Updated with a link to Briana Mordick's blog post on the same topic.
EPA today released a draft report with the agency's latest findings on its investigation into drinking water contamination in Pavillion, Wyoming. Back in 2009, EPA stated that it had detected contamination in 11 drinking water wells in this ranching community, and the contaminants included toxic chemicals that are used in hydraulic fracturing. That finding made fracking one possible cause of the contamination, and the EPA continued to investigate.
So while today's draft report is big news, it is not a shocker that EPA has concluded that "the data indicates likely impact to ground water that can be explained by hydraulic fracturing."
EPA suggests there are three possible ways that the fracking chemicals could have gotten into ground water: the wholly inadequate construction of gas wells that it found in the area, fracture fluid movement from thin discontinuous tight sandstone units into sandstone units of greater permeability, and/or fracking creating new fractures or enlarging existing ones and thereby increasing the connectivity of the fracture system. My colleague Briana Mordick has post a lot of insight into the technical issues on her blog.
EPA found that hydraulic fracturing in the Pavillion gas field occurred in zones of producible gas located within an Underground Source of Drinking Water (USDW). While the agency concludes the best explanation is that inorganic and organic constituents associated with hydraulic fracturing have contaminated ground water, it says more investigation is needed to determine if compounds associated with hydraulic fracturing made it to drinking water wells in the area.
Here are some of the toxic contaminants that EPA found in the ground water in the area: diethylene glycol, triethylene glycol, benzene, toluene, ethylbenzene, and xylenes (BTEX), trimethylbenzenes, gasoline range organics, and diesel range organics.
EPA also detected high concentrations of benzene, xylenes, gasoline range organics, diesel range organics, and total purgeable hydrocarbons in ground water samples taken near pits, and found that pits are a source of shallow ground water contamination in the area.
Thanks to EPA for pursuing this case and trying to get to the bottom of it. We are very concerned about the extensive amount of ground water contamination in the area, but this investigation will shed light on what happens underground when fracking occurs so that contamination can be better prevented in the future. This type of scientific inquiry is essential to fully understand the risks of fracking--including how and where a well is fracked--and how to reduce them. EPA has made its draft report available for public comment and will also be engaging independent scientists to conduct a peer review.
No one can accurately say that there is "no risk" where fracking is concerned. This draft report makes obvious that there are many factors at play, any one of which can go wrong. Much stronger rules are needed to ensure that well construction standards are stronger and reduce threats to drinking water. That's why we support federal regulation of fracking under the Safe Drinking Water Act--so regardless of where one lives, there would be at least minimum federal standards in place. As John Fenton, the Chair of Pavillion Area Concerned Citizens, said today: "This investigation proves the importance of having a federal agency that can protect people and the environment."