Duke Study Finds Higher Gas Levels in Drinking Water Wells Near Marcellus Fracking Sites
Some homeowners living near shale gas wells appear to be at higher risk of drinking water contamination from stray gases, according to a new Duke University-led study, Increased Stray Gas Abundance in a Subset of Drinking Water Wells Near Marcellus Shale Gas Extraction.
The scientists analyzed 141 drinking water samples from private water wells across northeastern Pennsylvania’s gas-rich Marcellus Shale basin.
They found that, on average, methane concentrations were six times higher and ethane concentrations were 23 times higher at homes within a kilometer of a shale gas well. Propane was detected in 10 samples, all of them from homes within a kilometer of drilling.
“The methane, ethane and propane data, and new evidence from hydrocarbon and helium content, all suggest that drilling has affected some homeowners’ water,” said Robert B. Jackson, a professor of environmental sciences at Duke’s Nicholas School of the Environment. “In a minority of cases the gas even looks Marcellus-like, probably caused by poor well construction.”
The ethane and propane data are “particularly interesting,” he noted, “since there is no biological source of ethane and propane in the region and Marcellus gas is high in both, and higher in concentration than Upper Devonian gases” found in formations overlying the Marcellus shale.
The scientists examined which factors might explain their results, including topography, distance to gas wells and distance to geologic features. “Distance to gas wells was, by far, the most significant factor influencing gases in the drinking water we sampled,” said Jackson.
The team published its peer-reviewed findings this week in the online Early Edition of the Proceedings of the National Academy of Sciences.
Shale gas extraction—a process that includes horizontal drilling and hydraulic fracturing—has fueled concerns in recent years about contamination of nearby drinking water supplies.
Two previous Duke-led studies found direct evidence of methane contamination in water wells near shale-gas drilling in northeastern Pennsylvania, as well as possible hydraulic connectivity between deep brines and shallow aquifers. A third study, conducted with U.S. Geological Survey scientists, found no evidence of drinking water contamination from shale gas production in Arkansas. None of the studies found evidence of current contamination by hydraulic fracturing fluids.
The new study is the first to offer direct evidence of ethane and propane contamination.
“Our studies demonstrate that the integrity of gas wells, as well as variations in local and regional geology, play major roles in determining the possible risk of groundwater impacts from shale gas development. As such, they must be taken into consideration before drilling begins,” said Avner Vengosh, professor of geochemistry and water quality at Duke’s Nicholas School.
“The new data reinforces our earlier observations that stray gases contaminate drinking water wells in some areas of the Marcellus shale. The question is what is happening in other shale gas basins,” Vengosh said.
“The helium data in this study are the first in a new tool kit we’ve developed for identifying contamination using noble gas geochemistry,” said Thomas H. Darrah, a research scientist in geology, also at Duke’s Nicholas School. “These new tools allow us to identify and trace contaminants with a high degree of certainty through multiple lines of evidence.”
Co-authors of the new study are Nathaniel Warner, Adrian Down, Kaiguang Zhao and Jonathan Karr, all of Duke; Robert Poreda of the University of Rochester; and Stephen Osborn of California State Polytechnic University. Duke’s Nicholas School of the Environment and the Duke Center on Global Change funded the research.
Visit EcoWatch’s FRACKING page for more related news on this topic.
By James O'Hare
There are 20 million people in the world facing famine in South Sudan, Somalia, Nigeria and Yemen. In developed nations, too, people go hungry. Venezuela, for instance, is enduring food insecurity on a national level as a result of economic crisis and political corruption. In the U.S., the land of supposed excess, 12.7 percent of households were food insecure in 2015, meaning they didn't know where their next meal would come from.
Artists are taking the climate crisis into frame and the results are emotional, beautiful and stirring.
So you've seen the best climate change cartoons and shared them with your friends. You've showed your family the infographics on climate change and health, infographics on how the grid works and infographics about clean, renewable energy. You've even forwarded these official National Oceanic and Atmospheric Administration graphs that explain the 10 clear indicators of climate change to your colleagues at the office.
As the Trump administration moves full speed ahead on boosting the oil and fossil fuel industry, opposition to increased pipeline construction is cropping up in different communities around the country.
By Simon Evans
Last Saturday, two dead whales washed up on the coast of Suffolk, in eastern England, and a third was spotted floating at sea.
What happened next illustrates how news can spread and evolve into misinformation, when reported by journalists rushing to publish before confirming basic facts or sourcing their own quotes.
By Monica Amarelo and Paul Pestano
Sun safety is a crucial part of any outdoor activity for kids, and sunscreen can help protect children's skin from harmful ultraviolet rays. Kids often get sunburned when they're outside unprotected for longer than expected. Parents need to plan ahead and keep sun protection handy in their cars or bags.
By Joe McCarthy
A lot of people take part in community clean-up efforts—spending a Saturday morning picking up litter in a park, mowing an overgrown field or painting a fence.
A coalition of conservation groups and others announced Thursday that a historic number of comments and petitions of support have been submitted to the U.S. Department of the Interior in support of Bears Ears National Monument. Despite the entirely inadequate 15-day comment period ending on May 26, more than 685,000 comments in support of Bears Ears National Monument have been collected.