Natural gas found in drinking water near fracked wells

science

Robert Jackson

A Marcellus shale gas extraction well pad and farm in Pennsylvania. New research finds contaminated drinking water, in some cases, in homes within one kilometer of these wells.

By John Roach, Contributing Writer, NBC News

Elevated levels of methane and other stray gases have been found in drinking water near natural gas wells in Pennsylvania's gas-rich Marcellus shale region, according to new research. In the case of methane, concentrations were six times higher in some drinking water found within one kilometer of drilling operations.
"The bottom line is strong evidence for gas leaking into drinking water in some cases," Robert Jackson, an environmental scientist at Duke University in Durham, N.C., told NBC News. "We think the likeliest explanation is leaky wells," he added.
Producing natural gas from shale rock formations involves a technique called hydraulic fracturing, or fracking, that shoots several million gallons of water laced with chemicals and sand deep underground to break apart chunks of shale, freeing trapped gas to escape through cracks and fissures into wells.
The technique has unlocked the potential to usher in a new era of energy independence and may serve as a bridge to a clean energy future. But the fast-developing industry has raised a host of environmental concerns, including the potential for drinking water near natural gas wells to become contaminated.
The new research builds on earlier work from Jackson and his colleagues that also found high concentrations of methane near natural gas wells. In this new study, Jackson's team analyzed 141 drinking water samples from private wells across northeastern Pennsylvania.
In addition to the higher methane concentrations, the new study documented higher ethane and propane concentrations. Ethane concentrations were 23 times higher at homes within a kilometer of a shale gas well. Propane was detected in 10 samples, all from wells within one kilometer of drilling.
All the gases appear to be fossil in origin. "That is the point of the ethane and propane analyses in the paper," Jackson said. "Those are gases that are not generated by microbes" that can live in the ground and affect well water.
The researchers also conducted chemical analyses of hydrocarbon and helium that suggest the gas found in some instances comes not just from the ground, but from leaky steel pipes used in the extraction system, Jackson added.
"If you have a casing leak (in the tubing), you might expect to see other things through time," he noted, "not just the gases, but whatever is coming up out of the well."
The methane contamination may be a result of cracks in the cement that surrounds the outside of the steel tubing and serves as a barrier between the rock that is drilled through and the well. An improper cement job, Jackson explained, could permit gas from a pocket at mid-depth to move into the space outside the well, and move up to the drinking water.
"In that case, you would never expect to see Marcellus gas or, more importantly, fracking chemicals and metals and salts" in the drinking water, he said.
The biggest known risk of high methane concentrations in drinking water is an explosion or fire due to the buildup of the gas in a confined space such as a basement or a shed, Jackson noted. "The flip side of that is the Environmental Protection Agency doesn't regulate methane in drinking water, so we really don't know much about the health risks."
Naturally occurring methane is "ubiquitous" in water wells throughout the study region, Steve Everley, with the natural gas industry group Energy-in-Depth, writes in a blog post that characterizes the new study as full of flaws. Chief among them, Everley argues that methane is ubiquitous in the region, and that the Duke University research team found methane in water wells "nowhere near natural gas wells."
The group also notes that the new research does not find evidence of fluids used during fracking in the groundwater. "On that point, at least, we're happy to agree with them," Everley writes.
Radisav Vidic is a civil and environmental engineer at the University of Pittsburgh who recently conducted a review study of the scientific literature about environmental issues related to hydraulic fracturing. The new research, he told NBC News, will "help us to better understand the whole picture of potential risks," related to the fast-evolving industry.
But, he added, there is a lack of background data on these drinking water wells from before the onset of drilling for comparison. So, the findings of higher methane contamination near natural gas drilling is "not a direct proof" of a link, he said. "We don't have the data from before the industry came to town."
Jackson and his team are trying to build this baseline data, which requires greater disclosure from the natural gas industry through the release of well records, for example, so researchers can compare the chemical signature of the methane, ethane and propane they find in drinking water with the natural gas wells.
"The long term goal is to understand why problems occur and keep them from happening somewhere else," he said. "We want to work productively to make things better."
The new research appears in a paper published online today by the Proceedings of the National Academy of Sciences. 
John Roach is a contributing writer for NBC News. To learn more about him, visit his website.

Louis Meeks’ well water contains methane gas, hydrocarbons, lead and copper, according to the EPA’s test results. When he drilled a new water well, it also showed contaminants. The drilling company Encana is supplying Meeks with drinking water. (Abrahm Lustgarten/ProPublica)

Oldest water on Earth found deep underground

Science

B. Sherwood Lollar et al.

A scientist takes a sample of water from a mine deep
 underground in Ontario, Canada. The water turned 
out to be 2.6 billion years old, the oldest known
 water on Earth.

By Charles Q. Choi
LiveScience
A pocket of water some 2.6 billion years old — the most ancient pocket of water known by far, older even than the dawn of multicellular life — has now been discovered in a mine 2 miles below the Earth's surface.
The finding, announced in the May 16 issue of the journal Nature, raises the tantalizing possibility that ancient life might be found deep underground not only within Earth, but in similar oases that may exist on Mars, the scientists who studied the water said.
Geoscientist Barbara Sherwood Lollar at the University of Toronto and her colleagues have investigated deep mines across the world since the 1980s. Water can flow into fractures in rocks and become isolated deep in the crust for many years, serving as a time capsule of what their environments were like at the time they were sealed off.
In gold mines in South Africa 1.7 miles (2.8 kilometers) deep, the scientists previously discovered microbes could survive in pockets of waterisolated for tens of millions of years. These reservoirs were many times saltier than seawater, "and had chemistry in many ways similar to hydrothermal vents on the bottom of the ocean, full of dissolved hydrogen and other chemicals capable of supporting life," Sherwood Lollar said. [Strangest Places Where Life Is Found on Earth]
To see what other ancient pockets of water might exist, Sherwood Lollar and her colleagues investigated copper and zinc mines near the city of Timmins in Ontario, Canada. "As the prices of copper, zinc and gold have gone up, mines now go deeper, which has helped our search for long-isolated reservoirs of water hidden underground," Sherwood Lollar said.
'Mind-blowing' find"Sometimes we went down in cages — they're not called elevators underground — that dropped us to the levels we wanted to go," Sherwood Lollar told OurAmazingPlanet. "Other times, we went down ramp mines, which have curling spiral roadways, so we could actually drive all the way down."
The scientists analyzed water they found 2 miles (2.4 km) deep. They focused on noble gases such as helium, neon, argon and xenon. Past studies analyzing bubbles of air trapped within ancient rocks found that these rare gases could occur in distinct ratios linked with certain eras of Earth's history. As such, by analyzing the ratios of noble gases seen in this water, the researchers could deduce the age of the water.
The scientists discovered the fluids were trapped in the rocks between 1.5 billion and 2.64 billion years ago.
"It was absolutely mind-blowing," Sherwood Lollar said. "These weren't tens of millions of years old like we might have expected, or even hundreds of millions of years old. They were billions of years old."
The site was formed by geological activity similar to that seen in hydrothermal vents. "We walked along what used to be ocean floor 2.7 billion years ago," Sherwood Lollar said. "You could still see some of the same pillow lava structures now seen on the bottom of the ocean."
Signs of life?This ancient water poured out of the boreholes the team drilled in the mine at the rate of nearly a half-gallon (2 liters) per minute. It remains uncertain precisely how large this reservoir of water is.
"This is an extremely important question and one that we want to pursue in our future work," Sherwood Lollar said. "We also want to see if there are habitable reservoirs of similar age around the world."
Sherwood Lollar emphasized they have not yet found any signs of life in the water from Timmins. "We're working on that right now," she said. "It'd be fascinating to us if we did, since it'd push back the frontiers of how long life could survive in isolation."
And the implications of such a finding would extend beyond the extremes of life on Earth.
"Finding life in this energy-rich water is especially exciting if one thinks of Mars, where there might be water of similar age and mineralogy under the surface," Sherwood Lollar said.
If any life once arose on Mars billions of years ago as it did on Earth, "then it is likely in the subsurface," Sherwood Lollar said. "If we find the water in Timmins can support life, maybe the same might hold true for Mars as well."