May 10, 2011
Methane Gas Is Contaminating Drinking Water
A report released in the Proceedings of the National Academy of Sciences on Monday reveals that a controversial natural gas production technique, which is key to a century of U.S. domestic supply, is causing contamination of drinking water.
Scientists from Duke University collected 68 drinking water samples that showed potentially harmful levels of methane in drinking water near drilling sites in Pennsylvania and New York."In aquifers overlying the Marcellus and Utica shale formations of northeastern Pennsylvania and upstate New York, we document systematic evidence for methane contamination of drinking water associated with shale gas extraction," the report said.
Fracking involves releasing natural gas trapped in shale formations by blasting a mix of water, sand and chemicals into the rock. It has helped find water supplies in the U.S. for 100 years, though environmentalists believe it can contaminate water supplies.
The report said methane concentrations were detected in 51 of 60 drinking-water wells across the region, regardless of gas industry operations, but concentrations were much higher closer to natural-gas wells.
According to the report, levels were 17-times higher on average in shallow wells from active drilling areas than in wells from nonactive areas.
It said "greater stewardship, data, and possibly regulation are needed to ensure the sustainable future of shale-gas extraction and to improve public confidence in its use."
One homeowner in Bradford County, Pa. said that there is so much methane coming out of her tap that she can light her water on fire. There is a natural gas well located 800 feet from her house.
"Not every homeowner within a kilometer (of a drilling site) will have high methane concentrations," Stephen Osborn, a postdoctoral associate at Duke University's Center on Global Change, said in a statement. "If you are a homeowner within a kilometer, and our study shows this, I would be a little bit concerned."
The study did not specify exactly how much methane is getting into drinking water sources, and what part of the drilling is potentially involved. While wells closer to drilling sites had more methane, 85 percent of the wells in the study had some.
President Barack Obama asked the U.S. Department of Energy last week to form a panel of academic and environmental experts to identify any immediate steps that can be taken to improve the safety and environmental performance of fracking after a series of high-profile natural gas drilling spills.
Fracking has opened up new supplies of natural gas that will reduce imports of the fuel, and drillers say that methane contamination was present in drinking water before drilling began.
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