The summary conflates two papers, a review paper in Science which summarizes the state of knowledge about fracking the Marcellus Shale (Vidic et al. 2013), and a study of an individual incident published this month in PNAS in which researcher purport to have found a single instance of minor contamination from a fracking well (Llewellyn et al. 2015). Neither paper is particularly damning or inflammatory, so at first blush it's not immediately obvious why the fracking PR flacks have gone to DEFCON 3 on this. The key is to read the review paper first. This is almost always the best way to start because review papers are supposed to give a full and balanced overview of the current state of scientific knowledge on a topic. TL;DR, I know, but stick with me for a few paragraphs and I think I can make the problem clear.
Vidic paints a rather favorable picture of the fracking industry's response to problems that have arisen during the fracking boom in the Marcellus shale. It absolves them of any responsibility for the infamous "burning tapwater" we've all seen in Youtube videos. It states they have been quick to respond to wastewater leaks and well blowouts before contamination could spread. It says the industry has redesigned wells in response to concerns that they might leak fracking water as they pass through the aquifer. And it says that fracking water that returns to the surface ("flowback") is treated and re-used for more fracking -- an expensive environmental "best practice".
Vidic does raise some important concerns, however, and the most important is this. At present recycling flowback into more fracking water is practical because production is booming. But at some point production will level off and begin to decline, and when that happens the industry will be producing more flowback than it can use economically. In Texas, where fracking was pioneered, flowback was disposed of in deep wells -- a process not without its drawbacks, but better than leaving the contaminated water on the surface. Pennsylvania doesn't have enough disposal capacity to handle today's flowback, which helps make recycling fracking water attractive at the present time.
We now have enough context to understand Llewellyn, and why Llewellyn is so upsetting to the industry. Llewellyn's paper documents a single instance of minor contamination which matched the chemical fingerprint of flowback from a nearby well. This contamination was well below a level that would be cause for any concern. Llewellyn concludes the most likely cause was a small spill from the flowback holding pit, although it can't rule out the possibility that the contamination occurred inside the well. Taken with the picture Vidic paints of an industry that is generally on top of stuff like this, the occurrence of a single mishap with negligible consequences is hardly damning. So why has the fracking industry unleashed its flying PR monkeys on this?
Because the fracking industry apparently has made no plans for when the day comes it can no longer recycle all the flowback it uses, and it doesn't want the public to think about that.
It would be sensible for them to prepare for the flowback problem now on the upswing of the boom, for the same reason the industry has been able to be so responsive to date: these are good times for the industry in the Marcellus Shale. They're flush. Although preparing for the problem now would be expensive, it wouldn't slow the boom appreciably, and it would add jobs. But... if the industry can kick the flowback can far enough down the road, we'll have to ask it to fix the problem while production and probably the regional economy is in decline. Doing something about the problem then will cost jobs and require money nobody will have.
So if the industry isn't forced to do something about the looming problem soon, it will become politically if not financially impossible to make them do that ever. That's why the industry is allergic to the very mention that surface contamination from flowback is even possible. In the scheme of things the Llwewllyn incident is negligible, but when fracking starts producing more waste than the industry can use surface contamination is going to become a lot more common and a lot worse.
Vidic raises some other serious long term concerns. Nobody knows where most of the fracking water used goes. The geology of the area is complex enough, but it is further complicated by many old gas and oil wells, quite a few of which are not fully documented. Contamination of the aquifer is a quite plausible possibility that needs further scientific study -- study that has been hindered by lack of research funding and industry transparency. More research might lay this concern to bed; or it may require changes in the industry's operation. We don't know. But we do know that some day we'll have a wastewater problem, and if we wait to address that it will be politically impossible to do anything about.
Vidic, R. D., et al. "Impact of shale gas development on regional water quality." Science 340.6134 (2013): 1235009.
Garth T. Llewellyn, Frank Dorman, J. L. Westland, D. Yoxtheimer, Paul Grieve, Todd Sowers, E. Humston-Fulmer, and Susan L. Brantley. "Evaluating a groundwater supply contamination incident attributed to Marcellus Shale gas development." PNAS 2015 ; published ahead of print May 4, 2015,