taminants were an order of magnitude higher at the Fort
range characterization studies. Method 8330 was ade-
Lewis grenade range than at the Fort Richardson range,
quate for characterization of explosives contamination
probably due to a higher usage at Fort Lewis. Although
of army ammunition plants and depots, where concen-
RDX concentrations were moderate at these ranges, the
trations were much higher, but these limits are inade-
size of these ranges is small compared with other train-
quate to delineate contamination at training ranges.
ing ranges, and remediation seems doable if judged to
The distribution of explosives residues at all the
be of sufficient concern with respect to groundwater
ranges investigated was spatially very heterogeneous.
contamination.
For soils at hand grenade ranges, concentrations of
At the Fort Lewis artillery range, surface and near-
explosives-related compounds differed by over two
surface soil samples were collected at a 105-mm how-
orders of magnitude for soil samples collected less than
itzer firing point and at the main impact area. At the
a meter apart. At artillery firing points, concentrations
firing point, samples were collected in front of two
of propellant residues differed by as much as an order
howitzers that had each fired about 600 rounds in the
of magnitude over the same distance. At artillery impact
same position. Samples were collected at distances out
areas, the spatial heterogeneity was large as well,
to 10 m and 20 m for the two guns. Overall, 2,4-DNT,
although it is difficult to define numerically since many
a component of single-based propellant, was found at
of the concentrations were below detection limits. Con-
concentrations as high as 237,000 g/kg in surface soil.
centrations of explosives residues for soils collected in
Whether 2,4-DNT is leaching deep into the profile is
areas that were visibly free of craters, however, often
uncertain because only two shallow subsurface sam-
had explosives concentrations as high or higher than
ples were collected.
soils collected from the rim of a fresh crater. Thus
In the artillery range impact area, soil samples were
thought must be given to sampling methods such as
collected in and around craters formed by detonation
compositing in order to provide representative samples
of various artillery and mortar rounds. Concentrations
for a given area.
of explosives residues associated with these high-order
From preliminary estimates of residues produced
detonations were very low, often below a detection limit
from high-order detonations and the frequency of low-
of 1 g/kg (1 part per billion). RDX, the analyte of most
order detonations, it appears that low-order detonations
concern for groundwater contamination, was always
produce a large portion of the residues deposited on
less than 100 g/kg in these soil samples
surface soils in artillery impact areas. Continued work
Soil samples were also collected under and adjacent
is underway to provide better estimates of the amount
to a 155-mm round that had undergone a low-order
of residues produced from detonations of various mili-
detonation. In this case, the concentration of TNT was
tary munitions and these experiments will provide better
extremely high in the surface soil under the round
estimates in the future.
(1.5%) and was still substantial in soils collected at 5-
and 10-cm depths. Clearly the residues of explosives
LITERATURE CITED
resulting from low-order detonations are many orders
of magnitude higher than those that result from high-
American Public Health Association (1985) Standard
order detonations and efforts should be made to locate
Methods for the Examination of Water and Wastewater,
and eliminate the resulting debris from low-order deto-
16th edition. Washington, D.C.
nations.
Ampleman, G., S. Thiboutot, and S. Dsilets (2000)
Results of analysis of water samples obtained from
Evaluation of the explosives contamination in soils at
five monitoring wells and five seeps that border the
CFB Chilliwack and CFAD Rocky Point. In Proceed-
artillery range at Fort Lewis indicated a low level (<1
ings of the Fifth International Symposium and Exhibi-
g/L) of RDX contamination. The source of this con-
tion on Environmental Contamination in Central and
tamination was not determined. Results of soil analy-
Eastern Europe, Prague, Czech Republic, September
ses from Fort Lewis and Fort Richardson indicate that
2000.
very low concentrations of explosives residues are more
Brannon, J.M., P. Deliman, J.A. Gerald, C.E. Ruiz,
widespread at testing and training ranges than observed
C.B. Price, C. Hayes, S. Yost, and M. Qasim (1999)
previously. The use of an analytical method that has
Conceptual model and process descriptor formulations
lower detection limits than the current standard method
for fate and transport of UXO. U.S. Army Engineer
for explosives residues, SW-846 Method 8330 (U.S.
Waterways Experiment Station, Technical Report IRRP-
EPA 1994), detection limit of 250 g/kg, allowed delin-
99-1.
eation of contamination at training ranges. The GC-ECD
Dauphin, L., and C. Doyle (2000) Study of ammuni-
method developed recently by Walsh and Ranney
tion dud and low-order detonation rates. U.S. Army
(1998) has detection limits near 1 g/kg for many explo-
Defense Ammunition Center, McAlester, Oklahoma.
sives residues and is particularly appropriate for use in
Environmental Protection Agency (1979) Chemistry
26
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