For people living near oil and gas development in the Marcellus and Utica formations, the safety and quality of their drinking water is understandably a major concern. Though some residents may worry about oil, gas and their byproducts contaminating groundwater, Applied Geochemistry recently released a study that may comfort neighbors of the oil and gas industry.
Energy InDepth reports the study, led by Don Siegel of Syracuse University, analyzed more than 21,000 groundwater samples collected from well by third parties before Chesapeake Energy Company began drilling the formations.
The summary of the study points to current chemical levels in northeastern Pennsylvania that are similar to “historical data”:
We see no broad changes in variability of chemical quality in this large dataset to suggest any unusual salinization caused by possible release of produced waters from oil and gas operations, even after thousands of gas wells have been drilled among tens of thousands of domestic wells within the two areas studied.
These findings reiterate those of the similar studies from both the U.S. Geological Survey and Environmental Protection Agency, which found not only that most private well water contained ion and metal levels that exceed federal drinking water standards before shale development, but also that fracking had not caused ‘widespread, systematic impacts’ to sources of drinking water.”
However, the new study challenges the findings of a Duke University study (Warner et al 2012), which sourced the metal-rich brine in the area’s water to oil and gas development.
“The saline water is naturally-occurring connate brine or salt water which has not been flushed away by circulating meteoric water,” writes Bert Smith, an author of the new study. “Rather than vertical migration of salt water from deep strata such as the Marcellus shale as suggested by Warner et al (2012).”
Read the full study or the summary here.