Well water contamination in a rural community in southwestern Pennsylvania near unconventional shale gas extraction

Abstract

Reports of ground water contamination in a southwestern Pennsylvania community coincided with unconventional shale gas extraction activities that started late 2009. Residents participated in a survey and well water samples were collected and analyzed. Available pre-drill and post-drill water test results and legacy operations (e.g., gas and oil wells, coal mining) were reviewed. Fiftysix of the 143 respondents indicated changes in water quality or quantity while 63 respondents reported no issues. Color change (brown, black, or orange) was the most common (27 households). Well type, when known, was rotary or cable tool, and depths ranged from 19 to 274 m. Chloride, sulfate, nitrate, sodium, calcium, magnesium, iron, manganese and strontium were commonly found, with 25 households exceeding the secondary maximum contaminate level (SMCL) for manganese. Methane was detected in 14 of the 18 houses tested. The 26 wells tested for total coliforms (2 positives) and E. coli (1 positive) indicated that septic contamination was not a factor. Repeated sampling of two wells in close proximity (204 m) but drawing from different depths (32 m and 54 m), revealed temporal variability. Since 2009, 65 horizontal wells were drilled within a 4 km (2.5 mile) radius of the community, each well was stimulated on average with 3.5 million gal of fluids and 3.2 million lbs of proppant. PA DEP cited violations included an improperly plugged well and at least one failed well casing. This study underscores the need for thorough analyses of data, documentation of legacy activity, pre-drill testing, and long term monitoring.

Analysis of non-methane hydrocarbon data from a monitoring station affected by oil and gas development in the Eagle Ford shale, Texas

“…Environmental impacts of UOG exploration can be manifold , and concerns have focused on water contamination ( Jackson et al, 2013;Vengosh et al, 2014;Alawattegama et al, 2015) and air emissions (Field et al, 2014;Moore et al, 2014), which can come from various steps in the UOG exploration process, such as during the hydraulic fracturing backflow period. Atmospheric emissions are dominated by emissions of methane, the dominant component of natural gas and a strong greenhouse gas Elementa: Science of the Anthropocene • 4: 000096 • doi: 10.12952/journal.elementa.000096 (Brandt et al, 2014).…”

Neutrosophic Optimization Model and Computational Algorithm for Optimal Shale Gas Water Management under Uncertainty

“…The integrated framework representative of the multiobjective shale gas water management optimization model is presented based on a real-life scenario, hypothetical proposition, data, information, and a quick review of the published research (Lutz et al [12], Rahm and Riha [54], Rahm et al [55], Zhang et al [22], Alawattegama [56]). The unified optimal shale gas water planning model was structured to manifest the real-life scenario in the current and future characteristic features of shale gas extraction processes.…”

Current perspectives on unconventional shale gas extraction in the Appalachian Basin

“…[22] Well completion records obtained from the PA DEP showed that one company reported using an average of 3.2 million gallons of fracking fluid and 300,000 lbs of proppant per well in wells drilled in Butler County, PA in 2008 to 2012. [23] The large number and size of the storage containers for the water, chemicals, and proppant, the mixers and pressure pump trucks, as well as the accommodations for control operations, require a well pad of sizable dimensions, often 3-7 acres (Fig. 3).…”