mheslep said:
What I read is that most of pollution in the Ohio river comes from sewage and agriculture runoff. Mercury is a problem, but that comes from coal plant combustion into the air that then deposits into the water shed, and not from coal mining - another reason to prefer natural gas.
I lived on the Ohio river for the first 17 years of my life, in an, at the time, pretty heavily industrialized area (Cincinnati) a few hundred miles downstream from major coal mining concentrations in Ohio and Pennsylvania. During my time there the water of the Ohio river was pretty much toxic, afaik. Sewage and agriculture have a lot to do with it. But the contribution from mine drainage was also significant, afaik.
Quantifications of this are, I would suppose, on the internet. I'm not going to look them up. My point is that I think that what feathermoon said about this is essentially, if not exactly, true.
Anyway, I do agree with your point that natural gas is preferrable to coal.
The unanswered question concerns the long term effect that fracking will have on the potable water supplies of a rather large portion of the US population.
We can, and should to a certain extent, imo, treat it as a scientific question ... and continue the experiment.
However, because it's potentially such a dangerous practice, and because so many people are potentially at risk, then I think that tight oversight and regulation of the natural gas industry is called for.
As for the OP. People should be aware of the dangers of fracking, and I think that the documentary, while factually wrong wrt certain things, does what documentaries of this sort are intended to do ... it raises the public consciousness wrt a certain, potential problem.
I think that the best course of action is to not panic, continue fracking, continue innovating wrt this technology, and watch it very very closely.