In August, the Pennsylvania Department of Environmental Protection reported 243 water wells were contaminated by gas drilling statewide. Videographer Scott Cannon, during a program on fracking he presented at American Legion Post 477 in Pittston on Nov. 13, said 20 percent to 80 percent of chemicals put in the ground during fracking for natural gas stay in the ground.
But there is another adverse effect to the way drillers fracturing rock in the Marcellus Shale in the search for natural gas. Water and chemicals used to break shale in the hydraulic fracturing process mix with brine and radiated soil already in the ground, so the water comes up worse than when it went in and can’t be put back into the ecosystem, Cannon said.
According to the U.S. Environmental Protection Agency, the geologic formations that contain oil and gas deposits also contain naturally-occurring radionuclides, which are referred to as “NORM,” or naturally-occurring radioactive materials. They include uranium, thorium and radium and their decay products, and lead-210.
According to the EPA, much of the petroleum in the earth’s crust was created at the site of ancient seas by the decay of sea life. The result is, petroleum deposits often are found in aquifers containing brine, or salt water. Radionuclides and other minerals that are dissolved in the brine separate and settle out, forming various wastes above ground such as mineral scales inside pipes, sludges, contaminated equipment or components and water that flows back out.
Uranium and thorium are not soluble in water, but their radioactive decay product, radium, and some of its decay products are somewhat soluble.
“In all rock and soil, there is a certain amount of trace radioactivity,” said Wilkes University geology professor Brian Redmond. “Such small amounts of uranium are not normally present in any amounts to be dangerous.”
He said water deep below the surface that has been in contact with rock for a long time tends to pick up dissolved material such as salt.
“Since the Marcellus Shale is very deep, you would not want to take that water from down deep and let it near surface,” Redmond said.
He said water that is present in the Marcellus Shale includes tiny amounts of radioactives. The amount is not significant, but it is measurable.
“It should be one of the things that should be measured,” Redmond said. “It should be measured at least once to make sure there’s not a problem.”
The radioactivity is in incredibly tiny quantities as it decays within the earth and goes through a whole series of steps as the uranium decays, he said. One of the intermediate steps is radium.
“When radium decays, it turns into radon gas,” Redmond said. “Being a gas, it can move around a little more and can get out into the air or into somebody’s house. It doesn’t last long, maybe three days.”
But the radioactivity in the water should prevent its release into the ecosystem.
That’s why there should be testing, Redmond said.
“People and companies, some are very diligent and dependable, and some aren’t,” the geology professor said. “That’s why have regulatory agencies.”
According to Marcellus Shale Coalition, a natural gas drilling advocacy group, “Flow-back water, which is the water that returns to the surface during the hydraulic fracturing process, is managed in accordance with state and federal regulations. In the Appalachian Basin, flow-back is almost entirely recycled and reused to fracture additional wells. A small percentage of this flow-back water is disposed of in EPA-regulated underground injection wells.”
DEP last year announced a study to look at naturally occurring levels of radioactivity in by-products of oil and natural gas development. DEP began to sample and analyze the naturally occurring radioactivity levels in flow-back waters, treatment solids and drill cuttings, as well as associated matters such as the transportation, storage and disposal of drilling wastes.
Routine DEP reviews of data on radioactivity in wastes have shown the oil and natural gas industry and other industries generate very low levels of natural radioactivity, DEP said. While drill cuttings and other materials from drillers occasionally triggered radiation monitors at landfills, less than half 1 percent of all drill cuttings produced by Marcellus Shale drilling in 2012 and disposed of in landfills triggered radiation monitors, according to DEP.
DEP Secretary E. Christopher Abruzzo has said that if the agency were to find any levels of immediate concern to public health or safety, the department would take action.