Quote:
Originally Posted by piercehawkeye45
<snip>
Once again, shale formations are thousands of feet deep (8,000 or so)
and aquifers are below 1,000 ft if not 100. That leaves 7,000 feet of
very low permeability rock for the chemicals to travel.
And remember, this is going against gravity!
In order for the chemicals to travel that 7,000 feet, there must be a TREMENDOUS pressure gradient.
If there are chemicals still left in the ground, that means there either is
a very small pressure gradient from the rock and the borehole or a lot of friction,
which means it is a near impossibility for the chemicals to reach the surface.
Also, gas companies are not deliberately leaving toxins and carcinogens in the ground.
I mentioned this. This are irrecoverable with our current technology.
What contaminates groundwater are leaks or failure of the steel
and concrete coverings separating the borehole from the aquifer.
This has nothing to do with the injection process and is preventable.
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Although the EPA Report will not be out until the end of this year,
the link/article I cited above was pretty explicit.
Quote:
A pair of environmental monitoring wells drilled deep into an aquifer in Pavillion, Wyo.,
contain high levels of cancer-causing compounds and at least one
chemical commonly used in hydraulic fracturing, according to new water test results
released yesterday by the Environmental Protection Agency.
<snip>
The EPA said the water samples were saturated with methane gas
that matched the deep layers of natural gas being drilled for energy.
The gas did not match the shallower methane that the gas industry
says is naturally occurring in water, a signal that the contamination
was related to drilling and was less likely to have come from drilling waste spilled above ground.
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I readily agree this gas field has been drilled and fracked
for many years, and so technology has (almost certainly) improved.
But nonetheless, that aquifer is now contaminated.
Other than "dilution is the solution", what does the industry offer
to mitigate such events, particularly if 20 years from now we find that
today's best practices are not sufficient.