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 microroentgens 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 5,900 readings were collected on more than 600 leases and other oil and gas facilities.

Most 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 5,900 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.

No readings greater than 50 µR/hr were found for equipment on leases/facilities in RRC Districts 1 and 8A.