Study: Airborne methane plume found near Bradford County gas migration site

Study: Airborne methane plume found near Bradford County gas migration site by Laura Legere, June 27, 2012, The Times Tribune
The 3½-hour survey conducted for the environmental organization by Gas Safety Inc. in Leroy Twp. on June 8 found average ground-level methane concentrations in a roughly 2-square-mile area at nearly twice normal background levels for the region’s air. The methane concentration in the air spiked to 22 parts per million – more than 10 times the highest background level of 1.95 parts per million – during a roadside survey north of Route 414 and Rockwell Road. The concentration and size of the plume “clearly indicate that one or more methane emissions were present and releasing substantial amounts of methane into the atmosphere,” according to the report. The scientists ruled out nearby farm or other natural sources of so-called biogenic methane, like animal manure, and found no elevated levels downwind of a nearby Chesapeake Energy natural gas well pad that might have indicated leaking from above-ground infrastructure at the site. The methane levels were much higher than amounts that naturally seep through the earth or that are caused by the breakdown of biological material in wetlands, the researchers said. … “The underground extent of methane contamination is significantly greater than the plume we identified,” Dr. Payne said. The state and Chesapeake have been investigating the source of methane in at least three water wells, two streams and a wetland in the same area of Leroy Twp. since May 19, when residents reported changes in their water. Two Chesapeake natural gas wells on a pad a half-mile from the affected water wells are being investigated as a potential source of the stray gas. … Methane bubbling in one tributary to Towanda Creek unsettled the rocky streambed and turned it the consistency of pudding. As of the end of May, three water wells had been vented and the homes were provided with water treatment units or replacement bulk water and methane monitoring alarms. A fourth home was provided bottled water as a precaution. … The report indicated that the well water at five homes in the study area are now “supersaturated” with methane, meaning the amount of gas is too high to be contained in the water and begins to escape to the atmosphere. The researchers also observed bubbling in the main stem of Towanda Creek, apparently along a fault line, and measured high levels of methane just above the soil along its banks.