munitions were extracted from the data generated by the U.S. Army Defense
Ammunition Center, McAlester, OK (Dauphin and Doyle 2000).
Results and Discussion
Hand grenade ranges, Fort Lewis and Fort Richardson
The results from the analysis of the soil samples collected from the Fort
Lewis hand grenade range are presented in Table 3. Of the 19 target analytes of
the method, RDX, TNT, HMX, 2,4DNT, 2ADNT, 4ADNT, 1,3,5TNB and
3,5DNA were found at concentrations exceeding 10 :g kg-1 (10 parts per billion)
in at least one sample. RDX, TNT and 4ADNT were detected in every sample
analyzed from the grenade range. RDX, TNT and HMX were consistently found
at the highest concentrations with maximum values of 51,200, 75,200, and
10,100 :g kg-1, respectively. Diagrams showing the concentrations of RDX, TNT
and HMX for these samples are shown in Figures 8, 9, and 10, respectively.
For the surface/10-cm-depth sample pairs, concentrations were consistently
higher in surface samples than in samples collected at the 10-cm depth. In neither
case were the values normally distributed. Therefore, for the following
discussion, ranges and median values for each analyte rather than means and
standard deviations will be used as listed in the following tabulation:
-1
-1
Surface, g kg
10 cm, g kg
Analyte
Range
Median
Range
Median
RDX
316 to 51,200
1,560
76 to 7,390
195
TNT
51.1 to 75,100
543
11.9 to 2,060
56.0
HMX
172 to 10,100
728
<1 to 1,540
53.4
The ratio of TNT to either 4ADNT or 2ADNT was generally higher at the sur-
face than at the 10-cm depth, probably because the soil remained wetter at depth,
thereby creating a condition more favorable to transformation. Detonations in the
sandy soil in this range probably mix the soil profile to some extent. Therefore,
one 10-cm-depth sample had concentrations of RDX and TNT of 7,390 and
2,060 :g kg-1, respectively.
For the surface samples collected in the wheel pattern 11.5 m from the
launching area, RDX concentrations ranged from 424 to 28,000 :g kg-1. A
chromatogram of the extract from the center sample of the wheel analyzed on the
RTX-5 column is presented in Figure 11. Likewise, TNT concentrations ranged
from 126 to 40,600 :g kg-1, and HMX concentrations from 455 to 3,900 :g kg-1.
1
Personal Communication, March 2000, Mr. Mark Serben, Office of the Product
Manager for Mortar Systems, TACOM, Picatinny Arsenal, NJ.
21
Chapter 2 Characterization of Explosives Contamination at Military Firing Ranges
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