Paper No. 2
Presentation Time: 9:15 AM

EFFECT OF SHALE GAS DRILLING ON GROUNDWATER QUALITY, TIOGA COUNTY, PENNSYLVANIA


WENDEL, Paul J.1, RAMASAMY, Shaker2, LIANG, Bingqing3, FORD, Wayne2, WIEST, Logan A.4, STAUFFER, Tyler2, DRAKE, Brandon2 and SEPIOL, John2, (1)Department of Education, Otterbein University, 1 South Grove Street, Westerville, OH 43081, (2)Department of Chemistry and Physics, Mansfield University, 105 Grant Science Center, Mansfield, PA 16933, (3)Department of Geography, University of Northern Iowa, ITTC 214, Cedar Falls, IA 50614, (4)Earth and Environmental Science, Temple University, Philadelphia, PA 19122, pwendel@otterbein.edu

The study examines water quality related to Marcellus-Shale-gas extraction in Tioga County, PA by horizontal drilling and slick-water hydrofracturing. In Phase I (January 2011 through May 2011), 46 private drinking water wells less than 400 m from the nearest gas drill site (mean distance = 282 m) and 52 private drinking water wells greater than 400 m from the nearest gas drill site (mean distance = 1736 m) were selected by a randomization procedure, sampled, and tested for pH and conductivity; barium and strontium concentrations also were measured by atomic emission spectroscopy and used as a proxy for presence of flowback fluid. Statistical tests reveal no significant difference between water samples taken less than 400 m from the nearest gas drill site and water samples taken more than 400 m from the nearest gas drill site, but there was a weak negative correlation between conductivity and distance to the nearest well. In Phase II, most of the water wells (n = 89) were resampled and analyzed (October 2012 through May 2013). Preliminary results indicate a repeat of the Phase I finding of a weak negative correlation between conductivity and distance to the nearest well; a modest county-wide increase in median pH over two years; and evidence of changes in analyte concentrations when new gas wells were drilled within 400 m of a drinking water source.