Flawed Fracking Wells Taint Pennsylvania's Drinking Water

[Buster's Uncle]

Flawed Fracking Wells Taint Pennsylvania's Drinking Water
LiveScience.com
By Becky Oskin, Senior Writer  20 minutes ago



Marcellus Shale natural gas drilling in Pennsylvania.



Fetid, flammable, polluted drinking water in Pennsylvania homes near natural gas drilling sites was contaminated by methane escaping from flawed fracking wells, a new study shows.

Based on geochemical forensics work, the research makes a direct link between tainted drinking water and leaky gas wells in the Marcellus Shale. The rock layer is thousands of feet below the surface, but the leaks are shallow, where cement and steel are supposed to shield water supplies from natural gas inside wells. Scientists saw the same connection in Texas, above the Barnett Shale, they report today (Sept. 15) in the journal Proceedings of the National Academy of Sciences.

"This does provide pretty strong evidence that it's a well integrity problem and not a fracking problem," said lead study author Tom Darrah, a geochemist at The Ohio State University in Columbus.

The energy industry has contested claims that fracking can contaminate water supplies. Fracking is the process of shattering deeply buried rock to release trapped natural gas. Oil and gas companies have claimed that drinking water pollution may be caused by methane gas slowly bubbling up naturally through cracks in rock layers. Other groups have debated whether the methane came from fracking, horizontal drilling or leaking wells.

In the study, researchers traced methane gas in more than 130 Pennsylvania and Texas water wells to poorly sealed, cracked or failing fracking wells. Several layers of cement and steel typically protect shallow underground water supplies from gas and fluids pulsing through fracking wells. The thickest layers are at the top, to create a buffer between the well and groundwater. The wells narrow with depth, similar in shape to a telescope.

Both the cement and steel casings can fail because of damage during installation, corrosion, design flaws or age — known as "well integrity problems." Methane gas will escape through any openings.

The discovery means there is hope for Pennsylvania's polluted drinking water, Darrah said. Fixing existing wells and keeping a sharp eye on new drilling sites could reduce contamination.

"There's actually a little bit of good news," Darrah told Live Science. "If we improve well integrity, we can eliminate a lot of the environmental problems that have surrounded fracking so far," he said.


Widespread effects

About 6 percent of Pennsylvania's fracking wells have documented well leaks, according to a June 30, 2014, study by engineering professor Anthony Ingraffea of Cornell University in Ithaca, New York. Up to 100,000 new fracking wells could be drilled in Pennsylvania in the next few decades.

But methane isn't the only contaminant in drinking water wells near natural gas fracking sites. Dangerous levels of arsenic and barium have also been found. Salty natural brines from deep rock layers are also migrating upward toward the surface. An Environmental Protection Agency review of nationwide well safety and fracking's effects on water supplies is due this year.

The boom in fracking (or hydraulic fracturing) has boosted U.S. natural-gas production by 30 percent in the past decade. The drilling has also sparked an increase in moderate earthquakes in states such as Oklahoma, Arkansas and New Mexico, as well as fears of widespread environmental contamination. Leaking wells also emit methane into the atmosphere, where the greenhouse gas is about 34 times more efficient at trapping infrared radiation (the greenhouse effect) than carbon dioxide, though methane breaks down much more quickly than CO2.


Measuring methane

Darrah said multiple lines of evidence confirm the methane leaks come from the Marcellus and Barnett shales, or from shallower methane pockets in overlying rocks. Carbon isotopes revealed the methane was created by heat and pressure, not from microbes in groundwater. (Isotopes are versions of the same element with different numbers of neutrons in their nuclei.)

Trace amounts of noble gases helped determine how fast the gas bubbled into drinking water supplies. Naturally rising methane should have about 10,000 times more helium than the gas polluting the drinking water wells, Darrah said. But the helium, neon and argon suggest the methane zipped to the surface via a fracking well, and then leaked out into groundwater.

"Somehow, these gases managed to get to the surface without going through any water or rock, and in some cases, we could actually document well integrity was the problem," Darrah said.


http://news.yahoo.com/flawed-fracking-wells-taint-pennsylvanias-drinking-water-162146112.html

[Buster's Uncle]

Study: Leaky wells, not fracking, taint water
Associated Press
By SETH BORENSTEIN  6 hours ago



This 2012 image provided by Stanford University, shows fracking operations at a wellpad overlying the Marcellus Formation in Pennsylvania. A new study says that the drilling procedure called fracking didn't cause much-publicized cases of tainted water, blaming contamination on leaky natural gas wells instead. (AP Photo/Stanford University, Rob Jackson)



WASHINGTON (AP) — The drilling procedure called fracking didn't cause much-publicized cases of tainted groundwater in areas of Pennsylvania and Texas, a new study finds. Instead, it blames the contamination on problems in pipes and seals in natural gas wells.

After looking at dozens of cases of suspected contamination, the scientists focused on eight hydraulically fractured wells in those states, where they chemically linked the tainted water to the gas wells. They then used chemical analysis to figure out when in the process of gas extraction methane leaked into groundwater.

"We found the evidence suggested that fracking was not to blame, that it was actually a well integrity issue," said Ohio State University geochemist Thomas Darrah, lead author of the study. He said those results are good news because that type of contamination problem is easier to fix and is more preventable.

The work was released Monday by The Proceedings of the National Academy of Sciences.

In fracking, highly pressurized chemicals and water are pumped deep underground to break shale and release natural gas for harvesting.

The fracking process has become highly charged. It started a boom of natural gas drilling and with it, an initial surge of reports of water contamination nearby. People started pointing fingers at the fracking process, thinking that the fracturing allowed methane to travel up, outside the pipes, into water supplies.

In at least two cases around one well in Texas, scientists saw people's homes have their water supplies go from clean to contaminated during the year of study, with methane levels jumping ten-fold, said Stanford University environmental sciences professor Rob Jackson, co-author of the study. Methane while not particularly toxic is explosive and a potent greenhouse gas.

"I don't think homeowners care what step in the process the water contamination comes," Jackson said. "They just care that their lives have changed because drilling has moved next door."

The scientists reached their conclusions by chemically analyzing methane and other chemicals in the groundwater. That let them link the contamination to particular wells, and then to discover what part of the drilling process was responsible. For example, they studied the precise proportions of methane, helium, neon and argon. Those proportions pointed to leaky pipes and seals, because the results would have been different if the contamination had come from fracking.

Since the fracking boom started in Pennsylvania in 2008, the state has identified 243 cases of private water supply contamination "impacted by oil and gas activities." That is out of more than 20,000 wells drilled there.

Jackson and colleagues have been studying water contamination around natural gas wells for years and for this study they didn't chose a random sample, but aimed at areas that seemed to have most complaints of contamination. And even in those areas, it was only in a minority of dozens of sites that they could they connect the contamination to the natural gas wells, he said. In some cases, the contamination was natural and had no connection to gas wells, Jackson said.

Terry Engelder, a professor of geosciences at Pennsylvania State University who wasn't part of the study, praised it, saying "focusing on frack fluids at depth is not the real problem."

The problem of leaky wells is one the gas industry has known about for decades, Darrah said. That includes the pipes the gas flow through and the cement that encases the pipes, keeping it from escaping.

It is possible the high pressure of fracking or the bends in unconventional wells could lead to problems with the well's piping, but there's no evidence yet proving that, Jackson said. Another issue could be the hurry drillers are in during a boom, leading to poor quality wells, he said.

Cindy Dunn, president of the environmental group PennFuture, said it isn't surprising that the methane leaks problem is more due to poor pipes and cement seals, calling for states to update regulations covering that topic.

Dave Spigelmyer, president of the Marcellus Shale Coalition of drillers, said his industry is working with state officials "to modernize and dramatically strengthen shale development-related regulations."

Cornell University engineering professor Anthony Ingraffea, who wasn't part of the study, praised it, adding that he's worried because "it's impossible to drill and cement a well that will never leak."

"There's still serious and significant harm from what's coming before fracking and what's coming after fracking," Ingraffea said.

___

Online:

Journal: http://www.pnas.org


http://news.yahoo.com/study-leaky-wells-not-fracking-taint-water-144023834.html

[Buster's Uncle]

Leaky equipment, not fracking, behind tainted U.S. water : study
Reuters
4 hours ago



BOSTON (Reuters) - The contamination of water supplies near U.S. shale gas fields appears to be the result of leaky cement wells and casings and not the controversial production technique of hydraulic fracturing, according to a study released on Monday.

So-called "fracking" is a way of extracting natural gas from deep layers of rock using high-pressure fluid injections. The method has triggered a surge in U.S. gas production, but raised fears that breaking up rock formations underground could allow gas to seep into drinking water.

Scientists from several universities, including Duke, Ohio State, Stanford and Dartmouth, analyzed more than 130 drinking-water well samples overlying the Marcellus and Barnett shale gas formations and attempted to trace the source of any contamination, according to the study.

The researchers found eight clusters of drinking-water wells that were tainted by hydrocarbons and linked them, using "gas geochemistry data," to leaky cement from three production casings and one underground well used by energy companies to extract the gas.

The study said the research data "appear to rule out gas contamination by upward migration from depth through overlying geological strata triggered by horizontal drilling or hydraulic fracturing.

"Determining the mechanisms of contamination will improve the safety and economics of shale-gas extraction," according to the study, published on Monday in the Proceedings of the National Academy of Sciences.

The U.S. Environmental Protection Agency is in the midst of a years-long study into the impacts of fracking on drinking water, and is scheduled to release a draft this year, after reports of drinking water so badly contaminated that homeowners could light it on fire.

The Marcellus formation lies beneath a swath of New York, Pennsylvania and West Virginia. The Barnett formation is beneath a portion of northern Texas.

(Reporting by Richard Valdmanis. Editing by Andre Grenon)


http://news.yahoo.com/leaky-equipment-not-fracking-behind-tainted-u-water-204145946.html