A new peer-reviewed study by researchers at Duke University contains both good and bad news for the Marcellus Shale gas drilling industry and homeowners who live in those regions and get their water from wells.
The good news is that there is still no evidence of the fluids used in hydraulic fracturing reaching groundwater.
This was the second comprehensive study by the Duke researchers of the water wells in northeastern Pennsylvania. Specifically, they looked for brine contamination from shale gas exploration, and found none.
“This paper confirms what we found in the first study, which was we don’t see any evidence of changes in salts or the fracking chemicals,” study co-author Robert Jackson said on Metronews Talkline.
The Marcellus Shale is located about a mile underground, well below the groundwater aquifers and the bore holes are cased with steel and concrete. Industry officials say that makes it virtually impossible for drilling fluids to get into nearby water wells.
And they are correct, so far. However, there is another key part of the study which could be the bad news.
Researchers raised concerns that there are, at least in northeastern Pennsylvania, “pathways,” unrelated to drilling, that exist between the Marcellus Shale and shallow groundwater aquifers. These pathways mean it’s possible that Marcellus brine could migrate to the groundwater.
That means, according to Jackson, “The concern is, for a minority of homeowners, we think there are some people who are more vulnerable, conceivably or potentially, to communication to what goes on underground.”
However, even that possibility must be tempered by the fact that researchers say they don’t know how long it might take for contaminated water to travel from the Marcellus Shale to the aquifers.
“Is it years or thousands of years?” asked Jackson. “That’s really the biggest uncertainty in my view.”
The Duke study is helpful, but it will likely add to the controversy surrounding Marcellus Shale drilling.
The industry can use the report to say, accurately, that there is no evidence that hydraulic fracturing is contaminating well water. That’s an important finding given the amount of drilling that’s going on and some of the hysteria associated with the potential risk.
But drilling opponents can counter by saying that contamination could still happen.
More study is needed to make sure the drilling is done responsibly. In the meantime, Jackson has some good advice:
“Get a pre-drilling (water well) test,” said Jackson. “It helps everybody. It keeps companies from paying for bad water that they didn’t cause and protects homeowners if their water (quality) declines.”