The final samples collected from the artillery impact area were associated
with a 155-mm round that had undergone a low-order detonation (Figure 20).
This round was broken open and partially filled with the unexploded main
charge. Analysis of the soil just below this round revealed a 2,4,6TNT
concentration of 15,100,000 :g kg-1, or 1.5 percent (Table 8). This was four
orders of magnitude higher than any samples associated with craters formed from
high-order detonations. This sample also contained high concentrations of
4ADNT and 2ADNT, 110,000 and 102,000 :g kg-1, respectively; moderately
high concentrations of 2,4DNT and 1,3,5TNT; and detectable concentrations of
other isomers of DNT and 1,3DNB. The main charge remaining in the broken
round was also sampled and analyzed. It contained 99.96 percent TNT with a
small percentage of the manufacturing impurity, 2,4DNT (0.04 percent). High
concentrations of TNT, its associated impurities, and transformation products
were found in surrounding surface soils. Figure 21 shows a chromatogram for the
extract of a soil sample collected 15 cm west of the round. Samples of soil
collected at depths of 5 and 10 cm below this round also had very high 2,4,6TNT
concentrations, 710,000 and 46,300 :g kg-1, respectively. The 5-cm sample had
even higher concentrations of 4ADNT and 2ADNT than the surface soil.
Concentrations of 2,4,6TNT, 4ADNT, and 2ADNT were still moderately high in
the soils collected at a distance of 15 cm on three sides of this low-order round.