What Coal Mining Hydrogeology Tells us about the Real Risks of Fracking

Younger, P. (2016) What Coal Mining Hydrogeology Tells us about the Real Risks of Fracking. [Audio]

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Publisher's URL: https://www.geolsoc.org.uk/CoalHydroFracking16

Abstract

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.

Item Type:Audio
Additional Information:Presented at the 2016 Geological Society's London Lectures Series.
Status:Published
Glasgow Author(s) Enlighten ID:Younger, Professor Paul
Authors: Younger, P.
College/School:College of Science and Engineering > School of Engineering > Systems Power and Energy
Publisher:The Geological Society of London
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