But methane isn't harmful. Also the article doesn't mention the quantities, but another does. [1] It seems that the most that's been found is about 70mg/L, which is not a lot.
[1] http://realclearscience.com/blog/2013/06/theres-methane-in-y...
[1] http://realclearscience.com/blog/2013/06/theres-methane-in-y...
Methane is a pretty inert molecule. It's only a hazard in really high concentrations where it acts as an asphyxiant. I don't know of any metabolic toxicity (but maybe there is).
Obviously, this study needs to be repeated many more times and more regulations need to be put on fracking, but the technology is getting better already.
http://www.businessinsider.com/there-are-many-scary-chemical...
They lied.
They claimed there would be no contamination to the groundwater. Now we see there is. What chemical is next? We don't know.
EDIT: also, since many of the chemicals are liquids and they are injected into an aquifer that feeds wells, the only thing we really need to know is: are any of the chemicals lighter than water. Even if they are not, once the water is pumped out, the remaining liquids will certainly be next.