By Sharon Udasin
The effects of fracking on nearby water sources may be worse than previously thought, according to a new study that found hydraulic fracturing can alter the composition of surface water and not just groundwater.
The study, published Thursday in Science, is the first to link fracking to small increases in salt concentrations in surface water, particularly during the early stages of production. While the highest salt levels were well below what the Environmental Protection Agency (EPA) considers harmful, researchers identified a robust association between new wells and water quality changes, triggering public health concerns.
“Our work provides the first large-scale sample evidence showing that hydraulic fracturing is related to the quality of nearby surface waters for several U.S. shales,” Christian Leuz, co-author of the study and a professor at the University of Chicago’s Booth School of Business, said in a news release.
The authors analyzed almost 61,000 surface water measurements that had been taken from 2006 to 2016 near about 46,000 hydraulic fracturing wells across 408 watersheds. They investigated the presence of bromide, chloride, strontium and barium, the ions most common in high concentrations in frack “flowback” — the fluid that returns to the surface following fracking operations. Their findings indicated a small but consistent increase in barium, chloride and strontium, but not in bromide.
While Leuz acknowledged that the concentrations might not be alarming at face value, he warned that measurements taken in rivers are susceptible to considerable dilution. In addition, monitors are sometimes situated a couple miles downstream from a fracking site and across entire watersheds — which can be almost as big as a county, he added.
By averaging data from all the wells throughout such expansive spaces, some of which showed impacts and others of which did not, the researchers ended up with these smaller, but still statistically significant, salt concentrations, according to Leuz.