Frack Overflow

I'm no chemist, but I'm willing to go out on a limb and say that water shouldn't catch fire. A frequent image used by the anti fracking movement is that of people setting fire to their taps, with the implicit claim that this is the result of nearby fracking operations.



YouTube videos are about as anecdotal as evidence can possibly get, so I was quite happy to place a large mental asterisk beside the whole flaming tap debate, with a view to doing some more research before forming an opinion. To be frank, I was not expecting to find any particular correlation between flaming taps and local fracking operations.

A 2011 paper by Osborne et al. details the sampling of water from 60 drinking water wells, drawing from bedrock aquifers, in the vacinity of the Marcellus and Utica shale formations in North America, where extensive fracking has been undertaken. 51 of these samples contained methane gas in some quantity. Using isotopic ratios of 13C in methane, they deduced whether the source was sub-surface methanogenic bacteria, or if the isotope ratio matched that of thermogenic methane (of the "fossil" variety, which would suggest a relationship with local mining activities). For wells within 1km proximity of active mining sites, the isotope ratio strongly implicated thermogenic methane as the predominant source of contamination, with other wells showing primarily microbial methanogenic sources. The amount of methane present in those wells near active drilling was also an average of 17 times higher.

What's interesting is that the same study used isotope ratios to look for signatures of contamination by hydraulic fracturing fluids or deep brines (which would have lay otherwise undisturbed prior to being poked by a drill), and found no evidence of such contamination. This would suggest that methane was getting into the water by some means other than through fractures opened by the fracking process, as this would have probably been accompanied by these other contaminants. This makes some degree of sense, as the depth of drinking water wells was around 60 to 90m, while the hydraulic fracturing was taking place at between around 1000 and 2000m. That's a pretty large slab of rock. One possible explanation is that the hydraulic fracturing process caused perturbations in pockets of methane higher up in the geology, which then migrated to a level where it could interact with the water table. Perhaps a more concerning possibility is that methane escaped from the mining well itself, and laterally migrated into the water table.

Compared to the UK, the United States has a fairly unregulated mining industry, so the integrity of mining wells may not be monitored as closely as we might like. That's not to say that no such lapses could possibly happen under the regulatory framework of the UK (or anywhere else for that matter), or even that these callous frackers don't in fact go to extreme lengths to control for leaks (after all, they can't sell that methane if it escapes), but given the incentive for any company to attempt to minimise overheads as long as the regulator's head is turned the other way, this state of affairs leaves me deeply concerned. Perhaps a nice glass of flaming water will help me to relax.

We're not quite finished with water. Next blog will deal with those mysterious "fracking fluids" so stay tuned for:

• What do they put in that stuff anyway?
• Where do they get all that water from?
• What do they do with it after they're done with it? Are you sure it doesn't end up in my drinking water?