personnel. Two people will operate the Whaler and three will sample from the LCU, The sampling program will proceed from less contaminated areas of the lagoon to the more highly contaminated areas in order to lessen the probability of sample contamination. Aquatic Survey Goals and Methods Purpose: To define the activity levels in the lagoon and reef environment ARR in order to assess levels of external exposure and the degree of eecon- — tamination. Objective Method A, To assess surface exposure over the reef. Only reef covered w/less than 3 feet of water will be assayed, Personnel operating from rafts or on foot utilizing B-y survey meters, B, Immersion dose in off-shore beaches, Analysis of water and sediment sewaples and in-situ detection methods using the Boston Whaler. Cc. Definition of activity levels in the lagcon and major out®low areas over the reers, l. Assessment of sediment concentration Using the Whaler and LCU, sedi A) shore to 10 fm terrace in lagoon. material, and bottom water will be levels, B) terrace to deep basin of lagoon. C) deep basin, D) craters. cores, grab samples, suspended collected and analyzed. An in-sivu detector will be used to define relative activity levels of the bottom. <A detailed bottom survey using an in-situ NaI detector will be conducted off Runit, followed by extensive sediment sampling. The device used to obtain a botte:s sample in any area will depend entirely on the composition of the sediment. The sediment in the Lagoon varies from fine sand to coral and algae. The percent of each type of bottom material depends on location, although, in general, a higher percentage of fine material is found closer to shere where a@ corer may be used, In the deeper area of the lagocn higher percentages of formanifers and nolimeda debris dominate. [In these areas dredging and grab sampling will be more successful. -23-