Chapter 6
 
Table 2 - Summary statistics for 1996/1999 surface samples
 
 
Measured Parameter
(µg/g dry sed. unless noted)		 n MEDIAN ARITHMETIC MEAN STD. DEV.
(% of mean)		 MAX MIN # NATURAL BACKGROUND ENRICHMENT RATIO*
C. perfringens 
(spores/g dry sed.)		 216 385 831 180 15000 0
% fines (wt. %) 220 44.8 47.4 80 99 0
Ag (silver) 216 0.16 0.27 102 3 0 0.05 5.40
Al (aluminum) wt % 218 5.27 5.06 34 10 0.07 6.69 0.76
Ba (barium) 217 330 326 35 1180 5.04 377 0.86
Ca (calcium) wt % 218 1.22 1.27 60 5 0 1.06 1.20
Cd (cadmium) 218 0.11 0.16 132 2 0 0.18 0.90
Cr (chromium) 218 66.7 67.9 58 231 0 59 1.15
Cu (copper) 217 32.9 39.1 93 275 0 8 4.89
Fe (iron) wt. % 218 2.85 2.77 46 9 0 3.57 0.78
Hg (mercury) ppb 183 120 119 71 388 0
Mn (manganese) 218 861 977 59 4627 64.46 544 1.80
Ni (nickel) 218 23.0 24.8 74 212 0 25 0.99
Pb (lead ) 218 31.8 36.1 60 147 2.87 23 1.57
Ti (titanium) wt % 218 0.37 0.37 57 2 0 0.41 0.89
V (vanadium) 218 72.8 68.4 41 129 0 90 0.76
Zn (zinc) 218 95.4 103 59 294 0 68 1.52
Zr (zirconium) 218 112 112 78 1145 4.70 132 0.84


# Zeros in the minimum value represent measured concentrations reported as below the detection limit.
* The enrichment factor is calculated as the ratio of the mean to the background. Bold type indicates enrichment. [an error occurred while processing this directive]