Drilling chemicals could move quickly to aquifers, study says
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 Shale boom.
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 Shale's geology.
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 firstname.lastname@example.org or 304-348-1702.