Evolving shale gas management: water resource risks, impacts, and lessons learned

Abstract

Unconventional shale gas development promises to significantly alter energy portfolios and economies around the world. It also poses a variety of environmental risks, particularly with respect to the management of water resources. We review current scientific understanding of risks associated with the following: water withdrawals for hydraulic fracturing; wastewater treatment, discharge and disposal; methane and fluid migration in the subsurface; and spills and erosion at the surface. Some of these risks are relatively unique to shale gas development, while others are variations of risks that we already face from a variety of industries and activities. All of these risks depend largely on the pace and scale of development that occurs within a particular region. We focus on the United States, where the shale gas boom has been on-going for several years, paying particular attention to the Marcellus Shale, where a majority of peer-reviewed study has taken place. Governments, regulatory agencies, industry, and other stakeholders are challenged with responding to these risks, and we discuss policies and practices that have been adopted or considered by these various groups. Adaptive Management, a structured framework for addressing complex environmental issues, is discussed as a way to reduce polarization of important discussions on risk, and to more formally engage science in policy-making, along with other economic, social and value considerations. Data suggests that some risks can be substantially reduced through policy and best practice, but also that significant uncertainty persists regarding other risks. We suggest that monitoring and data collection related to water resource risks be established as part of planning for shale gas development before activity begins, and that resources are allocated to provide for appropriate oversight at various levels of governance.

Comparing the relationship between knowledge and support for hydraulic fracturing between residents of the United States and the United Kingdom

“…'Split estates' (where the current or past landowner has sold the subsurface rights) are also relatively common [1], especially in the South and Midwest. There also has been substantial development on government land-these government bodies then own the mineral rights in these contexts, and may enact additional regulations [35]. This is especially common in the western US, which is proportionately more dominated by public lands.…”

The Problem of Wastewater in Shale Gas Exploitation The Influence of Fracturing Flowback Water on Activated Sludge at a Wastewater Treatment Plant

“…The longer the drilling fluid remains in the reserve, the more its chemical composition differs from the initial composition. Moreover, depending on the structure and origin of shale formations and geochemical characteristics of the reserve, the flowback water may also contain heavy metals and radioactive compounds whose negative effects on human health are commonly recognized [11][12][13]. Somewhat less knowledge is available about the influence of drilling fluids on the natural environment.…”

“…However, prior to recycling, the flowback water has to be treated via flowback water cleaning systems. Rham et al [4,[12][13] demonstrated that in the case of low-salinity flowback water (on the order of ca. 12,000 mg Cl -/l) the treatment mainly consists of the removal of sediment, suspended matter, and hydrocarbon contaminants.…”

“…To this end, electrodialysis, reverse osmosis, and thermal methods can be applied. Flowback water without prior desalination can be pumped into the depleted deposits or between the isolated absorbent layers in the deposit [12].…”

“…11,000-19,000 m 3 of drilling fluid, which consists of 90.6 % of water and 0.4% of added components such as the aforementioned polymers to increase viscosity, anticorrosion agents, surfactants, gelling agents, buffers, and others [5,[12][13][14]. It has been assumed that ca.…”