206 RADIOLOGICAL CLEANUP OF ENEWETAK ATOLL investigated, set up, and make the measurement. Oncelocated in an area of interest, measurements typically could be madeat the rate of two per hour, including travel time between adjacent 50-meter grid points. This contrasted markedly with the 3-7 days required to analyze a sample chemically in the laboratory. The principal weaknesses of the IMP were mechanical ones—difficulties experienced in maintaining the germanium detector and the vehicle itseif. Consequently, three IMPs were used in the cleanup project, with the objective of having two active and one on standbyat all times. SUBSURFACE SOIL SURVEYS An intrinsic weakness of the IMP wasthat it only measured radioactivity generated close to the surface. It was known that some of the soi contamination was subsurface, due to the decontamination methods useq during the nuclear test period. All known or suspected burial sites were surveyed by the DOE-ERSP using subsurface sampling techniques, Samples were taken—on reestablished grid patterns and at predetermined depths in each area of interest—by laboratory technicians under the direction of EIC. The samples were placed in l-gallon cans, marked, and transported to Enewetak Island where the ERSP radiological laboratories were established. A portion of each sample was then chemically analyzed for transuranic content. The laboratory analysis for each sample took up to 10 days to complete. The remainder of the sample was archived at the Las Vegas, Nevada,office of ERSP. BRUSH REMOVAL EXPERIMENTS Use ofthe in situ system required lanes to be cleared of sufficient brush to allow visual survey and radiological monitoring for debris which might affect IMP readings. Much of the surface of the islands was covered with dense thickets of Scaevola and Messerschmidia, 6 to 8 feettall. It had been planned to cut the vegetation at ground level without disturbing the surface soil. Brush removal experiments at Enjebi during the last week of July 1977 indicated that such precision could not be achieved with the equipment on hand.52 Coordination with forest and agriculture industry Officials indicated that even their specialized equipment would disturb the soil. During these experiments, a 1,000-by-1,000-foot area on Enjebi was surveyed for debris by the FRST, after which the USAE attemptedto cut