Underground Injection Control National Technical Workgroup Report on Naturally Occurring Radioactive Material
Final Work Product #4
August 17, 1998
|SUBJECT:||Transmittal of National UIC Technical Workgroup Work Product|
|FROM:||Paul S. Osborne, Workgroup Chair
Nathan M. Wiser, Workgroup Co-Chair
|TO:||Robert J. Blanco, Director
Implementation and Assistance Division,
OGWDW - MC4606
Attached is a final work product of the national UIC technical workgroup entitled NORM (naturally occurring radioactive waste). This product is a memorandum on Region 4 letterhead with two attachments. The first attachment is a 1997 bibliography produced for the Department of Energy and the second attachment is a 1995 report prepared by The Cadmus Group. The memorandum and these two attachments provide an update for Regional and State UIC personnel on the status of NORM waste as it relates to the UIC Program. We believe that this work product provides good reference material for Regional and State UIC contacts.
During our July 1998 national UIC technical workgroup meeting in Denver, there was strong support for placing the memorandum on NORM (prepared by Bill Mann, Region 4) on the OGWDW web site with a hot link to the Argonne National Lab to allow the public to learn more about NORM. If you have any questions regarding our recommendation or the need for more information, please call Paul Osborne (303-312-6125), or Nathan Wiser (312-353-9569).
|cc:||Connie Bosma (w/attachments)|
|Mario Salazar (w/attachments)|
July 21, 1998
|To:||UIC Technical Workgroup Members, Regions I-III, V-X & HQ|
|From:||William Mann, Geologist, Region IV|
Attached for your use is a bibliography of papers, reports, etc. on naturally occurring radioactive material (NORM) in petroleum industry wastes. The bibliography was prepared for the U. S. Department of Energy by the Argonne National Laboratory. It is current as of July, 1997. EPA's Underground Injection Control (UIC) Technical Workgroup provides this bibliography of NORM articles to those needing information on the subject or those wishing to keep abreast of current research. Portions of the Cadmus Group report on NORM are also inclosed for your use. This report contains basic information on NORM and reviews several methods commonly used for the disposal of NORM waste.
As early as 1993, EPA's Office of Air and Radiation considered promulgating guidance or standards for NORM waste; however, at the present time there are no federal regulations that specifically control the management and disposal of elevated levels of NORM wastes associated with the production of oil and natural gas. Because NORM waste is generated in primary oil field operations intrinsic to exploration, development or production activities, it is an exempt waste under RCRA Subtitle C. Lacking federal regulations, several states have enacted or proposed regulations that apply to NORM at oil and gas facilities. A summary of these regulations are included in the Cadmus report.
Radioactive material occurs naturally at low levels in soils and rocks. NORM is present in geologic formations from which oil and gas are produced. The material generally consists of the radionuclides uranium and thorium and their daughter products, including radium. Oil and gas production processes often mobilize NORM in formations into the produced fluids (oil, gas, and water). However, NORM is usually associated with the water phase of produced fluids. As produced water is extracted and fluid pressure and temperature are reduced, the solubility of the NORM is changed and radionuclides precipitate out of solution and deposit on the walls of tubing, casing and surface processing equipment. Production and processing equipment may contain elevated levels of NORM contaminated scale or sludge that can cause disposal problems when the equipment is taken off-line for maintenance, repair, or replacement.
NORM contamination of scale can occur when dissolved radium in produced water coprecipitates with barium, strontium, or calcium sulfates. These sulfates form hard, insoluble deposits on the inside of tubing, wellheads, injection wells, and other water handling equipment. Sludge deposits consist of accumulations of heavy hydrocarbons and produced formation sand. NORM accumulates in sludge when radium coprecipates with silicates and carbonates inside production equipment with the greatest amount found in oil and water storage tanks. The presence of NORM in petroleum industry wastes has been recognized since the 1930's; however, concerns about NORM contaminated scale and sludge did not arise until the mid-1980's, when industry and regulators realized that elevated levels of NORM occurrence was more widespread than originally thought.
Management and disposal alternatives of elevated levels of NORM scale and sludge, and tubular goods, storage tanks, etc. contaminated with NORM has changed greatly in the past few years. In the past, oil and gas production wastes were commonly disposed of in pits, surface waters, or by well injection . Currently, most NORM waste is being store on-site in drums pending the development of regulations governing disposal.