A recent study by Stanford researchers published in the Environmental Science and Technology Journal found evidence of well stimulation fluids (hydraulic fracking fluids) in underground sources of drinking water near a Pavillion, WY hydraulic fracturing field.
Stimulation fluids are used to "fracture" or make cracks in the shale in order to gain access to deep underground oil or gas trapped between impervious rock. These fluids often contain a mixture of chemicals, some of which are toxic to the environment, humans, or both in high enough concentrations. Once the stimulation chemicals are injected into the ground to "fracture" the shale rock, cracks (fractures) can allow the fluids to flow into groundwater.
— Frack Action (@FrackAction) April 4, 2016
According to the study, the most significant findings (in water samples from the area) were high levels of salt and anomalous ions in the regions deep groundwater -- common elements of fracking fluid. It is thought that from their chemical composition, fractures may have allowed the migration of fracking fluids directly into the aquifer.
Many of the wells were also shallow drills, less than 2,000 feet, which can increase the risk of fracking fluid migrating into deep underground aquifers through cracks.
Long list of chemicals found
This is a list of some of the hydraulic fracturing fluid chemicals used that were found in wells near Pavillion, WY:
- Butyl Benzene
- Isopropyl Benzene
According to the study, although many of the chemical levels were small or trace amounts, the groundwater has a strong upward flow, which means that future migration to the surface from deep underground contamination could easily occur.
— SPE Penn State (@SPE_PennState) April 6, 2016
Other impacts include the use of unlined pits to "dispose of diesel fuel-based (invert) drilling mud and production fluids (flow-back, condensate, produced water)," which resulted in groundwater contamination. The authors suggested that since the study has shown groundwater contamination from the use of these unlined pits in the Pavillion field, it is likely that other fracking locations using this method will have similar findings.
The authors also noted that since the study has, for the first time, established a link between hydraulic fracturing practices and groundwater contamination, they urge investigations into other locations across the nation. To ensure water safety in the Pavillion area, the authors suggested regular monitoring and testing of wells.