Fracking Caused Groundwater Contamination In Pavillion, Study Concludes
Hydraulic fracturing or fracking has contaminated water resources in the Pavillion area, according to a new study from Stanford University. Dominic DiGiulio, the lead author of the study, also wrote the 2011 Environmental Protection Agency draft report that first linked fracking to groundwater contamination in the Pavillion area.
DiGuilio left the EPA in 2014, but continued researching Pavillion as a visiting scholar at Stanford. For the current paper, which was published Tuesday in the scientific journal Environmental Science and Technology, DiGuilio and his co-author, Stanford researcher Rob Jackson, reviewed more than a thousand public documents.
In those documents, they found evidence that on several occasions, oil and gas companies fracked directly into water-bearing formations in the Wind River aquifer.
“Undiluted diesel fuel was used for hydraulic fracturing in the 1960s,” DiGiulio said. “And there was at least one example where undiluted diesel fuel was actually injected into the formation.”
The study also details how companies hydraulically fractured areas where the fractures would have had to travel just tens of feet to reach water resources in the Wind River formation. The researchers also noted changes in the water chemistry of the formation that indicate fracking has had an effect.
“This is really the first documented case of impact to underground sources of drinking water,” DiGuilio said.
But while the researchers are confident fracking has impacted groundwater resources, they stopped short of saying that fracking has contaminated the area’s water wells. Most water wells in the Pavillion area currently tap shallower water resources than those where contamination was detected. But in the future, new wells could try to access those deeper resources, or the contamination could move into shallower groundwater.
“That’s why there needs to be additional deep monitoring wells out there, to look at the potential for future impact,” DiGuilio said. “To try to get a better idea of the areal and vertical extent of the contamination that’s associated with hydraulic fracturing.”
DiGuilio and Jackson also recommend additional monitoring in the vicinity of unlined waste pits. Historically, there were dozens of unlined oil and gas waste pits in the Pavillion field that were used to dispose of various drilling byproducts, including diesel and other hydrocarbons. Those pits, the study concludes, could affect water quality for wells currently tapping groundwater in the area.
The study focused exclusively on Pavillion, but DiGiulio says the findings are potentially relevant elsewhere, if researchers identify other fields where oil and gas companies are fracking near or into drinking water resources.