People are exposed to natural (background) radiation from many different types of sources, such as radiation from the sun and from naturally occurring minerals in water, rock and soil. The background radiation levels are mostly due to the naturally occurring forms of radiation in the earth’s crust, called radionuclides, such as Radium-226, Cesium-137, Strontium-90, Uranium-238 and Potassium-40. Only a small amount of background radiation comes from man-made elements.
Naturally occurring radionuclides produce what is known as Naturally Occurring Radioactive Material (NORM). Material containing NORM can be found in a variety of products, including refractory brick used in boilers, ceramic insulators and sand blasting sand. NORM can often be found in well-drilling operations in the build-up of pipe scale. The granite countertop in your kitchen may also contain a very small amount of NORM. NORM can also occur in the form of technologically enhanced naturally occurring radioactive material (TENORM). This happens when minerals that contain naturally occurring radionuclides are artificially purified, which increases the amount of the radioactive isotope.
Missouri Code of State Regulations 10 CSR 80-3.010(2)A(13) states that NORM may be accepted in sanitary landfills permitted to accept special waste, with prior written approval from the department. The process for determining whether a material is NORM or TENORM, and allowed to be disposed of in a permitted landfill, is fairly straightforward. The process involves the steps outlined below.
- The material slated for disposal must be analyzed in a laboratory. The radiological analysis must include what material was analyzed, what process was used and the analytical results, including the radiation activity levels (expressed in pCi/g) for each radioactive isotope.
- A letter must be sent to the department's Waste Management Program, requesting that the material be determined to be NORM or TENORM. The letter must include a description of the material, the source of the material and the amount for disposal. Included with the letter should be a copy of the radiological assay developed by the laboratory that analyzed the material samples.
- The department's Waste Management Program will reply, in writing, stating whether the material is NORM or TENORM and whether it is allowed or not allowed to be disposed of in a landfill. The acceptance letter can then be provided to a landfill and the landfill can then make the final determination as to whether it will accept the material as a special waste.
If you have any questions about disposing NORM or TENORM material, please contact the department’s Waste Management Program. To learn about other activities that may be exempt from permitting requirements, visit Activities Potentially Exempt from Solid Waste Regulations.