NORM (Naturally Occurring Radioactive Material)
Jurisdiction over oil and gas NORM waste is split between the Texas Department of State Health Services (DSHS) and the Railroad Commission. The DSHS regulates the possession, use, transfer, transport, and storage of NORM and the Railroad Commission regulates the activities associated with disposal of oil and gas NORM waste. Learn more about the regulation of oil and gas NORM below.
What is NORM?
NORM, or naturally occurring radioactive material, is found almost everywhere. It is found in the air and in soil, and even in radioactive potassium in our own bodies. It is found in public water supplies and foods such as brazil nuts, cereal, and peanut butter.
The average person in the United States is exposed to about 360 millirems of radiation from natural sources each year. A millirem, or one one-thousandth of a rem, is a measure of radiation exposure. More than 80% of this exposure level comes from background radiation sources. Consumer products contribute 10 millirem/year, while living or working in a brick building can add another 70 millirem/year. A person who smokes one and a half packs of cigarettes per day increases his or her exposure by 8000 millirem/year, while porcelain false teeth can add another 1600 millirem/year to a person's exposure level.
UNITS OF MEASUREMENT FOR RADIOACTIVITY
|Microroentgens per hour-
|A measure of exposure from X-ray and gamma ray mR/hr radiation in air.Measurement of the intensity of radiation in air. A microroentgen = one millionth of a roentgen.|
|Picocuries per gram-
|A measure of the radioactivity of one gram of radionuclide that decays at a rate of 3.7E-2 disintegration per sec.|
|An acronym for roentgens equivalent man.
Relates to the adsorption of radiation on parts of the body over time.
One REM ~ One Roentgen.
RADIATION LIMITS AND COMPARISONS
|Limits from Texas regulations for control of radiation (above background):|
|For protection of general public:||
|For radium in water:||
|For radium in drinking water:||
|EPA suggested action level for radon in residences:||
|Examples of radiation exposure levels:|
|Terrestrial background Texas Gulf Coast:||
|Terrestrial background Texas Panhandle:||
|Cosmic (sea level):||
|Cosmic ray (10,000 ft):||
NORM in the Oil and Gas Field
NORM encountered in oil and gas exploration, development and production operations originates in subsurface formations, which may contain radioactive materials such as uranium and thorium and their daughter products, radium 226 and radium228. NORM can be brought to the surface in the formation water that is produced in conjunction with oil and gas. NORM in these produced waters typically consists of the radionuclides, radium 226 and 228. In addition, radon gas, a radium daughter, may be found in produced natural gas.
Because the levels are typically so low, NORM in produced waters and natural gas is not a problem in Texas unless it becomes concentrated in some manner. Through temperature and pressure changes that occur in the course of oil and gas production operations, radium 226 and 228 found in produced waters may co-precipitate with barium sulfate scale in well tubulars and surface equipment. Concentrations of radium 226 and 228 may also occur in sludge that accumulates in oilfield pits and tanks. These solids become sources of oil and gas NORM waste. In gas processing activities, NORM generally occurs as radon gas in the natural gas stream. Radon decays to Lead-210, then to Bismuth-210, Polonium-210, and finally to stable Lead-206. Radon decay elements occur as a film on the inner surface of inlet lines, treating units, pumps, and valves principally associated with propylene, ethane, and propane processing streams.
Workers employed in the area of cutting and reaming oilfield pipe, removing solids from tanks and pits, and refurbishing gas processing equipment may be exposed to particles containing levels of alpha-emitting radionuclides that could pose health risks if inhaled or ingested.
Railroad Commission Regulations for Disposal of Oil and Gas NORM
The Commission regulates the disposal of oil and gas NORM under Environmental Protection, Subchapter F, Oil and Gas NORM. Subchapter F establishes the requirements for oil and gas NORM waste disposal for the purpose of protecting public health and the environment. Oil and gas NORM waste is defined as any solid, liquid, or gaseous material or combination of materials (excluding source material, special nuclear material, and by-product material) that spontaneously emits radiation in its natural physical state, is discarded or unwanted, constitutes, is contained in, or has contaminated oil and gas waste, and exceeds the exemption criteria specified in 25 Texas Administrative Code §289.259(d)(1)(B) and (d)(2) prior to treatment or processing that reduces the radioactivity concentration.
Subchapter F contains exclusions from certain activities, exemptions for certain disposal activities, and prohibitions against certain activities. Subchapter F also authorizes certain disposal methods and requires a permit for others.
The activities excluded from Subchapter F are activities that are regulated by the Texas Department of State Health Services (DSHS). These excluded activities include: recycling activities, decontamination of equipment unless the contamination is only as a result of disposal activities, and possession use, transfer, transport, and/or storage unless this occurs at a disposal site and occurs to facilitate disposal.
The disposal activities prohibited by Subchapter F include disposal of produced water by injection into a well permitted by the Commission or by discharge to surface waters in accordance with Commission regulations. In addition, disposal of equipment that has been decontaminated by a specific licensee in accordance with the DSHS regulations for decontamination and that meets the exemption criteria of §289.259 is exempt.
The disposal methods prohibited by Subchapter F include discharge of oil and gas NORM waste other than produced water, spreading of oil and gas NORM waste on public or private roads, and any other method that is not specifically provided for by Subchapter F.
The disposal options for NORM-contaminated solids differ from the options for NORM-contaminated equipment. NORM-contaminated solids, such as pipe scale, may be disposed of on the site where they were generated by burial or placement in a well that is being plugged and abandoned. Contaminated soil may be landspread under certain conditions. Subchapter F also authorizes disposal of oil and gas NORM waste at a licensed facility and injection of NORM treated by a DSHS specific licensee provided the operator complies with specific requirements contained in the rule. NORM-contaminated equipment that is waste, i.e., equipment that is no longer wanted, may be recycled as scrap metal under DSHS regulations or disposed of. The equipment must be decontaminated if it is to be released for unrestricted use (e.g., used for some purpose other than for oil and gas activities). Subchapter F does not allow the burial of NORM-contaminated equipment. Buried flow lines that contain NORM, however, may remain buried contingent on the lease agreement. NORM-contaminated tubulars and other equipment may also be placed in a plugged and abandoned well.
The Commission’s Statewide Rule 14 (§3.14), relating to well plugging, require equipment to be removed from a lease when the last well on the lease is plugged.
Rule 14(d)(12) requires all tanks, vessels, related piping, and flow lines be emptied, and requires all tanks, vessels, and related piping to be removed in 120 days.
Scrap metal dealers routinely screen for gamma radiation and reject scrap at their selected µR/hr settings. This factor in combination with the requirements of Subchapter F and Rule 3.14 and necessitate that NORM-contaminated equipment be decontaminated and that NORM waste and equipment be properly disposed when a lease is abandoned.
Subchapter F contains permit requirements and standards for those disposal methods requiring a permit. Permits for disposal of oil and gas NORM waste by underground injection are issued under Rule 9. Permits for surface disposal of oil and gas NORM waste are issued under Rule 8. Permits for disposal of oil and gas NORM will contain requirements necessary to protect public health and the environment.
Texas Department of State Health Services (DSHS) for NORM
Texas Regulations for Control of Radiation (TRCR) Part 46, “Licensing of Naturally Occurring Radioactive Material (NORM)” became effective on July 1, 1993. TRCR Part 46 established radiation protection standards for the possession, use, transfer, transport, and/or storage of NORM or the recycling of NORM-contaminated materials. In April of 1999, TRCR Part 46 was recodified to 25 TAC §289.259.
The Texas Department of State Health Services (DSHS) regulations are based on risk assessment of NORM waste and NORM-contaminated equipment. The regulations contain exemption criteria for NORM contained in or that has contaminated soils, materials in the recycling process, and equipment. In addition, the regulations exempt possession, storage, use, transportation, and commercial distribution of natural gas and natural gas products and crude oil and crude oil products containing NORM and exempt possession of produced water containing NORM.
Oil and gas waste with radioactivity at levels above the exemption levels are oil and gas NORM wastes. Oil and gas NORM wastes must be managed in accordance with the Commission’s NORM disposal regulations. Transfer of NORM-contaminated equipment is allowed provided the equipment is used in oil and gas operations. However, NORM-contaminated equipment that is being discarded must be decontaminated before it is disposed of or sent to a scrap recycling facility.
Any person who possesses NORM above the exemption levels is a general licensee under the DSHS regulations. Operators have a duty to determine whether or not they possess NORM above the exemption levels. The DSHS regulations require a specific license to perform decontamination work.
The DSHS NORM regulations contain special worker protection requirements for oilfield workers. These requirements generally address worker hygiene and vessel entry.
Commission NORM Survey of Equipment at Leases and Facilities
Staff of the Commission district offices performed field surveys from December, 1999 to mid-March, 2000. The purpose of the survey was to measure levels of NORM in equipment being used at production leases and other associated oilfield facilities to estimate the number of sites at which NORM-contaminated equipment may be located and to estimate an approximate range of the level of NORM at various sites across the state. The leases were chosen randomly to ensure a representative sample. Measurements were collected using an energy-compensated pulse rate “micro-R” meter that provides a scaled reading in microroentgen per hour (µR/hr.) Equipment measurements were taken at locations where gamma radiation most likely would be detected if present such as flow lines, tanks/vessels, pipe, pumps, valves, and injection headers. Background readings were also collected for comparison. More than 5900 readings were collected on more than 600 leases and other oil and gas facilities.
The majority of the readings of oil and gas equipment collected during the field survey demonstrate that the radiation levels are typically below the regulatory limit for release of equipment for unrestricted use (use for purposes other than oil and gas activities.) Of the 612 sites surveyed, only 59 sites had equipment with readings above 50 µR/hr, the limit above which the equipment cannot be released for unrestricted use. Out of over 5900 readings, only 203 readings were above 50 µR/hr. The survey, however, indicates that specific geographic areas tend to have elevated NORM levels. The geographic distribution is evident from the randomly-selected leases and facilities surveyed in each commission district at which NORM readings of equipment were greater than 50µ/hr.