Drilling Chemicals Could Move Quickly to Aquifers, Study Says
2 May 2012
By Ken Ward Jr.
CHARLESTON, W.Va. -- Chemicals injected into the ground by natural
gas drillers could migrate toward drinking water supplies much
more quickly than previously thought, according to a new study
that raises questions about West Virginia's ongoing Marcellus
Some scientists and industry officials have argued that thick
layers of impermeable rock would keep "fracking fluids" used by
modern natural gas operations tucked safety away underground, far
below aquifers used for residential drinking water.
But using computer modeling, hydrogeologist Tom Myers found in the
new study that hydraulic fracturing used by the natural gas
industry could exacerbate existing cracks and faults in
underground rock formations.
This could allow toxic chemicals used in hydraulic fracturing
fluids to migrate upward toward water wells in perhaps only "a few
years," according to Myers.
"The evidence for potential vertical contaminant flow is strong,"
Myers wrote in his study.
Myers is a private consultant based in Nevada who does work for
the federal government and environmental groups. Research for the
study was paid for by the Park Foundation and the Catskill
Mountainkeeper, two groups that have opposed drilling and fracking
in New York portions of the Marcellus Shale.
The new study was published in Ground Water, the peer-reviewed
journal of the National Groundwater Association, a non-profit
group that represents scientists, engineers and businesses.
In their push for more natural gas, drilling operators are
increasing using a combination of vertical drilling and hydraulic
fracturing, or "fracking," a process that shoots vast amounts of
water, sand and chemicals deep underground to break apart rock and
release the gas. West Virginia political leaders are hoping this
practice expands as gas companies seek to tap into the vast
reserves in the Marcellus Shale, a formation that stretches from
95,000 square miles from southern New York and into eastern Ohio.
In a massive public relations effort, industry officials argue
that fracking chemicals cannot possibly pollute drinking water,
because fracking occurs far below aquifers used for wells and
chemicals would take far too long to ever possibly migrate through
thick layers of rock.
The new study by Myers is the first scientific paper to strongly
challenge those arguments, and also may be the first peer-reviewed
research to attempt to evaluate the issue.
Myers used computer software to try to project where and how
quickly fracking fluids could move over time.
His models estimated that industry's fracking will speed up the
movement of those chemicals, reducing travel times for the same
distance from thousands of years to 100 years. When Myers factored
in natural faults and cracks in the underground rock, fluids could
travel 10 times faster than that.
The fastest travel times occurred when man-made fractures
intersected with natural faults, with the study finding under
those conditions that "contaminants could reach the surface areas
in tens of years, or less."
Also, the study found, forces from hydraulic fracturing can
continue for nearly a year after the actual fracking is completed.
This could mean chemicals left underground are continuing to be
pushed away from the drill site long after the actual drilling is
done. Restoring the natural balance of the pressure systems
underground could take up to six years, the study said.
The nonprofit journalism organization ProPublica, which has
extensively covered the debate over the natural gas boom, was the
first media outlet to report on Myers' findings.
ProPublica said that "several scientists called Myers' approach
unsophisticated" and that assumptions Myers used in his models
didn't accurately reflect what is known about the Marcellus
Terry Engelder, a Penn State geologist who has been a proponent of
shale drilling, told ProPublica that if fluids could flow through
the Marcellus as quickly as Myers argues, fracking wouldn't be
needed to free up gas deposits.
"This would be a huge fracture porosity," Engelder said. "So I
read this and I say, 'Golly, does this guy really understand
anything about what these shales look like?' The concern then
arises from using a model rather than observations."
Myers noted that there is little hard data on exactly how
underground fluid flows are impacted by hydraulic fracturing, and
recommended that more information be collected before and after
drilling to allow for more concrete studies.
"There is no data to verify either the pre- or post-fracking
properties of the shale," Myers wrote, "... But there are almost
no monitoring systems that would detect contaminant transport as
considered herein. Several improvements could be made."
Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.