More questions cast doubt on the Duke study which claims to prove there is a link between gas drilling and high concentrations of methane in nearby well water, including from someone quoted in the Duke study itself:
The [Pennsylvania] commonwealth’s longtime stray gas inspector said he is "a little bit disappointed" with the study. Fred Baldassare, who now owns Echelon Applied Geoscience Consulting, said the authors fail to address the prevalence of naturally occurring thermogenic methane – gas that comes from deep underground, not from the breakdown of biological matter near the surface – in shallower geological layers between the surface and the Marcellus Shale.
"I’m not saying that gas well activity doesn’t cause gas migration, because of course it has," said Baldassare, whose research is cited three times in the Duke paper. "We have documented cases of gas migration to private water supplies as a result of drilling activity." But he added, "I think we have to take great care in trying to define what’s there naturally before we make judgments and conclusions about the origin of the gasses."
In documented cases of stray gas caused by drilling in Susquehanna and Bradford counties, state regulators have found the gas migrating not from the Marcellus Shale but from shallower gas-bearing formations.
Baldassare said he is concerned the study might imply a migration straight from the Marcellus to aquifers, which he said he would "absolutely dispute."(1)
Former secretary of the Pennsylvania Department of Environmental Protection (DEP) John Hanger had this to say on his blog:
DEP furthermore found that the gas that was migrating in the Dimock area was Devonian gas located at about 1,000 to 3,000 feet. Devonian gas is above Marcellus gas. DEP concluded that the Devonian gas had not been isolated as a result of poor drilling practices.
Bradford and Susquehanna counties have had many more gas migration problems than counties in Southwest Pennsylvania. Had Duke University done this study in Washington, Greene, and counties in the Southwest it would have reached different conclusions. The reasons for the geographic difference in the incidence or rate of gas migration include geological differences in the counties, quality of gas drilling in the respective areas, or some of both.
Gas migration has been a problem in Pennsylvania for decades, well before the first Marcellus well was drilled in 2005.(2)
And this from industry group Energy in Depth (EID):
Problem #1: The data itself: Small data set, no random sampling, and no baseline information whatsoever.
Problem #2: Authors intentionally down-play the fact that thermogenic methane was found in nearly every well they sampled – even in wells in areas with no natural gas development to be found.
Problem #3: Authors concede that hydraulic fracturing likely had zero impact on water wells – but you’d never know by the paper’s title, or by the op-ed they ran in Tuesday’s Philadelphia Inquirer.
Problem #4: Authors blame methane migration on failures in well-casing (without any supporting evidence) – but don’t include anything about well-casing in their recommendations section.
Problem #5: Once again, politics plays a central role in guiding the direction and recommendations of the paper.(3)
See full explanations for each of EID’s “problems” by clicking the “Durham Bull” link below.
(1) The Daily Review (May 11, 2011) – DEP to review study linking shale drilling to methane contamination
(2) Facts of the Day (May 9, 2011) – Comments on Duke University Study Regarding Methane Contamination of Water Wells
(3) Energy in Depth (May 10, 2011) – Durham Bull