Four samples of lagoon-bottom silt from the northeast corner of Rongelap Atoll gave beta activity values ranging from 8,000 to 12,000 B-/min/g. Activity was uniformly distributed to a depth of 6 to 7 in. Lagoon depths were 40, 55, 60, and 120 ft. The data in Table 2.6 indicate a considerable reservoir of activity available for contaminating marine food species. Data presented in Chapter 4 confirm that this activity contaminates the food supply. 2.2.5 Water Water samples were collected from cisterns, wells, tree boles, barrels, exposed soil profiles, and ocean and lagoon sides of the islands. The ocean and lagoon water samples were collected within 10 ft of the water line to evaluate the movement of activity from the islands into the surrounding waters. Exposed profiles and well water samples were selected to describe any movement of activity into the fresh water lens and the remainder of the samples were collected to evaluate the hazard from drinking the water. Gross beta activities of the above samples are presented in Table 2.7. The scarcity of potable water is demonstrated by the few islands from which cistern water was obtainable. * TABLE 2.7 Summary of Gross Beta Activity in Water Beta Activity (3°/min/liter) Sources of Water Ocean Island Likiep La g000 Side Cistern Oc ean Side Top nba) =—-NDA NDA 290 Rongelap 80 330 6,300 Busch Eniaetok 36 460° NDA 260 23,000 Unurik 50 Labared} 7,700 Kabelle 2,300 60 380 170 Lomuilal Bikar Eniwetak 12 Bottom 1,350 | 16,000 37 28 170 t Barrel Tree Bole Soi Exposed Soil Profile NDA 28 430 44,000 14,000 ‘ 56 100 Well 8,100 15,000 (a) No detectable activity Or prev -ll- 3fU cu