Repository for Oil and Gas Energy Research (ROGER)

Abstract:
Abstract Unconventional oil and gas (UOG) extraction using fracking can damage groundwater resources, a crucial resource in many countries. Protecting groundwater will become more urgent as climate change and population growth increase pressure on water demand, especially in water-scarce countries. But despite the strategic importance of groundwater, it is often poorly managed during UOG extraction. This review considers three types of regulation (command-and-control, market-based and voluntary) in countries where UOG extraction is allowed, to identify the best suite of regulations to protect groundwater resources during this process. We propose a regulatory framework that includes both ?hard? command-and-control regulations and ?soft? market-based and voluntary regulations. If regulations are to protect groundwater resources effectively, public disclosure of UOG operations must be required and the information must be stored in publicly accessible databases. This would allow for independent scientific review of data by academia and the private sector, in addition to government scrutiny of the data. These parties can then make recommendations to government, allowing timeous and appropriate adaptive management and the amendment of regulations as necessary. And, most importantly, these regulations must be properly enforced to avoid (in some cases irreversible) damage to groundwater resources. This article is characterized under: Engineering Water > Sustainable Engineering of Water Human Water > Water Governance Science of Water > Water Quality

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Well plugging, the main strategy for reducing methane emissions from millions of unplugged abandoned oil and gas (AOG) wells in the U.S. and abroad, is expensive and many wells remain unplugged. In addition, plugging does not necessarily reduce methane emissions and some categories of plugged wells are high emitters. We analyze strategies and costs of five options for reducing methane emissions from high-emitting AOG wells - those which are unplugged and plugged/vented gas wells. The five options are: plugging without gas venting, plugging with gas venting and flaring, plugging with gas venting and usage, gas flaring only, and gas capture/usage only. Average plugging costs ($37,000 per well) can be justified by the social cost of methane, which considers air quality, climate, and human/ecosystem impacts. Savings as measured by natural gas prices and alternative energy credits can offset low plugging costs (<$15,400 per well) but are not large enough to offset average plugging costs. Nonetheless, reducing methane emissions from AOG wells is a cost-effective strategy for addressing climate change that has comparable costs to some current greenhouse gas mitigation options and can produce co-benefits such as groundwater protection. Therefore, we recommend including the mitigation of AOG wells in climate and energy policies in the U.S., Canada, and other oil-and-gas-producing regions.

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This mixed-methods study examined the impacts of shale natural gas energy development (SGD) related activities upon outdoor recreation in Pennsylvania. Much of the ongoing and proposed SGD infrastructure in Pennsylvania is located either within or adjacent to public lands, waters, and protected areas, raising concerns about the potential environmental and social impacts upon recreation stakeholders. The extensive body of SGD research within the United States has suggested there are numerous positive and negative impacts upon the general public. Yet, the impact of SGD upon outdoor recreation users remains unclear. While SGD impacts are becoming progressively evident to both recreationists and natural resource managers, few studies have sought to specifically assess the extent to which SGD alters outdoor recreation behaviors, experiences, and activities. This statewide survey of Pennsylvanians (n = 2240) found that 23.4% of respondents had encountered SGD related activities while participating in outdoor recreation. Study findings also noted that 13.8% of respondents had changed their outdoor recreation behaviors or experiences as a result of encountering SGD related activities. Moreover, a sub-sample, representing 12.3% of respondents, identified specific SGD related impacts (e.g., aesthetic, environmental, infrastructure) upon their outdoor recreation behaviors, experience, and activities which sometimes resulted in substitution behaviors and/or a lack of perceived ‘fit’ between the energy development and the landscape and environment. From a policy and management standpoint, study findings highlight the specific and nuanced impacts of SGD upon certain sub-populations of outdoor recreationists as well as the importance of assessing and communicating recreation experience and use impacts to all recreationists when planning, developing, and managing SGD and related decisions in the United States. Management Implications This study found that only a small population of Pennsylvania outdoor recreationists were impacted by SGD related activities. In the regions of Pennsylvania where SGD was most prominent (e.g., North Central and Southwest), outdoor recreation impacts were considerably higher. Moreover, a sub-sample of respondents found that SGD impacted their outdoor recreation behaviors, their in situ recreation experiences, and/or the environmental setting and landscape in which they recreated. Study findings suggest a two-tiered communication approach, accounting for perceptions of both behavioral and/or landscape environmental quality impacts, may be the most comprehensive strategy for addressing and communicating the impacts of SGD upon outdoor recreationists.

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Impacts from energy development have been shown to affect different demographic, stakeholder, and community groups in different ways, which in turn may differ across energy regimes, project lifecycles, and geographies. This research examines the social and structural influences which may amplify or attenuate the varied impacts of unconventional oil and gas development (UOGD) in a heretofore under-examined energy impact geography: the periphery region of Ohio’s Utica Shale. We conduct fifty-four (54) interviews in five Ohio communities to test and extend the Goldilocks Zone analytic framework of energy impacts, in which some energy periphery communities have been shown to experience moderate, positive spillover economic gains but minimal social harms in virtue of their socio-geographic distance from core UOGD activity. We find support for a Goldilocks Zone in the Utica Shale periphery, however the size and strength of effects are attenuated by the varied population densities, geographic and political economy diversities, natural resource legacies, and industry mixes and dependences of the Appalachian Range. This research contributes to the limited scholarship examining the effects of energy development in periphery impact geographies as well as provides baseline energy impact and perception data in a region that has received very little academic scrutiny despite ongoing and significant future potential for unconventional oil and gas development. Finally, this article tests and extends the Goldilocks Zone of energy impacts analytic framework in a new social, geographic, and energy context.

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Political conservatives are consistently more supportive of hydraulic fracturing (fracking) in the U.S., while political liberals are consistently more opposed, yet the processes shaping this division are largely unexplored. Here, we illustrate how political polarization in support for fracking can be understood by how risk and benefit perceptions mediate the relationship between political ideology and support for fracking, with liberals seeing greater risk and less benefit. Importantly, however, especially for understanding opinion formation around the issue of fracking, perceived knowledge exacerbates this division. Liberals who report being more informed about fracking are likely to see greater risk from fracking. Conservatives who report being more informed, however, do not see a significantly different level of risk than do conservatives who are less informed but are much more likely than any other group to see greater benefit from fracking. The result is that those who perceive themselves as highly knowledgeable about fracking are the most likely to be polarized by political ideology in their perceptions of the level of risk and benefit associated with fracking and, in turn, their level of support for the technology. We discuss the implications of these findings for communication and decision-making in the politically polarized environment around fracking.

Abstract:
—Based on the systemic comparative analysis of data, the paper overviews economic, geologic, and environmental problems and possible impact of shale gas recovery on the air, surface and ground water and their radioactive contamination, as well as the effects on the geologic environment and seismic activity in areas of extraction, landscapes, lands, and biological resources. It has been established that considerable risks exist that cast doubt on the feasibility of shale gas recovery in Europe.

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Hydraulic fracturing or “fracking” is an emerging “unconventional” technology in the oil and gas exploitation sector linked to high levels of uncertainty. In this paper, we examine the level of support for fracking in the province of Newfoundland and Labrador. This province is also one of the regions of the country in which fracking could be performed and whose economy could substantially benefit from the availability of this new source of energy resources. However, there remain serious obstacles to the social acceptability of fracking among the people of Newfoundland and Labrador and, in particular, the prospect of fracking in Western Newfoundland is a highly controversial issue. This area hosts one of the most highly valuable natural areas in the province (Gros Morne National Park). We identify key factors to oppose or support fracking. Using a multinomial logit model, we characterize different groups of citizens who oppose or support fracking and also other ‘conventional’ extractive technologies. Institutional issues, environmental risks, and socio-economic factors will be considered when explaining attitudes towards fracking. Further understanding the acceptability of this ‘unconventional’ technology should help public regulators make decisions and design optimal policies in the oil and gas extraction sector.

Abstract:
Production of unconventional oil and gas continues to rise, but the effects of high-density hydraulic fracturing (HF) activity near aquatic ecosystems are not fully understood. A commonly used biocide in HF, 2,2-dibromo-3-nitrilopropionamide (DBNPA), was studied in microcosms of HF-impacted vs. HF-unimpacted surface water streams to (1) compare the microbial community response, (2) investigate DBNPA degradation products based on past HF exposure, and (3) compare the microbial community response differences and similarities between the HF biocides DBNPA and glutaraldehyde. The microbial community responded to DBNPA differently in HF-impacted vs. HF-unimpacted microcosms in terms of 16S rRNA gene copies quantified, alpha and beta diversity, and differential abundance analyses of microbial community composition through time. The difference in microbial community changes affected degradation dynamics. HF-impacted microbial communities were more sensitive to DBNPA, causing the biocide and byproducts of the degradation to persist for longer than in HF-unimpacted microcosms. Seventeen DBNPA byproducts were detected, many of them not widely known as DBNPA byproducts. Many of the believed to be uncharacterized brominated byproducts detected may pose environmental and health impacts. Similar taxa were able to tolerate glutaraldehyde and DBNPA, however DBNPA was not as effective for microbial control as indicated by a smaller overall decrease of 16S rRNA gene copies/mL after exposure to the biocide and a more diverse set of taxa was able to tolerate it. These findings suggest that past HF activity in streams can affect the microbial community response to environmental perturbation such as the biocide DBNPA. Importance Unconventional oil and gas activity can affect pH, total organic carbon, and microbial communities in surface water altering their ability to respond to new environmental and/or anthropogenic perturbations. These findings demonstrate that DBNPA, a common hydraulic fracturing (HF) biocide, affects microbial communities differently as a consequence of past HF exposure, persisting longer in HF-impacted waters. These findings also demonstrate that DBNPA has low efficacy in environmental microbial communities regardless of HF impact. These findings are of interest, as understanding microbial responses is key for formulating remediation strategies in UOG impacted environments. Moreover, some of DBNPA degradation byproducts are even more toxic and recalcitrant than DBNPA itself, and this work identifies novel brominated degradation byproducts formed.

Abstract:
Meeting energy demands and achieving energy independence is one of the highest goals on any nation’s priority list. The increase in energy demands in the U.S. and the need for affordable energy have caused substantial developments in the fracking arena over the last two decades. Although the fracking process has dominated the last decade because of its contribution to more affordable energy, the negative environmental impacts have certainly been questioned. Therefore, it is imperative to calculate the real net cost of fracking by weighing its benefits against its negative environmental impacts as well. This research study is a foundational study that identifies the major cost centers and the impacts needs assessment for the fracking process across its different life cycle phases through an extensive literature review, a comprehensive Life Cycle Cost Analysis (LCCA), and dynamic cost modeling. Datasets were analyzed at a macro-level to find the life cycle cost of fracking using several data sources and implementing life cycle analysis and assessment approaches. A Monte-Carlo simulation was used during the analysis to account for the range of values at the macro-level, rendering this model to be dynamic in nature, and the costs to be more reliable. The results demonstrated that air and water pollution are some of the highest impacting factors in the fracking process, and the most expensive. It was duly noted in the study that dependence on depletable energy sources like shale gas is very costly and economically and environmentally unsustainable, which urge a sustainable calculated transition towards more renewable energy in the imminent future. Finally, this study provides a major platform as a fracking LCC framework for different future studies.

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Radium measurements in high total dissolved solids (TDS) fluids from oil and gas extraction can have unfavorable precision and accuracy, in part because these high-level impurities incur attenuation. γ spectroscopy is often recommended for determining radium activities in these fluids, but even this method can produce a range of reported activities for the same sample. To reduce measurement duration and to maintain or improve accuracy, we propose a method to rapidly assess both 226Ra and 228Ra and to account for the self-attenuation of γ rays in high-TDS oil and gas fluids when they are monitored by a well detector. In this work, comparisons between a NaCl-only and a multi-cation-chloride synthetic brine spiked with known amounts of 226Ra and 228Ra indicated that both the TDS concentration and the type of TDS (i.e., Na only vs Na–Mg–Ba–Ca–Sr) influenced self-attenuation in well-detector γ spectroscopy, thus highlighting the need to correct for this TDS-influenced self-attenuation. Radium activities can be underestimated if the correction is not applied. For instance, 226Ra activities could be ∼40% lower in a sample when measured directly at the 186 keV energy level if the attenuation of the high TDS of the fluid is not considered. We also showed that using a NaCl-only brine to match the matrix of high-TDS oil and gas brines is inadequate to produce accurate measurements, rather, the full set of cations should be included.

Abstract:
Produced water (PW) is the largest by-product of the oil and gas industry. Its management is both economically and environmentally costly. PW reuse for irrigation offers an alternative to current disposal practices while providing water to irrigators in drylands. The aim of this investigation was to evaluate the environmental effects of irrigation with PW. The SALTIRSOIL_M model was used to simulate the irrigation of sugar beet with 15 PWs of a wide range of qualities in four climates of different aridity and on four contrasting soil types. The impacts on soil salinity, sodicity and pH as well as on crop yield and drainage water salinity were estimated. Well-drained soils with low water content at field capacity (Arenosol) are less sensitive to salinisation while a relatively high gypsum content (Gypsisol) makes the soil less vulnerable to both sodification and salinisation. On the contrary, clayey soils with higher water content at field capacity and lower gypsum content must be avoided as the soil structural stability as well as a tolerable soil electrical conductivity for the crop cannot be maintained on the long-term. Soil pH was not found to be sensitive to PW quality. Drainage water quality was found to be closely linked to PW quality although it is also influenced by the soil type. The impact of drainage water on the aquifer must be considered and reuse or disposal implemented accordingly for achieving sustainable irrigation. Finally, increasing aridity intensifies soil and drainage water salinity and sodicity. This investigation highlights the importance of adapting the existing irrigation water quality guidelines through the use of models to include relevant parameters related to soil type and aridity. Indeed, it will support the petroleum industry and irrigators, to estimate the risks due to watering crops with PW and will encourage its sustainable reuse in water-scarce areas.

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Abstract. Methane has been rising rapidly in the atmosphere over the past decade, contributing to global climate change. Unlike the late 20th century when the rise in atmospheric methane was accompanied by an enrichment in the heavier carbon stable isotope (¹³C) of methane, methane in recent years has become more depleted in ¹³C. This depletion has been widely interpreted as indicating a primarily biogenic source for the increased methane. Here we show that part of the change may instead be associated with emissions from shale-gas and shale-oil development. Previous studies have not explicitly considered shale gas, even though most of the increase in natural gas production globally over the past decade is from shale gas. The methane in shale gas is somewhat depleted in ¹³C relative to conventional natural gas. Correcting earlier analyses for this difference, we conclude that shale-gas production in North America over the past decade may have contributed more than half of all of the increased emissions from fossil fuels globally and approximately one-third of the total increased emissions from all sources globally over the past decade.

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Current concerns and discussions regarding hydraulic fracturing and other activities of the oil and gas industry and geothermal energy sector are forcing a reassessment of formation waters as well as their impacts on the environment. In this review paper, the chemical and the most important physicochemical properties of low- to high-salinity formation waters are analysed and critically evaluated. Especially the complex interactions of the dissolved salts, the isotonicity and the relevance of the pH of virgin formation waters are discussed in this context for the first time. These “by-products” of the oil and gas industry are presented in a new light, whereby a clear distinction made between live and dead formation waters. Due to this significant differentiation, most research results of the past must be critically assessed and reclassified. With the highlighted importance of the composition of formation and injection waters, the most common causes for early termination of the production phases, the possible long-term damages to reservoirs and the origin of man-made earthquakes are described. Treatment concepts for dead formation/ process waters, as well as conclusions regarding an environmentally friendly management thereof, are mentioned.

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Scientific evidence suggests earthquakes occurring in Oklahoma since 2009 are not “acts of God”, but very likely triggered by wastewater injection in disposal wells by oil and gas (O&G) companies. While sustaining the O&G industry's contribution to the economy is generally important, achieving environmental and public protection may in part rely on how earthquake inducers are held liable for damage. We use a Bayesian Tobit censored model, estimated using Markov Chain Monte Carlo (MCMC) methods to determine factors that influence public preferences for how much liability O&G companies should assume for induced earthquake-related damage. Data are from a survey of Oklahomans collected in 2017 by Survey Sampling International (SSI). Results suggest people would, on average, hold O&G companies liable for 75% of the earthquake damage. We find socio-demographic, earthquake, locational, and O&G industry-related factors as the main drivers of earthquake damage liability. However, their effects on damage liability vary between respondents that have had their property damaged by earthquakes and those that in some way benefit from O&G companies through jobs and gas-leases. We provide insights by which individuals might lobby representatives to impose new liability or regulatory mechanisms on O&G companies to avoid or compensate for earthquake damage.

Abstract:
Growing attention has been paid to understanding public risk perceptions of shale gas development. This research has largely been conducted in the United States and Europe. Arguably, the environmental and social risks posed by drilling are potentially more severe in places like China, due to its geography and political system. However, little is known how those constantly exposed to risks (the “affected” public) evaluate these risks. In this study, in-depth interviews were conducted with local residents (n=25) in Weiyuan County, Sichuan Province, the region with the largest shale gas reserves in the country, to identify the perceived risks of the affected Chinese public and to explore underlying factors that impact risk perception. Our results suggest that affected Chinese residents were most concerned about groundwater contamination and air pollution above all other risks, and they tended to link risks to spatial proximity to shale gas wells. The multifaceted nature of perceived benefits played a novel and nuanced role in Chinese residents’ risk perception. Pride and disempowerment were found to attenuate the risk judgments of affected Chinese residents, which has not been observed in previous literature. Our findings provides policymakers with insight into how to improve risk communications to enhance understanding of affected publics, as well as to better design compensation schemes that may address inequities.

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Unconventional oil and gas (UOG) exploitation may generate large volumes of wastewater, with dire environmental consequences if not properly managed. We systematically reviewed literature, reports, and fracking databases to determine possible volumes of wastewater that may be generated during UOG extraction. We then determined ranges of expected UOG extraction wastewater volumes for different UOG production scenarios in South Africa. Based on the results, we discuss associated wastewater management implications for South Africa, where UOG exploitation is planned in the future. The recommendations emanating from this article are equally important for other countries already extracting UOG resources, or that plan to do so in the future.

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Hydraulic fracturing and horizontal drilling in the Marcellus Shale present a novel use of chemical additives at unprecedented volumes. Reuse of produced water has become a popular option in Pennsylvania, complicating our understanding of the fate of chemical additives due to the variability of produced water chemistry. This study investigates the effect of pH, temperature, ionic strength and the presence of pyrite on the kinetics of degradation of dazomet, a commonly-used biocide, under a range of conditions expected during hydraulic fracturing. The results show that the degradation rate of dazomet is highly dependent on many of the variables tested. The hydrolysis is base-catalyzed over the pH range of interest which results in half-lives decreasing from 8.5 h to 3.4 h as the pH is increased from 4.1 to 8.2. Dissolved FeII ions catalyze dazomet degradation kinetics with solutions of 0.8 mM FeII causing degradation rates to increase by 190% over iron-free water. Increasing temperatures from 34 °C to 57 °C quadrupled hydrolysis rates (estimated activation energy of 60 kJ/mol). Reaction with oxygen-exposed pyrite surface led to accelerated degradation of dazomet, but unoxidized pyrite had no effect on the degradation rate of dazomet. The key hydrolysis products of dazomet degradation are formaldehyde and methyl isothiocyanate which are shown to be significantly more toxic than the parent compound. The study points to the need to assess the specific environmental conditions and any toxic by-products in conducting risk assessments for geological applications.

Abstract:
Background Preliminary studies suggest that offspring to mothers living near oil and natural gas (O&G) well sites are at higher risk of congenital heart defects (CHDs). Objectives Our objective was to address the limitations of previous studies in a new and more robust evaluation of the relationship between maternal proximity to O&G well site activities and births with CHDs. Methods We employed a nested case-control study of 3324 infants born in Colorado between 2005 and 2011. 187, 179, 132, and 38 singleton births with an aortic artery and valve (AAVD), pulmonary artery and valve (PAVD), conotruncal (CTD), or tricuspid valve (TVD) defect, respectively, were frequency matched 1:5 to controls on sex, maternal smoking, and race and ethnicity yielding 2860 controls. We estimated monthly intensities of O&G activity at maternal residences from three months prior to conception through the second gestational month with our intensity adjusted inverse distance weighted model. We used logistic regression models adjusted for O&G facilities other than wells, intensity of air pollution sources not associated with O&G activities, maternal age and socioeconomic status index, and infant sex and parity, to evaluate associations between CHDs and O&G activity intensity groups (low, medium, and high). Results Overall, CHDs were 1.4 (1.0, 2.0) and 1.7 (1.1, 2.6) times more likely than controls in the medium and high intensity groups, respectively, compared to the low intensity group. PAVDs were 1.7 (0.93, 3.0) and 2.5 (1.1, 5.3) times more likely in the medium and high intensity groups for mothers with an address found in the second gestational month. In rural areas, AAVDs, CTDs, and TVDs were 1.8 (0.97, 3.3) and 2.6 (1.1, 6.1); 2.1 (0.96, 4.5) and 4.0 (1.4, 12); and 3.4 (0.95, 12) and 4.6 (0.81, 26) times more likely than controls in the medium and high intensity groups. Conclusions This study provides further evidence of a positive association between maternal proximity to O&G well site activities and several types of CHDs, particularly in rural areas.

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Water samples from 50 domestic wells located <1 km (proximal) and >1 km (distal) from shale-gas wells in upland areas of the Marcellus Shale region were analyzed for chemical, isotopic, and groundwater-age tracers. Uplands were targeted because natural mixing with brine and hydrocarbons from deep formations is less common in those areas compared to valleys. CH4-isotope, predrill CH4-concentration, and other data indicate that one proximal sample (5% of proximal samples) contains thermogenic CH4 (2.6 mg/L) from a relatively shallow source (Catskill/Lock Haven Formations) that appears to have been mobilized by shale-gas production activities. Another proximal sample contains five other volatile hydrocarbons (0.03–0.4 μg/L), including benzene, more hydrocarbons than in any other sample. Modeled groundwater-age distributions, calibrated to 3H, SF6, and 14C concentrations, indicate that water in that sample recharged prior to shale-gas development, suggesting that land-surface releases associated with shale-gas production were not the source of those hydrocarbons, although subsurface leakage from a nearby gas well directly into the groundwater cannot be ruled out. Age distributions in the samples span ∼20 to >10000 years and have implications for relating occurrences of hydrocarbons in groundwater to land-surface releases associated with recent shale-gas production and for the time required to flush contaminants from the system.

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Oilfield wastewater is commonly discarded by pumping it into deep geologic formations, but this process is now known to cause earthquakes. Here, he authors show that high-density oilfield wastewater may sink deeper in the Earth’s crust than previously considered possible, thus increasing fluid pressure and inducing earthquakes for years after injection rates decline.

Abstract:
Methane (CH4) enters waters in hydrocarbon-rich basins because of natural processes and problems related to oil and gas wells. As a redox-active greenhouse gas, CH4 degrades water or emits to the atmosphere and contributes to climate change. To detect if methane migrated from hydrocarbon wells (i.e., anomalous methane), we examined 20 751 methane-containing groundwaters from the Upper Appalachian Basin (AB). We looked for concentrations (mg/L) that indicated AB brine salts (chloride concentrations ([Cl]) > 30; [Ca]/[Na] < 0.52) to detect natural methane, and we looked for concentrations of redox-active species ([SO4] ≥ 6; [Fe] ≥ 0.3) to detect anomalous methane. These indicators highlight natural contamination by methane-containing brines or recent onset of microbial oxidation of methane coupled to iron- or sulfate-reduction. We hypothesized that only waters recently contaminated by methane still exhibit high iron and sulfate concentrations. Of the AB samples, 17 (0.08%) from 12 sites indicated potential contamination. All were located in areas with high densities of shale-gas or conventional oil/gas wells. In contrast, in southwestern Pennsylvania where brines are shallow and coal, oil, and gas all have been extracted extensively, no sites of recent methane migration were detectable. Such indicators may help screen for contamination in some areas even without predrill measurements.

Abstract:
Rural observations of air quality and meteorological parameters (NOx, O3, NMHCs, SO2, PM) were made over a 2.5-year period (2016–2018) before, during and after preparations for hydraulic fracturing (fracking) at a shale gas exploration site near Kirby Misperton, North Yorkshire, England. As one of the first sites to apply for permits to carry out hydraulic fracturing, it has been subject to extensive regulatory and public scrutiny, as well as the focus for a major programme of long-term environmental monitoring. A baseline period of air quality monitoring (starting 2016) established the annual climatology of atmospheric composition against which a 20-week period of intensive activity on the site in preparation for hydraulic fracturing could be compared. During this ‘pre-operational phase’ of work in late 2017, the most significant effect was an increase in ambient NO (3-fold) and NOx (2-fold), arising from a combination of increased vehicle activity and operation of equipment on site. Although ambient NOx increased, air quality limit values for NO2 were not exceeded, even close to the well-site. Local ozone concentrations during the pre-operational period were slightly lower than the baseline phase due to titration with primary emitted NO. The activity on site did not lead to significant changes in airborne particulate matter or non-methane hydrocarbons. Hydraulic fracturing of the well did not subsequently take place and the on-site equipment was decommissioned and removed. Air quality parameters then returned to the original (baseline) climatological conditions. This work highlights the need to characterise the full annual climatology of air quality parameters against which short-term local activity changes can be compared. Based on this study, changes to ambient NOx appear to be the most significant air quality ahead of hydraulic fracturing. However, in rural locations, concentrations at individual sites are expected to be below ambient air quality limit thresholds.

Abstract:
Since advances in horizontal drilling and hydraulic fracturing technologies have opened oil and gas development in previously unreachable areas, air pollution emissions have increased from the burning (i.e., flaring) or releasing (i.e., venting) of natural gas at oil and gas extraction sites. While venting and flaring is a growing concern, accounting of how much gas is vented and flared, and where this occurs, remains limited. The purpose of this paper is to describe two methods for estimating venting and flaring volumes - self-reports required by state law and satellite imagery radiant heat measurements - and to compare these methods using the case of Texas Eagle Ford and Permian Basin venting and flaring practices from 2012 to 2015. First, we used data self-reported by companies to the Texas Railroad Commission (TxRRC), and National Oceanic and Atmospheric Administration (NOAA) data captured by satellite-based Visible Infrared Imaging Radiometer Suite sensors, to estimate the annual total volumes of gas vented and flared in the Eagle Ford and Permian Basin from 2012 to 2015. Next, we developed a method using a geographic information system to link and compare TxRRC and NOAA county-based and point-based volume estimates. Finally, we conducted case studies of two oil and gas fields to better understand how TxRRC and NOAA venting and flaring volumes differ. We find both TxRRC and NOAA estimated venting and/or flaring volumes steadily increased from 2012 to 2015. Additionally, TxRRC reports captured about half the volumes estimated by NOAA. This suggests that self-reported volumes significantly underestimate the volume of gas being vented or flared. However, this research is limited by the data currently available. As such, future research and policy should further develop methods to systemically capture the extent to which oil and gas extraction facilities vent and flare natural gas.

Abstract:
Using data on the geographic location of fracking wells in four U.S. states with mandatory disclosure between 2011 and 2013 — Colorado, Oklahoma, Pennsylvania, and Texas — this paper analyzes the socio-demographic characteristics of people living close to fracking activity. Geo-coded well data from the FracFocus registry are merged to blockgroup-level socio-demographic data from the 2006–2010 American Community Survey and population density and land use data from EPA's Smart Location Database 2010. Different buffer zones around fracking wells are applied to capture effects at different spatial scales and to compare only areas with similar geological properties. We explain the distance to the nearest well within a county with fracking activity or within a buffer zone by race/ethnicity, income, educational attainment, various land-use control variables, and county fixed-effects. We find robust evidence that minorities, especially African Americans, disproportionately live near fracking wells, but less consistent evidence for environmental injustice by income or educational attainment. Strong heterogeneity across states can be observed, suggesting that an improvement in disclosure laws in other states, that would make similar analyses possible, is of great importance.

Abstract:
Unconventional oil and gas extraction is on the rise across the United States and comprises an integral component in meeting the nation’s energy needs. The primary by-product of this industrious process is produced water, which is a challenging matrix to remediate because of its complex physical and chemical composition. Forward osmosis is a viable option to treat high-salinity produced water; however, fouling has been an issue. This study aimed to treat produced water before using forward osmosis as a remediation option. Trials consisted of a series of five experiments in order to evaluate the performance of the membrane. Samples were treated by centrifugation, activated carbon, filtration, ferric chloride, as well as coagulants and a polymer. It can be concluded that forward osmosis can be used to extract water from high-salinity oil field brines and produced water, and that pretreating the produced water decreased the tendency for fouling. The pretreatment with the overall best performance was activated carbon, which also yielded the lowest total organic carbon concentrations of 1.9 mg/L. During remediation trials using produced water pretreated with activated carbon as the feed solution, there was a 14% decrease in flux over the course of the 7 h trials. The membrane performance was restored after washing.

Abstract:
Shale oil and gas exploitation not only consumes substantial amounts of freshwater but also generates large quantities of hazardous wastewater. Tremendous research efforts have been invested in developing membrane-based technologies for the treatment of shale oil and gas wastewater. Despite their success at the laboratory scale, membrane processes have not been implemented at full scale in the oil and gas fields. In this article, we analyze the growing demands of wastewater treatment in shale oil and gas production, and then critically review the current stage of membrane technologies applied to the treatment of shale oil and gas wastewater. We focus on the unique niche of those technologies due to their advantages and limitations, and use mechanical vapor compression as the benchmark for comparison. We also highlight the importance of pretreatment as a key component of integrated treatment trains, in order to improve the performance of downstream membrane processes and water product quality. We emphasize the lack of sufficient efforts to scale up existing membrane technologies, and suggest that a stronger collaboration between academia and industry is of paramount importance to translate membrane technologies developed in the laboratory to the practical applications by the shale oil and gas industry.Open image in new window

Abstract:
In the last decade, extensive application of hydraulic fracturing technologies to unconventional low-permeability hydrocarbon-rich formations has significantly increased natural-gas production in the United States and abroad. The injection of surface-sourced fluids to generate fractures in the deep subsurface introduces microbial cells and substrates to low-permeability rock. A subset of injected organic additives has been investigated for their ability to support biological growth in shale microbial community members; however, to date, little is known on how complex xenobiotic organic compounds undergo biotransformations in this deep rock ecosystem. Here, high-resolution chemical, metagenomic, and proteomic analyses reveal that widely-used surfactants are degraded by the shale-associated taxa Halanaerobium, both in situ and under laboratory conditions. These halotolerant bacteria exhibit surfactant substrate specificities, preferring polymeric propoxylated glycols (PPGs) and longer alkyl polyethoxylates (AEOs) over polyethylene glycols (PEGs) and shorter AEOs. Enzymatic transformation occurs through repeated terminal-end polyglycol chain shortening during co-metabolic growth through the methylglyoxal bypass. This work provides the first evidence that shale microorganisms can transform xenobiotic surfactants in fracture fluid formulations, potentially affecting the efficiency of hydrocarbon recovery, and demonstrating an important association between injected substrates and microbial growth in an engineered subsurface ecosystem.

Abstract:
Although aquatic vertebrates and humans are increasingly exposed to water pollutants associated with unconventional oil and gas extraction (UOG), the long-term effects of these pollutants on immunity remains unclear. We have established the amphibian Xenopus laevis and the ranavirus Frog Virus 3 (FV3) as a reliable and sensitive model for evaluating the effects of waterborne pollutants. X. laevis tadpoles were exposed to a mixture of equimass amount of UOG chemicals with endocrine disrupting activity (0.1 and 1.0 μg/L) for 3 weeks, and then long-term effects on immune function at steady state and following viral (FV3) infection was assessed after metamorphosis. Notably, developmental exposure to the mixture of UOG chemicals at the tadpole stage affected metamorphic development and fitness by significantly decreasing body mass after metamorphosis completion. Furthermore, developmental exposure to UOGs resulted in perturbation of immune homeostasis in adult frogs, as indicated by significantly decreased number of splenic innate leukocytes, B and T lymphocytes; and a weakened antiviral immune response leading to increased viral load during infection by the ranavirus FV3. These findings suggest that mixture of UOG-associated waterborne endocrine disruptors at low but environmentally–relevant levels have the potential to induce long-lasting alterations of immune function and antiviral immunity in aquatic vertebrates and ultimately human populations.

Abstract:
The effluent produced during hydraulic fracturing (i.e. flowback and produced water; FPW), is a complex hyper-saline solution that is known to negatively impact the survival and the fitness of the water flea Daphnia magna, but to date effects on behavior are unstudied. In the current study, the effects of FPW on phototactic behavior of D. magna were examined. Exposure of naïve animals to FPW resulted in a dose-dependent increase in the speed of appearance of daphnids in the illuminated zone of the test apparatus (i.e. a faster positive phototaxis response). A similar dose-dependent response was observed in a test solution where the salt content of FPW was recreated in the absence of other components, suggesting that the effect was largely driven by salinity. The effect of FPW was significant when the raw FPW sample was diluted to 20% of its initial strength, while the effect of salt-matched solution was significant at a 10% dilution. A distinct effect was observed following FPW pre-exposure. After a 24 h pre-exposure to 1.5% FPW, Daphnia displayed a significantly inhibited positive phototaxis response when examined in control water, relative to control animals that were not pre-exposed to FPW. This effect was not observed in salinity pre-exposed animals, however these daphnids displayed a significantly reduced phototactic response when tested in saline waters, indicating a loss of the positive phototaxis seen in naïve organisms. These data indicate that FPW can induce perturbations in the behavior of aquatic invertebrates, an effect that may influence processes such as feeding and predation rates.

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Article: Quantifying methane emissions in the Uintah Basin during wintertime stagnation episodes

Abstract:
Hydraulic fracturing fluids are injected into unconventional oil and gas systems to stimulate hydrocarbon production, returning to the surface in flowback and produced waters containing a complex mixture of xenobiotic additives and geogenic compounds. Nonionic polyethoxylates are commonly added surfactants that act as weatherizers, emulsifiers, wetting agents, and corrosion inhibitors in hydraulic fracturing fluid formulations. Understanding the biodegradability of these ubiquitous additives is critical for produced water pre-treatment prior to reuse and for improving treatment trains for external beneficial reuse. The objective of this study was to determine the effect of produced water total dissolved solids (TDS) from an unconventional natural gas well on the aerobic biodegradation of alkyl ethoxylate and nonylphenol ethoxylate surfactants. Changes in surfactant concentrations, speciation and metabolites, as well as microbial community composition and activity were quantified over a 75-day aerobic incubation period. Alkyl ethoxylates (AEOs) were degraded faster than nonylphenol ethoxylates (NPEOs), and both compound classes and bulk organic carbon biodegraded slower in TDS treatments (10 g L−1, 40 g L−1) as compared to controls. Short-chain ethoxylates were more rapidly biodegraded than longer-chain ethoxylates, and changes in the relative abundance of metabolites including acetone, alcohols, and carboxylate and aldehyde intermediates of alkyl units indicated metabolic pathways may shift in the presence of higher produced water TDS. Our key finding that polyethoxylated alcohol surfactant additives are less labile at high TDS has important implications for produced water management, as these fluids are increasingly recycled for beneficial reuse in hydraulic fracturing fluids and other purposes.

Abstract:
Greenhouse gases (GHGs) produced by the extraction of natural gas are an important contributor to lifecycle emissions and account for a significant fraction of anthropogenic methane emissions in the USA. The timing as well as the magnitude of these emissions matters, as the short term climate warming impact of methane is up to 120 times that of CO2. This study uses estimates of CO2 and methane emissions associated with different upstream operations to build a deterministic model of GHG emissions from conventional and unconventional gas fields as a function of time. By combining these emissions with a dynamic, techno-economic model of gas supply we assess their potential impact on the value of different types of project and identify stranded resources in various carbon price scenarios. We focus in particular on the effects of different emission metrics for methane, using the global warming potential (GWP) and the global temperature potential (GTP), with both fixed 20-year and 100-year CO2-equivalent values and in a time-dependent way based on a target year for climate stabilisation. We report a strong time dependence of emissions over the lifecycle of a typical field, and find that bringing forward the stabilisation year dramatically increases the importance of the methane contribution to these emissions. Using a commercial database of the remaining reserves of individual projects, we use our model to quantify future emissions resulting from the extraction of current US non-associated reserves. A carbon price of at least 400 USD/tonne CO2 is effective in reducing cumulative GHGs by 30–60%, indicating that decarbonising the upstream component of the natural gas supply chain is achievable using carbon prices similar to those needed to decarbonise the energy system as a whole. Surprisingly, for large carbon prices, the choice of emission metric does not have a significant impact on cumulative emissions.

Abstract:
The development of shale petroleum resources has industrialized rural landscapes. We investigated how traffic from energy development expands and intensifies the road-effect zone through increased dust exposure, and how birds and invertebrates inhabiting the road-effect zone in agricultural areas of the Bakken region might be affected by dust exposure. We used dust collectors, trail cameras, and sweep-netting at increasing distances from unpaved roads to determine dust deposition, relative bird abundance, and invertebrate abundance, respectively. We found that traffic associated with fracking along unpaved roads emitted substantial dust 180 m into adjacent crop fields. But neither bird abundance or behavior, nor invertebrate abundance or community composition, appeared to be affected by dust or traffic. These findings suggest that wildlife in previously intensified agricultural landscapes like crop fields are resilient to intensification from energy development, but the same might not be true for wildlife in previously undisturbed habitat.

Abstract:
In 1980, solid waste from oil and gas fields was exempt from US federal hazardous waste regulations (according to the US Environmental Protection Agency's Resources Conservation and Recovery Act, RCRA). However, recent developments in oil and gas extraction from deep shale formations warrant a closer look at this exemption. We obtained lab reports submitted to state regulators to characterize the solid waste generated from 231 shale gas wells in Pennsylvania. Of the 40 chemicals listed as toxic in RCRA, eight were present in our samples and two exceeded RCRA toxicity limits for classification as a hazardous waste (Ba and Cr). We also found overlap with chemicals listed in international lists of toxicity, suggesting that these wastes could pose health problems that would not be regulated by RCRA. Radiation in solid waste is regulated at the state-level; the maximum detected concentrations of radium-226 and radium-228 (51 picocuries/g and 8.87 picocuries/g, respectively) exceed the regulatory limits for landfills in Ohio and New York, however it is common practice to ship waste across state lines. Removing the RCRA oil and gas exemption would increase testing and reporting burdens but would leave most shale waste management practices unchanged while protecting against some hazardous outliers.

Abstract:
Flowback and produced water (FPW) is a complex, often brackish, solution formed during the process of hydraulic fracturing. Despite recent findings on the short-term toxicity of FPW on aquatic biota, longer-term impacts of FPW on fish have not yet been investigated and the mechanisms of chronic effects remain unknown. The aim of the present study was to observe the effect of a diluted FPW on ionoregulatory endpoints in the rainbow trout Oncorhynchus mykiss, following a 28-d sub-chronic exposure. A salinity-matched control solution (SW), recreating the salt content of the FPW, was used to differentiate the specific effect of the salts from the effects of the other FPW components (i.e. organics and metals). Overall, fish ionoregulation was not impacted by the chronic exposure. An accumulation of strontium (Sr) and bromide (Br) occurred in the plasma of the FPW-exposed fish only, however no change of plasma ions (Na, K, Cl, Ca, Mg) was observed in SW- or FPW-exposed fish. Similarly, exposures did not alter branchial activity of the osmoregulatory enzymes sodium/potassium ATPase and proton ATPase. Finally, FPW exposure resulted in modifications of gill morphology over time, with fish exposed to the fluid displaying shorter lamellae and increased interlamellar-cell mass. However, these effects were not distinct from morphological changes that also occurred in the gills of control groups.

Abstract:
Unconventional oil and gas technologies—such as hydraulic fracturing—have drastically increased the volume of oil and gas produced in the U.S., while simultaneously bringing drilling closer to residential areas. We examine quality of life impacts of unconventional oil and gas production, arguing that how people perceive its local effects is rooted in their political identities. Using survey data from three northern Colorado communities, we employ counterfactual mediation methods to understand relationships between political identity, perceived socio-environmental and community changes from oil and gas development, and self-reported quality of life. We find significant differences in how people perceive local development based upon political identity, whereby Tea Party supporters see little negative impact, and in turn are likely to believe that local development improves their quality of life. At the other extreme, Democrats perceive more negative community changes from oil and gas development and are more apt to believe that it reduces their quality of life. Republicans who do not support the Tea Party and political independents hold more mixed views. Overall, our analysis suggests that people's perceptions of local energy development and how it matters for their quality of life is, to some degree, a function of their political identities.

Abstract:
Shale gas extraction is a highly controversial process. Despite significant proven or potential reserves, public reaction to extraction have often been negative. In some cases, this has prevented exploration. In this paper, we investigate the structure of public attitudes to shale gas extraction in the context of the United Kingdom, using a dedicated survey of 4992 respondents. We find that public attitudes to shale gas extraction have a unidimensional structure, such that all questions about the virtues and limitations of extraction are treated as a single issue. Nonetheless, this general structure masks two distinct attitudinal structures. Those with more familiarity with shale gas have a very strong unidimensional attitudinal structure, while those with the least familiarity have a two-dimensional attitudinal structure; representing distinctions between perceived positive and negative attributes. This suggests an important role for information in conditioning responses to shale gas, a factor with implications for how government addresses policy relating to shale gas extraction.

Abstract:
Despite extensive social science research into public perceptions and social responses to fracking, scholars have only begun to examine the relationship between distance to development and support or opposition for it. Importantly, the emerging studies are exclusively from the United States, and focus on communities and regions in which fracking already exists – in contrast to areas where it is proposed and still going through planning approvals. This paper reports public responses to proposed fracking in County Fermanagh, Northern Ireland, United Kingdom. A total of 120 people participated in an in-person survey with a qualitative followup in four locations: the village right next to the development site, two other villages just inside and just outside the wider fracking concession area, and in the capital city of Belfast, 150 km away. A clear spatial pattern of opinion was found, from almost universal opposition to fracking next to the site, to an even threeway split between proponents, opponents and ‘neutrals’ to fracking in general, in Belfast. Results show that some risks are perceived to be more local than others, whilst perceived (economic) benefits are recognised mainly at the national level. Content analysis of local and national newspapers revealed a very clear and similar pattern. Connections to Fermanagh, through visits or long-term residence, were also clear predictors of opposition to fracking. The spatial pattern of support for fracking in Northern Ireland differs substantially from each of the contrasting patterns observed in the United States. We discuss likely reasons for this and implications for both research and policy.

Abstract:
Unconventional oil and gas development (UOGD) in the United States is increasingly being conducted on multi-well pads (MWPs) and in residential areas. We measured air pollution, noise, and truck traffic during four distinct phases of UOGD: drilling, hydraulic fracturing, flowback, and production. We monitored particulate matter (PM2.5), black carbon (BC), A-weighted (dBA) and C-weighted (dBC) noise using real-time instruments on 1 and 5-minute timescales, and truck traffic for 4-7 days per phase at a large 22-well pad sited in a residential area of Weld County, Colorado. Hydraulic fracturing, which requires frequent truck trips to move supplies and diesel engines to power the process, had the highest median air pollution levels of PM2.5 and BC and experienced the greatest number of heavy trucks per hour compared to other phases. Median air pollution was lowest during drilling at this MWP, possibly because an electric drill rig was used. The equivalent continuous noise level (Leq) exceeded guidelines of 50 dBA and 65 dBC for A-weighted and C-weighted noise, respectively, during all development phases. Our data show that these multiple stressors are present around the clock at these sites, and this work provides baseline measurements on likely human exposure levels near similarly sized MWPs.

Abstract:
In South America, Colombia is known as an important oil-producing country. However, the environmental impact of crude oil industry has not been studied deeply and few studies have been carried out for evaluating responses of algae and its adaptation under specific conditions. Enzymatic and physiological effects in Chlorella vulgaris and its potential for bioremediation after exposure to produced water (PW) were assessed using different PW concentrations (0, 25, 50, 75 and 100%) and crude oil. Variables such as cell density, growth rate (μ), percentage of growth inhibition (% I), chlorophyll a and b and cell diameter were evaluated during 5 days. Furthermore, enzymatic biomarkers such as superoxide dismutase (SOD) and catalase (CAT) were also measured. Results showed that the treatment with 100% PW had the highest cell density and μ; similarly, 25% PW treatment had a similar behaviour, being these two treatments with the highest growth. A dose-dependent response was seen for chlorophyll a and b and cell diameter, showing significant differences between treatments and the control. Different levels of SOD and CAT were observed in algae exposed to PW. At 24 h, an increase in SOD and CAT activity was observed, probably due to effects caused by xenobiotics. After 72 h, a decrease in the activity of both enzymes was observed. The results evidenced that C. vulgaris can adapt easily to PW, showing an increase on its growth and stabilisation in its antioxidant activity. Additionally, cell diameter results and decrease of hydrocarbons and phenols show the potential of these algae to degrade xenobiotics from PW.

Abstract:
Article: Emission scenarios of a potential shale gas industry in Germany and the United Kingdom

Abstract:
The drilling phase of oil and natural gas development is a growing area of environmental justice (EJ) research, particularly in the United States. Its emergence complements longstanding EJ scholarship on later phases of the oil and gas commodity chain, such as pipeline transport, refining, and consumption. The growing scholarly attention to the EJ implications of drilling has been prompted by the surge in development of unconventional oil and gas resources in recent decades. More specifically, the oil and gas industry’s adoption of horizontal drilling and hydraulic fracturing (a.k.a., “fracking” or “fracing”) as methods for extracting oil and gas from a wider range of geologic formations has simultaneously heightened oil and gas production, brought extractive activities closer to more people, intensified them, and made well pad siting more flexible. Here, we provide a critical review of the novel EJ research questions that are being prompted by these on-the-ground changes in extractive techniques and patterns, propose an interdisciplinary conceptual framework for guiding EJ inquiry in this context, discuss key methodological considerations, and propose a research agenda to motivate future inquiry.

Abstract:
Understanding how energy infrastructure affects local biodiversity and soil characteristics is important for informing restoration and management. However, the rapid rate of modern oil and gas development is beyond the limit of current knowledge and mitigation strategies. In a mixed-grass prairie in western Oklahoma, we assessed the presence and directionality of biodiversity and environmental gradients associated with energy development in an observational framework. Specifically, we sampled arthropods, vegetation, soil temperature, and soil moisture on the edge of active oil well pads and at 1 m, 10 m, and 100 m away from the well pad. Though variable, the abundance and biomass of most arthropod orders was lower on the pad and 1 m away compared with 10 m and 100 m away, suggesting that the pad itself negatively influenced arthropods but that these effects were limited in spatial extent. However, vegetation structure and composition varied more extensively. Vegetation height, shrub cover, and warm season grass cover increased sixfold, threefold, and fourfold, respectively, from on the oil pad to 100 m away. Forb cover was 5× higher at 10 m from the well pad than on the pad, 1 m away, and 100 m away from the pad. Soil surface temperature was lower at sites farther from well pads, but we found no relationship between soil moisture and distance from well pad. Well pad effects on arthropods and soil temperature appear to be limited to the pad itself, though long-term changes in vegetation structure extend significantly beyond the well footprint and demand a better understanding of the effectiveness of restoration activities around well pads.

Abstract:
Shale gas fracturing flowback water (SGFFW) contained high concentration of colloids and organics which can cause severe fouling for membrane distillation (MD). It is desirable to identify the key foulants for MD fouling for real SGWWFs treatment. In this study, coagulation and membrane filtrations with different molecular weight cut-off (MWCO) were applied to try to separate the different fractions and identify the key fouling/wetting component and evaluate the efficacy in alleviating MD fouling for real SGWWFs treatment. The organics with molecular weight of 20 kDa, which also belongs to humic acid-like components, protein-like components and fulvic acid-like components removed by coagulation can effectively mitigated MD fouling. However, the rest fraction of high molecular weight components of 20 kDa and low molecular weight components (i.e., 200 Da) removed by UF membrane, has less significant effect on the water flux of MD. Despite the further removal of small MW compounds, and even the removal of Ca2+ and Mg2+by NF slightly affect the water flux, indicating that the aromatic protein (21.2%) could cause severe wetting of the MD membrane. However, SEM-EDS demonstrated that the combination of organic fouling and crystallization of Ca and Ba contribute to the fouling of MD membrane. These studies demonstrated the removal of high molecular weight colloids by coagulation and aromatic protein with the molecular weight of 200Da might be vital for MD fouling and wetting, respectively.

Abstract:
The Bacharach Hi Flow® Sampler (BHFS) has been widely used to monitor methane leaks from industrial sources, however results have been challenged due to possible instrument performance issues. This study focused on improving the understanding of the BHFS performance by investigating its characteristics and potential failure modes. BHFS operation was split into three modes: catalytic oxidation (CO), thermal conductivity (TC) and a transition region. Good linear performance was observed in CO and TC modes (R2 > 0.992), however, the calibration factor changed between experiments highlighting the importance of regular calibration. Measurements in the middle region were dominated by noise with poor linearity. Instrument failure due to high non-methane hydrocarbons occurred sometimes; a hypothesis to explain this has been established. We found the BHFS to be a suitable instrument for measuring methane emissions if operated correctly and with knowledge of its limitations. Some key operational guidelines are provided in the conclusions.

Abstract:
Northeastern British Columbia (Canada) is an area of intense natural gas exploitation by hydraulic fracturing. Hydraulic fracturing can release contaminants, including trace metals, many of which are known developmental toxicants. To date, there is limited data on human exposure to contaminants in this region. We aimed to examine trace metals in urine and hair samples from 29 Indigenous and non-Indigenous pregnant women from two communities (Chetwynd and Dawson Creek) in Northeastern British Columbia. We recruited 29 pregnant women who provided spot urine samples over five consecutive days and one hair sample. We measured 19 trace metals in pooled urine samples from each participant and in the first 2 cm of hair closest to the scalp. We compared urinary and hair concentrations to those measured in women from the general population using data from the Canadian Health Measure Survey (CHMS), or reference values found in the literature for trace metals not measured in the CHMS. Median urinary (0.49 μg/L) and hair (0.16 μg/g) concentrations of manganese were higher in our participants than in the CHMS (<0.05 µg/L in urine) or reference population (0.067 μg/g in hair). In hair, median values for barium (4.48 μg/g), aluminum (4.37 μg/g) and strontium (4.47 μg/g) were respectively 16, 3, and 6 times higher compared with median values in a reference population. Concentrations of barium and strontium in hair were higher in self-identified Indigenous participants (5.9 and 5.46 μg/g, respectively) compared to non-Indigenous participants (3.88 and 2.60 μg/g) (p-values = 0.02 and 0.03). Our results suggest higher gestational exposure to certain trace metals in our study population compared to reference populations.

Abstract:
With the increased development of oil and gas activities in northern Colorado, public concerns over the environmental impacts associated with well drilling and hydraulic fracturing have continued to rise. Issues such as leakages of “toxic” products from oil and gas operations to the subsurface environment (such as groundwater contamination) have led to community action and state regulations related to the establishment of groundwater quality monitoring sites in oil and gas activity areas, particularly those adjacent to urban development. Colorado Water Watch was a groundwater quality monitoring network comprised of seven monitoring wells in northern Colorado to monitor groundwater quality near oil and gas wells and give early warnings of contamination. Our study is aimed at developing a quantitative methodology to find ideal monitoring locations as well as evaluate them. We utilized hydraulic and geological data to select the most preferred sites to monitor groundwater quality, understand the temporal trends and identify unique anomaly signals in the oil and gas active area (Wattenberg field, northern Colorado). In addition to the site selection methodology, water quality data from Colorado Water Watch over 2 years is used to do evaluate the performance using entropy information and Principal Component Analysis. The analysis indicates that the earliest functional monitoring site (CHILL) is the most informative monitoring well, and the most recently installed monitoring sites (Gilcrest and LaSalle) are the least informative and least important stations due to their low data efficiency.

Abstract:
Hydraulic fracturing (fracking) chemicals are used to maximize the extraction of hard-to-reach underground energy resources. Large amounts of fracking fluid could escape to the surrounding environments, including underground and surface water resources, during the chemical mixing stage of the hydraulic fracturing water cycle due to equipment failure or human error. However, the impact of pollution resulting from operational discharges is difficult to assess in aquatic ecosystems. In this study, pathological investigations, chromosomal aberrations, DNA damage, and biochemical and hematological parameters were used to evaluate the effects of such chemicals on Nile tilapia. Chromosomal aberrations are considered very sensitive genetic markers of exposure to genotoxic chemicals and are used as indicators of DNA damage. The appearance of different types of chromosomal aberrations (gaps and breaks) due to chemical exposure was significantly reduced by treatment with spirulina. Various deleterious findings in Nile tilapia, in the current study, could attributed to the presence of fracking chemicals in the aquatic environment. However, the presence of spirulina in the diet reduced the hazards of such chemicals. In addition, cytogenetic studies in the current work revealed the importance of spirulina in ameliorating the genotoxic effects of a mixture of some chemicals used in fracking.

Abstract:
This paper explores how a novel and water-intensive method of energy production – high-volume hydraulic fracturing (a.k.a., “fracking” or “fracing”) – has taken hold in a river basin that is over-appropriated, is managed via a water governance regime that did not anticipate hydraulic fracturing's idiosyncrasies, and where public concern about dedicating freshwater to hydrocarbon production is high. Via a grounded examination of hydraulic fracturing water use in Colorado’s busiest oilfield and most crowded river basin, I argue that the practice has come to exist – and persist – despite these countervailing forces because it is an ephemeral energy-water assemblage. It is always in motion, is tough to monitor, and emerges only to disappear and reemerge again. This shape-shifting capacity distinguishes hydraulic fracturing from better-known energy-water couplings such as the hydroelectric dam and from historical surface irrigation practices in the American West. It also has consequences. While the uncritical energy-water literature suggests that these energy-water relations have been sufficiently characterized by volumetric gallons-per-well estimates, and the physical ephemerality of the hydraulic fracturing assemblage keeps its on-the-ground complexities elusive, an abridged and uncomplicated picture of hydraulic fracturing endures in the academic literature and public discourse. The partial understandings that result make this assemblage simpler to produce and reproduce. This study responds to calls for more nuanced analyses of energy-water relations. It also contributes to assemblage theory by examining the relationship between instability and stability in the lives of an assemblage, which underscores the importance of processes of disassembly and reassembly within assemblage-style analyses.

Abstract:
The contamination of surface water and ground water by human activities, such as fossil fuel extraction and agriculture, can be difficult to assess due to incomplete knowledge of the chemicals and chemistry involved. This is particularly true for the potential contamination of drinking water by nearby extraction of oil and/or gas from wells completed by hydraulic fracturing. A case that has attracted considerable attention is unconventional natural gas extraction in Susquehanna County, Pennsylvania, particularly around Dimock, Pennsylvania. We analyzed surface water and groundwater samples collected throughout Susquehanna County with complementary biological assays and high-resolution mass spectrometry. We found that Ah receptor activity was associated with proximity to impaired gas wells. We also identified certain chemicals, including disclosed hydraulic fracturing fluid additives, in samples that were either in close proximity to impaired gas wells or that exhibited a biological effect. In addition to correlations with drilling activity, the biological assays and high-resolution mass spectrometry detected substances that arose from other anthropogenic sources. Our complementary approach provides a more comprehensive picture of water quality by considering both biological effects and a broad screening for chemical contaminants.