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