Three Pennsylvania wells likely contaminated by fracking, Not just methane, but traces of fracking fluid made wells froth by Scott K. Johnson, May 6, 2015, arstechnica
The illusion of simplicity
Still, we occasionally get a relatively simple case, even if its broader implications are minimal. In the summer of 2010, three nearby homes in northeast Pennsylvania started having disturbing problems with their water wells. Methane was seeping up—in one case accumulating to levels that necessitated evacuating a home due to the explosion risk—and the wells were muddy and foaming. (A nearby river even began bubbling a few months later.)
Methane sometimes makes its way into wells without help from humans and can go unnoticed until proper sampling takes place, but the concentrations here were pretty high. Foaming isn’t a great sign, either. One of the water wells had even been tested before the gas drilling began, and there were no signs of methane.
Over several months leading up to this, ten gas wells had been drilled and fracked within a couple kilometers of these homes. The Pennsylvania Department of Environmental Protection tested the affected wells, inspected the gas wells, and determined that the gas company (Chesapeake Appalachia LLC) was culpable. After replacement water wells had the same problems, the company eventually bought out the homes as part of a settlement with the owners.
Even so, the water well tests didn’t yield unambiguous evidence of how they were contaminated. Nothing much was detected beyond the methane (which is an explosion risk but not otherwise a health hazard [but can quickly kill by asphyxiation]), leaving the foam a mystery.
A group of Penn State researchers led by environmental consultant Garth Llewellyn (who worked for the affected homeowners during their lawsuit) decided to turn some bigger analytical guns on the question. They subjected water samples collected during the investigation to a type of testing capable of revealing many more compounds, even at concentrations lower than one part per trillion. For comparison, they also got 30 samples of water used to frack gas wells in the area—though they didn’t have any samples from the suspect gas wells near the affected homes.
The testing allowed the researchers to fingerprint the water samples based on the many faintly present organic compounds they contained. All of the fracking water samples had a similar fingerprint (which is good). The impacted water wells shared that same fingerprint, while local, uncontaminated water wells did not.
The researchers also looked for a particular compound that has been used before to infer the presence of fracking fluids—2-butoxyethanol, a surfactant common in cleaning products. They detected 2-butoxyethanol in some of the frack water samples as well as one of the three affected water wells, where it was present at less than 0.5 parts per trillion. When 8 of the 10 natural gas wells were re-fracked in 2012, 2-butoxyethanol was among the chemicals the company reported using (via the Frac Focus website).
Although it wasn’t detected in two of the three water wells (which, to be clear, doesn’t guarantee it wasn’t there), 2-butoxyethanol is a good candidate to have caused the foaming in those wells as methane bubbled up. It’s also possible that some of the other low-level organic compounds were responsible, instead.
The researchers also analyzed the isotopic composition of the methane from the water and gas wells and the ratio of chlorine to bromine in the various water samples. The results told them that the methane in the drinking water wells matched the methane in the gas wells, but it was unlikely that fracking fluid had mixed with the deep, salty water and come back up to reach the wells. Instead, the fracking fluid that contaminated the water wells was probably just on its way down.
… In this case, the gas pressure in that unsealed space around several of the well pipes was measured to be higher than regulations allowed before the problems with the water wells began—so we know gas escaped the confines of the well pipe and could have been pushing outward into the rock.
While stray gas like that has been suspected of reaching water wells in other places, hints of fracking fluid reaching water wells is rare. The researchers think that during the pressurized injection of the frack water, some may have leaked through that unsealed portion of the borehole and taken the same path as the escaping natural gas—perhaps traveling through fractures.
The case for contamination from the fracked wells is pretty tight, although there was also a leak of frack water from a surface holding pit that could potentially have provided a more traditional source for some of the contaminants. [Emphasis added]
Evaluating a groundwater supply contamination incident attributed to Marcellus Shale gas development by Garth T. Llewellyn, Frank Dorman, J. L. Westland, D. Yoxtheimer, Paul Grieve, Todd Sower, E. Humston-Fulmer, and Susan L. Brantley, approved April 2, 2015 (received for review October 22, 2014), Published online before print on May 4, 2015, DOI10.1073/pnas.1420279112, Proceedings of the National Academy of Sciences
New techniques of high-volume hydraulic fracturing (HVHF) are now used to unlock oil and gas from rocks with very low permeability. Some members of the public protest against HVHF due to fears that associated compounds could migrate into aquifers. We report a case where natural gas and other contaminants migrated laterally through kilometers of rock at shallow to intermediate depths, impacting an aquifer used as a potable water source. The incident was attributed to Marcellus Shale gas development. The organic contaminants—likely derived from drilling or HVHF fluids—were detected using instrumentation not available in most commercial laboratories. More such incidents must be analyzed and data released publicly so that similar problems can be avoided through use of better management practices.
High-volume hydraulic fracturing (HVHF) has revolutionized the oil and gas industry worldwide but has been accompanied by highly controversial incidents of reported water contamination. For example, groundwater contamination by stray natural gas and spillage of brine and other gas drilling-related fluids is known to occur. However, contamination of shallow potable aquifers by HVHF at depth has never been fully documented. We investigated a case where Marcellus Shale gas wells in Pennsylvania caused inundation of natural gas and foam in initially potable groundwater used by several households. With comprehensive 2D gas chromatography coupled to time-of-flight mass spectrometry (GCxGC-TOFMS), an unresolved complex mixture of organic compounds was identified in the aquifer. Similar signatures were also observed in flowback from Marcellus Shale gas wells.
A compound identified in flowback, 2-n-Butoxyethanol, was also positively identified in one of the foaming drinking water wells at nanogram-per-liter concentrations. The most likely explanation of the incident is that stray natural gas and drilling or HF compounds were driven ∼1–3 km along shallow to intermediate depth fractures to the aquifer used as a potable water source.
Study links foam in water wells to shale well sites by Laura Legere, May 4, 2015, Pittsburgh Post-Gazette
White foam in northeastern Pennsylvania water wells likely was caused by Marcellus Shale gas well sites that have already been blamed for causing natural gas to infiltrate residential water supplies, a paper published by the journal Proceedings of the National Academy of Sciences reported on Monday.
Environmental consultant Garth Llewellyn and biochemistry and geosciences researchers with Penn State University used a novel method to identify low levels of organic compounds that they said likely explain foaming from three water wells in Bradford County between 2010 and 2012. Test results from commercial laboratories during investigations at the sites had not picked up on what was causing the foaming — they reported no unsafe levels of compounds other than natural gas in the water, while other compounds, like glycols and surfactants, had appeared inconsistently or at barely detectable levels.
The same or similar organic compounds that the researchers traced in the water, including 2-n-Butoxyethanol, or 2-BE, are known to be used in drilling and hydraulic fracturing additives or to appear in waste fluids from oil and gas operations.
The researchers said it is impossible to “prove unambiguously” that the contaminants in the water came from shale gas-related activities because they were unable to secure samples of fluids that were used at or near the well site. But they said that multiple strands of evidence, including timing, well construction problems and the presence of matching compounds in both shale fluids and the water wells, make shale activity “the most probable source.”
The researchers do not suspect that fracking chemicals traveled upwards from the Marcellus Shale. Rather they said the most likely explanation is that the compounds were driven about 1 to 3 kilometers along natural underground fractures to the aquifer. The trigger might have been drilling, fracking or the leaking pit, the researchers said, but a particular point of weakness identified was an uncased section of the well deeper than 300 meters underground that intersected with an existing fault. …
Chesapeake Energy, the company that drilled the suspected wells, was fined $900,000 in 2011 for allowing natural gas to contaminate water supplies in Bradford County. The Oklahoma City-based company reached a $1.6 million settlement with the homeowners in 2012. The company declined to comment.
… Mr. Llewellyn, the paper’s lead author, and his firm Appalachia Hydrogeologic and Environmental Consulting, provided litigation support and environmental consulting services to the impacted households, the paper disclosed. Mr. Llewellyn said that the state’s investigation and the private case focused on natural gas contamination, but he remained puzzled by the foam, which he likened to dishwashing suds.
Penn State researchers used a tool called 2D gas chromatography coupled to time-of-flight mass spectrometry, which allowed them to identify classes of contaminants, like hydrocarbons, without pinpointing individual chemicals one by one.
The researchers said their results raise questions about the sufficiency of conventional analytical techniques to explain water impacts in some cases.
Normally, very low detections of compounds could be dismissed, but the persistent foam indicated something was wrong, Penn State geosciences professor Susan Brantley said.
The study is not the only time shale gas activity has been implicated in causing thick suds in drinking water or groundwater in the state.
Last May, the Department of Environmental Protection found 2-BE and other chemicals in a Susquehanna County water well after a resident complained of rank, foamy water. DEP said the chemicals were consistent with the surfactant Air Foam that was used to drill a natural gas well 1,500 feet away.
In 2011, DEP fined Pennsylvania General Energy Co. $28,960 for discharging Airfoam HD from a Marcellus Shale well bore to a spring and into Pine Creek in Lycoming County. [Emphasis added]
Fracking Chemicals Detected in Pennsylvania Drinking Water by Nicholas St. Fleur, May 4, 2015, New York Times
The paper, published in the Proceedings of the National Academy of Sciences, addresses a longstanding question about potential risks to underground drinking water from the drilling technique known as hydraulic fracturing, or fracking. The authors suggested a chain of events by which the drilling chemical ended up in a homeowner’s water supply. “This is the first case published with a complete story showing organic compounds attributed to shale gas development found in a homeowner’s well,” said Susan Brantley, one of the study’s authors and a geoscientist from Pennsylvania State University.
The industry has long maintained that because fracking occurs thousands of feet below drinking-water aquifers, the drilling chemicals that are injected to break up rocks and release the gas trapped there pose no risk. …
In 2012, a team of environmental scientists collected drinking water samples from the households’ outdoor spigots. An analysis showed that the water in one household contained 2-Butoxyethanol or 2BE, a common drilling chemical. … In April 2011 the three homeowners in Bradford County sued the drilling company, Chesapeake Energy Corporation, over reports of finding natural gas and sediment in their drinking well water. In May of that year, the Pennsylvania Department of Environmental Protection cited the oil and gas company for violating the Pennsylvania Oil and Gas Act and Clean Streams Law by letting natural gas enter the drinking wells, though the company admitted no fault. In 2012, the homeowners settled the lawsuit and the company bought the three households.
… Garth T. Llewellyn, a hydrogeologist with Appalachia Hydrogeologic and Environmental Consulting and the lead author of the report, said that when his team sampled water wells that were farther away from the drilling sites, they did not find any of the compounds found in the three households. “When you include all of the lines of evidence, it concludes that that’s the most probable source,” he said.
Victor Heilweil, a hydrogeologist from the University of Utah who was not involved with the study but reviewed its details, said it was noteworthy for showing “the detailed geologic fabric explaining how these contaminants can move relatively long distances from the depth to the drinking well.”
An environmental scientist from Stanford University, Rob Jackson, who also reviewed the paper, said it “clearly shows an impact of oil and gas drilling on water quality.” [Emphasis added]
[Refer also to:
When Laura Amos looks out her dining room window, she doesn’t see the west Colorado landscape. She sees the huge water tank the EnCana gas company fills every few weeks.
Just across her fence looms the gas company’s G33 well pad, with four wells that Amos says have contaminated her water. Amos’ water supply is contaminated by natural gas; that much is certain, although the source of that gas has not been officially settled.
But Amos is more concerned with a different kind of contamination. Looking out at the water tank that dominates her view, the Silt resident argues that EnCana’s hydraulic fracturing on its nearby wells has contaminated her water.
EnCana, which has been providing drinking water to the Amos home since January, denies that chemicals from the “frac’ing” have leaked into the Amos water well.
Tuesday, Amos spoke to the Post Independent about her efforts to prove EnCana is the source of the contamination.
Last week, EnCana laid out its case to the Colorado Oil and Gas Conservation Commission in Rifle. EnCana engineer Joel Fox and water-well expert Tony Gorody said hydraulic fracturing fluid could not have entered Laura Amos’ water well.
COGCC staff has recommended fining EnCana for contaminating the Amos well with gas from its wells. It will hold a hearing on the matter in October. However, the COGCC staff has agreed with the gas company that the Amos well shows no signs of fracturing chemicals associated with natural-gas production.
“The dates our water well was impacted exactly bracket the dates of (EnCana’s) hydraulic fracturing,” she said.
Since her well “blew up” on May 1, 2001, Amos has made two allegations that frac’ing caused her well to blow its top, and that 2BE, a chemical used in the process, leaked into her well. Amos has been diagnosed with an adrenal gland tumor and she says it was caused by that contamination.
Amos said she pressured the company to admit it used 2BE in frac’ing, but EnCana repeatedly denied using the chemical. Then, she said, she received a letter from the COGCC in 2004 that confirmed EnCana used the compound during one frac’ing job in June 2001. That, according to Amos, was “38 days after they knew gas was flowing” to her well.
Amos also questions EnCana’s testing of her well water.
“The premise is we can trust the people who are doing the testing. … But the people who are causing the problem tested it,” she said. “This company has a long history of lying and denying.”
She also contends the company did not test her water for 2BE until January, three years after the blowup, long after the chemical would have disappeared from her well water.
“Tony Gorody implied (the well was) tested for 2BE or frac’ing fluid in May and August of 2001 and was not detected,” she said. “The truth is, this past winter they tested for 2BE, three and a half years after the initial impact.”
At the COGCC meeting last week, Gorody said thermogenic, or production-type, gas contaminated the Amos well.
“Hydraulic frac’ing created or opened up a hydrogeological connection (from the EnCana wells) with my water well,” Amos said. “This is a fact. Wells would not be economical without hydraulic frac’ing. They’ve got an obligation to protect hydraulic frac’ing and to keep it available to them.”
On this sunny, blue-sky day, Amos and her daughter Lauren look out over their barbed-wire fence at excavating equipment moving back and forth over the G33 well pad, a stone’s throw away.
“We used to have gorgeous property here. Now it’s an industrial wasteland.” [Emphasis added]