Surface spills contaminating water in Marcellus Shale; levels considered too low to be harmful

Surface spills of chemicals are contaminating residential wells near Marcellus Shale fracking operations in northeast Pennsylvania, says a study of 64 private water wells by researchers published in Proceedings of the National Academy of Sciences, Lisa Song reports for InsideClimate News. The contamination, which was not caused by fracking compounds that were injected deep underground, was found to be at low concentrations that are not considered harmful to humans.

"Brian Drollette, a chemical and environmental engineering graduate student at Yale University and the paper's first author, called the results encouraging for local residents because they showed fracking fluids were not moving upward from the Marcellus shale to shallower groundwater aquifers—at least not in the short term," Song writes. "The study authors said this could help improve public health because residential wells near known surface spills could be monitored and targeted for treatment." (Drollette graphic: Increase in Pennsylvania gas wells from 2007-2014)

Homeowners affected by the spills "can remove the chemicals from their water using simple filtration systems," said Desirée Plata, another study author, Song writes. "Drollette said the conclusions of his study only apply to northeastern Pennsylvania. Due to differences in geology, 'our results don't necessarily translate to other shale [fields] in the U.S.,' he said."

Spills can be linked to "faulty gas well casings, leaking waste containment ponds, underground fuel storage tanks, migration from deep shale (formations approximately 1 mile deep) and surface releases associated with hydraulic fracturing activities," Drollette and Plata write for Phys.org. "We determined that the likely exposure pathway was from surface operations at gas well sites and not from deep subsurface transport."