os TABLE VI NT OF VARIATION) RELATIONSHIP OF PLUTONIUM CONCENTRATION VARIABILITY (COEFFICIE CANYON WITH SOIL PARTICLE SIZE FRACTION AND SOIL DEPTH IN MORTANDAD 62 0.58 0.93 0.62 44 0.65 0.46 0.55 13 0.11 0.16 Q.50 0.38 0.44 0.49 0.35 independent of the magnitude of plutonium concentra- least-squares techniques cto determine the signif- tion within the ranges of observed data. ieance of plutonium concentration vs depth relation- and horizontal inhomogeneity in plutonium contamina- Only four comparisons were those from Glenn, Trinity tion within study areas comprises a part of the total observed variabilicy, while soil particle size Site (Ground Zero and Area 21), and macroplot 1 at fractions do not appear to contribute significantly Rocky Flats. to the overall variability at those sires examined. Regression slopes for the first three areas were positive, whereas the slope was negative Ic would appear that a The relationship between UV and soil depth was statistically significant in the study areas at clear definition of such relationships would be Trinity and Glenn and at macroplot 1 at Rocky Flats. instrumental in efficient study design and would The CV increased with depth at the Trinity Sire and provide insight as to the mechanisms of soil pluto-~ Glenn study areas and decreased with depth in macro- nium mobility. ‘plot 1 at Rocky Flats. Conclusions.--Plutanium concentration variability in soils from 7 geographical regions ranged from The CV was relatively consistent, the diversity of environments and er “age” se However, of the considering that plutonium concentrations varied plutonium at che various study sites likely con- through 6 orders of magnitude and appeared to be tribute to overali variability and certainly complicate interpretation of data between sites. TABLE VII Highest CVs were associated with accidental LINEAR REGRESSION OF SOIL COEFFICTENT releases of plutonium. OF VARIATION WITH DEPTH ay a Glenn 0.38 0.02 0.59" Trinity Ground Zero 0.93 0.05 0.83" Trinicy Area 21] 0.75 0.04 0.827 NTS-A-13, Strata 1 1.8 -0.02 G.17 NTS-A-13, Strata 6 0.63 0.02 6.16 NTS-A-5, Sctrata lL 0.98 0.01 0.06 NTS-A-5, Strata 4 lL.1 -0.02 0.28 Janet 1.7 0.02 0.27 rocky Flats Macroplot 1 1.6 -0.06 0.534 Macroplot 2 2.2 -0.05 0.22 Equation of rhe form v = a_ nd x = soil depth (cm). + a, X. where y = CV uncontaminated ecosystems. Differences in methodologies at the various study sites make comparison of the data difficulec and emphasize the need for coordination of etfort between sites to improve the utilicy and compar- ability of the data. Studies should be designed to look specif~ ically at the components of overall variability. Data from Rocky Flats and Los Alamos indicate cthac the analytical componenc of overall variability concributes less than 35% to the total. Other fac- tors which might be considered include variability in mass of soil particle size fractions within study plots and the relationship of plutonium CV to the variability in other soil physical-chemical properties. Ont ay wat Location This type of release would be che most likely source of plutonium to presently @ee 0.48 to 3.2. Lower CV values were generally associated with fallout and effluent sources of plutonium. “4 ee for the Rocky Flats area. mee (Table VIT). significant (p < 0.05): e1~ ships Vertical 7 7.5-12.5 12.5-22 gow 0.54 wed 0.58 Oo 2.5-7.5 te os 0.64 0.49 e+ 0.65 0.84 te 0.48 79 0-2.5 All available data were examined using linear (2 to 23 mm) (1 to 2mm) a Soil Particle Size Fraction (500 to 1000 um) (105 to 500 um) wea (53 to 105 um) 6 53 um) oO (< oOo Depch Profile (cm)