Here is how the report from the researchers themselves characterized their findings:
We investigated a case where Marcellus Shale gas wells in Pennsylvania caused inundation of natural gas and foam in initially potable groundwater used by several households. With comprehensive 2D gas chromatography coupled to time-of-flight mass spectrometry (GCxGC-TOFMS), an unresolved complex mixture of organic compounds was identified in the aquifer. Similar signatures were also observed in flowback from Marcellus Shale gas wells. A compound identified in flowback, 2-n-Butoxyethanol, was also positively identified in one of the foaming drinking water wells at nanogram-per-liter concentrations. The most likely explanation of the incident is that stray natural gas and drilling or HF compounds were driven ∼1–3 km along shallow to intermediate depth fractures to the aquifer used as a potable water source.The researchers conclude that the water was likely contaminated by drilling based on the presence of 2-n-Butoxyethanol.
Here is how one environmental site, EcoWatch, reported on this study:
But slowly and consistently over the last few years the evidence of water contamination has accumulated as the science has slowly and steadily caught up with the technology. And now scientists have published more compelling evidence of harm.
Yesterday a new study was published in the Proceedings of the National Academy of Sciences, which analyzed drinking water taken from three homes in the heart of the shale fields in Pennsylvania.
And they found what the industry’s critics will argue is damning evidence: traces of a compound commonly found in Marcellus Shale drilling fluids.
The scientists believe they have answered one of the outstanding issues surrounding fracking and water pollution, by outlining a series of events by which the fracking chemicals could have contaminated the water.
In 2012, the scientists collected drinking water samples from the households and subsequent analysis in one of the samples found 2-Butoxyethanol or 2BE, a common drilling chemical which is also a potential carcinogen.
And they believe they know how this chemical has ended up in the drinking water. “This is the first case published with a complete story showing organic compounds attributed to shale gas development found in a homeowner’s well,” Susan Brantley, one of the study’s authors and a geoscientist from Pennsylvania State University told the New York Times.
Brantley added that: “These findings are important because we show that chemicals traveled from shale gas wells more than 2 kilometers (1.25 miles) in the subsurface to drinking water wells.”Is drilling the only explanation for the presence of this compound, though, or even the most likely one?
Energy in Depth had several things to say about that. Here is a portion of their comments:
Fact #1: The study’s attempt to blame drilling activities hinge on the researchers’ post-hoc discovery of “very low concentrations” of a trace compound (2-butoxyethanol or 2-BE) commonly found in hundreds of household products.
The researchers base their argument almost entirely on the detection of trace concentrations of undifferentiated hydrocarbon compounds in three wells, two of which were water “replacement” wells, and the third, a single detection of a trace concentration of compound 2-BE in a separate replacement well. As the report states:
“When we analyzed a subset of the household waters with GCxGC-TOFMS in 2012, we detected very low concentrations of 2-BE. This compound is of special interest because [EPA] has suggested that 2-BE could be an indicator of contamination from HVHF activities.”
2-BE can be an indicator of a lot of things, actually – a fact that the authors concede in the end, though not in the actual report text itself. No, what the researchers bury deep in the supplemental reading packet is the fact that 2-BE is found in hundreds if not thousands of household products, including things as common as Windex and cosmetic products. From thatsupplemental document:
“… 2-BE is used in industry as a solvent for paints and surface coatings and as an ingredient for paint thinners, herbicides, degreasers, dyes, soaps, and cosmetics. … Domestic US production of 2-BE has steadily increased — reported amounts include 59 million kilograms, 123 million kilograms, 136 million kilograms, and 185 million kilograms for years 1975, 1984, 1986, and 1995, respectively …. 2-BE could also result from consumer product use, such as outdoor use of liquid cleaners and paints.”
Other likely sources not considered by this study include the discharge of common household chemicals containing 2-BE (and other products) into subsurface septic systems present at these homes. In fact, elevated nitrate levels in some of the samples suggest septic or agricultural impacts may be present.
Yet, at no point do the researchers consider that the “very low concentrations of 2-BE” could be from any one of these multiple, common and commercial sources.
Further, as the Agency for Toxic Substances and Disease Registry (ATSDR) points out, most people are exposed to this compound several times a day in the workplace or at home. And here’s something that might surprise you: It’s also approved for use by the U.S. FDA as a food additive.
Additionally, 2-BE is known to have a very short half-life in the environment, around seven to 28 days depending on external conditions. Its biodegradability is one of the reasons why it is considered a safe and effective product for drilling both gas wells and water wells. Would 2-BE used in the drilling of a gas well in 2009 show up in tests done in 2012? Not likely, according to the science.
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