the activity found in the 0- to 5-cm samples. Analysis of selected The samples for cesium-137 indicated a similar vertical distribution. distrisource cesium-137 data did not indicate the Rocky Flats oriented bution reflected by the plutonium-239 data. The results (activity per unit area) for the 0- to l-cm and O- to 5-cm sampling techniques exhibit about the same relative uncertainty, although the trend of the data indicates that the results for the 0- to I-cm technique are somewhat more variable than the results for the O- to 5-cm technique. The average coefficients of variation are 42 and 30 percent, respectively. INTRODUCTION Investigators have applied numerous sampling techniques for plutonium in soil (reviewed by Bernhardt, 1976). The techniques are generally tailored to match the investigator's program objectives; e.g., primarily inventory or hazard assessment, which in most cases is for airborne resuspension. The Nevada Applied Ecology Group (NAEG) techniques (Fowler et al., 1976) and those described by the Nuclear Guide 4.5 (NRC, 1974) are oriented emphasis is to account for most of is stipulated as including the top 1974). Regulatory Commission Regulatory towards inventory determination. The the plutonium; and a surface sample 5 cm of soil (Bernhardt, 1976; NRC, Since most of the plutonium is usually on the surface, the distribution of plutonium is fairly uniform at 5 cm, and small errors in the sampling depth will have a limited impact on both the mass of material sampled and total plutonium sampled. An error of plus or minus 1 cm will only affect the mass of material by about 20 percent for a O- to l-cm sample. The phenomenon of resuspension has been reviewed by Oksza~Chocimowski (in press), Lem et al. (1977), and Anspaugh et al. (1975). Sampling for resuspension assessment must include the plutonium concentration in the surface layer of soil and the size distribution of the plutonium and associated soil aggregates. Particle size, which is important but difficult to realistically determine, has been studied by Bernhardt, 1976; Johnson et al., 1976; Little et al., 1973; Tamura, 1976, 1977. The depth involved in resuspension mechanics is not clearly known, but is dependent upon an array of soil and climatological factors and is generally believed to be within the surface 1 cm. The proposed Environmental Protection Agency (EPA) guidance for trans-~ uranics in the environment specifies soil samples be related to the top l cm, and the soil fraction less than 2 mm (10-mesh sieve) in diameter 646