Does Fracking Contaminate Aquifers?
When a well is fracked, is it possible for the manmade cracks to allow briny water or chemicals into aquifers?
The answer is a resounding no. Two scientific papers released earlier this week make this point abundantly clear. First, there was a lengthy report on an investigation into six wells drilled into the Marcellus Shale in Greene County, Pennsylvania. The report, by a bunch of federal government scientists as well as colleagues from West Virginia University and the University of Pittsburgh, studied these wells closely. They used microseismic monitoring, tracers, isotopic fingerprinting to look for evidence that a frack job could create pathways for chemicals to infiltrate aquifers or shallow gas pockets.
The results? The horizontal portions of the wells were about 8,100 feet below the surface. The closest new manmade fractures came to drinking water was a distance of “more than 5,000 feet.”
Same day, another paper was published in the Proceedings of the National Academy of Sciences. This one was from scientists at Duke, Stanford and Ohio State University. It examined the concentration of noble (inert) gases in methane to determine the source of methane in shallow aquifers.
The authors write:
All of these data are inconsistent with scenario 6 (direct migration of gases upward through the overlying strata following horizontal drilling or hydraulic fracturing) because in this scenario, gas/liquid partitioning would significantly fractionate the diagnostic gas isotope ratios during migration through the water-saturated crust.
Got that? They don’t see evidence of gas coming up through the rock.
So, fracking doesn’t create pathways for gas (and briny water and chemicals etc. etc.) to migrate upwards. But in order to frack a well, you must drill a well. A nice spherical borehole through the rock. And that hole needs to be controlled, with pipe and cement. That’s where the problems come in — poorly constructed wells with leaky cement.
But at least we’re heading in the right direction and asking the right questions now. That’s progress.