The recognition of naturally occurring radioactive material (NORM) associated with oil and gas fields started nearly at the same time as the discovery of radioactivity itself. Radium in produced water is typically the source of the majority of the NORM. Four processes within oil and gas formations, solubility, alpha recoil, cation exchange, and coprecipitation lead to high radium activity in pore fluids. These processes occur regardless of the type of reservoir (conventional high permeability oil and gas reservoirs or unconventional low permeability organic-rich shale source rocks). Following well stimulation via hydraulic fracturing fluids and some solids that return to the surface contain elevated radium. The data on radium from oil and gas wells across the USA is severely lacking relative to the volumes of produced water, especially considering that large volumes are beneficially used or disposed of to surface waters. Novel treatment and accurate measurements of radium are necessary prior to beneficially reuse or dispose produced water in order to protect human and environmental health. More measurements of radium in produced water should be obtained and made publicly available.

This chapter examines the history of fracking as a new technology for enhancing the production of oil and gas, looking for explanations of why the practice is restricted or banned in some jurisdictions but permitted and fostered in others. The classic risk-perception paradigm, which emphasizes the role of public opinion, the mass media, and grass-roots activism, provides useful insight into how and why fracking was banned first in France and later in the UK. Risk perception provides less insight into why fracking is generally acceptable in some states of the US but not in others. Several contextual factors favoring fracking in the US are explored: private ownership of mineral rights and royalty policies, favorable state regulatory climates, a national interest in energy security, and vocal support of fracking from national political leaders of both parties. We look at fracking governance in Texas, North Dakota and Pennsylvania, where fracking technologies are treated as acceptable extensions of conventional technologies and where the practice is neither widely feared nor stigmatized. These states appreciate the benefits of employment and tax revenue fracking operations stimulate.

In efforts to understand the potential impacts of the Marcellus Shale extraction activities on stream health, we performed a baseline study on a focal pair of small streams in the Tenmile Creek watershed in Greene County, Pennsylvania. Bates Fork had intensive Marcellus Shale well drilling activity and several violations upstream from our study site. A tributary, Fonner Run, served as a control stream site with no drilling activity. Through two years of monitoring, we established baselines for water chemistry and biological communities of bacteria, fish and salamanders. In addition, we compared population genetic diversity of two darter species with microsatellite markers. Although no conclusive differences were found between the stream-pair, we established baseline parameters and gained insight into refining tools to detect the signature of Marcellus Shale extraction impacts on small streams in southwestern Pennsylvania. We conclude this chapter with lessons learned from this case study, future directions and suggestions for improved monitoring and detection of Marcellus Shale impacts on streams in southwestern Pennsylvania.

Pristine shale formations are limited subsurface microbial habitats owing to their limited physical space. However, the process of drilling and hydraulic fracturing to recover natural gas from these formations greatly enhances their habitability for microbial life. Drawing upon over a decade of research, this chapter introduces fractured shales as dynamic microbial ecosystems, with particular emphasis on microbial processes that negatively impact on shale gas extraction, including input fluid degradation, biogenic sulfide production and biofilm formation. Collectively, these processes have the potential to sour natural gas, corrode extraction infrastructure, restrict the flow of gas and generally increase costs of resource recovery. The use and efficacy of biocides to control these impacts is discussed. This review presents a biogeographical overview of the fractured shale formations studied to date, highlighting a paucity of information on fractured shales outside the United States, and concludes with a discussion on the remaining knowledge gap.

The extensive forests of the Appalachian basin have high ecological value providing critical ecosystem services as well as important habitat for vulnerable species. The Marcellus and Utica shale plays underlay much of this ecosystem, and the overlap between core forest habitat and the shale plays results in an ecosystem that is at high vulnerability to disturbance. We summarize the current extent of development and the documented and predicted effects on the Appalachian forest ecosystem. Development fragments forest habitat and results in loss of core forest primarily as a result of linear infrastructure such as pipelines and roads. USG is associated with higher levels of noise and other disturbance, increased spread of invasive plants and increased risk of contamination to surface water. Future planning and policies should be designed to protect the health and integrity of the core forests of the Appalachian basin by implementing practices to minimize fragmentation, the spread of invasive plants, noise pollution and degradation of water quality and aquatic resources as well as refining techniques for minimizing the overall footprint and implementing site reclamation.

The water demand associated with unconventional fossil fuel extraction and the management of the associated produced wastewater present significant environmental challenges. Water usage for unconventional fossil fuel extraction varies in different areas of the country, but overall is a small fraction of total water withdrawals for most locations. Produced water volumes and quality also vary nationwide, and disposal can have significant environmental impacts, especially if produced water is discharged to surface waters. This work discusses water use and requisition, changes in quantity and management of produced water nationwide from 2007 to 2017, and the environmental effects of management options. As unconventional natural gas production expands, selection of management options that do not lead to significant environmental impacts must be prioritized.

The first peer-reviewed analysis of how methane emissions affect the greenhouse gas footprint of shale gas was published by my colleagues and I in 2011. We suggested that methane emissions from shale gas, as well as from conventional natural gas, were probably great enough to completely offset any climate advantage that might accrue from reducing carbon dioxide emissions from a switch from coal to natural gas. The paper has stimulated further investigation in the subsequent nine years, with a growing number of research papers on this topic, as reviewed here. The initial conclusion that methane emissions from both shale gas and conventional natural gas make these very poor bridge fuels continues to hold true. The greenhouse gas footprint of shale gas is worse than that of coal, when methane emissions are considered and compared to carbon dioxide over an integrated 20-year time period after emission. Increased emissions from shale gas production in North America alone have probably caused roughly 40% of total global increase in atmospheric methane from all sources. Unless methane emissions can be drastically reduced, shale gas is not a viable option in a climate-smart future.

Methane is a potent greenhouse gas and can create explosion risk at elevated concentrations. Because there are several major anthropogenic sources of methane and other natural sources of methane that are elevated due to climate feedbacks, there is currently no scientific consensus on the cause of increasing global atmospheric methane concentrations. Methane dissolved in groundwater can also have multiple sources that are difficult to distinguish. Luckily, methane has several naturally occurring stable and radioactive isotopes that can help to differentiate these sources. In this chapter I will present an overview of the isotopic composition of various methane sources, including stable and radioactive isotopes of both carbon and hydrogen; give examples of using isotopes to decipher atmospheric methane sources at the local, regional, and global level; and then give examples of using isotopes to distinguish between major sources of methane in groundwater. All of these examples will include natural gas sources, since that is the theme of this book, although isotope tools can be applied to many other types of methane sources.

Historical data can be used to evaluate water impacts from unconventional oil and gas extraction. “Grey” literature measurements of water quality before, during, and after unconventional extraction activities offer a potentially powerful resource for the evaluation of water quality impacts, and these data have rapidly expanded with regulatory response to the unconventional boom. However, historical data are limited in the variety of measured constituents and require substantial effort to reconstruct, revisit, and re-evaluate. Ultimately, available data were limited as data from only a single county (Bradford) included constituents necessary to use the vast majority of these elemental ratio systems. Further, even when data were available, they were often measured with relatively poor sensitivity, precluding their use as early indicators of contamination. This case study accentuates the continued need to establish background conditions, particularly in regions that have accumulated historical impacts, and further, ensure these characterizations incorporate sensitive testing for known chemistries associated with emerging and novel processes.

This chapter presents an overview of the development of the unconventional gas (UG) industry in Australia, particularly in Queensland where most activity has occurred to date. We explore government commitment to the establishment of the UG Industry as a new export product, and subsequent government facilitation of the growth of the industry via the retreat from regulation, the reduction of rigour around the permitting and approvals process and the reluctance to consider cumulative impacts of multiple UG operations in the same area. The issues of public health, water security, domestic energy supply and pricing, and greenhouse gas emissions are considered. In the final analysis, a sustainable ecological development approach should be the ultimate outcome of the adaptive environmental management regime, and indeed was the stated policy of government pre-UG industry. If this was adopted, then the future of the unconventional gas industry in Australia would be limited.

The United States has an abundance of shale plays and unconventional oil and gas drilling now occurs in over 30 states. Major development has occurred in North Dakota, Texas, Louisiana, Arkansas, Michigan, Oklahoma, Wyoming, Colorado, Pennsylvania, Ohio, and West Virginia. The technological advances included the combination of horizontal drilling and hydraulic fracturing, new slick water formulations, and improvements in drilling technologies and fracking design such as “zipper fracking”. The upstream sector includes pre-drilling activities, pad preparation, drilling, hydraulic fracturing, and completion. The midstream sector includes pipeline construction and maintenance and processing facilities that separate the products of mixed gas. These processing facilities can be quite extensive, especially in Southwestern Pennsylvania, Eastern Ohio, and the panhandle of West Virginia where wet gas predominates. This review presents an overview of unconventional gas extraction in the Appalachian Basin as currently practiced in Pennsylvania, Ohio, and West Virginia.

Emissions from unconventional oil and gas development can impact ground-level air quality. The largest impacts are on ozone (O3) and are driven by emissions of volatile organic compounds (VOCs). In the western U.S., ozone events in excess of EPA standards have been linked to VOC emissions from oil and gas operations. In Texas and the eastern U.S., ozone impacts are more modest, but may contribute to exceedances of EPA standards in some downwind cities. Some of the emitted VOCs are hazardous air pollutants that may cause cancer or other health effects. Thus, these emissions may also generate environmental injustice for communities living near oil and gas sources. Unconventional oil and gas sources also contribute to fine particulate matter (PM2.5) and nitrogen oxides (NOx). However, they are minor sources of these pollutants. Similarly, combustion associated with the oil and gas industry emits NOx, but the industry is a small contributor to overall emissions. In rural areas of the western U.S., these NOx emissions contribute to the high ozone events.