New Duke Study Confirms Shale’s Water Efficiency

A new study released by Duke University this month finds that on a per-unit basis, the development of natural gas from shale formations actually produces less wastewater than so-called “conventional” wells. That’s certainly good news, especially considering the fact that the U.S. EPA, numerous experts, and many public officials (including President Obama himself) have all stressed the need to increase production of natural gas in the United States.

From the report (subs. req’d):

“For the Marcellus shale, by far the largest shale gas resource in the US, we quantify gas and wastewater production using data from 2,189 wells located throughout Pennsylvania. Contrary to current perceptions, Marcellus wells produce significantly less wastewater per unit gas recovered (~35%) compared to conventional natural gas wells.” (emphasis added, p. 2)

One of the most common talking points used by the other side is that hydraulic fracturing requires too much water, and that treating or disposing of wastewater poses too many risks to justify continued development. But as we can see, the technological advancements that have allowed us to access oil and natural gas trapped in shale and other tight reservoirs across the country have also come with increased efficiencies. That means more energy with less impact, which is good news for consumers and the environment.

Of course, the study also highlights a potential concern, albeit one that is being addressed far more comprehensively than the authors care to admit: the total volume of produced water coming from shale wells.

As development has increased in the Marcellus, a lot of other things have increased too: jobs, economic opportunity, and even the quality of the air folks are breathing. And, as one would expect, development has also brought with it an increased need to process and even recycle wastewater. The authors state that growing volumes of wastewater are “challenging industry to identify and develop alternative disposal methods” beyond underground injection.

Luckily, that’s a challenge the industry has met head on – and well before this Duke/Kent State study was ever released. Last summer’s headline said it all: “Marcellus flowback recycling reaches 90 percent in SWPA [Southwest Pennsylvania].” Last spring, the Pittsburgh Post-Gazette similarly observed: “Gas drillers recycling more water, using fewer chemicals.”

Of course, the researchers point out the difference between flowback (which comes out of a well after the fracturing process) and produced water, or brine, which is produced from the well over time. But the researchers also opined that “most estimates focus on flowback and do not specifically consider drilling and brine wastewater…likely underestimating the total wastewater volume generated.”

But as the Pittsburgh Business Times reported back in August: “About 65 percent of brine from this region [Southwest Pennsylvania] was reused.” PBT even has a handy searchable tool of state data that includes drilling fluid, produced fluid, flowback, and many other categories of wastewater. Also worth mentioning is that, back in 2010, then-Governor of Pennsylvania Ed Rendell (D) said: “The technology in treating [produced] water is improving rapidly,” a reflection of real-world industry advancements in the Marcellus.

Unfortunately, the decision to leave out these details leaves readers with the impression that the industry is essentially unaware of the issues related to wastewater treatment, reuse, and disposal. In that respect, the researchers make a pretty significant error of omission, although the good news is that reality paints a much more reassuring picture than what was portrayed in the report. (Be sure also to check out for more facts about water usage, disposal, and recycling.)

But hey, if you are willing to cite the Howarth study as credible science – as the researchers for this study do (p. 3) – then you’re probably going to make at least a few errors when discussing responsible development. Thankfully, though, on the most important point – shale’s relative efficiency when it comes to water usage – these guys (despite their best intentions) appear to have gotten it right.

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