FIGURE 6-25. CACTUS AND LACROSSE CRATERS ON ISLAND YVONNE. Cactus Crater, foreground (viewed from the west), was selected as the disposal site for all contaminated debris and soil removed from other islands during the cleanup. (Spring 1977) depth of excision to meet Conditions A and D, which could not be provided until better subsurface information became available. No further action was taken until JTG issued a tasking letter on 6 February 1979 including assigned priorities for five identified areas of the island. Soil sampling and the in situ survey began immediately on Southern Yvonne and was completed in a few days. The in situ survey of the area between Fig/Quince and Cactus Crater was in progress on 15 February when DNA requested information upon which to base a decision regarding additional cleanup of Yvonne versus cleanup of Pearl. The response provided to DNA on 24 February summarized the status of information for both islands and provided volume estimates indicating that for Yvonne about 18,000 yas of soil would have to be excised to bring the surface TRU concentration down to 160 pCi/g, or about 13,000 ya? if the target level was 400 pCi/g. The volume estimate to remove areas with surface TRU greater than 80 pCi/g from Pearl was 23,500 ya, The information supplied was only one of a large number of diverse factors considered in making the decision to excise soil from Pearl first, then the Fig/Quince area. 195