RADIONUCLIDE CONCENTRATIONS IN SURFACE GROUNDWATER AT RONGELAP, UTIRIK, LIKIEP, AILUK, MEJIT, WOTHO, AND UJELANG Groundwater salinities shown in Table 4 range well sites sampled during the survey. from 0.3 to 1 ppt at the These salinities are sufficiently low so that this groundwater can be used for drinking if the need arises; however, we do not know how these salinities may change with time. It is difficult to assess the significance of the radionuclides detected in groundwater simple hole liners did at in the the not different ground extend atolls. On many lined with wood, above the islands, metal, ground or runoff, a the concentrations of radionuclides Most human traffic, detected of surface into the pit. during a well Concentrations and other activity transporting contaminated debris result, well was concrete. surface. radionuclides in the water will be affected by wind, the any As single period may not necessarily reflect the long-term average concentrations or the concentrations that might be observed if a lined well were extended above the surface. During the period sampled, most groundwater concentrations were everywhere higher than the concentrations in cistern water. concentrations of 90, exceeded the and Ailuk but were lower than the and Ujelang. solution Concentrations were everywhere of At all atolls, the levels the comparable cistern water. 90¢, and levels in cisterns at 137 or Cs less in than Rongelap, filtered the concentrations 1376, Groundwater Likiep, in cistern water at Utirik, transuranics to of Wotho, groundwater concentrations in groundwater in are below the EPA recommended concentration guidelines for drinking water. 14 RADIOLOGICAL DOSE ASSESSMENT OF INGESTION OF ATOLL WATER SUPPLIES Radiological and groundwater. doses are Although calculated the for preferred source latter is used in cases of severe drought. sources, the intake of of water both is cistern water the former, the By calculating the doses for both the dose from any annual intake combination can be readily determined. 14