Sept. 15 (Bloomberg) — Homes in a Texas community face
worsening water contamination caused by nearby gas production,
according to a study released today.
The findings from an analysis by independent academics
counter statements by driller Range Resources Corp. and state
regulators, who have said their evidence shows gas drilling
wasn’t responsible for the presence of explosive methane in the
homeowners’ water wells. Separate testing that found evidence of
contamination from drilling at seven areas in Pennsylvania also
was included in the study.
“People’s water has been harmed by drilling,” Rob
Jackson, professor of environmental and earth sciences at
Stanford University and Duke University, said in a statement.
“In Texas, we even saw two homes go from clean to contaminated
after our sampling began.”
The case in Weatherford, Texas, has drawn international
media scrutiny, intervention by the U.S. Environmental
Protection Agency that was later shelved and lawmakers’ scrutiny
of the EPA’s actions. Residents have appealed to the EPA to
reopen its investigation.
Today’s study, published in the peer-reviewed Proceedings
of the National Academy of Sciences, linked contamination to
failures of cement or production casing, not the injection of
water, chemicals and sand into the ground. It challenges
supporters of oil and gas, who say there is no evidence that
recent boom in drilling or production has contaminated water.
Safe Levels
The spread of horizontal drilling and hydraulic fracturing
has led to a boom in U.S. production, much of it in the
Marcellus Shale in Pennsylvania and the Barnett Shale in Texas.
The boom in production has spurred complaints from homeowners
who say fracking has made their well water unhealthy.
The results from the Duke-led study showed the water from
five of the 20 wells tested exceeds minimum safety level,
including the two wells that were clean and then acquired
dangerous levels of methane in later tests. Researchers said the
gas wasn’t from the production zone of the Barnett shale, but
from the shallower Strawn formation. That gas was likely
conducted through the drilling rings to the groundwater, the
paper said.
Range Resources say it’s not responsible for the gas in the
wells, and said the cause could have been older oil or gas
wells, or water wells that penetrated into the Strawn.
No Link
“Exhaustive studies have clearly demonstrated that no
aspects of Range’s activities caused or contributed to the long-standing and well documented fact that gas is naturally
occurring” in the aquifer, spokesman Matt Pitzarella said in an
e-mail.
The Texas Railroad Commission, which regulates oil and gas
drilling, reached a similar determination, issuing a report in
May saying that there are increasing levels of methane in wells,
but its origin is “inconclusive.” The commission said it
halted its investigation and recommended residents “properly
ventilate and aerate their water systems.”
The Weatherford case is one of only three in which the EPA
has preliminarily linked water woes to hydraulic fracturing, and
then subsequently dropped its investigation in the face of
congressional and industry criticism.
‘Substantial Endangerment’
In 2010 the EPA did its own testing in Weatherford and
found dangerous levels of methane it termed “an imminent and
substantial endangerment” to homeowners. It issued a notice of
violation and sued Range soon after. Two years later, the agency
settled with an agreement that called for Range to conduct four
sets of tests of 20 wells in the area. The results showed
minimal levels of methane, except in one well that had been
disconnected by the homeowner.
Residents reported increasing signs of methane, blaming it
for some health woes and the risk of explosion.
Jackson and the four other researchers analyzed the
quantity and isotopes of noble gases such as helium and neon in
the groundwater near shale-gas wells in order to try to
determine if the fugitive gases are naturally occurring or
caused by gas production. They said it’s the first time this
analysis of noble gases has been done.
The research linked contamination to failures of cement or
production casing. Even though the methane in the water wells
came from shallower depths, its movement into the groundwater
was caused by inadequate cementing of the gas wells, Jackson
said.
“It’s not naturally occurring because of the other things
we found” along with the methane, he said, referring to the
noble gases. “So much methane is pushing through that this
other stuff gets pushed out.”
To contact the reporter on this story:
Mark Drajem in Washington at
mdrajem@bloomberg.net
To contact the editors responsible for this story:
Jon Morgan at
jmorgan97@bloomberg.net
Steve Geimann