The Applied
Geochemistry Academic Journal recently released a study
using pre-drilling groundwater samples to examine impacts on shallow
groundwater aquifers that might result from shale gas extraction. The study is
entitled “Pre-drilling water-quality data of groundwater prior to shale gas
drilling in the Appalachian Basin: Analysis of the Chesapeake Energy
Corporation dataset” and will be part of the Journal’s Sixty-Third Volume
scheduled for publication in December 2015.
The researchers
analyzed the inorganic chemical composition of water samples collected before
drilling from domestic wells in northeastern Pennsylvania and from water wells
in southwest Pennsylvania, eastern Ohio, and north-central West Virginia.
Based on the sample
results, the researchers opined that most of the shallow groundwater in those
regions tends to exceed federal drinking water standards naturally prior to
shale development. As stated in the study, “these exceedances are not random,
but are related to factors such as geological formation/lithology, sample
turbidity, age or residence time of the groundwater, and where within the
groundwater flow system the sample was collected.” In addition, evaluation of
actual groundwater quality conditions showed that those conditions are similar
to the ones analyzed in historical data.
The researchers
concluded that there is no obvious link between increased unconventional
drilling and the existence of chemicals in water wells. They declared that “[w]ithout
a proper understanding of pre-existing groundwater geochemical variability,
investigators may incorrectly conclude that unconventional oil and gas
development has altered shallow groundwater quality when it has not.”
Written by Chloe Marie - Research Fellow
09/11/2015
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