Two studies from the Nicholas School of the Environment were among the highly read and most cited peer-reviewed papers published in American Chemical Society journals in the past five years.

The journal Environmental Science & Technology (ES&T) Letters has tapped the 2015 paper, "Water Footprint of Hydraulic Fracturing," as one of its five "Highly Read Editors’ Choice" selections. Authored by Ph.D. student Andrew Kondash and Avner Vengosh, professor of earth and ocean sciences, the paper evaluated the total amount of water used and wastewater generated by fracking in the U.S.

The other study, "Impacts of Shale Gas Wastewater on Water Quality in Western Pennsylvania"—also by Vengosh and his lab at Duke—has been recognized by ES&T as one of the journal's most cited articles.

“It is a great honor because these are the...leading journals of environmental science," Vengosh said. "We’ve been working on fracking-related issues since 2010."

The 2015 report on the water footprint of hydraulic fracking found that 250 billion gallons of water were used between 2005 and 2014—accounting for just one percent of all industrial water use nationwide.

The study also showed that conventional oil and gas wells generate more than three barrels of wastewater for each barrel of oil produced. Unconventional wells such as those used in fracking, by contrast, generate only about a half of barrel of wastewater for each barrel of oil produced.

Kondash said the goal in conducting their study was to aggregate individual, smaller data that had already been published into a a larger-scale study that would paint a bigger picture.

“We had found previous studies that had looked at singular regions and quantified the water use associated with that," he said. "But we hadn’t really seen any large scale studies that incorporated all of the major players in the United States at the time."

The other study on shale wastewater in Western Pennsylvania evaluated the impact of water contamination from fracking discharge.

The report, published in 2013, found that radium levels in sediment at the site of oil and gas wastewater discharge from fracking were about 200 times greater than in samples collected upstream. Vengosh and his team also documented high levels of radioactivity and metals in water and sediments at the same site.

In light of the results of his studies, Vengosh, who studies the pros and cons of fracking, said the proliferation of fracking could have both environmental and political benefits. It could decrease reliance on non-renewable coal resources and give the U.S. more economic independence from the Organization of Petroleum Exporting Countries.

At the same time, he explained that while increasing shale oil and gas mining has reduced carbon dioxide emissions and other contaminants due to coal residuals, it has also increased methane emissions, which contain several times the atmospheric warming capacity of carbon dioxide.

Jeffrey Vincent, Stanback Dean of the Nicholas School, summarized the dilemma presented by fracking.

“Here, you have a new source of energy that has enabled the United States to reduce its dependence on foreign fuel, that has enabled the U.S. to rely upon an energy source that is much less greenhouse-gas-intensive," Vincent said. "But that also comes with the risk of overuse of scarce water supplies and risk of contamination from discharge."

Vengosh—who has also been recognized as one of ES&T Letters' 10 most highly prolific authors over the past five years—said his team has consistently received pushback from both the fracking industry and environmentalists over the conflicting results of his papers. But he praised Duke for accepting his findings despite fracking industry pressure to reduce the publication of results discouraging the expansion of fracking operations.

“I think we are demonstrating that science can oftentimes lead to conflicting results," he said. "After climate change, this is one of the most debated topics in environmental science today, so we’ve been at the forefront of that."

Since publishing his 2015 paper, Vengosh's lab has broadened its research to examine the effects of using recycled wastewater from fracking on the success rate of irrigation in California.

Kondash said he believes that quantifying the amount of water used for fracking operations has helped Vengosh's lab formulate future studies on how wastewater from discharge is produced and how it can be treated and reused.

He also hopes the additional recognition garnered for their studies will help them obtain grants for future testing.

“We’re really excited to be honored, but if nothing else, hopefully this will put a spotlight on our work,” Kondash said.