soll removal was necessary. The fourth area, 5-S-3, did show additional high TRU concentrations and soil removal was conducted. The boundary of the area with TRU activity above 160 pCi/g, is shown in Figure 7-93, although some soil outside this boundary was also removed. Following the completion of subsurface soil removal, IMP measurements were taken and the results indicated no TRU concentrations greater than 80 pCi/g. The estimated amount of soil removed was 318 cubic meters (416 cubic yards) and the estimated curies of TRU activity removed (based on final data) was 0.07 for this subsurface soil removal. The following table gives the arithmetic mean for selected depth intervals based on data from the fission product sampling program. 90sr, pCi/g 137 Cs, pCi/g 0-5 em 0-40 cm 0-60 em 14.8 8.4 6.10 3.9 5.1 2.9 Total Samples 102 426 Tables thd 7-4 pre 7-3 give summary statistics for the 0-15 em depths for the 137cs5, 99S and estimated 40pu results, respectively, and Figures 7-94 and 7-95 show isopleths for the 0-40 em data over the entire island of Pearl for !°"Cs and Sr, respectively. Final Characterization After the completion of the subsurface soil removal, the highest 0.5 hectare average TRU was 63.5 pCi/g based on final data. The previous highest 0.5 hectare estimate was at 5-S-3, but the subsurface soil removal reduced the surface average considerably. Table 7-5 gives the arithmetic means for the final IMP data for TRU, !3%Cs and 6%Co, and Figure 7-96 shows isopleths on the final TRU concentrations for Pearl. The island average transuranics value reported in the Certification is 36 pCi/gm for surface soil, and the transuranicsclassification is Agricultural. APPROXIMATE HIGH TIDE LINE, 1972 PEARL—LUJOR Som FIGURE 7-94. ISOPLETHS ON !97c¢s ACTIVITY IN pCi/g (AVERAGE IN TOP 40 CM) FOR ISLAND PEARL 318