A new study of the fluids used in the controversial practice of hydraulic fracturing, or fracking, shows that several of them may not be as safe as the energy industry says they are, and some are downright toxic.
A team of researchers at the Lawrence Berkeley National Laboratory and University of the Pacific looked at more than just the process of fracking – which involves injecting water mixed with chemicals into underground rock formations to extract gas and crude oil. In their report, the researchers list the chemicals that are most often used, based on industry reports and databases. Among them were "gelling agents to thicken the fluids, biocides to keep microbes from growing, sand to prop open tiny cracks in the rocks and compounds to prevent pipe corrosion."
"The industrial side was saying, 'We're just using food additives, basically making ice cream here,'" said team leader William Stringfellow. "On the other side, there's talk about the injection of thousands of toxic chemicals. ...we looked at the debate and asked,' What's the real story?'"
The story so far has been that fracking is an environmentally safe way to extract oil and gas from underground deposits trapped in shale. Its rapid growth has helped the United States dramatically increase oil production. In April, Texas generated more oil than Iraq, OPEC's second-largest producer.
Yet fracking has also been met with opposition because of reports of contaminated well water and increased air pollution around drilling sites. Further, the injection of wastewater into disposal wells at fracking sites has been linked to earthquakes.
Stringfellow's team found that fracking fluid is, in fact, mixed with plenty of food-grade and other non-toxic materials, but some of them may not be safe. At the recent 248th National Meeting & Exposition of the American Chemical Society (ACS), the team reported that eight of the compounds are toxic to mammals.
"There are a number of chemicals, like corrosion inhibitors and biocides in particular, that are being used in reasonably high concentrations that potentially could have adverse effects," Stringfellow said. "Biocides, for example, are designed to kill bacteria. It's not a benign material."
As for food-grade materials, disposal after use isn't always a simple matter. "You can't take a truckload of ice cream and dump it down the storm drain," Stringfellow said. "Even ice cream manufacturers have to treat dairy wastes, which are natural and biodegradable. They must break them down rather than releasing them directly into the environment."
Beyond that, the researchers could find very little information about the safety of fully one-third of the chemicals added to water used in fracking. "It should be a priority to try to close that data gap," Stringfellow said.