Development of shale gas by hydraulic fracturing (‘fracking’) is opposed by campaigners who hypothesise (amongst other things) that potable ground water supplies could be polluted by upward migration of fractures and any fluids they contain. There are very strong reasons for doubting this hypothesis, not least because migration of fractures to prolific aquifers would be highly unlikely to lead to pollution, but almost certain to result in drowning of the shale gas wells, rendering them unusable.
Hence, despite having contrasting motivations, shale gas developers and environmental guardians turn out to have a strong common interest in avoiding inter-connection to aquifers. There is in fact a century-long analogue for such a ‘confluence’ of interests, provided by the history of longwall coal mining beneath the sea and major aquifers. Where large-scale mining proceeded from the surface downwards, major hydraulic inter-connection of shallow and deep zones did indeed result in widespread water pollution.
However, where new mines were developed at depth without any connections to shallow old workings), complete hydraulic isolation from the near-surface hydrogeological environment was successfully maintained. This was despite the fact that longwall mining produced far greater stratal disruption than shale gas fracking ever could.
A detailed example is presented from the successful operation of the Selby Coalfield beneath one of the UK’s main aquifers. This profound and sustained historical analogue provides a very clear lesson: given the lack of hydrogeological connectivity to shallow aquifers, shale gas fracking per se cannot contaminate shallow ground water. Provided operators observe long-established laws governing hydrocarbon wells and associated surface operations, other hydrogeological risks will also be minimal.
Opponents of shale gas developments should therefore focus attention on more realistic potential impacts, most of which are familiar from almost any planning application, such as increased truck traffic on minor roads.
Paul Younger (University of Glasgow)
Paul L Younger FREng holds the Rankine Chair of Engineering and is Professor of Energy Engineering at the University of Glasgow. He was formerly Pro-Vice-Chancellor for Engagement at Newcastle University, where he also established and led the Sir Joseph Swan Institute for Energy Research and, subsequently, the Newcastle Institute for Research on Sustainability. A geologist by first degree, Paul trained in hydrogeology in the USA as a Harkness Fellow in the mid-1980s, subsequently developing a career in environmental engineering.
He is perhaps best known for his research and outreach on the environmental management of water in active and abandoned mines worldwide, which won the Queen’s Anniversary Prize for Higher Education for Newcastle University in 2005. He is a Fellow of the Geological Society and a Chartered Geologist, as well as a Chartered Engineer. He was elected a Fellow of the Royal Academy of Engineering in 2007 and has received honorary doctorates for his mine water pollution work from leading universities in Spain and South America. His current research focuses on deep geothermal.
In parallel with his mainstream academic work, Paul has founded and directed four companies in the water and energy sectors and has authored more than 400 items in the international literature, including the well-received books “Mine Water: Hydrology, pollution, remediation” (Kluwer, 2002), “Groundwater in the Environment: An Introduction” (Blackwell, 2007), “Water: all that matters” (Hodder, 2012) and “Energy: all that matters” (Hodder, 2014).
His knowledge of shale gas was gained through serving on the Joint Royal Academies’ Expert Panel, which reported to the UK government in 2012, and on the Independent Expert Panel on Unconventional Gas, which reported to the Scottish Government in June 2014. When not otherwise engaged, Paul’s preferred activities include exploring the Scottish Highlands and Islands, singing and playing traditional music, and indulging his love of the Spanish and Gaelic languages and cultures.