The United States Geological Survey (USGS) in cooperation with the Pike County Conservation District recently completed a study of residential groundwater wells in Pike County, Pennsylvania. The results of the study were published in July 2014 in USGS Scientific Investigations Report 2014-5117 which can be viewed on the USGS website. Go to www.usgs.gov and type “SIR 2014-5117” in the search block. The purpose of the study, started in the summer of 2012, was to look at the quality of groundwater and provide a baseline of water quality data from shallow groundwater found in bedrock below the earth’s surface (0-1000ft deep) prior to any natural gas development in our region. Groundwater found in this bedrock supplies Pike County’s population with the majority of its drinking water.
The recent gas drilling boom in counties to the west of Pike County is focused on layers of rock below the surface (7000-9000ft deep) called Marcellus Shale. This shale formed millions of years ago underlies almost all of Pike County and has the potential for supplying new reserves of natural gas for human use. Thus, there is the potential for future natural gas drilling in Pike County by a process called hydraulic fracturing.
Starting in summer 2012, USGS Hydrogeologist Lisa Senior with assistance from the Pike County Conservation District sampled twenty (20) wells throughout Pike County in various shallow, geologic formations. These twenty wells were sampled once in the summer of 2012, and from the assessment of these twenty wells, four wells were chosen to be sampled monthly for one year, ending in June 2013. This monthly sampling provided an opportunity to understand how groundwater quality might change naturally by seasonal factors (i.e. a temporal assessment).
The seasonal (temporal) aspect of the groundwater study indicated up to a 20 percent variance of concentrations of some of the tested components. Sampling showed that some of the wells in Pike County already had detectable concentrations of methane with two wells showing relatively elevated concentrations. It should be noted that this methane is different than methane related to gas drilling operations (the detected methane has a different isotopic fingerprint than that related to gas drilling). Many of the wells also showed detectable levels of components associated with fracking brine. Most of the components were natural, although some may be anthropogenic from sources such as road salt. (Anthropogenic = caused by humans: relating to or resulting from the influence that humans have on the natural world.)
Groundwater sampling completed under this study focused on a full range of tests that included such parameters as methane, dissolved gases, radioactivity, major ions, nutrients, radon-222, stable isotopes, and brine-related ingredients such as barium, strontium, and chloride.
This 2012-2013 groundwater quality study provided important information about Pike County’s groundwater in bedrock aquifers. Future gas drilling and development or other land use changes could impact Pike County groundwater and having a frame of reference for our current groundwater is important. Additional studies are needed to continue to answer questions derived from this baseline study.
The Pike County Conservation District is proud to work with the US Geological Survey to better assess both the quantity and quality of Pike County’s groundwater resource. Funding for this study was supplied by the Pike County Conservation District, USGS and the Pike County Commissioners through the Pike County Scenic Rural Character Preservation Program. For more information please visit: www.pikeconservation.org