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LJ ROCKY :FLATS SOIL PLUTONIUM""Z'0 SURVEYS FROM 1970 TO ] 99] The rangc;s now are: 0.000 to 0.1 pCi/gram, >0.1 to 0.5 pCi/gram >0.5 to 0.9 pCJgram >0.9 to 10,0 pCi/gram >:10.0 pCi/gram The spatial display makes is easier to distinguish the soil plutonium79240 distribution for Sectors 1 and 2. ' No sub-arrea of Sector 1 corresponds to the median range determined for map 1. Three categories 1, 3 and 4 noted above (listed on page 16 and 17) are represented in Sector 1 on map 3. Category 2 is not directly represented. Category 2 is a borderline case. The results of the higher resolution sampling would seem to confirm this. The category 1 area bordering Sector 2 is prominent. The spatial distribution is much more focused directly east of the 903 pad and maintains an easterly profile and is strong enough to influence the whole sector. Sector 2 data fits into two categories, 1 and 3. The highest concentrations are the border areas with Sector 1 along an easterly line noted in all three maps. The concentrations drop off dramatically in an eastern direction. The remaining sectors all show levels within category 3. Discussion The data are adequate to show >he distribution of plutoniumJ9+290 within the two-mile radius. However the four- mile radius is not as clearly definable. The strong association of plutoniunn~"'2°0 distributed along the east axis begs the need for a higher level of resolution east of Indiana Street in an area extending from the boundary between Sectors 6 and 7. The easterly line separating Sector 1 and Sector 2 is a better focal line to establish a zone of plutoniumJ9'Z'° above the state standard rather than the Sectors. Sectors 6 and 7 are borderline for comparison ' to the standard. This consistency is supported in all three maps, both in the spatial distribution of the data in the more refined data sets, Sectors 1 and 2, and the entire data set for the 13 sectors, at least since 1975. This is important since non-parametric methods sometimes are used with poor data to strengthen or massage the data to make it more useful. This data set is not poor. The data lends ' itself to comparison to events and consistency over time. Those areas of concern against the standard or some other benchmark can be reliably determined, visually. The choice of statistical analysis to prepare models to predict future concentrations is another question. Such a question ' would have to be answered before data collection to ensure the design could support such predictions. c,-,.- :--..~..,-. ....::.:..............: 22 :........................................::................:..:.::.............:.::................:..:.:...............::..........:.::.:.............::.:..:.......::...........:..:..:.........:..:......:.....:.. .