| “ Runit (Yvonne) Cleanup and Crater Containment 441 FIGURE 8-33. COMPACTING SOIL-CEMENT MIXTURE. Soil-cement procedures were tested the week of 11 February 1979. Full- scale operation began the following week and continueduntil 26 July 1979. The mound which resulted rose 25 feet above the tremie level, or 28 feet above reef level. Approximately 1,143 cubic yards of contaminated debris und 49,492 cubic yards of soil were contained in the soil-cement mound. The compaction factor for soil placed by this process was 1.01:1. Subsequent core sampling revealed that the soil-cement was packed firmly, fairly impermeable, and did not represent a source threat of radionuclides.9! In all, over 104,000 cubic yards of contaminated soil were placed in the Cactus Crater containmentstructure by the combined tremie and soil-cement operations (Figure 8-34).92 THE DONUT HOLE Because of delays in collecting debris from the Aomon Crypt (described in Chapter 7) and the island of Runit itself (described in a subsequent section), all the contaminated debris could not be encasedin slurry during the tremie operation as originally planned. The POD design providedfor disposal of debris during the soil-cement operation by building dikes in which the debris would be placed and encased with contaminatedslurry.