Stols™ Magnetic Survey At Sandia National Laboratory Technical Area 2

Technical Area 2 (TA2), a 45 acre site located at Kirtland AFB in Albuquerque NM, was run by<br>Sandia National Laboratory (SNL) as a nuclear weapons assembly facility from 1948 to the mid<br>1950’s, and as an explosive device development facility since the mid 1950’s. Presently, SNL<br>is developing an environmental remediation plan for TA2 which will allow for the safe closure<br>of the facility. One main concern of SNL is the location of underground burial containers, such<br>as 55 gallon drums, which may contain radioactive or chemical waste products.<br>In order to create a maps of buried ferromagnetic objects located at TA2, the Surface Towed<br>Ordnance Location System (STOLS™) was deployed by GEO-CENTERS, INC. at this site. This<br>survey, which covered over approximately 20 acres, was performed in September, 1993. Total<br>field magnetic data was recorded on seven separate magnetometers at a rate of 20 samples per<br>second per sensor. The magnetometers were mounted on a sensor platform which is towed by<br>a low magnetic signature vehicle and positioned with a GPS navigation system. Concurrent with<br>the survey a reference magnetometer was deployed in an adjacent area to record the low<br>frequency variations in the Earth’s ambient field. These reference data were later subtracted from<br>the survey data to produce a total field magnetic anomaly map of the site. Data was collected<br>at sufficient density to allow for final interpolation onto a 10 cm grid. All data were collected,<br>processed and analyzed in the field, on the same day of the survey.<br>The STOLS™ magnetometer surveys at TA2 resulted in very dense and highly accurate magnetic<br>anomaly maps of the facilities. The magnetic anomalies detected in the data were modeled to<br>produce a catalog of buried ferromagnetic objects at the sites. Buried objects are described in<br>terms of latitude, longitude, depth and size. Detected objects included fence posts, roadbeds,<br>buried pipes and barrels.