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Submission made to the HF Review panel.
By Barrie Clarke, geologist at Dalhousie, for the
Hydraulic Fracturing Panel in Nova Scotia April, 2014. Only a Matter of Time
1.
Most people, including politicians and resource-sector executives,
consider issues on time-scales of
hours to years, but earth scientists routinely deal with natural
processes that occur over decades to millions of years. The issue, and
consequences, of hydraulic fracturing properly belong in the latter
category.
2.
A time-bomb is a device that is set to cause destruction to people or
property at some time in the future,
after the agent that set the device is remote, in space and/or time,
from its destructive effects. Conventional time-bombs have fuses that
are hours to days in length, but environmental time-bombs have "fuses"
that are decades to millennia in length.
3.
Arsenic poisoning of the groundwater in Waverley, NS, in the 1970s, for
example, was the unanticipated
legacy of the gold-mining time-bomb set in the 1870s. Its arsenic- and
mercury-contaminated mine tailings still constitute present-day
environmental problems and future clean-up costs (Parsons et al. 2012).
Those human-health and remediation costs are borne
by people today, not the gold-mining companies of yesteryear.
Fool us once, resource-extraction industry - shame on you.
4. Naturally occurring, deep-seated, low-viscosity materials (e.g., gas, petroleum, brine) always migrate upwards
to
lower pressure. The toxic cocktail of man-made fracking fluids will
behave in exactly the same way. This migration of fluids is subject only
to
D'Arcy's Law, which states that the fluid flow rate is directly
proportional to the permeability (k), the hydraulic pressure gradient
(dh/dL), and the cross-sectional area of the flow (A),
and not to unscientific claims of safety by the petroleum industry.
5. Fracking deliberately destroys the impermeability (k=0)
of rocks containing oil and gas; once their permeability is greater than zero (k>0), all fluids, both natural and synthetic,
begin their upward migration, even if the well casing is properly sealed.
In the absence of any stratigraphically higher
impermeable horizons, those fluids will have hydraulic connectivity with
the surface and must eventually reach the groundwater system (Vengosh et al.
2013).
6.
"The complexities of contaminant transport from hydraulically fractured
shale to near-surface aquifers
render estimates uncertain, but a range of interpretive simulations
suggest that transport times could be decreased from geologic time
scales to as few as tens of years. Preferential flow through natural
fractures [and] fracking-induced fractures could further
decrease the travel times... (Myers, 2012).
7. For balance, Flewelling and Sharma (2014) offer the expected, contrary, dismissive, industry-funded
view.
8. Fluid migration times are longer
than the history of fracking in relatively shallow horizontal wells, but it's only a matter of time until
the
fracking fluids reach the groundwater system. What goes down, must come
up. The petroleum industry already knows this. How else to explain the
Bush-Cheney "Halliburton exemption" from the anti-pollution provisions
of the Safe Drinking Water Act in the USA?
http://www.independentwatertesting.com/education-center/148-what-is-the-halliburton-loophole.html
9.
Poisoning of the groundwater again in Nova Scotia could, therefore,
become the undesirable 2114 legacy
of a fracking time-bomb set in 2014, but by that time the frackers will
be long gone with their environmentally untaxed profits, and future
generations will be left to pay in terms of their health and their taxes
again.
Fool us twice, resource-extraction industry - shame on us.
10.
Humans can, and eventually must, live without fossil fuels, but never
without water. So, where will
the people of North Dakota, Pennsylvania, Texas, and New Brunswick
migrate when their groundwater becomes irretrievably contaminated by
fracking fluids, except to pristine places such as Nova Scotia, which
had the prudence and good sense to reject hydraulic
fracturing in 2014?
D. Barrie Clarke clarke@dal.ca
Adjunct, Department of Earth Sciences Dalhousie University, Halifax, NS B3H 4R2
Resources
Much of the objective scientific information that the Hydraulic Fracturing Panel needs to consider is available
on-line in places such as the Council of Canadian Academies panel website: http://www.scienceadvice.ca/en/assessments/in-progress/shale-gas.aspx and
(in English) from Germany's premier geological research institute (GeoForschungsZentrum-Potsdam): [http://]http:// /www.shale-gas-information-platform.org/
Also, because the shale gas issue should not be considered in isolation, I highly recommend
Energy for Future Presidents by
Richard
A. Muller (W. W. Norton & Company, 2012, ISBN 978-0-393-34510-0) as
a comprehensive and highly readable account of all current and future
energy options.
References
Flewelling,
S. A. and Sharma, M., 2014. Constraints on upward migration of
hydraulic fracturing fluid and
brine. Groundwater 52, 9-19. doi: 10.1111/gwat.12095 Myers, T. 2012.
Potential contaminant pathways from hydraulically fractured shale to
aquifers. Groundwater 50, 872-882. doi: 10.1111/j.1745-6584.2012.00933
Parsons,
M.B., LeBlanc, K.W.G., Hall, G.E.M., Sangster, A.L., Vaive, J.E., and
Pelchat, P., 2012. Environmental
geochemistry of tailings, sediments and surface waters collected from 14
historical gold mining districts in Nova Scotia; Geological Survey of
Canada, Open File 7150. doi:10.4095/291923
Vengosh,
A., Warner, N., Jackson, R., and Darrah, T., 2013. The effects of shale
gas exploration and hydraulic
fracturing on the quality of water resources in the United States.
Procedia Earth and Planetary Science 7, 863-866. doi:
10.1016/j.proeps.2013.03.213
Acknowledgements
I wish to thank G.B., J.C., J.D., A.F., A.M., D.P., M.P., and J.W. for their constructive comments on this
document.
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