190 These standards subsequently were modified by the Department of Energy (DOE) to include all the transuranics, not just plutonium. e land-use cleanup standards also were revised to permit not more than 40 pci/g for residential islands, 80 pci/g for agricultural islands, and 160 pCi/g for food-gathering islands. 3.3 Disposal Options During the planning stages a major consideration was the method disposal for any plutonium-contaminated material. Several options initially considered “including returning it to the United States, casting it into concrete blocks, dumping it into a crater with a crete cap, or dumping it in the ocean or lagoon" (Defense Nuclear Agency 1981, p. 94}. Although strong arquments were made for lagoo or ocean dumping, the Environmental Protection Agency (EPA) beli that national policy prohibited such disposal. This view prevailed over that of the Energy Research and Development Administration ( and the final environmental impact statement (April 1975} identifi Crater entombeent as the selected disposal method. Disposal criterla were reviewed again in August 1977 by the so-called Bair Committee. This group advocated ocean dumping as the preferred solution with lagoon dumping as an acceptable alternative but recognized that an change would require the EIS to be reopened and that EPA oppositi those alternatives would still remain. The Bair Committee's final was that "terrestial disposal on Runit Island with a concrete cove was the best practical alternative (letter from W. J. Bair, et al. J. L. Liverman, Assistant Administrator for Environment and Safety ERDA, August 17, 1977). Thus, the cleanup plan finally adopted ca for radiologically contaminated soil and debris present on many is in the atoll to be collected and transport:d to Run‘t and contain in @ soil-cement matrix in Cactus Crater, #"..counded by; = concrete kefwall, and covered by a concrete cap. 3.4 Radicactive Contaminants The radionuclides of principal concern at Enewetak are the trahs- uranics, mainly plutonium-239, and the fission products, stronti 90 and cesium-137. The transuranics are relatively insoluble and therefore have remained very near the surface. ‘The strontium and cesi however, are more soluble and have leached to a considerable dept Indeed, the DNA (1980) stated: The AEC's radiological survey had disclosed that, except on tHe island of Runit, most high transuranic concentrations were in the top few centimetres of soil. This was not the case with suburanics which, because of their water solubility, were dis} tributed to considerable depth. ... Excision of soil contaminated with suburanics [fission products], however, was simply not practicable. ‘To do so would require such extensi soil removal as to render the island useless for habication subsistence agriculture. Thus, the subsequent cleanup concentrated on the problem of transuranics.