The process of extraction of natural gas from black shale has been around a long time, but public concern has increased in recent years. Both public and private figures are calling for stricter regulations on hydraulic fracturing, also known as hydro-fracking. In states that allow this process, there have been cases of environmental pollution, including: contaminated ground water and increased levels of illness. In addition, the companies may provide no plan for efficient waste handling or accident mitigation, and potentially-harmful concentrations of radioactivity are released into the environment.
The Marcellus Shale site is located in the north-eastern region of the United States. This area spans underground from Ohio and West Virginia northeast into Pennsylvania and southern New York. Small areas of gas-shale also exist in areas of Maryland, Kentucky, Tennessee and Virginia.
Marcellus is a black shale with a detectable radioactive signature, which has become a major natural gas supplier, referred to as a super gas field. Low density, and organically rich, the depth spans to more than a mile below the earth’s surface. Recent estimates put the natural gas potential at 500 trillion cubic feet. A comparison for just how large this is; New York uses about 1.1 trillion cubic feet of gas per year. With new technology for fracking and the construction of a pipeline, interest in exploiting this resource has increased dramatically.
Hydraulic Fracturing: Chemistry of FrackingThe basis for this process is horizontal drilling. A vertical well is drilled down to the appropriate depth, containing the gas-containing shale, and then is curved horizontally within the subject rock.
Providing maximum exposure to the gas-bearing rocks, a solution of water, sand, and chemicals are pumped through the shale at high pressure to create fracturing in the rock. This process releases the gas. The proprietary chemicals used in this process might include: a biocide, gel, friction reducer, other agents to prevent corrosion of the pipes, and a material such as sand, to keep the fracture open for gas release.
Radioactive Pollution from the Marcellus Fracking SiteMany pollutants are produced from the fracking process, including chemicals that contaminate the wetlands and soil surrounding the site. In addition, groundwater contamination from leaks, spills, or ineffective processing can add to increased detrimental effects in the environment. Unfortunately, radiation increases are largely ignored when the risks of fracking are discussed.
Hydraulic fracturing has a strong potential of concentrating the already existing radionuclides, making them accessible to human contact either through disposal or handling. In the 1980s, at other gas drill sites, higher concentrations of radioactivity presented concerns about site workers and the general public when dealing with disposal and by-products from the process.
Type of Radiation Danger from FrackingWhat kind of radiation is a danger, when releasing natural gas through the hydraulic fracturing process? The prime suspect is Radium-226. Abundant in gas-producing shale, Radium-226 is formed when the natural Uranium-238 decays in the environment. An alpha-emitter with a gamma ray, Radium-226 has a half-life of 1600 years, and is found in rock, soil, water, plants, animals, and human life, at very low levels. The decay product of radium is radon, another biological hazard with a long list of health issues attached to it.
Radium is soluble in water, and is carried easily by the large volumes of water that are used as part of the hydro-fracking process. A build-up in pipes and on equipment could increase radiation levels, and pose a risk to the workers. Filters in the treatment facilities can also concentrate the radioactive material.
Studies performed on the Marcellus shale through core samples and analysis of the process show that the amount of radioactivity is 20 times higher than background and would be concentrated through the process.
The cleanup technology has also been in question. Congressman Tim Bishop, representing the 1st district of New York, released a statement in November, 2011. In part, Congressman Bishop notes,
“How can systems designed with technologies to treat domestic sewage and nutrients be expected to safely remove industrial chemicals and naturally occurring radioactive materials from the wastewater stream?”
Risks From Hydro-FrackingIncreased radiation levels from the hydro-fracking system and cleanup have the potential of posing a severe health risk to the surrounding population and site workers. Risks are the result of the concentration of Radium-226. Radium-226 and its decay product, radon, can affect individuals topically and through inhalation and ingestion of contaminated water. With so much unrest on this subject, more research is required to allay health fears and concerns.
SourcesNew York State Department of Environmental Conservation
Division of Mineral Resources. Supplemental Generic Environmental Impact Statement on the Oil, Gas and Solution Mining Regulatory Program. (2009). Accessed December 04, 2011.
Rubin, K. Hundreds of New Yorkers turn out for DEC hearing to oppose hydraulic fracturing. (2001). Accessed December 04, 2011.
Department of Environment Conservation. Marcellus Shale. (2011). Accessed December 04, 2011.
Geology. Marcellus Shale- Appalachiuan Basin Natural Gas Play. Accessed December 04, 2011.
Congressman Tim Bishop. Bishop Calls for Closer Scrutiny of Hydro-Fracking Wastewater. (2011). Accessed December 04, 2011.
Resnikoff, Marvin, et.al. Radioactivity in Marcellus Shale. (2010). Accessed December 04, 2011