A new study, which can boast of having one of the most comprehensive water quality datasets in the Appalachian basin prior to Marcellus and Utica shale development, was recently released in the journal, Applied Geochemistry.
The study, led by Don Siegel of Syracuse University, analyzed over 21,000 samples of groundwater collected by third party contractors from individual domestic or stock water-supply wells before Chesapeake Energy Corporation drilled nearby Marcellus and Utica shale oil and gas wells. According to the study’s summary:
“Our comparison of these results to historical groundwater data from NE Pennsylvania, which pre-dates most unconventional shale gas development, shows that the recent pre-drilling geochemical data is 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.”
The study falls in line with previous studies from the United States Geological Survey (USGS), which also found major ions and metals in exceedance of federal drinking water standards in a majority of private water wells in Pennsylvania, West Virginia and Ohio prior to development. Of course, it also bolsters the findings of the Environmental Protection Agency’s (EPA) comprehensive five year study, which found that “hydraulic fracturing activities have not led to widespread, systemic impacts to drinking water resources.”
Due to a lack of water well standards in Pennsylvania, residents have always had water quality issues throughout the Commonwealth. Now, because of regulatory framework for oil and gas development, operators are required to take a baseline sample of water wells near drilling operations. According to the report:
“The geochemical dataset we describe consists of data compiled from Chesapeake’s groundwater quality survey programs designed to sample domestic/stock water wells within a radius of 762-1219 m from proposed unconventional oil and gas well sites prior to drilling operations. The spacing of sampling was done according to accepted state regulatory programs, but Chesapeake often went beyond the requirements of these programs (for example the required pre-drill sampling distance per Pennsylvania Department of Environmental Protection (PADEP) regulations in Pennsylvania is 762 m, but Chesapeake often extended that sampling distance to 1219 m).” (Emphasis added, p. 40)
Pre-drill water sampling locations in Northeastern Pennsylvania. (Pg. 39)
After analyzing these baseline water samples it was revealed that a majority of those utilizing a private water well are exceeding at least one federal drinking water standard, prior to shale development. According to the report:
“Chesapeake’s dataset, the most comprehensive for these areas, shows that exceedance of at least one water-quality standard occurs in 63% of water well samples in NE Pennsylvania and 87% in the Western area. In NE Pennsylvania, 10 % of the samples exceeded one or more of the United States Environmental Protection Agency’s (USEPA) primary maximum contaminant levels (MCLs_ for drinking-water supplies, 46.1% of the samples exceeded one or more of USEPA secondary maximum contaminant levels (SMCLs) and another 7% exceeded one or more of USEPA health advisory or regional screening levels for tap water.” (Emphasis added, p. 1)
Northeastern Pennsylvania pre-drilling water samples (p. 44)
Southwestern Pennsylvania pre-drilling water samples (p. 48)
Much like previous studies, this new study again directly debunks a Duke University study (Warner et al 2012.), which attempted to placed blame on shale development for the presence of metal-rich formation brines in water wells. According to one of the new study’s authors, Bert Smith,
“The saline water is naturally-occurring connate brine or salt water which has not been flushed by circulating meteoric water; rather than vertical migration of salt water from deep strata such as the Marcellus shale as suggested by Warner et al. (2012).”
This latest report follows a previous study released earlier this year by the same research team, which evaluated more than 2,300 baseline samples and found “there is no significant correlation between dissolved methane concentrations in groundwater and proximity to nearby oil/gas wells.” That report contradicted the two most controversial papers (2011 and 2013) that came from Robert Jackson and his team at Duke Univ. (Prof. Jackson is now at Stanford). As readers will remember, those Duke papers tried to establish a causal link between the existence of methane in water wells in Pennsylvania and shale development nearby, arguing that the closer a water well is to a gas well, the more likely it is to be “contaminated” by methane. But the Duke researchers had no baseline data and a small sample size, among many other problems. The new
This new study again confirms that poor water quality has existed in the Appalachian region long before shale development ever began. And, thanks to the oil and natural gas industry, residents living in the region are getting a true look at their existing water quality issues without the associated costs with getting their water sampled.