New tracers could resolve water contamination questions
Oil and gas companies drilled a total of 1,365 “unconventional” natural gas wells . . . just in Pennsylvania . . . just in 2012. “Unconventional” means the controversial practice of hydraulic fracturing, or fracking, was used—which means the drillers sent gallons and gallons of the mystery chemical soup known as fracking fluid down underneath the Pennsylvania countryside. And that means 1,365 possible new sources of groundwater contamination.
But with natural gas production booming, questions surrounding water contamination remain unsettled. What if there were a reliable way to prove that some of the nasty stuff sent a mile down a well does or does not migrate into the water table? A few enterprising teams are starting to emerge with some low-cost methods that do just that.
BaseTrace, a startup led by CEO Justine Chow, is synthesizing individualized DNA molecules that can be used as tracers in fracking fluid. DNA has countless numbers of unique sequences, so BaseTrace can create tiny bits of the stuff that serve as a kind of fingerprint for individual drilling operations. Drillers add a bit of their unique DNA tracer to their fracking fluid. If someone’s water gets contaminated, testers can look for a DNA sequence that can pinpoint the exact source. Chow says the DNA tracer is detectable on a parts-per-quadrillion scale and only a thimbleful of the tracer would be needed for the several million gallons of water used in every fracking job.
Another idea, spun out of research by Andrew Barron and others at Rice University into a company called FracEnsure, involves a totally different type of tracer: magnetic nanoparticles. Barron describes the particles as resembling rust, but with other naturally occurring metals added in varying amounts to create a unique signature. To test for contamination, he can run a water sample through a magnetic separator that would find the tiny particles and identify specifically which well or set of wells they came from.
“When you have a water source you think is contaminated, the concentration of these particles is going to be tiny,” says Barron. “How do you find a needle in a haystack? You take a magnet and you wander around the haystack and the needle will fly out.”
Both ideas are getting close to commercialization, potentially dropping down wells by the start of 2014. Both tracers are themselves harmless (unlike some existing tracer tech, such as that involving radioactivity) and would add only minimal costs to a frack job. Industry is interested, since it could help them prove they are not responsible for water contamination. Of course, if the opposite proves true, these clever tracers might help send the natural gas industry packing. ❧
—Dave Levitan
Photo: ©Duskbabe/Dreamstime
