Methane in Water Seen Sixfold Higher Near Fracking Sites

[Purveyor]

By Mark Drajem - Jun 24, 2013

Water wells close to gas-drilling sites in Pennsylvania had methane levels more than six times higher than more distant wells, evidence that the boost in production is causing leaks, Duke University researchers found.

The chemical fingerprint of the methane, the key component of natural gas, along with the presence of ethane and propane, indicate that much of the gas is from deep underground, such as the Marcellus Shale, according to a study released today. Production in the Marcellus is booming through hydraulic fracturing, or fracking, to break up rock and free trapped gas.

“Distance to gas wells was, by far, the most significant factor influencing gases in the drinking water we sampled,” said Rob Jackson, an environmental sciences professor at Duke in Durham, North Carolina, and the study’s lead author. The evidence “all suggest that drilling has affected some homeowners’ water.”

The peer-reviewed study, released in the Proceedings of the National Academy of Sciences, is a follow-up and extension of a 2011 study by Jackson and his co-authors, which drew criticism from the drilling industry. That study tested drinking water supplies in northeastern Pennsylvania including the town of Dimock, where the state said gas wells failed and leaked. It found no evidence of the chemicals used in fracking in water wells; it did link drilling to elevated methane leaks.

MORE...

http://www.bloomberg.com/news/2013-06-24/methane-in-water-seen-sixfold-higher-near-fracking-sites.html

[yardwork]

1. Nobody ever would have expected that!

[AndyA]

2. Nothing to worry about, folks--methane won't harm you...

The oil companies are responsible, they care about you and the environment...

[Buzz Clik]

3. Great post.

When I get the time, I will check to see a) what background methane is typically found in water; b) what the concentrations were found in the Duke study, and c) what the regulated levels are. All very relevant to the conclusions.

[SidDithers]

5. Yeah. That's kind of important information that's missing, isn't it...nt

Sid

[Recursion]

6. And whether pre-existing methane in water is one way they determine where to frack or not (nt)

[Buzz Clik]

8. Fascinating question.

[Champion Jack]

4. The gas companies used to claim that there is no evidence that any wells have been compromised

...because they paid the people who were harmed to keep quiet.

[xchrom]

7. Du rec. Nt

[hootinholler]

9. Kicking this for more recs! n/t

[Uncle Joe]

10. Kicked and recommended.

Thanks for the thread, Purveyor.

[limpyhobbler]

11. Somebody will be around soon to tell us why this doesn't prove anything. nt

[Buzz Clik]

12. Here's the abstract from the paper:

Abstract

Directional drilling and hydraulic-fracturing technologies are dramatically increasing natural-gas extraction. 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 shale-gas extraction. In active gas-extraction areas (one or more gas wells within 1 km), average and maximum methane concentrations in drinking-water wells increased with proximity to the nearest gas well and were 19.2 and 64 mg CH4 L^-1 (n = 26), a potential explosion hazard; in contrast, dissolved methane samples in neighboring nonextraction sites (no gas wells within 1 km) within similar geologic formations and hydrogeologic regimes averaged only 1.1 mg L^-1 (P < 0.05; n = 34). Average ?¹³C-CH₄ values of dissolved methane in shallow groundwater were significantly less negative for active than for nonactive sites (-37 ± 7‰ and -54 ± 11‰, respectively; P < 0.0001). These ?¹³C-CH₄ data, coupled with the ratios of methane-to-higher-chain hydrocarbons, and ?²H-CH₄ values, are consistent with deeper thermogenic methane sources such as the Marcellus and Utica shales at the active sites and matched gas geochemistry from gas wells nearby. In contrast, lower-concentration samples from shallow groundwater at nonactive sites had isotopic signatures reflecting a more biogenic or mixed biogenic/thermogenic methane source. We found no evidence for contamination of drinking-water samples with deep saline brines or fracturing fluids. We conclude that greater stewardship, data, and—possibly—regulation are needed to ensure the sustainable future of shale-gas extraction and to improve public confidence in its use.

This is pretty significant. They are observing methane concentrations more than 20 times background and, because the concentrations exceed water solubility, explosion hazard become real. The isotopic signatures are consistent with the shale formations, not the original water.

There are multiple possibilities of how the methane is getting into the groundwater: 1) leaking casings at the level of the ground water that allows the methane to escape; 2) leaking casing below the ground water; 3) fracturing of the strata beyond just the shale. Possibilities 1 and 2 can be corrected by more rigorous standards for casing construction and monitoring. Case 3 is truly bad news and could be a big set back for the industry.