A Duke University study of well water in northeastern Pennsylvania suggests that naturally occurring pathways could have allowed salts and gases from the Marcellus shale formation deep underground to migrate up into shallow drinking water aquifers.
The study found elevated levels of salinity with similar geochemistry to deep Marcellus brine in drinking water samples from three aquifers, but no direct links between the salinity and shale gas exploration in the region.
What was found in the groundwater is not hydraulic fracturing or fracking products. But what was found does leave the door open to fracking materials also migrating upward to foul ground water, a possibility that is likely to trigger more debate on fracking.
“This is a good news-bad news kind of finding,” said Avner Vengosh, professor of geochemistry and water quality at Duke’s Nicholas School of the Environment.
The good news, he said, is that it’s unlikely that hydraulic fracturing for shale gas has caused the elevated salinity. He said the locations of the samples containing brine don’t correlate with the locations of shale-gas wells.
The results from the new study also are consistent with water-quality tests conducted in the aquifers in the 1980s before rapid shale-gas development began.
The bad news is that the geochemical fingerprint of the salinity detected in well water from the Lock Haven, Alluvium and Catskill aquifers suggests a network of natural pathways exists in some locations, especially in valleys.
These pathways allowed gases and Marcellus brine to migrate up into shallow groundwater aquifers from deeper underground shale gas deposits.
“This could mean that some drinking water supplies in northeastern Pennsylvania are at increased risk for contamination, particularly from fugitive gases that leak from shale gas well casings,” Vengosh said.
Chesapeake Energy Corp,the Oklahoma-based firm is the No. 1 driller in Ohio.
Rig Count Interactive Map by Baker Hughes, an energy services company.
Shale Sheet Fracking, a Youngstown Vindicator blog.
The Ohio Environmental Council, a statewide eco-group based in Columbus.
Earthjustice, a national eco-group.
People's Oil and Gas Collaborative-Ohio, a grass-roots group in Northeast Ohio.
Concerned Citizens of Medina County, a grass-roots group.
No Frack Ohio, a Columbus-based grass-roots group.
Fracking: Gas Drilling's Environmental Threat by ProPublica, an online journalism site.
Pipeline, blog from Pittsburgh Post-Gazette on Marcellus shale drilling.
Allegheny Front, environmental public radio for Western Pennsylvania.