It has been proven that it does contaminate. That also doesn't consider the pools of wastewater on the surface. There are peer reviewed studies out there that state the evidence. Sadly, there is also a lot of misinformation being pushed by the oil and gas industry.
huh. weird. I thought it was known to be happening, but not yet widespread.
http://ofmpub.epa.gov/eims/eimscomm.getfile?p_download_id=52...
"We did not find evidence that these mechanisms have led to widespread, systemic impacts on
drinking water resources in the United States. Of the potential mechanisms identified in this report,
we found specific instances where one or more mechanisms led to impacts on drinking water
resources, including contamination of drinking water wells. The number of identified cases,
however, was small compared to the number of hydraulically fractured wells. "
Also the sort of vague claim with no support that "well it hasn't happened yet" is kind of annoying. Nothing is zero risk. we can argue about p(bad_things) <.001 or .1 or whatever, but i think it's foolish to just pretend everything will be sunshine and rainbows forever.
I actually asked a family member who is an ecologically minded geologist about this (while we were at Yellowstone, no less). He said the primary issues now are twofold.
1) Law relating to public land use is terrible and biases insanely in the way of leasing for exploitation. In that the government is both required by law to lease and that the price is far shy of what a market would support (as it hasn't been updated in decades)
2) Inspection and fining of terrestrial operations is typically more self-reported (though only necessary if "sufficient" oil / chemicals have spilled). Measures are then put in place afterwards to monitor the well / location.
Admittedly, he wasn't in legal, but thought I'd share. Also, have to put a plug, if anyone has a lead on good-conscience geology jobs looking for someone with a BSc, I'd be thrilled to forward you on to him (contact me at {username}.co at gmail). He could have made easy money working in petrogeology but felt that wasn't something he could support.
When we were signing up for fracking under our land, we contacted the Ohio Dept of Natural Resources fellow who's responsible for tracking such things (groundwater contamination), and he said he had seen no evidence in 30 years of drilling (including recent) fracking. That's a pretty strong statement from the person whom you'd assume feels responsible for environmental protection
