Geochemical evidence for possible natural migration of Marcellus Formation brine to shallow aquifers in Pennsylvania

1121181109.full.pdf (application/pdf Object).

Geochemical evidence for possible natural migration of Marcellus Formation brine to shallow aquifers in Pennsylvania

The debate surrounding the safety of shale gas development in the
Appalachian Basin has generated increased awareness of drinking
water quality in rural communities. Concerns include the potential
for migration of stray gas, metal-rich formation brines, and hydraulic
fracturing and/or flowback fluids to drinking water aquifers.
A critical question common to these environmental risks is the
hydraulic connectivity between the shale gas formations and the
overlying shallow drinking water aquifers. We present geochemical
evidence from northeastern Pennsylvania showing that pathways,
unrelated to recent drilling activities, exist in some locations
between deep underlying formations and shallow drinking water
aquifers. Integration of chemical data (Br, Cl, Na, Ba, Sr, and Li) and
isotopic ratios (87Sr∕86Sr, 2H∕H, 18O∕16O, and 228Ra∕226Ra) from
this and previous studies in 426 shallow groundwater samples and
83 northern Appalachian brine samples suggest that mixing relationships
between shallow ground water and a deep formation
brine causes groundwater salinization in some locations. The
strong geochemical fingerprint in the salinized (Cl > 20 mg∕L)
groundwater sampled from the Alluvium, Catskill, and Lock Haven
aquifers suggests possible migration of Marcellus brine through
naturally occurring pathways. The occurrences of saline water do
not correlate with the location of shale-gas wells and are consistent
with reported data before rapid shale-gas development in the region;
however, the presence of these fluids suggests conductive
pathways and specific geostructural and/or hydrodynamic regimes
in northeastern Pennsylvania that are at increased risk for contamination
of shallow drinking water resources, particularly by fugitive
gases, because of natural hydraulic connections to deeper

COMMENTS

It’s hard to believe that the following two headlines are about the same study:

1) New Duke research shows no fracking contamination in PA

2) Pennsylvania Fracking Can Put Water at Risk, Study Finds

But that is exactly the case about the Duke study that was reported yesterday and circulated on various lists.  I have included links plus the first few lines of each story below.

Winston-Salem Journal (North Carolina) (via AP)
New Duke research shows no fracking contamination in PA

“New research on Marcellus Shale gas drilling in Pennsylvania may only add fuel to the debate over whether the industry poses long-term threats to drinking water.

A paper published on Monday by Duke University researchers found that gas drilling in northeastern Pennsylvania did not contaminate nearby drinking water wells with salty water, which is a byproduct of the drilling.

“These results reinforce our earlier work showing no evidence of brine contamination from shale gas exploration,………”



Bloomberg Businessweek
Pennsylvania Fracking Can Put Water at Risk, Study Finds

“Hydraulic fracturing for natural gas in Pennsylvania may contaminate drinking-water supplies, a study by Duke University professors concluded……..”


Obviously, for many people the headline will be the predominant message.  Here is the message the authors of the study chose for their paper:

Geochemical evidence for possible natural migration of Marcellus Formation brine to shallow aquifers in Pennsylvania

http://www.pnas.org/content/early/2012/07/03/1121181109.full.pdf


Clearly the second (Bloomberg) headline represents the authors’ intended message more accurately.  In fact, the paper covers both topics – the migration of deep brines into shallow aquifers as well as the absence of evidence that these findings show a direct connection to gas drilling.  However, the potential for migration is certainly indicated, which refutes the industry claim that nothing can ever move up through the thousands of feet of “impermeable” rock.  The authors also point out the that the time scale for brine migration is not known but that migration of methane would be much faster, and that more investigation is necessary to understand the process.



For those interested, this was the story on yesterdays All Things Considered.  
NPR News

Rising Shale Water Complicates Fracking Debate

I would say this was a “balanced” story.  I know that there is a lot of outrage (which I share) about “balanced stories” because of bogus counter claims by industry shills raising a “debate”, (best exemplified by climate change deniers).  But in this case the authors themselves point out the limitations of their study and proper reporting should present this.

The coverage of this story (an abbreviated form of the AP story) on local NPR station WSKG was so truncated that it, in my mind, left the listener with little understanding of the study.

Jim Weiss

Yup;

Gives a window into how confused many citizens (and politicians) must be at this point (in time).

Also shows, I believe the ENORMOUS influence of the industry on the media – sorta like: no evidence that smoking causes cancer but probably even higher stakes.

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