Toward strategic management of shale gas development: Regional, collective impacts on water resources

Shale gas resources are relatively plentiful in the United States and in many countries and regions around the world. Development of these resources is moving ahead amidst concerns regarding environmental risks, especially to water resources. The complex nature of this distributed extractive industry, combined with limited impact data, makes establishing possible effects and designing appropriate regulatory responses challenging. Here we move beyond the project level impact assessment approach to use regional collective impact analysis in order to assess a subset of potential water management policy options. Specifically, we examine hypothetical water withdrawals for hydraulic fracturing and the subsequent treatment of wastewater that could be returned or produced from future active shale gas wells in the currently undeveloped Susquehanna River Basin region of New York. Our results indicate that proposed water withdrawal management strategies may not provide greater environmental protection than simpler approaches. We suggest a strategy that maximizes protectiveness while reducing regulatory complexity. For wastewater treatment, we show that the Susquehanna River Basin region of New York State has limited capacity to treat wastewater using extant municipal infrastructure. We suggest that modest private investment in industrial treatment facilities can achieve treatment goals without putting public systems at risk. We conclude that regulation of deterministic water resource impacts of shale gas extraction should be approached on a regional, collective basis, and suggest that water resource management objectives can be met by balancing the need for development with environmental considerations and regulatory constraints. # 2011 Elsevier Ltd. All rights reserved. * Corresponding author. Tel.: +1 607 254 7163. E-mail addresses: bgr4@cornell.edu (B.G. Rahm), sjr4@cornell.edu (S.J. Riha). Available online at www.sciencedirect.com journal homepage: www.elsevier.com/locate/envsci 1462-9011/$ – see front matter # 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.envsci.2011.12.004 Author's personal copy Canada, and more recently the United Kingdom have moved forward with development while France and some regional governments (Quebec, Canada) have placed temporary or permanent moratoria on the high-volume hydraulic fracturing process, citing concerns with respect to environmental safety, public health, and consistency with current policies. Shale gas development entails a range of activities that have various environmental impacts. More comprehensive discussions of these activities and the risks associated with various impacts have been presented from various perspectives (e.g. Christopherson, 2011; Kargbo et al., 2010; NYSDEC, 2011; Zoback et al., 2010). Major environmental concerns generally revolve around several key activities associated with shale gas development. Water resources, their use, and their potential contamination as a result of a wide range of development activities figure prominently among those concerns. Other issues involve potential noise, visual and air quality impacts associated with vehicle traffic, well pad construction and land clearing activities, and use of diesel fuel for on-site compressors and equipment. Activities associated with establishment and construction of well pads and associated service roads and delivery pipeline networks have the potential to disrupt land use patterns, disturb sensitive habitat, and introduce invasive species. Trucking demands related to transportation of materials, water, and waste lead to concerns over road use, road safety, and road maintenance. Still other impacts are possible that are related to community character and the ‘‘boom and bust’’ cycle associated with extractive development. Our focus here, however, is on water resources. Multiple activities associated with shale gas development have the potential to impact water resources and/or waterrelated infrastructure (e.g. Arthur et al., 2010; Soeder and Kappel, 2009; Veil, 2010). Developing shale gas requires a range of typical construction-associated activities. To establish well pads, soil is often removed and sometimes stored. Material and chemical storage areas are established. Roads, parking, and vehicle maintenance areas must be constructed. All of these activities lead to concerns over the risk of spills and leaks that could impact surface and groundwater quality, as well as erosion and water contamination resulting from storm events. Developing shale gas also involves more unique activities such as vertical drilling, often through potable groundwater supplies; and horizontal drilling through the shale formation itself. During these operations, millions of gallons of water need to be acquired and transported to the well pad, mixed with a number of chemical additives, and pumped under high pressure into the well in order to fracture the shale (high-volume hydraulic fracturing). This water then interacts with native constituents present at depth in the shale geology. When pressure is taken off the well, some of this water returns to the surface relatively quickly (flowback water), where it is sometimes treated and reused for hydraulic fracturing of other gas wells. Flowback water that is not reused, as well as water that is returned to the surface over the life of the gas well (produced water), must be stored and then treated and/or disposed of. Improper or poorly managed drilling, water withdrawal, or water treatment could potentially lead to water quantity and quality impacts. Because of concerns for potential environmental impacts such as those discussed above, coupled with the broad occurrence of shale gas throughout the world, managing and regulating the development of shale gas resources is a growing global interest and challenge. In the United States, shale gas resources are currently being extracted in Pennsylvania, Texas, and several other states, despite concerns from some stakeholders that it carries understudied or unacceptable environmental risks (USEPA, 2011a). While rapid development has occurred, regulation of this growing industry has evolved more slowly, and has taken many forms. The federal government provides some oversight through the Clean Water Act, Safe Drinking Water Act, Clean Air Act, and National Environmental Policy Act. The implications of this legislation are discussed at length elsewhere (GWPC and AC, 2009; Tiemann and Vann, 2011). However, the role of the federal government in the US has so far been limited, although recent efforts by federal agencies such as the EPA could mean that this might change (USEPA, 2011a). For the most part states, and in some cases regional authorities, have taken the lead role in regulation of shale gas development in the US (GWPC, 2009). Within the US, states regulate shale gas development and its impact on water resources in different ways (GWPC, 2009). In Pennsylvania (PA), for example, drilling for gas in the Marcellus Shale has increased dramatically in the last several years and regulatory approaches have been reactive in nature, administered to address and mitigate recognized environmental issues after they have occurred. Over time, regulations have become increasingly stringent, and regulatory agencies have moved toward establishment of publically accessible databases which track and compile water resource related information (PADEP, 2010). In New York (NY), parts of which are underlain by the Marcellus Shale, policy makers have chosen not to permit high-volume hydraulic fracturing activities needed to exploit this resource while the NY State Department of Conservation (NYSDEC) reviews possible environmental impacts and proposes regulations to mitigate those impacts (NYSDEC, 2011). While NY is the only state thus far to essentially prohibit shale gas development until an environmental assessment is completed, the focus of this assessment has been the subject of debate. The preliminary environmental impact assessment (dSGEIS) developed by the NYSDEC was undertaken in response to a state law (State Environmental Quality Review Act) that directs the agency to conduct a comprehensive review of all the potential environmental impacts of new development activities. The dSGEIS contains a description of the activities associated with high-volume hydraulic fracturing and shale gas development in general, the potential environmental impacts associated with those activities, and proposed measures and regulations that have been identified to mitigate those impacts. It focuses largely on the project level and pays considerable attention to the potential impacts of an individual shale gas well on its immediate surroundings. This is valuable, especially to the state regulatory community who would be in charge of overseeing the day to day operations of developers. A major criticism of the dSGEIS, however, has been the lack of attention paid to cumulative impacts, which can be briefly defined as impacts resulting from interactions of multiple activities, and/or the collective impact of many similar activities over time and space. Although the dSGEIS acknowledges these impacts, it does not include a full analysis e n v i r o n m e n t a l s c i e n c e & p o l i c y 1 7 ( 2 0 1 2 ) 1 2 – 2 3 13 Author's personal copy of cumulative environmental impacts at the regional scale, nor does it strategically assess policy alternatives and their potential effect on regional environmental impacts. For complex developments such as shale gas, environmental assessment approaches that explicitly analyze cumulative impacts from a state/regional perspective have been shown to be essential (e.g. CEQ, 1997; Kay et al., 2010; Zhao et al., 2009). Moreover, it is recognized that environmental assessments that combine the ‘‘project-focused’’ approach of the dSGEIS with more strategic ‘‘planning-based’’ approaches can be effective for minimizing negative cumulative