High-volume Hydraulic Fracturing Research Articles

Using discriminant analysis to determine sources of salinity in shallow groundwater prior to hydraulic fracturing.

High-volume hydraulic fracturing (HVHF) gas-drilling operations in the Marcellus Play have raised environmental concerns, including the risk of groundwater contamination. Fingerprinting water impacted by gas-drilling operations is not trivial given other potential sources of contamination. We present a multivariate statistical modeling framework for developing a quantitative, geochemical fingerprinting tool to distinguish sources of high salinity in shallow groundwater. The model was developed using new geochemical data for 204 wells in New York State (NYS), which has a HVHF moratorium and published data for additional wells in NYS and several salinity sources (Appalachian Basin brines, road salt, septic effluent, and animal waste). The model incorporates a stochastic simulation to predict the geochemistry of high salinity (>20 mg/L Cl) groundwater impacted by different salinity sources and then employs linear discriminant analysis to classify samples from different populations. Model results indicate Appalachian Basin brines are the primary source of salinity in 35% of sampled NYS groundwater wells with >20 mg/L Cl. The model provides an effective means for differentiating groundwater impacted by basin brines versus other contaminants. Using this framework, similar discriminatory tools can be derived for other regions from background water quality data.

Hydraulic "fracking": are surface water impacts an ecological concern?

Use of high-volume hydraulic fracturing (HVHF) in unconventional reservoirs to recover previously inaccessible oil and natural gas is rapidly expanding in North America and elsewhere. Although hydraulic fracturing has been practiced for decades, the advent of more technologically advanced horizontal drilling coupled with improved slickwater chemical formulations has allowed extensive natural gas and oil deposits to be recovered from shale formations. Millions of liters of local groundwaters are utilized to generate extensive fracture networks within these low-permeability reservoirs, allowing extraction of the trapped hydrocarbons. Although the technology is relatively standardized, the geographies and related policies and regulations guiding these operations vary markedly. Some ecosystems are more at risk from these operations than others because of either their sensitivities or the manner in which the HVHF operations are conducted. Generally, the closer geographical proximity of the susceptible ecosystem to a drilling site or a location of related industrial processes, the higher the risk of that ecosystem being impacted by the operation. The associated construction of roads, power grids, pipelines, well pads, and water-extraction systems along with increased truck traffic are common to virtually all HVHF operations. These operations may result in increased erosion and sedimentation, increased risk to aquatic ecosystems from chemical spills or runoff, habitat fragmentation, loss of stream riparian zones, altered biogeochemical cycling, and reduction of available surface and hyporheic water volumes because of withdrawal-induced lowering of local groundwater levels. The potential risks to surface waters from HVHF operations are similar in many ways to those resulting from agriculture, silviculture, mining, and urban development. Indeed, groundwater extraction associated with agriculture is perhaps a larger concern in the long term in some regions. Understanding the ecological impacts of these anthropogenic activities provides useful information for evaluations of potential HVHF hazards. Geographic information system-based modeling combined with strategic site monitoring has provided insights into the relative importance of these and other ecoregion and land-use factors in discerning potential HVHF impacts. Recent findings suggest that proper siting and operational controls along with strategic monitoring can reduce the potential for risks to aquatic ecosystems. Nevertheless, inadequate data exist to predict ecological risk at this time. The authors suggest considering the plausibility of surface water hazards associated with the various HVHF operations in terms of the ecological context and in the context of relevant anthropogenic activities.

Assessing dissolved methane patterns in central New York groundwater

Abstract Study region Groundwater in Chenango County (central New York State, USA), which is underlain by Devonian sedimentary bedrock. This region has conventional natural gas wells and is under consideration for future shale gas development using high-volume hydraulic fracturing. Study focus The study examines current patterns of dissolved methane in groundwater, based on 113 samples from homeowner wells in the spring of 2012. Samples were analyzed for methane and other water quality parameters, and each well characterized by its landscape position and geology. Statistical testing and regression modeling was used to identify the primary environmental drivers of observed methane patterns. New hydrological insights for this region There was no significant difference between methane concentrations in valleys versus upslope locations, in water wells less than or greater than 1 km from a conventional gas well, and across different geohydrologic units. Methane concentrations were significantly higher in groundwater dominated by sodium chloride or sodium bicarbonate compared with groundwater dominated by calcium bicarbonate, indicating bedrock interactions and lengthy residence times as controls. A multivariate regression model of dissolved methane using only three variables (sodium, hardness, and barium) explained 77% of methane variability, further emphasizing the dominance of geochemistry and hydrogeology as controls on baseline methane patterns.

Quantifying the potential effects of high-volume water extractions on water resources during natural gas development: Marcellus Shale, NY

Abstract Study region The Marcellus Shale, New York State, USA. Study focus Development of natural gas resources within the Marcellus Shale will require large volumes of water if high-volume hydraulic fracturing expands into New York State. Although this region has ample fresh water resources, it is necessary to explore the response of hydraulically connected groundwater and surface water systems to large withdrawals. Because such effects would not be apparent from a typical water budget approach, this study applied groundwater flow modelling under scenarios of high-volume water withdrawals. Emphasis on water quantity, in contrast with other lines of research concerning water quality, introduced an important perspective to this controversial topic. New hydrological insights for the region The potential effects of the withdrawal scenarios on both the water table and stream discharge were quantified. Based on these impact results, locations in the aquifer and stream networks were identified, which demonstrate particular vulnerability to increased withdrawals and their distribution. These are the locations of importance for planners and regulators who oversee water permitting, to reach a sustainable management of the water resources under changing conditions of energy and corresponding water demand.

Fracking as a Community Issue in Michigan

This report presents the opinions of Michigan local government leaders on issues in their communities related to the process of extracting natural gas through high-volume hydraulic fracturing and horizontal drilling of underground shale deposits, also known as “fracking.” The findings in this report are based on a statewide survey of local government leaders in the Fall 2013 wave of the Michigan Public Policy Survey (MPPS).

Special Issue on Environmental Impacts of Shale Gas Development

Shale oil and gas holds great promise as a newly accessible domestic source of energy. Shale gas is expected to grow from 23% of total U.S. dry gas production (in 2010) to more than 49% in 2035 [U.S. Energy Information Administration (U.S. EIA) 2012]. Many shale gas basins in the United States have great potential, including the Fayetteville in Arkansas, the Haynesville in Louisiana and Texas, and the Marcellus in Pennsylvania and West Virginia. Similarly, shale oil basins including the Bakken (North Dakota) and the Eagle Ford (Texas) will contribute to the U.S. oil supply over the coming decades. The potential economic benefits are significant, with estimates of $5.1 trillion in capital expenditures related to the industry between 2012 and 2035 (IHS Global Insight 2012). Engineering and technological development has paved the way for this shale energy transformation through the use of directional drilling and high volume hydraulic fracturing. Similarly, research into the potential adverse impacts of shale development has increased significantly over the past few years. Research has focused on impacts on water (Vidic et al. 2013; Olmstead et al. 2013), air (Pacsi et al. 2013; Roy et al. 2014), human health (Korfmacher et al. 2013; Finkel and Law 2011), and ecology (Entrekin et al. 2011; Drohan et al. 2012). This special issue includes six papers covering important aspects of environmental issues associated with shale development. Geng et al. present results of simulation of migration of pressurized air during drilling of a well. They report that compressed air is capable of creating a high-pressure gradient in groundwater at hundreds of meters from the drill hole in a confined aquifer. Their work suggests observational wells placed prior to drilling could alert drillers to pressure buildup. Gilmore et al. evaluated the potential effect of water and wastewater truck transport associated with development of Marcellus shale gas. Their work highlights the importance of including all truck trips (including empty returns) when evaluating impacts and also suggests policy changes that could reduce impacts by improving planning. He et al. considered the formation of barium and strontium sulfate in produced water from Marcellus shale development. Formation of precipitates can interfere with reuse of produced water, and equilibrium predictions are not always reliable due to the presence of organic matter. Mauter and Palmer describe an expert elicitation related to current practices and future trends in wastewater management, focused on the Marcellus shale gas formation in Pennsylvania. Their work concludes that long-term water reuse is a viable strategy for management of produced water from shale development for companies with ongoing activity. Strong et al. evaluated the biodegradability of produced water from shale development in the Marcellus and Bakken regions. A wide range of organic compounds were found, as were many halophilic bacterial species capable of biodegradation of these organics. Wilson et al. consider shale-produced waters in comparison with other fossil fuel wastewaters to develop an anion ratio-based source identification method. Applying this method to data collected in Pennsylvania allowed identification of sources of changes in surface water quality. We would like to thank the ASCE Journal of Environmental Engineering Special Issues Editor, Dionysios D. Dionysiou, and the ASCE publishing office personnel for their support during the development of this special section. Further, we are grateful to the important contributions of the reviewers during this process.

Occupational exposures in the oil and gas extraction industry: State of the science and research recommendations

The oil and gas extraction industry is rapidly growing due to horizontal drilling and high volume hydraulic fracturing (HVHF). This growth has provided new jobs and economic stimulus. The industry occupational fatality rate is 2.5 times higher than the construction industry and 7 times higher than general industry; however injury rates are lower than the construction industry, suggesting injuries are not being reported. Some workers are exposed to crystalline silica at hazardous levels, above occupational health standards. Other hazards (particulate, benzene, noise, radiation) exist. In this article, we review occupational fatality and injury rate data; discuss research looking at root causes of fatal injuries and hazardous exposures; review interventions aimed at improving occupational health and safety; and discuss information gaps and areas of needed research. We also describe Wyoming efforts to improve occupational safety in this industry, as a case example.

A Critical Review of the Risks to Water Resources from Unconventional Shale Gas Development and Hydraulic Fracturing in the United States

The rapid rise of shale gas development through horizontal drilling and high volume hydraulic fracturing has expanded the extraction of hydrocarbon resources in the U.S. The rise of shale gas development has triggered an intense public debate regarding the potential environmental and human health effects from hydraulic fracturing. This paper provides a critical review of the potential risks that shale gas operations pose to water resources, with an emphasis on case studies mostly from the U.S. Four potential risks for water resources are identified: (1) the contamination of shallow aquifers with fugitive hydrocarbon gases (i.e., stray gas contamination), which can also potentially lead to the salinization of shallow groundwater through leaking natural gas wells and subsurface flow; (2) the contamination of surface water and shallow groundwater from spills, leaks, and/or the disposal of inadequately treated shale gas wastewater; (3) the accumulation of toxic and radioactive elements in soil or stream sediments near disposal or spill sites; and (4) the overextraction of water resources for high-volume hydraulic fracturing that could induce water shortages or conflicts with other water users, particularly in water-scarce areas. Analysis of published data (through January 2014) reveals evidence for stray gas contamination, surface water impacts in areas of intensive shale gas development, and the accumulation of radium isotopes in some disposal and spill sites. The direct contamination of shallow groundwater from hydraulic fracturing fluids and deep formation waters by hydraulic fracturing itself, however, remains controversial.

Health and fracking: should the medical profession be concerned?

The use of natural gas that is obtained from high-volume hydraulic fracturing (fracking) may reduce carbon emissions relative to the use of coal and have substantial economic benefits for South Africa. However, concerns have been raised regarding the health and environmental impacts. The drilling and fracking processes use hundreds of chemicals as well as silica sand. Additional elements are either released from or formed in the shale during drilling. These substances can enter the environment in various ways: through failures in the well casing; via alternative underground pathways; as wastewater, spills and leaks on the wellpad; through transportation accidents; and as air pollution. Although many of these chemicals and elements have known adverse health effects, there is little evidence available on the health impacts of fracking. These health concerns have not yet been fully addressed in policy making, and the authors recommend that the voice of health professionals should be part of the public debate on fracking and that a full health impact assessment be required before companies are given the go-ahead to drill.

Introduction by the Onondaga Nation and activist neighbors of an indigenous perspective on issues surrounding hydrofracking in the Marcellus Shale

The introduction of an Indigenous perspective by Native spokespeople and their allies is a significant factor in an ongoing legal and discursive struggle over the future of unconventional gas drilling in New York. This paper analyzes the alliance between the Onondaga Nation of the Haudenosaunee (Iroquois) Confederacy and an ally organization known as Neighbors of Onondaga Nation (NOON) as they cooperate to oppose slick water high-volume horizontal hydraulic fracturing, commonly referred to as hydrofracking, in the Marcellus Shale. We trace the history of cooperation between NOON and the Onondaga Nation and locate it in relation to other Native/non-Native alliances. We characterize the responsibility-based approach to law that is suffused throughout Haudenosaunee worldviews and legal systems and contrast it with the rights-based approach of New York State and US environmental and property law, in particular as this rights-based approach structures and constrains the process used to determine the future of hydrofracking in New York. We also consider these differences in the context of Onondaga self-determination and Native American treaty derived sovereignty. We conclude by suggesting that alliances between Native Nations and non-Native organizations might expand opportunities for including Indigenous perspectives on the relationship between society and nature in important decision-making processes.

Reflecting Risk: Chemical Disclosure and Hydraulic Fracturing

In the last three years, twenty-two states have responded to public concern about high-volume hydraulic fracturing by requiring disclosure of the chemicals injected into oil and gas wells. Central to these policies is a nationwide website known as FracFocus, which now contains data on almost 56,000 wells. No environmental issue in recent memory has spurred such a fast and uniform policy response by the states, a response that is more remarkable given the contested nature of hydraulic fracturing. Drawing on the fields of risk science and decision science, the Article examines the virtues and perils of chemical disclosure as a policy response to uncertainty about the long-term health and environmental effects of high-volume hydraulic fracturing. The analysis suggests that the very aspects of the policy problem that make disclosure so appealing -- the relatively recent nature of the chemical use, the public controversy, and the high economic value of the activity -- also undermine the effectiveness of the approach. While the state policies produce more information about chemicals than the previous federal and state framework, they fail to meaningfully improve public understanding of risk. The lessons of risk science and decision science lead to a surprising conclusion: to truly improve public understanding of risk, chemical disclosure policies should be designed to inform experts. At the same time, states must develop communications that provide individuals with the information they need to make important decisions. The Article ends by proposing a new approach that would meet the needs of both audiences.

Public Health and High Volume Hydraulic Fracturing

High-volume horizontal hydraulic fracturing (HVHF) in unconventional gas reserves has vastly increased the potential for domestic natural gas production. HVHF has been promoted as a way to decrease dependence on foreign energy sources, replace dirtier energy sources like coal, and generate economic development. At the same time, activities related to expanded HVHF pose potential risks including ground- and surface water contamination, climate change, air pollution, and effects on worker health. HVHF has been largely approached as an issue of energy economics and environmental regulation, but it also has significant implications for public health. We argue that public health provides an important perspective on policymaking in this arena. The American Public Health Association (APHA) recently adopted a policy position for involvement of public health professionals in this issue. Building on that foundation, this commentary lays out a set of five perspectives that guide how public health can contribute to this conversation.

Navigating Medical Issues in Shale Territory

The introduction of natural gas drilling with high-volume hydraulic fracturing to Pennsylvania and neighboring states since 2004 has been accompanied by numerous reports of varied symptoms and illnesses by those living near these operations. Pollutants with established toxic effects in humans may be introduced into the environment at various points during gas extraction and processing. Some community residents, as well as employees of the natural gas industry, believe that their health has deteriorated as a result of these operations and have sought medical care from local practitioners, who may have limited access to immediate toxicological consultations. This article reviews taking an environmental exposure history in the context of natural gas activities, underscoring the importance of thorough and guided history-taking in the discovery of environmental exposure clusters. It also highlights the critical need for funding, research, and peer-reviewed studies to help generate the body of evidence that is needed by practitioners.

Hydrofracking and Policymaking in New York Municipalities

High Volume Hydraulic Fracturing (commonly referred to as fracking'' or hydrofracking'') is a contentious issue playing out in localities across the country. In New York State, politicians and courts have upheld the rights of local governments to prohibit shale gas development within their limits. In this paper, I examine land-use decisions toward hydraulic fracturing in municipalities across New York State. I find that the partisanship of local officials does not mediate the demands of pro-fracking and anti-fracking interest groups. Localities with pro-environment and higher socioeconomic status interests are more likely to pass a ban or moratorium on hydraulic fracturing. The supply of water in a municipality, which could be contaminated by gas drilling, does not by itself influence local action toward fracking, but it motivates anti-fracking interests. Most surprising, I find that in municipalities that stand to gain economically from gas drilling, protection of farmland leads to prohibitions on hydrofracking.

The Empire Fracks Back: The Case for Hydraulic Fracturing Strict Liability in New York

The possibility that New York will allow high-volume hydraulic fracturing in the near future raises the issue of liability for environmental and other extraction-related harms. Given the potential risk, New York courts should consider treating natural gas exploration under a strict liability regime. Natural gas producers facing strict liability for drilling mishaps would be forced to internalize the environmental and other social costs inherent in the drilling process, thus incentivizing producers to exercise a maximum of care.

State Legislative Oversight - A Case Study: New York State Legislature and High-Volume Hydraulic Fracturing of Natural Gas

New York’s position following other States’ development of fossil gas via high-volume hydraulic fracturing (HVHF) drilling, and the actions of its State Assembly and Senate Environmental Conservation (EnCon) Committees integrated the efforts and facilitated the communications of a wide network of stakeholder organizations and independent experts. These networking efforts were key factors explaining how New York State Legislature performed more effective oversight over agency HVHF well permitting processes than other states. In overseeing the New York State Department of Environmental Conservation (NYSDEC) HVHF permitting process, the legislature held committee investigations and hearings, reviewed agency regulations, made dozens of oversight recommendations to NYSDEC, and passed a temporary moratorium on issuing permits for hydraulic fracturing. Governor Paterson vetoed the moratorium because he felt it would deny new permits for low-volume hydraulic fracturing operations conforming to current requirements, and issued an executive order suspending “high-volume, horizontal hydraulic fracturing,” thus potentially allowing vertical drilling HVHF. Vertical HVHF requires more well pads and vertical bores to produce the same amount of gas, potentially increasing risk of upwards migration of gas and carcinogenic and radioactive fluids into aquifers from well casing failures caused by high-pressure fracking. Will Patterson’s failure to suspend all HVHF create pressure on NYSDEC to issue vertical HVHF permits, or will NYSDEC continue revising its permitting processes in response to public input and legislative oversight requests? If NYSDEC continues its process, oil & gas companies are likely to be subject to more stringent requirements and to experience fewer financial pressures to employ risky drilling practices in New York than in other states thanks in large part to New York State’s effective legislative oversight.

Methane and the greenhouse-gas footprint of natural gas from shale formations

We evaluate the greenhouse gas footprint of natural gas obtained by high-volume hydraulic fracturing from shale formations, focusing on methane emissions. Natural gas is composed largely of methane, and 3.6% to 7.9% of the methane from shale-gas production escapes to the atmosphere in venting and leaks over the life-time of a well. These methane emissions are at least 30% more than and perhaps more than twice as great as those from conventional gas. The higher emissions from shale gas occur at the time wells are hydraulically fractured—as methane escapes from flow-back return fluids—and during drill out following the fracturing. Methane is a powerful greenhouse gas, with a global warming potential that is far greater than that of carbon dioxide, particularly over the time horizon of the first few decades following emission. Methane contributes substantially to the greenhouse gas footprint of shale gas on shorter time scales, dominating it on a 20-year time horizon. The footprint for shale gas is greater than that for conventional gas or oil when viewed on any time horizon, but particularly so over 20 years. Compared to coal, the footprint of shale gas is at least 20% greater and perhaps more than twice as great on the 20-year horizon and is comparable when compared over 100 years.

The Rush to Drill for Natural Gas: A Public Health Cautionary Tale

Efforts to identify alternative sources of energy have focused on extracting natural gas from vast shale deposits. The Marcellus Shale, located in western New York, Pennsylvania, and Ohio, is estimated to contain enough natural gas to supply the United States for the next 45 years. New drilling technology-horizontal drilling and high-volume hydraulic fracturing of shale (fracking)-has made gas extraction much more economically feasible. However, this technique poses a threat to the environment and to the public's health. There is evidence that many of the chemicals used in fracking can damage the lungs, liver, kidneys, blood, and brain. We discuss the controversial technique of fracking and raise the issue of how to balance the need for energy with the protection of the public's health.