From the Associated Press:
A Wayne County, Pa. anti-drilling group has commissioned what it calls a first-of-its-kind survey of ground-level methane concentrations in Damascus Township, Pa.
This is in order to record baseline conditions before natural gas drilling begins.
The survey, conducted by Southborough, Mass.-based Gas Safety Inc. for Damascus Citizens for Sustainability, measured methane levels over four days in late August and early September along every public township road.
The study found that concentrations of the gas are "relatively low and reasonably consistent" in the township, with higher levels measured near cows, feed lots or animal pens on farms. The highest spike, of 4.7 parts per million of methane in the air, had no clear source and was short-lived.
Overall, the study found that baseline methane levels away from distinct sources of the gas were less than 1.9 parts per million and that future surveys should find that 99 percent of samples are below 2.01 parts per million to reflect unchanged conditions.
"We're trying to get at an idea of what's normal," one of the study's authors, Bryce Payne Jr., Ph.D., said. "These are the pre-existing conditions that are normal for the area now."
Leaders of Damascus Citizens for Sustainability called the survey a "powerful" tool for communities to track changes in methane levels that may be caused by shale gas drilling.
"Gas drilling companies have avoided legal liability for any methane contamination they may have caused by claiming that the gas had already been present before their activities started," Jeff Zimmerman, an attorney for the group, said.
Gas Safety conducts sampling with a vehicle-mounted instrument that tracks the time, place and methane concentration in air every one to five seconds. It has performed surveys using the same process in the heavily drilled areas of Dimock Township, Susquehanna County, and Leroy Township, Bradford County, after methane seeped into water supplies during nearby Marcellus Shale drilling operations.
In comparison to its Damascus survey, the Dimock and Leroy surveys showed a similar baseline methane concentration - about 1.9 parts per million - but markedly higher and more frequent and sustained peaks of between 5 and 20 parts per million that Gas Safety attributed to gas drilling impacts.
Thomas Shepstone, a regional representative of the natural gas industry organization Energy in Depth, said the comparisons ignore geological differences, including that "Damascus Township, unlike many areas of Bradford and Susquehanna counties, has never had a history of significant methane migration or burning faucets" that pre-dates Marcellus gas extraction.
"While baseline testing is never a bad idea, the generalizations made with regard to data and the several qualifications attached to conclusions make it a less than reliable assessment," he said.
Department of Environmental Protection spokesman Kevin Sunday criticized Gas Safety's Leroy Township surveys, calling them "riddled with bad methodologies and unsubstantiated conclusions."
Natural gas drilling in Damascus and most of Wayne County remains uncertain.
Other than a handful of exploratory gas wells, drilling has been on hold in the watershed for years as the Delaware River Basin Commission drafted and revised natural gas drilling rules, then called off a vote scheduled last November to adopt them.
No new date for a vote has been announced.
Chesapeake Energy Corp,the Oklahoma-based firm is the No. 1 driller in Ohio.
Rig Count Interactive Map by Baker Hughes, an energy services company.
Shale Sheet Fracking, a Youngstown Vindicator blog.
The Ohio Environmental Council, a statewide eco-group based in Columbus.
Earthjustice, a national eco-group.
People's Oil and Gas Collaborative-Ohio, a grass-roots group in Northeast Ohio.
Concerned Citizens of Medina County, a grass-roots group.
No Frack Ohio, a Columbus-based grass-roots group.
Fracking: Gas Drilling's Environmental Threat by ProPublica, an online journalism site.
Pipeline, blog from Pittsburgh Post-Gazette on Marcellus shale drilling.
Allegheny Front, environmental public radio for Western Pennsylvania.