“Researchers found it was unlikely that shale gas drilling had caused higher levels of salinity in some of the water wells sampled, since the briny wells were either not near drilling operations or showed higher salinity prior to drilling.
However, the examination also suggested that there must be natural pathways through which gases and salty brine liquid from deep in the Earth can travel in order to infiltrate and change the quality of shallow water wells.
“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.
The study focused on the northeastern Pennsylvania region and included 426 samples from groundwater aquifers in six counties overlying the Marcellus shale formation.
The formation is located about a mile underground and contains highly saline water that is naturally enriched with salts, metals and radioactive elements.
Valleys appeared to be particularly vulnerable, said Nathaniel Warner, a PhD student at Duke who was lead author on the study.”
Read more: AlterNet