3.9–4.7 percent house price decrease in the area where the earthquakes occurred. The earthquakes were too minor to have caused any damage but we find the effect on prices extends to a radius of about 25 km served by local newspapers. This evidence suggests that the earthquakes and newspaper coverage increased awareness of exploration activity and fear of the local consequences.

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Recently, oil and natural gas (O&NG) production activities in the Denver-Julesburg Basin have expanded rapidly. Associated nonmethane hydrocarbon (NMHC) emissions contribute to photochemical formation of ground-level ozone and include benzene as well as other hazardous air pollutants. Using positive matrix factorization (PMF) and chemical mass balance (CMB) methods, we estimate how much O&NG activities and other sources contribute to morning NMHC mixing ratios measured from 2013 to mid-2016 at a site in Platteville, CO, in the Denver-Julesburg Basin, and at a contrasting site in downtown Denver. A novel adjoint sensitivity analysis method is then used to estimate corresponding contributions to ozone and ozone-linked mortality in the Denver region. Average 6–9 am NMHC mixing ratios in Platteville were seven times higher than those in Denver in 2013 but four times higher in 2016. CMB estimates that O&NG activities contributed to the Platteville (Denver) site an average of 96% (56%) of NMHC on a carbon basis while PMF indicated 92% (33%). Average vehicle-related contributions of NMHC are estimated as 41% by CMB and 53% by PMF in Denver. Estimates of the fractional contribution to potential ozone and ozone-linked mortality from O&NG activities are smaller while those from vehicles are larger than the NMHC contributions. CMB (PMF) indicate that greater than 78% (40%) of annual average benzene in Denver is attributable to vehicle emissions while greater than 75% (67%) of benzene in Platteville is attributable to O&NG activities.

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Hydraulic fracturing (“fracking”) is a process in which subterranean natural gas-laden rock is fractured under pressure to enhance retrieval of gas. Sand (a “proppant”) is present in the fracking fluid pumped down the well bore to stabilize the fissures and facilitate gas flow. The manipulation of sand at the well site creates respirable dust (fracking sand dust, FSD) to which workers are exposed. Because workplace exposures to FSD have exceeded exposure limits set by OSHA, a physico-chemical characterization of FSD along with comprehensive investigations of the potential early adverse effects of FSDs on organ function and biomarkers has been conducted using a rat model and related in vivo and in vitro experiments involving the respiratory, cardiovascular, immune systems, kidney and brain. An undercurrent theme of the overall hazard identification study was, to what degree do the health effects of inhaled FSD resemble those previously observed after crystalline silica dust inhalation? In short-term studies, FSD was found to be less bioactive than MIN-U-SIL® 5 in the lungs. A second theme was, are the biological effects of FSD restricted to the lungs? Bioactivity of FSD was observed in all examined organ systems. Our findings indicate that, in many respects, the physical and chemical properties, and the short-term biological effects, of the FSDs share many similarities as a group but have little in common with crystalline silica dust.

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The rise of hydraulic fracturing and unconventional oil and gas (UOG) exploration in the United States has increased public concerns for water contamination induced from hydraulic fracturing fluids and associated wastewater spills. Herein, we collected surface and groundwater samples across Garfield County, Colorado, a drilling-dense region, and measured endocrine bioactivities, geochemical tracers of UOG wastewater, UOG-related organic contaminants in surface water, and evaluated UOG drilling production (weighted well scores, nearby well count, reported spills) surrounding sites. Elevated antagonist activities for the estrogen, androgen, progesterone, and glucocorticoid receptors were detected in surface water and associated with nearby shale gas well counts and density. The elevated endocrine activities were observed in surface water associated with medium and high UOG production (weighted UOG well score-based groups). These bioactivities were generally not associated with reported spills nearby, and often did not exhibit geochemical profiles associated with UOG wastewater from this region. Our results suggest the potential for releases of low-saline hydraulic fracturing fluids or chemicals used in other aspects of UOG production, similar to the chemistry of the local water, and dissimilar from defined spills of post-injection wastewater. Notably, water collected from certain medium and high UOG production sites exhibited bioactivities well above the levels known to impact the health of aquatic organisms, suggesting that further research to assess potential endocrine activities of UOG operations is warranted.

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The essence of policy conflicts remains largely underdeveloped, both theoretically and empirically. We explore policy conflict and explain its cognitive and behavioral characteristics using data from a survey administered to policy actors involved in oil and gas politics in Colorado, USA. The analysis begins with a description of the cognitive and behavioral characteristics of policy actors and then combines them into a single index to depict varying intensities of conflict. Cognitive characteristics are comprised of three dimensions: disagreement on public policy, perceived threats from opponents, and an unwillingness to compromise. Behavioral characteristics include engagement by policy actors in a range of activities, from mobilizing opponents to providing information to the media. Ordered Logit models are used to associate the attributes of policy actors with cognitive and behavioral characteristics and an index of conflict intensity that combines these two characteristics. The conclusion offers questions and recommendations for future research.

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BACKGROUND: Growing literature linking unconventional natural gas development (UNGD) to adverse health has implicated air pollution and stress pathways. Persons with heart failure (HF) are susceptible to these stressors. OBJECTIVES: This study sought to evaluate associations between UNGD activity and hospitalization among HF patients, stratified by both ejection fraction (EF) status (reduced [HFrEF], preserved [HFpEF], not classifiable) and HF severity. METHODS: We evaluated the odds of hospitalization among patients with HF seen at Geisinger from 2008 to 2015 using electronic health records. We assigned metrics of UNGD activity by phase (pad preparation, drilling, stimulation, and production) 30 days before hospitalization or a frequency-matched control selection date. We assigned phenotype status using a validated algorithm. RESULTS: We identified 9,054 patients with HF with 5,839 hospitalizations (mean age 71.1 ± 12.7 years; 47.7% female). Comparing 4th to 1st quartiles, adjusted odds ratios (95% confidence interval) for hospitalization were 1.70 (1.35 to 2.13), 0.97 (0.75 to 1.27), 1.80 (1.35 to 2.40), and 1.62 (1.07 to 2.45) for pad preparation, drilling, stimulation, and production metrics, respectively. We did not find effect modification by HFrEF or HFpEF status. Associations of most UNGD metrics with hospitalization were stronger among those with more severe HF at baseline. CONCLUSIONS: Three of 4 phases of UNGD activity were associated with hospitalization for HF in a large sample of patients with HF in an area of active UNGD, with similar findings by HFrEF versus HFpEF status. Older patients with HF seem particularly vulnerable to adverse health impacts from UNGD activity.

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The most massive waste stream generated by conventional and unconventional hydrocarbon exploration is the produced water (PW). The costs and environmental issues associated with the management and disposal of PW, which contains high concentrations of inorganic and organic pollutants, is one of the most challenging problems faced by the oil and gas industry. Many of the current strategies for the reuse and recycling of PW are inefficient because of varying water demand and the spatial and temporal variations in the chemical composition of PW. The chemical composition of PW is controlled by a multitude of factors and can vary significantly over time. This study aims to understand different parameters and processes that control the quality of PW generated from hydrocarbon-bearing Formations by analyzing relationships between their major ion concentrations, O, H, and Sr isotopic composition. We selected PW data sets from three conventional (Trenton, Edwards, and Wilcox Formations) and four unconventional (Lance, Marcellus, Bakken, and Mesaverde Formations) oil and gas Formations with varying lithology and depositional environment. Using comparative geochemical data analysis, we determined that the geochemical signature of PW is controlled by a complex interplay of several factors, including the original source of water (connate marine vs. non-marine), migration of the basinal fluids, the nature and degree of water-mineral-hydrocarbon interactions, water recharge, and processes such as evaporation and ultrafiltration processes, and production techniques (conventional vs. unconventional). The design of efficient PW recycle and reuse strategies requires a holistic understanding of the geological and hydrological history of each Formation and an account of temporal and spatial heterogeneities.

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In this study, a ground-based mobile measurement system was developed to provide rapid and cost-effective emission surveillance of both methane (CH4) and volatile organic compounds (VOCs) from oil and gas (O&G) production sites. After testing in several controlled release experiments, the system was deployed in a field campaign in the Eagle Ford basin, TX. We found fat-tail distributions for both methane and total VOC (C4–C12) emissions (e.g., the top 20% sites ranked according to methane and total VOC (C4–C12) emissions were responsible for ∼60 and ∼80% of total emissions, respectively) and a good correlation between them (Spearman’s R = 0.74). This result suggests that emission controls targeting relatively large emitters may help significantly reduce both methane and VOCs in oil and wet gas basins, such as the Eagle Ford. A strong correlation (Spearman’s R = 0.84) was found between total VOC (C4–C12) emissions estimated using SUMMA canisters and data reported from a local ambient air monitoring station. This finding suggests that this system has the potential for rapid emission surveillance targeting relatively large emitters, which can help achieve emission reductions for both greenhouse gas (GHG) and air toxics from O&G production well pads in a cost-effective way.

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Recent seismicity in Alberta and British Columbia has been attributed to ongoing oil and gas development in the area, due to its temporal and spatial correlation. Prior to such development, the area was seismically quiescent. Here, we show evidence that latent seismicity may occur in areas where previous operations may have occurred, even during a shutdown in operations. The global pandemic of COVID-19 furnished the unique opportunity to study seismicity during a period of 5 anthropogenic quiescence. A total of 389 events were detected within the Kiskatinaw area of British Columbia from April to August 2020, which encompasses a period with no hydraulic fracturing operations during a government imposed lockdown. Apart from a reduction in seismicity rate, the general characteristics of the observed seismicity were similar to the preceding time period of active operations. During the shutdown, observed event magnitudes fell between ML -1 and ML 1.2, but lacked temporal clustering that is often characteristic of hydraulic-fracturing induced sequences. Hypocenters occurred in a corridor 10 orientated NW-SE, just as seismicity had done in previous years in the area, and locate at depths associated with the target Montney formation or shallower (<2.5 km). A maximum of 21% of the detected events during lockdown may be attributable to natural seismicity, with a further 8% being attributed to dynamic triggering of seismicity from teleseismic events. However this leaves over 70% of the seismicity detected during lockdown being unattributable to primary activation mechanisms. Since we know this seismicity cannot be the result of direct pore-pressure increases (as no direct injection was occurring at the time) and 15 we see no patterns of temporal or spatial migration in the seismicity, we suggest that this latent seismicity may be generated by aseismic slip as fluids (resulting from previous hydraulic fracturing experiments) become trapped within permeable formations at depth, keeping pore pressures in the area elevated, and consequently allowing the generation of seismicity. This is the first time that this latent seismicity has been observed in this area of British Columbia.

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Fracking is a technology used for the extraction of shale gas contained in rocks on the Earth’s surface. The main characteristic of this method is that it consists of injecting pressurized water into the ground, thus creating a series of fractures through which the gas comes out to be collected later. Fracking has a number of both socio-economic and environmental implications that can be both beneficial (including increased energy security, economic growth, or reduced emissions of pollutants and climate change) and harmful (induced seismicity, increased global temperature, and potential greenhouse emissions if not properly implemented). The realization of a systematic review of the literature classifying the articles found according to the type of evidence they present; that it gathers all the impacts has allowed to group them and to give a general vision about the topic; that no articles have been found that have this same objective in the existing literature, thus contributing to the increase of the existing knowledge in this field. It is concluded that environmental risks, including those that could affect human health, should be integrated into the cost structure of fracking, as a risk premium or provision of funds to remedy possible negative effects.

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The expansion of unconventional oil and gas development (UOGD) by means of horizontal drilling and high-volume hydraulic fracturing has been accompanied by concerns regarding the potential impacts to water resources and public health. The ban on UOGD in New York State (NYS) allows natural processes that control groundwater chemistry and dissolved methane to be evaluated without complications that could arise in regions impacted by prior unconventional shale gas development. We evaluated the controls on the occurrence and spatial variability of methane, chloride, bromine, and iodine, covering much of NYS and encompassing a range of underlying bedrock geologies. Groundwater samples were collected from 108 domestic and public supply wells. Methane concentrations in groundwater ranged from <0.001-84.6 mg/L. The variables most consistently associated with methane occurrence in groundwater include: 1) bedrock geology penetrated by wells; 2) groundwater chemical composition; 3) and confinement characterization of the well. The geochemical parameters iodine, chloride, and sodium/calcium suggest that elevated concentrations of methane are likely associated with deep brines. Higher methane concentrations are frequently accompanied by both high bromine and iodine concentrations in this study, indicating that the potential of halogens as tracers for dissolved methane need to be further investigated.

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The pulmonary inflammatory response to inhalation exposure to a fracking sand dust (FSD 8) was investigated in a rat model. Adult male Sprague-Dawley rats were exposed by whole-body inhalation to air or an aerosol of a FSD, i.e., FSD 8, at concentrations of 10 or 30 mg/m3, 6 h/d for 4 d. The control and FSD 8-exposed rats were euthanized at post-exposure time intervals of 1, 7 or 27 d and pulmonary inflammatory, cytotoxic and oxidant responses were determined. Deposition of FSD 8 particles was detected in the lungs of all the FSD 8-exposed rats. Analysis of bronchoalveolar lavage parameters of toxicity, oxidant generation, and inflammation did not reveal any significant persistent pulmonary toxicity in the FSD 8-exposed rats. Similarly, the lung histology of the FSD 8-exposed rats showed only minimal changes in influx of macrophages following the exposure. Determination of global gene expression profiles detected statistically significant differential expressions of only six and five genes in the 10 mg/m3, 1-d post-exposure, and the 30 mg/m3, 7-d post-exposure FSD 8 groups, respectively. Taken together, data obtained from the present study demonstrated that FSD 8 inhalation exposure resulted in no statistically significant toxicity or gene expression changes in the lungs of the rats. In the absence of any information about its potential toxicity, a comprehensive rat animal model study (see Fedan, J.S., Toxicol Appl Pharmacol. 000, 000–000, 2020) has been 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.

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Cultured murine macrophages (RAW 264.7) were used to investigate the effects of fracking sand dust (FSD) for its pro-inflammatory activity, in order to gain insight into the potential toxicity to workers associated with inhalation of FSD during hydraulic fracturing. While the role of respirable crystalline silica in the development of silicosis is well documented, nothing is known about the toxicity of inhaled FSD. The FSD (FSD 8) used in these studies was from an unconventional gas well drilling site. FSD 8was prepared as a 10 mg/ml stock solution in sterile PBS, vortexed for 15 s, and allowed to sit at room temperature for 30 min before applying the suspension to RAW 264.7cells. Compared to PBS controls, cellular viability was significantly decreased after a 24 h exposure to FSD. Intracellular reactive oxygen species (ROS) production and the production of IL-6, TNFα, and endothelin-1 (ET-1) were up-regulated as a result of the exposure, whereas the hydroxyl radical (.OH) was only detected in an acellular system. Immunofluorescent staining of cells against TNFα revealed that FSD 8 caused cellular blebbing, and engulfment of FSD 8 by macrophages was observed with enhanced dark-field microscopy. The observed changes in cellular viability, cellular morphology, free radical generation and cytokine production all confirm that FSD 8 is cytotoxic to RAW 264.7 cells and warrants future studies into the specific pathways and mechanisms by which these toxicities occur.

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Residents of rural communities with histories of booms and busts in natural resource extraction often have divergent and simultaneously complex views on whether continued development of such industries is desirable. For instance, while many residents appreciate the economic benefits generated by these industries, some are also skeptical about disruptions resulting from expanding or continuing resource extraction. We use social representation theory and a mini-boom/bust framework to examine Bakken Shale residents’ perceptions of current and continued development of the oil and gas industry, including the role of industrial legacy and environmental concerns. Data from our 2016 survey indicates that about one in four residents see oil and gas development as positive for their community, but at the same time, felt relief that the most recent boom slowed in pace. We refer to this as the Goldilocks View of Development and see it as evidence of support for a mini-bust. In terms of continued development of the industry as represented by the construction of the Dakota Access Pipeline, we found a high level of support for construction, and that political party, belonging to a local organization, and trust in industry to address spills are key predictors of such support. As natural resource dependent communities such as those in the Bakken Shale continue to experience unconventional oil and gas development in a mini-boom/bust context, it is important to understand residents’ perceptions so that state and local governments can develop policies towards the industry that address local concerns.

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Unconventional oil and gas development (UOGD) expanded rapidly in the United States between 2004 and 2019 with resultant industrial change to landscapes and new environmental exposures. By 2019, West Texas’ Permian Basin accounted for 35% of domestic oil production. We conducted an online survey of 566 Texans in 2019 to examine the implications of UOGD using three measures from the Environmental Distress Scale (EDS): perceived threat of environmental issues, felt impact of environmental change, and loss of solace when valued environments are transformed (“solastalgia”). We found increased levels of environmental distress among respondents living in counties in the Permian Basin who reported a 2.75% increase in perceived threat of environmental issues (95% CI = −1.14, 6.65) and a 4.21% increase in solastalgia (95% CI = 0.03, 8.40). In our subgroup analysis of women, we found higher EDS subscale scores among respondents in Permian Basin counties for perceived threat of environmental issues (4.08%, 95% CI = −0.12, 8.37) and solastalgia (7.09%, 95% CI = 2.44, 11.88). In analysis restricted to Permian Basin counties, we found exposure to at least one earthquake of magnitude ≥ 3 was associated with increases in perceived threat of environmental issues (4.69%, 95% CI = 0.15, 9.23), and that county-level exposure to oil and gas injection wells was associated with increases in felt impact (4.38%, 95% CI = −1.77, 10.54) and solastalgia (4.06%, 95% CI = 3.02, 11.14). Our results indicate increased environmental distress in response to UOGD-related environmental degradation among Texans and highlight the importance of considering susceptible sub-groups.

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Leveraging waste heat has been considered to have significant potential for promoting the economic feasibility of wastewater treatment in unconventional oil and gas (UOG) production. However, its availability near well sites has not been fully understood and other energy sources may be also feasible. In this work, we quantitatively investigate the viability of using waste heat and well-pad natural gas to power on-site wastewater treatment by membrane distillation (MD) for twenty randomly selected wells located in the Denver-Julesburg (DJ) Basin, U.S. Results show that waste heat produced from on-site electrical loads is insufficient for MD treatment of all the wastewater generated during UOG production (2.2–24.3% of thermal energy required for MD treatment). Waste heat from hydraulic fracturing, which persists only for a short timeframe, is able to meet the full or partial energy requirement during the peak period of wastewater production (17–1005% of thermal energy required for MD treatment within the first two months of production), but this scenario varies among wells and is dependent on the energy efficiency of MD. Compared to waste heat, natural gas is a more consistent energy source. The treatment capacity of MD powered by natural gas at the well pad exceeds full wastewater treatment demands for all the twenty wells, with only two wells requiring short-term wastewater storage. Our work indicates that although waste heat has the potential to reduce the electricity consumption and cost of UOG wastewater treatment, it is unlikely to supply sufficient thermal energy required by MD for long-term treatment. Natural gas can serve as an alternative or complementary energy resource. Further investigations, in particular techno-economic analyses, are needed to identify the best suitable energy source or combination for on-site UOG wastewater treatment.

Abstract:
Unconventional gas (UG) continues to play an important role in Australia's energy supply, though it depends on having a social licence in local regions where it is planned or operating. Little research has examined how a social licence for UG development varies between pre-approval and operating phases of the industry. Using survey data for 800 residents, this research examines overall attitudes and underlying perceptions of coal seam gas (CSG) in two agricultural regions in Australia in different phases of UG development – Narrabri, New South Wales (NSW) in the pre-approval phase and the Western Downs, Queensland (Qld) in the operational phase. While the proposed development was considerably smaller in Narrabri than in the Western Downs, Narrabri residents were more likely to reject the proposed CSG development. However, this was not due to these residents having less favourable underlying perceptions of CSG development. In fact, they viewed some aspects of CSG development more favourably than their Qld counterparts. The difference was attributed to a unique phase effect which we argue reflects an enhanced “opportunity to say no” in the pre-approval phase of development. Nonetheless, underlying perceptions still predicted individual variation in attitudes and feelings toward CSG very well, suggesting that while enhanced opposition can be expected in the pre-approval phase, overall attitudes and feelings can also become more positive by improving the underlying drivers important for determining local residents' perceptions of the industry such as industry impacts and benefits, governance, distributional fairness, and trust in the industry.

Abstract:
Unconventional gas plays a significant role in transitioning to low carbon energy sources; however, its extraction is socially contested, and proponents increasingly face social licence issues. Explaining social acceptance for unconventional gas is complex, with multiple factors at play. This study uses comprehensive statistical modelling to explain social acceptance of a local coal seam gas (CSG) development in its pre-approval phase. Using a representative sample of 400 randomly selected residents in rural Australia, the statistical model explained 83% of variation in acceptance and measured interdependencies between eight factors determining acceptance. These factors were: effects from industry activity (perceived impacts and perceived benefits); distributional fairness (the spread of costs and benefits); the relational aspects between the host community and industry (perceptions of trust in industry, relationship quality and procedural fairness); governance of the industry (informal and formal governance, and trust in governing bodies); and knowledge (of the local CSG industry). Results showed that perceived impacts were the main driver of acceptance, with perceived benefits, distributional fairness, and trust in industry the next most important determinants. Relationship quality and procedural fairness predicted trust. Industry knowledge was only a minor determinant of acceptance. Those ‘rejecting’ CSG development had starkly more negative perceptions of the underlying factors than those ‘supporting’. However, both had higher self-rated knowledge than those who felt ‘lukewarm’ about CSG. This highly predictive statistical model can be used by industry to direct their efforts at the most important drivers of acceptance, such as benefit sharing and addressing concerns about impacts, and for planning their community engagement and communication. Policy makers and regulators can use the model to guide their expectations of industry when assessing projects for approval, including building trust through effective community engagement. Moreover, the research suggests that information is best targeted at residents with ‘lukewarm’ or less established views, and points to the importance of providing them with specific information about important factors underlying social acceptance such as benefit sharing, impact mitigation, procedural fairness, and governance, rather than general industry information. These insights help create the necessary preconditions for establishing a social licence to operate for an onshore gas development.

Abstract:
Unconventional oil and gas (UOG) production has rapidly expanded, making the U.S. the top producer of hydrocarbons. The industrial process now pushes against neighborhoods, schools, and people’s daily lives. I analyze extensive mixed methods data collected over three years in Colorado – including 75 in-depth interviews and additional participant observation – to show how living amid industrial UOG production generates chronic stress and negative mental health outcomes, such as self-reported depression. I show how UOG production has become a neighborhood industrial activity that, in turn, acts as a chronic environmental stressor. I examine two key drivers of chronic stress – uncertainty and powerlessness – and show how these mechanisms relate to state-level institutional processes that generate patterned procedural inequities. This includes inadequate access to transparent environmental and public health information about UOG production’s potential risks and limited public participation in decisions about production, with negative implications for mental health.

Abstract:
Technological advances in oil and gas drilling have enabled the productive extraction of natural gas in new regions. The benefits from employment and income opportunities can help stimulate economies and may be valued by local residents. At the same time, however, shale gas activity can alter natural landscapes and is associated with negative externalities, including potential groundwater contamination. While some previous research has examined the impact of shale development, our paper focuses on the local impacts in West Virginia, a state with a long history of resource-extraction and one whose economy has lagged the nation. Because of its history of resource extraction, communities in West Virginia who may have limited other economic prospects may value the activity differently. Additionally, most of the previous research used data during the initial boom, ignoring the slowdown that followed. Using the coarsened exact matching (CEM) technique, we match houses near producing wells with other similar houses, in order to examine how property values in West Virginia are affected by proximity to horizontal producing wells. This technique helps compensate for the relatively small number of housing transactions in West Virginia, ensuring we have a good counterfactual. After matching, we estimate the average capitalization effect of houses near producing shale wells. We find that the price of all houses (regardless of water source) decreases as the number of surrounding wells increases. However, we also find some evidence that this effect varies over time and that the negative capitalization effect attenuates over space.

Abstract:
This paper examines copy-and-paste regulating in hydraulic fracturing (HF) fluid disclosure regulation across US states. Using text analysis, cluster analysis and document coding, we compare HF regulations of twenty-nine states and two “model bills” drafted by the conservative American Legislative Exchange Council (ALEC) and the Environmental Defense Fund (EDF, an environmental NGO). In contrast to recent studies that have documented ALEC’s widespread influence across policy domains, we find limited evidence of ALEC influence in HF fluid disclosure regulations. Instead, elements of the EDF bill are more prevalent across state regulations. Yet, text similarity scores between states are higher than similarity scores between states and the EDF bill. In particular, Colorado and to a lesser extent Pennsylvania functioned as leader states for other states to follow. This indicates that state-to-state communication was a more influential channel of policy diffusion than interest group model bills in this instance. Future research should better examine processes of information sharing amongst state oil and gas regulators as regulatory text is but one channel of policy diffusion. The cluster analysis also reveals that contiguous states, often within the same shale basins, frequently have different regulations. This finding calls for a reconsideration of the current state-led environmental regulatory framework for HF, which has resulted in a patchwork of regulations across the US. Finally, through the use of novel text analysis tools, this paper adds methodological diversity to the study of policy diffusion within energy policy.

Abstract:
Although party affiliation is a strong predictor of differences in citizen opinion about a wide range of public policy issues, the picture is more complex for unconventional gas development (UGD) through hydraulic fracturing. Using data collected in Colorado (n = 390) around the time of the highly polarizing 2016 Presidential Election, we conduct a latent class analysis based on individual perceptions of the possible risks and benefits of UGD. Instead of finding attitudes polarized along party lines, citizens in Colorado parsimoniously cluster into three substantially sized groups that cannot be explained by party identification and sociodemographic variables. We also test the value of group membership by assessing association with individual voting behavior at the hypothetical ballot box using language from actual measures filed for placement onto the 2016 Statewide Ballot in Colorado. Results suggest that attitudes toward UGD may be better explained by perceptions of potential costs/disadvantages and benefits/advantages rather than traditional sociodemographic and political party variables. This suggests that understanding public opinion on fracking means moving beyond our traditional conceptualization of opinion formation, even in today’s politically polarized environment.

Abstract:
This article compares the topics that underlie public debate around hydraulic fracturing covered in newspapers across nine U.S. states over an eleven-year period. In analyzing more than 7000 newspaper articles using Latent Dirichlet Allocation (LDA) modeling, thirteen main topics emerge. While these topics fluctuate over time, their relative frequency and, hence, importance in the discourse remains largely constant. The environmental risks associated with the practice is the topic that receives more attention when all data are aggregated. We find that the frequency of the topics varies by state, and the nature of this variation is associated with the political leanings of the state, with media sources in Republican governed states more likely to report on the economic benefits associated with hydraulic fracturing. Finally, we show how all topics are associated with words that indicate the presence of conflict among stakeholders involved in discussions about the costs and benefits of hydraulic fracturing. In doing so, we describe how the association between topics and conflict varies according to which party governs the state, which provides evidence about the fundamental differences on how parties consider the practice of hydraulic fracturing in the states we study. We conclude the article by discussing the advantages and disadvantages of our methodological approach, which can be leveraged to discern trends in discussions about environmental and energy-related problems that exceed the specific case of hydraulic fracturing.

Abstract:
In this study, we explore the lived experiences of communities at the frontier of shale gas extraction in the United Kingdom. We ask: How do local people experience shale gas development? What narratives and reasoning do individuals use to explain their support, opposition or ambivalence to unconventional hydrocarbon developments? How do they understand their lived experiences changing over time, and what sorts of coping strategies do they rely upon? To do so, we draw insights from semi-structured interviews with 31 individuals in Lancashire, England, living or working near the only active shale gas extraction operation in the UK until the government moratorium was announced in December of 2019. Through these data, we identify several themes of negative experiences, including “horrendous” participation, community “abuse,” disillusionment and “disgust,” and earthquakes with the potential to “ruin” lives. We also identify themes of positive experiences emphasizing togetherness and community “gelling”, environmental “awareness,” everyday energy security with gas as a “bridging fuel,” and local employment with “high quality jobs.” Finally, we identify themes of ambivalent and temporally dynamic experiences with shale gas that move from neutral to negative regarding vehicle traffic, and neutral to positive regarding disgust with protesting behaviour and the diversion of community resources. Our study offers context to high level policy concerns and also humanizes community and resident experiences close to fracking sites.

Abstract:
The paper extends Apergis’s (Energy Policy, 128, 94–101, 2019) study on the role of fracking activities in housing prices across Oklahoma countries by explicitly considering the role of certain indicators determining the health profile of the population. The analysis employs a panel model approach using data from 76 Oklahoma counties, spanning the period 1996–2015. The findings clearly indicate that the overall impact of fracking on housing prices is negative, given that the health indicators are explicitly considered, i.e. fracking has lowered housing prices.

Abstract:
Thirty water wells were sampled in 2018 to understand the geochemistry and age of groundwater in the Williston Basin and assess potential effects of shale-oil production from the Three Forks-Bakken petroleum system (TBPS) on groundwater quality. Two geochemical groups are identified using hierarchical cluster analysis. Group 1 represents the younger (median 4He=21.49×10-8 cm3 STP/g), less chemically evolved water. Group 2 represents the older (median 4He=1389×10-8 cm3 STP/g), more chemically evolved water. At least two samples from each group contain elevated Cl concentrations (>70 mg/L). Br/Cl, B/Cl, and Li/Cl ratios indicate multiple sources account for the elevated Cl concentrations: septic-system leachate/road deicing salt, lignite beds in the aquifers, Pierre Shale beneath the aquifers, and water associated with the TBPS (one sample). 3H and 14C data indicate that 10.8, 21.6, and 67.6% of the samples are modern (post-1952), mixed age, and premodern (pre-1953), respectively. Lumped-parameter modeling of 3H, SF6, 3He, and 14C concentrations indicates mean ages of the modern and premodern fractions range from ∼1 to 30 years and 1300 to >30,000 years, respectively. Group 2 contains the highest CH4 concentrations (0.0018 to 32 mg/L). δ13C-CH4 and C1/C2+C3 data in groundwater (-91.7 to -70.0‰ and 1280 to 13,600) indicate groundwater CH4 is biogenic in origin and not from thermogenic shale gas. Four volatile organic compounds (VOCs) were detected in two samples. One mixed-age sample contains chloroform (0.25 μg/L) and dichloromethane (0.05 μg/L), which are probably associated with septic leachate. One premodern sample contains butane (0.082 μg/L) and n-pentane (0.032 μg/L), which are probably associated with thermogenic gas from a nearby oil well. The data indicate hydrocarbon production activities do not currently (2018) widely affect Cl, CH4, and VOC concentrations in groundwater. The predominance of premodern recharge in the aquifers indicates the groundwater moves relatively slowly, which could inhibit widespread chemical movement in groundwater overlying the TBPS. Comparison of groundwater-age data from five major unconventional hydrocarbon-production areas indicates aquifer zones used for water supply in the TBPS area have a lower risk of widespread chemical movement in groundwater than similar aquifer zones in the Fayetteville (Arkansas) and Marcellus (Pennsylvania) Shale production areas, but have a higher risk than similar aquifer zones in the Eagle Ford (Texas) and Haynesville (Texas, Louisiana) Shale production areas.

Abstract:
Unconventional natural gas developments (UNGD) may release air and water pollutants into the environment, potentially increasing the risk of birth defects. We conducted a case-control study evaluating 52,955 cases with birth defects and 642,399 controls born between 1999 and 2011 to investigate the relationship between UNGD exposure and the risk of gastroschisis, congenital heart defects (CHD), neural tube defects (NTDs), and orofacial clefts in Texas. We calculated UNGD densities (number of UNGDs per area) within 1, 3, and 7.5 km of maternal address at birth and categorized exposure by density tertiles. For CHD subtypes with large case numbers, we also performed time-stratified analyses to examine temporal trends. We calculated adjusted odds ratios (aOR) and 95% confidence intervals (CI) for the association with UNGD exposure, accounting for maternal characteristics and neighborhood factors. We also included a bivariable smooth of geocoded maternal location in an additive model to account for unmeasured spatially varying risk factors. Positive associations were observed between the highest tertile of UNGD density within 1 km of maternal address and risk of anencephaly (aOR: 2.44, 95% CI: 1.55, 3.86), spina bifida (aOR: 2.09, 95% CI: 1.47, 2.99), gastroschisis among older mothers (aOR: 3.19, 95% CI: 1.77, 5.73), aortic valve stenosis (aOR: 1.90, 95% CI: 1.33, 2.71), hypoplastic left heart syndrome (aOR: 2.00, 95% CI: 1.39, 2.86), and pulmonary valve atresia or stenosis (aOR: 1.36, 95% CI: 1.10, 1.66). For CHD subtypes, results did not differ substantially by distance from maternal address or when residual confounding was considered, except for atrial septal defects. We did not observe associations with orofacial clefts. Our results suggest that UNGDs were associated with some CHDs and possibly NTDs. In addition, we identified temporal trends and observed presence of spatial residual confounding for some CHDs.

Abstract:
Water risks are one of the key issues dominating environmental debates on shale gas development. Water withdrawals and wastewater discharges in shale gas fields of mountainous areas are more complicated than in plain areas due to different climatic, topographical and hydrological conditions, which would impact water resources. This research identifies the surface water-related risks from shale gas development in mountainous areas as water shortage and water pollution. Conceptions of accessibility for both water supply and water pollution are proposed to describe the vulnerability of water resources and the exposure to water pollution. Based on a risk probability model, a water risk assessment method for mountainous areas is constructed from the perspectives of dangers, exposures and vulnerabilities. Finally, the assessment method is applied in Chongqing, China. The results show that, from 2010 to 2020, the water consumption of shale gas development has a little impact on regional water resources in total, but more significant impacts are seen in a few areas, including the seasonal water-deficient areas in Western Chongqing, the urban and suburban areas with high pollutant loadings in Midwest Chongqing, and other areas with high pollutant accessibility and vulnerable water environments. The surface water-related risks of the shale gas development in Chongqing are principally composed of low and relatively low levels of risks, which cover 60% of the total area of Chongqing and display a spatial difference of west > northeast > southeast areas. Based on Monte Carlo method, the results of uncertainty analyses show the model is reliable. This research provides a reference for water comprehensive risk assessment of shale gas development in mountainous areas.

Abstract:
This study explores the effect of different phases of unconventional shale gas well-pad development on ambient air quality and the relationship between ambient concentrations of air pollutants and operator activity. The U.S. Department of Energy’s National Energy Technology Laboratory operated a mobile air-monitoring laboratory on two shale well pad sites in Pennsylvania and six shale well pad sites in West Virginia. The purpose of this study is to integrate expert knowledge and collected ambient air monitoring data by developing a Bayesian network (BN) model. The monitoring period included well-pad site development; construction, including vertical and horizontal drilling; hydraulic fracturing; flowback; and production. The observed data includes meteorological data with high time resolution and air quality data (volatile organic compounds (VOCs), ozone, methane and carbon isotopes in methane, carbon dioxide (CO2) and carbon isotopes in CO2, coarse and fine particulate matter (PM10 and PM2.5), and organic and elemental carbon). The results provide useful information for evaluating the influence of on- and off-site pollutant sources and determining future research efforts for building the BN model. The overall results of the developed six scenarios show that the prediction power of the proposed model for the vertical drilling phase is 94%. The high concentration of methane increases the probability of fracturing phase as source; the low concentration of PM10 and O3 occurrence increases the same probability to 82%; the low concentration of ethane and CO2 increases the probability to 98%. This study shows how expert Bayesian models can improve our ability to predict future air pollution risk associated with unconventional shale gas development.

Abstract:
Hydraulic fracturing (‘fracking’) is a policy problem that is both a spatial and temporal issue, touching on economic, environmental, health, safety, political and social concerns of interest to youth. This empirical study focuses on the impact of fracking on youth in communities in England. The Capabilities Approach is used as a lens for understanding the experiences of young people in their late teens. The article draws on focus groups with young people which took place within a 20-mile radius of exploratory fracking sites. The study contributes to the understanding of youth experience of controversial energy interventions. Findings suggest that fracking prevents young people from living the lives they have reason to value, and has, and will continue to have, a negative impact on wellbeing in the present and in the future. Fracking creates conditions of corrosive disadvantage for affected youth. Greater inclusion of youth perspectives in environmental decision-making is needed.

Abstract:
In 2014, a satellite-based map of regional anomalies of atmospheric methane (CH4) column retrievals singled out the fossil fuel rich San Juan Basin (SJB) as the biggest CH4 regional anomaly (“hot spot”) in the United States. Over a 3-week period in April 2015, we conducted ground and airborne atmospheric measurements to investigate daily wind regimes and CH4 emissions in this region of SW Colorado and NW New Mexico. The SJB, similar to other topographical basins with local sources, experienced elevated surface air pollution under low wind and surface temperature inversion at night and early morning. Survey drives in the basin identified multiple CH4 and ethane (C2H6) sources with distinct C2H6-to-CH4 emission plume ratios for coal bed methane (CBM), natural gas, oil, and coal production operations. Air samples influenced by gas seepage from the Fruitland coal formation outcrop in La Plata County, CO, had enhanced CH4, with no C2-5 light alkane enhancements. In situ fast-response data from seven basin survey flights, all with westerly winds, were used to map and attribute the detected C2H6 and CH4 emission plumes. C2H6-to-CH4 plume enhancement correlation slopes increased from north to south, reflecting the composition of the natural gas and/or CBM extracted in different parts of the basin. Nearly 75% of the total detected CH4 and 85% of the total detected C2H6 hot spot were located in New Mexico. Emissions from CBM and natural gas operations contributed 66% to 75% of the CH4 hot spot. Emissions from oil operations in New Mexico contributed 5% to 6% of the CH4 hot spot and 8% to 14% of the C2H6 hot spot. Seepage from the Fruitland coal outcrop in Colorado contributed at most 8% of the total detected CH4, while gas venting from the San Juan underground coal mine contributed <2%.

Abstract:
Spatial setback rules are a common form of oil and gas regulation worldwide - they require minimum distances between oil and gas operations and homes and other sensitive locations. While setbacks can reduce exposure to potential harms associated with oil and gas production, they can also cause substantial quantities of oil and gas resources to be unavailable for extraction. Using both theoretical modeling and spatial analysis with GIS tools on publicly available data, we determine oil and gas resource loss under different setback distances, focusing on Colorado counties as a case study. We show that increasing setbacks results in small resource loss for setbacks up to 1500 feet, but resource loss quickly increases with longer setbacks. Approximately $4.5 billion in annual resource revenues would be lost in Colorado under 2500-foot setbacks, a distance recently proposed in Colorado Proposition 112 and California AB 345.

Abstract:
Hydraulic fracturing is used to access oil and natural gas reserves. This process involves the high-pressure injection of fluid to fracture shale. Fracking fluid contains approximately 95% water, chemicals and 4.5% fracking sand. Workers may be exposed to fracking sand dust (FSD) during the manipulation of the sand, and negative health consequences could occur if FSD is inhaled. In the absence of any information about its potential toxicity, a comprehensive rat animal model study (see Fedan et al., 2020) 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. The goal of this study was to assess the effects of inhalation of one FSD, i.e., FSD 8, on factors and tissues that affect cardiovascular function. Male rats were exposed to 10 or 30 mg/m3 FSD (6 h/d for 4 d) by whole body inhalation, with measurements made 1, 7 or 27 d post-exposure. One day following exposure to 10 mg/m3 FSD the sensitivity to phenylephrine-induced vasoconstriction in tail arteries in vitro was increased. FSD exposure at both doses resulted in decreases in heart rate (HR), HR variability, and blood pressure in vivo. FSD induced changes in hydrogen peroxide concentrations and transcript levels for pro-inflammatory factors in heart tissues. In kidney, expression of proteins indicative of injury and remodeling was reduced after FSD exposure. When analyzed using regression analysis, changes in proteins involved in repair and remodeling were correlated. Thus, it appears that inhalation of FSD does have some prolonged effects on cardiovascular, and, possibly, renal function. The findings also provide information regarding potential mechanisms that may lead to these changes, and biomarkers that could be examined to monitor physiological changes that could be indicative of impending cardiovascular dysfunction.

Abstract:
During the past decade, the number of earthquakes has increased dramatically in the state of Oklahoma, largely attributed to induced seismicity from wastewater injections (hydraulic fracturing). The increased seismic disaster risk in Oklahoma has captured public attention and necessitated actions by decision makers to mediate the consequences. Geospatial modeling to identify the populations exposed to higher levels of potential risk can help prioritize locations for mitigation actions based on the underlying social vulnerability of residents. In this paper, we explore a method for integrating the spatial distribution of seismic risk (hazard exposure) with social vulnerability (hazard impact). Loss scenarios, social vulnerability metrics, and potential physical damage are combined in a geographic information system to identify the spatial vulnerability of an exposed population to the increased seismic risk, and the locations for targeting mitigation actions — areas with the greatest exposure and vulnerability. The results of induced seismicity earthquake scenarios show disproportionately higher losses for places with more minority populations (primarily African-American) and more renters when compared to the non-induced scenarios, suggesting a potential environmental justice concern.

Abstract:
The rise of unconventional oil and gas development in the form of hydraulic fracturing, or fracking, has drawn much attention from media, scholars, and policy makers, and Texas has frequently been the epicenter of this attention. This paper looks at fracking through a particular lens, that of an extraction process that relies heavily on water. This “water-energy nexus” has been studied in terms of the physical connections, but little research exists on how ordinary people might understand that nexus. This paper examines the effect of people's awareness of the water-energy nexus and county-level drought characteristics on their support for increased regulation of water issues associated with hydraulic fracturing. The analysis uses data from a Texas-based public opinion survey, and county-level data from the U.S. Drought Monitor and the Texas Railroad Commission. Multi-level modeling techniques are used to examine the impact of proximity, local water scarcity, and individual awareness of the water-energy nexus on people's willingness to support regulating aspects of water in hydraulic fracturing practices. The paper supports the hypothesis that individual awareness of the energy-water nexus and local water scarcity affects willingness to support greater regulation and concludes with some policy recommendations to improve policy transparency surrounding hydraulic fracturing.

Abstract:
Water is one of the most important commodities in the world and plays an essential role in the hydrocarbon industry. With increased agricultural production, rapid industrialization, population growth and climate change, the world is facing an extreme water crisis in many regions. Coupled with a surge in energy demand and consumption, this has greatly influenced the hydrocarbon industry. With increasing stress on water resources, it is essential to examine how water is managed within the hydrocarbon industry and devise ways to utilize water more efficiently, especially within water scarce regions such as the Middle East. Augmented by the recent activities in the oil and gas industry, it can be seen that an economical and efficient hydraulic fracturing job has become crucial for the successful development of unconventional reservoirs. However, exploitation of unconventional reservoirs is heavily water-intensive as compared to conventional reservoirs. In this study, a comprehensive investigation that deals with quantification of changes with respect to the variation in prime contributors within a traditional fracture design process is presented. To understand the significance of key design parameters, factors that affect productivity within typical Middle Eastern shale gas reservoirs were analyzed through simple constrained cases. Investigations reveal that parameters such as fracture aperture, natural fracture distribution, fracturing fluid viscosity and Young’s modulus are crucial to the overall production and water requirement. Furthermore, an outline for resource management within a traditional fracture design process is presented along with potential challenges for the region. Enhancing existing methodologies and incorporating key parameters highlighted within this study can contribute to the overall value chain. In addition to ultimately assisting in the verification of modern best practices, this investigative approach will create a paradigm for future studies for the region to assist in a simplistic prediction of fracture propagation and associated response to augment water usage.

Abstract:
California hosts ∼124,000 abandoned and plugged (AP) oil and gas wells, ∼38,000 idle wells, and ∼63,000 active wells, whose methane (CH4) emissions remain largely unquantified at levels below ∼2 kg CH4 h–1. We sampled 121 wells using two methods: a rapid mobile plume integration method (detection ∼0.5 g CH4 h–1) and a more sensitive static flux chamber (detection ∼1 × 10–6 g CH4 h–1). We measured small but detectable methane emissions from 34 of 97 AP wells (mean emission: 0.286 g CH4 h–1). In contrast, we found emissions from 11 of 17 idle wells—which are not currently producing (mean: 35.4 g CH4 h–1)—4 of 6 active wells (mean: 189.7 g CH4 h–1), and one unplugged well—an open casing with no infrastructure present (10.9 g CH4 h–1). Our results support previous findings that emissions from plugged wells are low but are more substantial from idle wells. In addition, our smaller sample of active wells suggests that their reported emissions are consistent with previous studies and deserve further attention. Due to limited access, we could not measure wells in most major active oil and gas fields in California; therefore, we recommend additional data collection from all types of wells but especially active and idle wells.