Naturally occurring radioactive material, or "NORM," is a term used to describe radioactive material that occurs naturally but is radioactively enhanced or concentrated through human activity. Radioactivity associated with NORM in waste generated by the exploration and production of gas and oil is produced by the decay of uranium and thorium. Radium-226, a decay product of uranium which occurs in the Devonian shale that is a source rock for much of the oil found in Kentucky, is the decay product of most concern, because unlike the highly insoluble uranium, the radium (Ra226) is water and brine-soluble and is brought to the land surface and often concentrated as a by-product of the production of oil. The process of development of the oil resources, including the waterflooding of producing formations, and surface activities to separate oil from wastewaters, has resulted in the surface disposal of concentrated levels of radium-226 in disposal pits, and the concentration of radium-226 on land areas associated with tank batteries used for separation of oil and produce (brine) water, at concentrations which exceed levels at which the Environmental Protection Agency has recommended that action should be taken to require removal and proper management of the radioactive materials and contaminated soil.
The principal contaminant of concern in the radiation problems associated with oil production activities appears to be radium-226, which was noted by the Louisiana Department of Environmental Quality to have "a number of physical and chemical features that make it a particularly potent hazard to human health:"
* It emits both alpha and gamma radiation
* It behaves much like calcium and is incorporated into the bones in the human body
* It is a known carcinogen
* It has a half-life of 1,620 years
* It undergoes radioactive decay to produce radon - another hazardous substance.
* Radium-226 can enter both aquatic and terrestrial food chains leading to human consumption.
The current level of information regarding the extent of the problem of oilfield radioactive wastes in the state is virtually nonexistent, and it is not known beyond the Martha oil field, whether a problem exists with oilfield waste radioactivity. Data developed on the Martha oil field through field surveys conducted by the Cabinet for Human Resources and the Natural Resources and Environmental Protection Cabinet, as well as a consultant for an oil company in the area, indicates the existence of numerous sites where levels of radium-226 has been detected at excessive levels. These areas include apparently dozens of brine/sludge pits in the Martha oil field that were formerly used for separation of oil and produced water (brine), and for disposal of oil-related sludges and clays as well as other land areas which currently or formerly supported tank batteries (oil/water separators) or piping and equipment storage, many of which exhibit levels of radium-226 as much as hundreds of times above the levels deemed unacceptable due to health consequences by the United States Environmental Protection Agency for human exposure.