A controversial form of drilling for natural gas from shale rock appears to be contaminating groundwater wells with methane in northeastern Pennsylvania and Upstate New York, according to a Duke University study.
Researchers tested 60 wells last year for methane and found that 13 of the 26 wells within a kilometer of "hydrofracking" sites had elevated methane levels, some to the point where the water could catch fire. Such levels were found in only one of the 34 wells beyond a kilometer of such drilling, according to study co-author Robert Jackson.
"I was extremely surprised. We did not expect to find so many houses with high methane concentrations near gas wells," said Jackson, an environmental science professor at Duke University. "It's pretty hard to explain away."
Hydraulic fracturing, or fracking, has come under increasing scrutiny as drilling intensifies in shale regions of the USA, especially the Barnett area in Texas, the Marcellus in Pennsylvania and the Utica in New York. This drilling method blasts waters, mixed with sand and chemicals, deep underground to fracture shale formation and allow natural gas to escape. Some of the liquid comes back to the surface.
The Duke scientists recommend doctors study the health effects of chronic low levels of methane, saying there is little research and the EPA does not regulate methane in drinking water.
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