MDN In-depth: Duke University Study Links Marcellus Shale Gas Drilling with Methane Contamination of Water Wells
A peer-reviewed study by Duke University researchers claims to show a link between natural gas drilling in the Marcellus Shale that uses horizontal drilling with hydraulic fracturing and an increased level of methane (natural gas) in water wells that are within 1,000 feet of the drilling. The report, titled “Methane contamination of drinking water accompanying gas-well drilling and hydraulic fracturing,” was published Monday online in the Proceedings of the National Academy of Sciences. A full copy of the five page report is embedded below so you can read it for yourself.
Duke researchers tested 68 water wells in Pennsylvania and New York, finding elevated levels of methane in 85% of the wells.
When they fingerprinted the methane – comparing the chemistry of the methane in the wells with that from natural gas wells in the region – “the signatures matched,” said Robert Jackson, a professor at Duke and a study author.
“At least some homeowners who claim that their wells were contaminated by shale gas extraction appear to be right,” he said.
The authors said it was the first “systematic evidence” of methane contamination of private drinking wells in areas where gas extraction is occurring.
The testing occurred in July and September, mostly in the northeastern Pennsylvania counties of Susquehanna and Bradford, but also in Wayne and Lackawanna, plus Otsego County in New York.*
What they did and did not find in their testing:
They did not find evidence of well-water contamination from fracking fluids or from the flow-back water, which contains high levels of salts and other contaminants, including radioactivity, that are naturally occurring in the Marcellus Shale formation.
But in at least nine wells [13 percent of the wells tested], they found methane at levels exceeding what the U.S. Department of the Interior calls an “action level,” indicating that the wellhead should be vented immediately.*
Researchers did not show how methane was getting into the water wells, but offered three possibilities:
- It’s happening naturally.
- It’s happening through new cracks caused by hydraulic fracturing.
- It’s happening via leaky gas well casings—problems with the protection drillers put in place to protect the bore hole from the surrounding water aquifer.
The researchers believe option #3 is the most likely cause—that’s their “best guess.”
Potential problems with this new study
Already news of the study has been picked up and trumpeted by more than 400 media outlets nationwide. It’s early days yet, but there’s been no real coverage of any challenges to the study. MDN offers the following observations:
(1) The study supposedly shows a link between shale gas drilling, ie horizontal drilling that uses hydraulic fracturing, and high levels of methane in water supplies located within 1,000 feet of said drilling. But a number of the water wells Duke tested are in Otsego County, NY, some 100 miles from the nearest horizontal/hydraulically fractured well—nowhere near 1,000 feet of any fracked gas drilling. In MDN’s review of the report, it’s not apparent why water wells located in a place where there are no fracked gas wells would be used. Perhaps the Otsego water wells are used as a “control” of some sort? If Duke found high levels of methane in any of the Otsego wells, it would strongly argue that the methane is naturally occurring and has nothing to do with gas drilling. MDN would like to know more about the Otsego wells tested.
(2) By the Duke researchers’ own admission (read the report), methane in water is not a health hazard. If there’s methane in the water, you don’t die or even get sick from drinking it. However, Duke says “it is an asphyxiant in enclosed spaces and an explosion and fire hazard.” So the whole point of the study is not that you’ll get sick from it, but you may have an explosion from it (if high levels of methane are indeed happening).
(3) The data sample of 68 drinking water samples is a very small sample, from just a few locations. To make broad, sweeping general conclusions from such a small data set is not good science. A larger study with more locations would be needed to prove conclusively gas drilling is causing an increase in methane levels in water supplies.
(4) Perhaps the biggest problem with this study: There were no baseline numbers to begin with. That is, methane is known to have been in water supplies for generations—it’s not uncommon. There are areas of the country where methane naturally rises to the surface—how do you think it was discovered in the first place? Do the locations where the Duke sampling was done have high levels of naturally occurring methane? We don’t know because the researchers have not established it. It could very well be the answer is “no,” but the problem is, you just don’t know. Sloppy science, sloppy results.
Is this agenda-driven science?
Tipoffs that this may be agenda-driven science, and not truth-seeking science, include two policy recommendations made in the study:
1. Consider regulating hydraulic fracturing under the Safe Drinking Water Act. That is, put the federal Environmental Protection Agency (EPA) in charge of something it has no business being in charge of: gas drilling/mining. This has been the drumbeat from those who oppose drilling—they hope to shut it down by using the “back door” of the EPA to do it.
2. Fully disclose chemicals used in hydraulic fracturing. Nothing wrong with that (in MDN’s opinion). But the study itself said it detected no chemical contamination from gas drilling in any of the water wells it tested—only high levels of methane. So if there’s no chemical contamination and the industry is doing fine with keeping chemicals out of water supplies, why regulate it? Why offer a policy recommendation about something that was proven to be absent by your own research? Makes no sense.
What do you think about the new study? Leave us a comment.
*Philadelphia Inquirer (May 10, 2011) – Duke study finds methane in well water near gas drilling sites
Jim, Do some digging around and you will find out that the problem of stray methane is endemic to gas drilling – the conclusion is that the process is deeply flawed.
“But a number of the water wells Duke tested are in Otsego
County, NY, some 100 miles from the nearest horizontal/hydraulically fractured
well—nowhere near 1,000 feet of any fracked gas drilling.”
How do you know it was “some 100 miles” from any fracked
wells? As a matter of FACT, the main author of the Duke study, Dr. Stephen G.
Osborn, was in Otsego County last summer and took samples from drinking wells
next to Gastem’s vertical exploratory Ross well, which had been initially
fracked a few months earlier.
How do I know this? Because Gastem’s CEO Orville Cole told me about
the Duke study and Dr. Osborn, in an email dated September
8. Don’t take my word for it. Ask Orville.And BTW, if you don’t publish this comment, I will publish a screenshot on our website and bring it to the attention of the media. If your website is going to fairly represent the issues, then it’s time to put up or shut up.
This is a game changer. A peer-reviewed publication by the National Academy of Sciences is the gold standard. What’s encouraging is that objective science is being focused on the issue. This study should be followed up with a larger study so that the problem can be better quantified.
I’m mystified by the correlation of gas concentration to distance from a drilling site since horizontal drilling and fracturing reaches long distances from a well head. This leads me, a layman, to think that the cement job around the well casing might be the culprit in most cases. Think of the bore hole as a straw. Now set a thinner straw inside the first one, and fill the gap between them with cement. The space between straws is narrow, and if the cement job is not perfect, gas under pressure will push its way up through any faults in the cement and ultimately find its way into the water table. Not only that, but the cement must adhere perfectly to the outer rock surface of the bore hole, or the gas will simply find pathways around the cement. Cement job technology might work OK to contain viscous oil, but gas is many orders of magnitude lighter. Again, just some thoughts of a layman.
Does this mean that drilling must end? No, it means that the industry must develop solutions to the problem and move on.
No need to always be so touchy Bob. It is a FACT that no horizontal hydraulically fractured wells have or are being drilled in New York (ever hear of the moratorium?). Yes, there are some wells drilled that are vertical and fracked–but the entire premise and basis of this study is that horizontally drilled/fractured wells are the culprit. Perhaps you should read the study Bob.
“I’m mystified by the correlation of gas concentration to distance from a drilling site since horizontal drilling and fracturing reaches long distances from a well head. This leads me, a layman, to think that the cement job around the well casing might be the culprit in most cases.”
This is exactly the issue for me – the stray gas seems completely unrelated to the hydraulic fracturing process, seemingly due to issues at the well head. This has significant implications for severity of the problem and possible remediation. No one wants stray methane in their water wells, however there are more solutions available to tackle this issue than, for example, heavy metals or nasty chemicals contaminating an aquifer.
Stray gas is an issue that the gas industry must address. Hydraulic fracturing, frac fluid contamination, frac zombies and all the hysteria related garners far too much attention when the biggest issue affecting water quality is methane from the well bore.
I think YOU should read the study, Jim, and so should MDN:
1- “Perhaps the Otsego water wells are used as a “control” of some sort?”
DUH….yeah!
2- “methane in water is
not a health hazard”
what we need to ask, is what else did they test for? Barium and strontium is showing up in tests by other labs, and residents have been found to have levels of each in their blood and bones many times the federal standard.
3- “The data sample of 68 drinking water samples is a very small sample”
Yes, and they are planning on getting more funding and extending their study, last I heard.
4- “methane is known to have been in water supplies for generations”
I know MDN read the study, so why read it selectively? It specifically states that the closer the water well is to the gas well, the higher the levels of thermogenic gas (gas from deeper, target formations), and at levels far, far above that of the biogenic gas, which is sometimes found in water wells at trace levels. The industry is deliberately telling a giant, flat-out LIE by conflating the incidence of trace levels of biogenic gas found in water in this region the far higher, dangerously high levels of thermogenic gas that are being found in water wells near their gas well drilling activities.
Reading Jim’s comments, I’m convinced that he is writing a book called “My Search for Secret Agendas”. First, he breathlessly reported that the NY Times had an anti-drilling bias. Then, he uncovered that the Associated Press had a liberal agenda. Now, apparently he has discovered a secret cabal within Duke University that is twisting science to its own dark purposes. Since the National Academy of Science peer-reviewed the study and approved it, it too must be part of the conspiracy.
Jim, you present a strong case that the Pod People are infiltrating our planet. Perhaps they live in secret cities under the Marcellus, and are determined to stop the drilling. But I’m not worried because I know that Donald Trump will get to the bottom of this conspiracy.
Thanks for the laugh Paul!
The Duke study states as plainly and clearly as
possible:”In aquifers overlying the Marcellus and Utica shale formations
of northeastern Pennsylvania and upstate New York, we document systematic
evidence for methane contamination of drinking water associated with shalegas
extraction.””and upstate New York.” As the map on the first page clearly
shows, the NY wells tested and shown to be contaminated with methane are all in
Otsego County. And at least some of these were near drilling sites where
“shalegas extraction” was “actively” taking place. The only active drilling
sites in Otsego County are Gastem’s vertical exploratory wells. Your
assertion that the water wells tested in NY were “some 100 miles” away from any
“horizontal/hydraulically fractured well” is an obvious attempt by you to
mislead readers, distort the findings of the study, and make assertions totally
unsupported by any evidence.
FACT: at least some of these high levels were found
near Gastem’s Ross well, which had been fracked about 6 months prior to
the water tests.
FICTION: “If Duke found high levels of methane in any of
the Otsego wells, it would strongly argue that the methane is naturally
occurring and has nothing to do with gas drilling.”
It strongly argues nothing of the kind. It’s pure invention on
your part, just another example of your constant and ongoing
embroidery of inconvenient fact with little lies and twists and “buts,” in order
to muddy the waters and introduce doubt where none actually exists.
If you were at all honest about any of this, you would retract
what you’ve said about the Otsego well tests and set the record straight. But
I’m not holding my breath.
Hmmm.. The study reveals that there is an increase of methane in wells within 1000′ of drilling. So the haudraulic fracturing is in a well bore at approximately 5000′ depth. 5000′ – 1000′ = 4000′ So is the methane coming from the gas well? Oh, and I wonder if they tested the water wells for methane content before the gas well was drilled for comparison.
Folks
Gas has been an issue in otsego county for a long time. i personally know of a water well on otsego lake, town of springfield that you can “light” with a match.