Industry said Barnett Shale research doesn’t establish link between fracking and water contamination
A new study investigating groundwater contamination in the Barnett Shale illustrates why caution should be exercised when drawing conclusions from scientific studies.
In this case, a University of Texas Arlington team led by Kevin Schug, the Shimadzu Distinguished Professor of Analytical Chemistry, published the peer-reviewed study, “A Comprehensive Analysis of Groundwater Quality in the Barnett Shale Region,” in the American Chemical Society journal Environmental Science & Technology. Schug was interviewed for this column.
The UT Arlington team tested 550 water samples collected from public and private water wells and found elevated levels of 10 different metals, elevated levels of methanol and ethanol, and 19 different chemicals compounds (including so-called BTEX: benzene, toluene, ethyl benzene and xylenes) associated with hydraulic fracturing.
The researchers concluded there is no direct evidence of fracking pollution, but did argue for more research into a possible link.
“These data do not necessarily identify UOG (unconventional oil and gas) activities as the source of contamination; however, they do provide a strong impetus for further monitoring and analysis of groundwater quality in this region as many of the compounds we detected are known to be associated with UOG techniques,” the authors noted in the paper.
Some of the authors made the link more explicitly in media interviews. “We can’t definitely say that it affected water here, but we can’t rule out that it was not the culprit,” Zacariah Hildenbrand, one of the lead authors, told the Star-Telegram.
“It is more likely that it has had an effect on water quality.”
Nor did the researchers give serious consideration to other possible causes of contaminated well water, other than unconventional oil and gas extraction, according to Ireland, who said in an email that a large number of water wells tapping into the Trinity aquifer that have long been contaminated, probably from a wide range of sources including “fertilizers, septic tank effluent, municipal sewage, animal feedlots, decaying vegetation and atmospheric deposition,” as noted by P. E. Hudak in 2012 based on water well samples collected in 2007.
Ireland notes there are many other reports and anecdotal reports demonstrating the existence of groundwater contamination long before fracking and unconventional oil and gas production began roughly 10 years ago.
“Due to these problems, the UTA paper does not present evidence that shows any relationship between water quality and unconventional oil and gas extraction in the Barnett Shale region, yet the researchers manage to presume a linkage throughout the paper,” Ireland said in an email.
What is a reader to make of this debate?
The scientists made a not unreasonable inference from their research. As Prof. Sheila Olmstead of the Lyndon B. Johnson School of Public Affairs at the University of Texas at Austin suggests, it would be “shocking” if there was no evidence of industrial activity in the Barnett Shale given that 20,000 wells have been drilled and fracked in the area.
Olmstead likes the works of Schug et. al. In an interview with American Energy News, she praised the effort in collecting samples from such a large sample of wells, as well as testing for a broad range of compounds.
But she also cautions about reading too much into the research. “The thing about this study is that everybody finds something to like or dislike in it,” she said in an interview.
Which validates Ireland’s point about not hinting at conclusions that aren’t justified by the data.
In today’s highly charged political debate over fracking and unconventional energy production, both sides – eco-activists and their supporters, industry and its supporters – spin even the slightest bit of information favorable to their position.
A study like this is seized upon, turned into a meme, tweeted and Facebooked and becomes social media debating fodder, while the main point – that the data are only suggestive and more study is required – is lost in the hubbub.
Frankly, the onus is on the smart reader to approach a story like this with caution.
Both the scientists and Ireland have legitimate arguments. And both agree it’s too early to draw conclusions, which is the best advice I could give readers. More work is required before we can say with confidence the groundwater contamination is the result of unconventional production.
The research team is looking at securing funding to press ahead with more studies, such as using detailed chemical signatures to determine if it is unconventional drilling processes contaminating ground water.
In the meantime, Hildenbrand said in an email that researchers found abnormalities in about 20 per cent of their samples and he suggested that property owners who live within the Barnett Shale region may want to consider having their water tested, just for peace of mind.