Hydraulic Fracturing for Natural Gas Pollutes Water Wells: Scientific American

Drilling for natural gas is booming in Pennsylvania—thanks to fracturing shale rock with a water and chemical cocktail paired with the ability to drill in any direction. Despite homeowner complaints, however, research on how such hydraulic fracturing, or fracking, is impacting local water wells has not kept pace. Now a new study that sampled water from 60 such wells has found evidence for natural gas–contamination in those within a kilometer of a new natural gas well.

“Methane concentrations in drinking water were much higher if the homeowner was near an active gas well,” explains environmental scientist Robert Jackson of Duke University, who led the study published online May 9 in Proceedings of the National Academy of Sciences. “We wanted to try and separate fact from emotion.”

The researchers discovered methane in 51 of the 60 wells tested—that is not out of the ordinary. A small amount of methane from both deep and biological sources is present in most of the aquifers in this region of Pennsylvania and New York State. By measuring the ratio of radioactive carbon present in the methane contamination, however, the researchers determined that in drinking water wells near active natural gas wells, the methane was old and therefore fossil natural gas from the Marcellus Shale, rather than more freshly produced methane. This marks the first time that drinking water contamination has been definitively linked to fracking.

In fact, concentrations were 17 times higher in those drinking water wells within one kilometer of an active natural gas well than those farther away. Also, average methane concentrations of 19 milligrams of methane per liter in those wells were well above the 10-milligram- per-liter recommendation (pdf) set by the U.S. Department of the Interior for action to reduce concentrations. Above 28-milligram-per-liter concentrations, such wells must be properly ventilated to reduce the risk of explosion. One well tested had methane concentrations of 64 milligrams per liter.

“I saw a homeowner light his water on fire,” Jackson notes. “The biggest risk is flammability and explosion.”

Few studies have been done to date on the health risks of chronic exposure to methane and other gaseous hydrocarbons. (The researchers also found ethane, propane and butane in some of the drinking water wells.)

At the same time, the researchers found no evidence that either the chemicals in fracking fluids or the natural contamination in deep waters were polluting relatively shallow water wells in the vicinity of the deep natural gas wells. That suggests that leaking wells are likely the source of such methane contamination, rather than any migration upward from the deep. “It’s easier to envision a gas well casing that’s leaking, especially with the high pressures, than it is to envision the mass movement of gas or liquids 5,000 feet upwards,” Jackson notes. “I don’t know that it’s impossible but I think it’s unlikely.”

Because of such concerns the U.S. Department of Energy has convened a special task force to improve the safety and environmental impacts of such fracking for natural gas, including how best to dispose of the voluminous wastewater as well as ensuring proper sealing of wells to prevent such groundwater contamination.

“America’s vast natural gas resources can generate many new jobs and provide significant environmental benefits,” noted Secretary of Energy Steven Chu in a prepared statement announcing the panel, “but we need to ensure that we harness these resources safely.” In fact, the panel is charged with providing “recommendations as to actions that can be taken to improve the safety and environmental performance of shale gas extraction processes and other steps to ensure protection of public health and safety,” according to Chu’s memo (pdf) laying out its mission, which must deliver “immediate steps to be taken to improve the safety and environmental performance of fracking” within 90 days of its first meeting.

Fracking is specifically exempted from much federal regulation, such as the Safe Drinking Water Act of 1974. Local regulatory requirements may not help: for instance, although the researchers discovered methane contamination at homes within 1,000 meters of active natural gas wells, the Pennsylvania Department of Environmental Protection only holds drilling companies responsible for drinking water within 305 meters. “That’s a ninefold increase in area,” Jackson notes. “Who pays for [testing]? Should gas companies be required to do it?”

And it remains to be seen whether natural gas delivers environmental benefits—such as reduced emissions of carbon dioxide when burned—given that it in itself is a potent greenhouse gas if it escapes during drilling or pipeline operations, so-called fugitive emissions. “We are interested in getting pre- and post-drilling samples,” Jackson says of his future research, although he has been threatened with subpoena. “We’d like to get data for fugitive methane emissions as well. This summer we’re going to try and detect methane in the air.”

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1. 1. Vendicar Decarian 04:54 PM 5/9/11

   This can’t be true. If it were true then the industry wouldn’t be claiming otherwise would they?

   It’s just logical that drilling into and fracturing rock containing pockets of pressurized gas could never, ever cause that gas to escape anywhere but through the one foot in diameter pipe that was stuck into the ground to catch it.

   There can’t be any cracks caused to be anywhere else in the shale. That is just way too inconvenient a truth to be true.

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2. 2. Unksoldr 05:14 PM 5/9/11

   Injecting chemicals into the ground can’t possibly affect the groundwater. Just like injecting tons of carbon dioxide into the atmosphere can’t have any effect on our environment. A true human can’t be ‘homeless’ on this planet, it would be like saying a wolf is homeless because it doesn’t have a doghouse.

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3. 3. joshnhale 06:15 PM 5/9/11

   Commenter, please understand the physics of forcing hydraulic fluid into the ground. When the bedrock breaks releasing the gas, thousands, if not millions of tiny fractures are created in the surrounding bedrock from the process. Then once the gas has begun to release, it goes out of the deposit in three dimensions away from any place that the rock is fractured.

   The natural gas industry has been fighting against these kinds of results since the beginning of the use of the fracking method. Also, of the hundreds of chemicals and compounds used in the hydraulic fluid, many of them are proprietary, thus nobody knows what the compounds name or chemical make up is… The toxicity of natural gas is one of the most underreported issues in our society today.

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4. 4. outsidethebox 06:51 PM 5/9/11

   What is the purpose of adding the chemicals to the high pressure water in this process?

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5. 5. Trent1492 07:17 PM 5/9/11

   “What is the purpose of adding the chemicals to the high pressure water in this process?”

   It enhances the profit margin of the operation. And we all know that anything that makes a profit is always good and anything that prevents one extra dime going into a corporation is a crime against humanity.

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6. 6. brian01 07:31 PM 5/9/11

   If you haven’t seen this, you should…

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7. 7. JamesDavis in reply to brian01 07:56 AM 5/10/11

   Now, brian01, you know none of that is true. You just made all that up to make the fracking gas companies look bad. You are not a true American by posting lies like that. The gas companies have no reason to lie about the safety of fracking.

   You also know that what I’m about to say is just a big lie too, to make the gas companies look bad, “The waste water that bursts, sometimes, hundreds of feet into the air and spreads over the ground for hundreds of acres, from gas fracking is radioactive to the point that it comes very close to a small nuclear melt down or staying out in the Sun of a desert for two days unprotected, and it takes it hundreds of miles before it disappears into the air. Land animals and marine animals have been killed as far away as 3 to 4 hundred miles from the waste water runoff.” You can also find that video on Sundance, but it is all a big lie created by these tree huggers like Robert Jackson to make the gas companies look bad.

   The gas companies are now taking land from people in West Virginia under the ‘Immanent Domain Law’ granted to utilities companies and the highway department by the West Virginia government so they can start fracking, on what use to be their land, for natural gas. The people are forced to move from their land until the gas company is finished fracking, which sometimes will take years. But, that is also a big lie to make the gas companies and greedy governments look bad.

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8. 8. drafter 11:24 AM 5/10/11

   There is a simple solution to this. 1. Require the oil companies install either a burner to everyones water well, and so that that energy isn’t wasted the burner should be used to heat the house or some other purpose. 2. Or require the oil companies to eliminate the other chemicals used or install separators at the wells so that they may recoup those same chemicals. Problem solved and everybody’s happy the oil companies still get the oil and the land owners get realatively clean water again and this would be cheaper then a huge class action suit where nobody wins. Note I said realatively clean water because even with out the oil companies drilling for water in oil/gas filled soils will give you contaminated water.

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9. 9. Shoshin 12:12 PM 5/10/11

   Maybe you guys should all take a breath and ask someone who has first hand experience with fracking… Like me.

   Firstly, it is impossible for fracs done at depths of a mile to propagate to surface and contaminate ground water. Rock mechanics won’t allow it. Think about it; a frac at a mile needs 20-40,000 horsepower to propagate a fracture maybe 30 -60 feet from the wellbore. To get within a few hundred feet of the surface, millions of HP are required, well out of the range of Halliburton, but theoretically possible with a Romulan quantum singularity warp core as your power source.

   As to gas in the water, it is possible or even likely that gas is migrating around the casing cement. Many gas bearing formations are encountered during the course of drilling a well. Some are shallow, some are deeper. Some have a lot of gas, some very little. Cementing into shales is very difficult as they tend to cave and slough in. Achieving a good bond between the cement and the rock is difficult.

   I wonder if the methane content increases or decreases in these wells over time. Maybe some work should be done on that?

   On our farm, we draw water from a coal seam. Have done so for over a century. Nice clean fresh water from a huge activated charcoal filter. Is there methane in there? Yes. In a hundred years has it hurt anyone? No. Methane solubility in water is extremely low.

   And people are exposed to far more methane during their own daily toilette activities and inhaling their own (or somebody else’s) noxious emissions than in their drinking water.

   Again, more fear-mongering by the eco-nuts. Since AGW is dead and buried, they need a new cause to rally the troops around an keep $$$$ coming in. I wouldn’t mind it so much if they just knew what they were talking about for a change.

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10. 10. SirFrancisBacon 03:08 PM 5/10/11

    If the process is completely safe, then energy companies should be facilitating research. They also should have no problem with the reversal of the exemption to the Safe Drinking Water Act.

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