The windrows that had been piled up during devegetation activities were removed after all the soil known to require cleanup had been lifted. Before removing them, each was first soil sampled and measured with the IMP at approximately 25 m intervals. The windrows with TRU activity less than 40 pCi/g were used for backfill at the subsurface excision locations. The remaining windrows were removed from the island as contaminated soil After the windrows were removed, the soil underneath was measured with the IMP at 25 m intervals. pCi/g in TRU activity and was removed. At nine locations, the soil exceeded 40 A total of 37,850 cubic meters (49,500 cubic yards) of contaminated soil, containing an estimated 2.33 curies of TRU activity (based on final data), was removed from Janet in the surface cleanup. The areas from which surface soil was lifted are shown in Figure 7-67. The surface cleanup phase began 6 July 1978 and was completed 23 March 1979. Subsurface Cleanup The areas suspected of being contaminated burial sites on Janet, shown in Figure 7-65, were investigated using the sidewall sampling method (see Section 6.9). In each case, a 25 m sampling grid was laid out to cover the suspect region; Figures 7-68 and 7-69 show these locations for the Item and Easy/X-Ray areas, respectively. The initial results of the soil sampling indicated the need for more data, so additional samples were taken at new locations, also shown in Figures 7-68 and 7-69. No further samples were taken in the Item area because the new data showed that no 0.0625 hectares (ha) average TRU activity exceeded 160 pCi/g. Figure 7-68 also gives the highest sample TRU for each sampling location for Item. There was still not enough data in the Easy/X-Ray area to arrive at a conclusion. In fact, several more iterations of sampling were required to finally define the boundaries of the two areas requiring excision. The boundaries and the highest sample TRU at each location are shown in Figure 7-69. The boundaries were established on the basis of the best available data type, the first preference being TRU fromsoil chemistry. Second choice was TRU computed from 241 Am IMP screening (see Sections 3.3, 4.3 and 6.9). If only gross alpha data from the laboratory were available, they were used, except when the data were on a possible excision boundary or showed TRU activity near 160 pCi/g. In those cases, the archived soil sample was retrieved and a laboratory gamma analysis performed. After the soil in the two subsurface pockets had been removed, new sidewall and bottom samples were taken in the excavation to verify that enough soi] had been removed. The results showed more soil required excision and two more lifts were required to remove all the TRU contamination exceeding 160 pCi/g. One of the extra lifts was caused by problems with the shifted grid in the west area (Section 6.4). After it was verified that the excisions were complete, the sites were backfilled with clean material from the windrows. radiological condition of the new surface. A final IMP survey was then done to establish the The subsurface cleanup began 6 December 1978, and was completed 18 April 1979. An estimated total of 2,000 cubic meters (2,600 cubie yards) of soil containing an estimated 0.19 curies of TRU activity was removed in the subsurface cleanup of Janet. Fission Products Sampling and Subsurface Investigations Janet was sampled at 50 m intervals, at the same locations as the initial IMP measurements, for the Fission Product Data Base (FPDB) in support of the dose assessment(see Section 6.11). In the west area, where the initial IMP survey was at 25 m spacing and the grid was shifted, only the 50 m points were sampled, and the correct grid was used (see Section 6.4). Samples were taken at 364 locations, and soil from 99 of these was analyzed for 9%Sr, All the samples were analyzed for gamma activity, and the results for the 0-15 cm profile for Cs and Sr are summarized in Tables 7-1 and 7-2. A summary of island average results for selected other profile ranges is given below. 286