Special EPA samples included: 1. Collection of a 5- to 10-cm sample using the 10- by 10- by 5-~cm-deep scoop to take a sample from the vertical wall of the hole. Since these samples were being taken only to determine the relative contamination below 5 cm for each site, five subsamples were not taken at each site. 2. 3. Five 15-subsample top l-cm samples were taken from Plot No. 21 of Site I (i.e., I-21). These samples were collected to obtain an indication of the variation between the results of five samples from a 2- by 2-m plot versus samples from the larger 12- by 14-m site. The five 10- by 10-cm subsamples for a single 5-cm composite sample were kept separate for plots I-1 and III-14 (i.e., Site I, Plot 1, etc.). An aliquot from each of the subsamples was taken for analysis prior to compositing the subsamples and taking the primary sample aliquot. This was done to obtain information on the variability of single 10- by 10-cm subsamples versus composites based on five such samples, SAMPLE PREPARATION AND ANALYSIS The samples were dried (24 hours or until constant weight) in an oven at 110° c. and then mixed and broken up by autogenous milling (on rollers in a paint can without steel balls) for several hours in cans. The samples were then dry-sieved through a 10-mesh screen (2 mm). A 10-g aliquot was then taken by coning and quartering for plutonium-239 anal- ysis. A 100-ml aliquot was taken from selected samples for cesium-137 analysis. The samples were analyzed by the Environmental Monitoring and Support Laboratory-Las Vegas, Methods Development and Analytical Support Laboratory. All samples were analyzed for plutonium-239* by the acid dissolution technique, with plutonium separation by ion-exchange from a hydro- chloric acid medium (Johns et al., in press). The cesium-137 results were obtained by gamma spectroscopy on both sodium iodide and GeLi systems. Results are reported as less than an indicated value when the 2~sigma counting error was equal to or greater than the indicated value. The less-than values have been assumed to be equal to the indicated value for purposes of data evaluation. *References to plutonium-239 include plutonium-240. 651