A team of U.S. and French scientists say they have developed a new tool that can specifically tell when environmental contamination comes from waste produced by hydraulic fracturing, better known as fracking. In peer-reviewed research published in the journal Environmental Science & Technology on Monday, the researchers say their new forensic tool can distinguish fracking wastewater pollution from other contamination that results from other industrial processes — such as conventional oil and gas drilling. Fracking is a controversial oil and gas well stimulation technique that uses a great deal of water, mixed with chemicals, to extract oil and gas from miles deep underground. Once the rock is fractured by the high pressure fluid, fossil fuels follow the fracking fluid to the surface. The disposal of this often-radioactive water mixture, known as “fracking fluid,” is widely considered to be one of the biggest environmental threats that fracking poses, along with the emissions of greenhouse gases like methane and carbon dioxide. There have been many claims of water contamination since the technique gained popularity in 2008, but it’s been difficult to determine if fracking was really the cause — mainly because fracking companies are not required to disclose what chemicals they use in the process (the mixture is often considered a trade secret). With the new tool, though, scientists no longer need to know the chemical make-up of the fracking fluid to determine whether it’s getting into the environment, Duke University geochemist Avner Vengosh told ThinkProgress on Monday. “This is one of the first times we’ve been able to demonstrate that, here, you have a spill in the environment, and yes, this is from fracking fluid and not from other source of contamination,” Vengosh said. “It’s a pretty cool way to overcome the issue of trade secrets.” In order to do this, Vengosh and a team of researchers from Dartmouth College, Stanford University, and the French Geological Survey among others created a tool that they say can trace the “isotopic and geochemical fingerprints” of the fracking process. In simpler terms, the tracer picks up what the researchers say is a unique, chemical fingerprint left behind by the fracking fluid injection process. The tracers track two elements — boron and lithium — which occur naturally in shale formations. When fracking fluid is injected underground, those two elements are naturally released along with oil, and the fracking fluid then becomes enriched with the elements. When the fluid comes back to the surface, Vengosh said they have an isotopic fingerprint that is different than any other type of wastewater, including wastewater from conventional oil and gas operations. “Many of the fracking operations today are happening in areas that have a legacy of 20, 30 years of conventional oil and gas development,” Vengosh said. “So when there’s contamination, [fracking companies] can say ‘Oh, it’s not us — it’s the legacy of 30 years of operations here.” “We now have the tools to say, well, sometimes you’re right and sometimes you’re wrong,” he added. As fracking has boomed across the United States, so has the use of water to do it. A 2013 report from Environment America showed that fracking wells nationwide produced an estimated 280 billion gallons of wastewater in 2012 — a huge number considering more than 55 percent of fracked wells are in areas experiencing droughts. Vangosh was also part of a research team that found there are more risks of drinking water contamination from fracking wastewater than was previously believed. In a peer-reviewed paper released last month, he and other scientists from Duke and Stanford found that even when fracking wastewater goes through water treatment plants, and is disposed of in rivers that are not drinking water systems, the treated water still risks contaminating human drinking water. That’s because there are generally drinking water systems downstream of those rivers, and treatment plants aren’t doing a good job of removing contaminants called halides, which have the potential to harm human health.