Duquesne, Pitt Research Shows Contamination of Drinking Water Wells

 In June 2022, fluids being used to fracture rock for natural gas extraction located more than a mile below the Earth’s surface erupted from an abandoned well (Fox Hill #1) in New Freeport, PA. This event is what is commonly referred to as a “frac out”, an event where frac fluids used to fracture the rocks at depth are connected with another well or pathway, bringing frac fluids into contact with groundwater and/or the surface.

More than three years later, residents remain unable to confidently use their water wells, leading Township Supervisors to declare a Disaster Emergency.

Understanding, and preventing, potential connections between frack outs and drinking water is complicated by SWPA's history of coal mining and gas extraction. This history can obscure the source of water contamination and delay efforts to address the situation and help residents.

Following the frack out in New Freeport, researchers sampled 66 local drinking water wells and measured the chemical composition of these waters. This new paper, published in Scientific Reports, documents the water quality changes that followed the frac out.

Specifically, samples that were collected in New Freeport were more like salty oil and gas waste waters than wells outside of New Freeport in most components of the Multi-contaminant Contamination Index (MCI), a measure based on water chemistry (Ca/Sr, Br/SO4, SO4/Cl, Mg/Na, Mg/Li) and the presence of light hydrocarbons in the water (i.e., methane, ethane, and propane).  This combination of measures allows differentiation between legacy contamination and more recent, frac out-driven contamination.

Given the ambiguity in water pollution assessments - is it historical contamination or the frac out itself? - this approach relies on the preponderance of evidence. The consistency in the MCI results in New Freeport well waters is compelling evidence that the frac out profoundly changed local well water chemistry even without sample data prior to the event for comparison.

Almost all of the waters measured in New Freeport were collected from locations far outside the zone of presumption, the designated area within 2500 feet of the actual well pad, designed by PADEP to protect nearby residents from well impacts.  In contrast, the horizontal portions of the well stretch miles from the pad and frac outs could occur anywhere along this length. This study strongly suggests the zone of presumption approach fails to effectively address frac out impacts.

This is part of a larger effort by scientists to provide tools that allow for a more precise attribution of pollution to its source. Frac outs are a particular example of why this is necessary. As one of the primary authors, Duquesne Biological Sciences Professor Dr. John Stolz, says, “you look at the number of frac outs the DEP has recorded and the number of wells drilled, this seems to occur roughly one percent of the time.  Not all frac outs impact populated areas, but as we continue to drill thousands of wells, this poses an important risk to people living near well pads, including those living far from the regulator’s ‘zone of presumption’.”

The Well Water Survey of Counties in Pennsylvania and Ohio at Duquesne University provides free water testing to communities with unconventional oil and gas development and other extractive industries and education on water quality and resources.

The University of Pittsburgh Water Collaboratory strives to elevate water resource sustainability and resilience by fostering research collaborations, communicating knowledge, innovating solutions, and improving the health of the Upper Ohio River Basin.          

Duquesne University

Founded in 1878, Duquesne is consistently ranked among the nation's top Catholic universities for its award-winning faculty and horizon-expanding education. A campus of more than 8,200 graduate and undergraduate students, Duquesne prepares students by having them work alongside faculty to discover and reach their goals. The University's academic programs, community service and commitment to equity and opportunity in the Pittsburgh region have earned national acclaim.

It's time for bigger goals. Follow Duquesne University on Facebook, X (formerly Twitter), Instagram and LinkedIn.
www.duq.edu