The overall project, of which this is a part, was
seeps. At Fort Richardson, we sampled a hand grenade
designed to develop techniques for assessing the poten-
range to determine whether the results would be con-
tial for environmental impacts from energetic materials
sistent with those obtained for the Fort Lewis grenade
on testing and training ranges. Techniques are being
range.
developed to define the physical and chemical proper-
ties, concentration, and distribution of energetics and
SITE DESCRIPTION, SOIL AND
residues of energetics in soils, estimate the concentra-
GROUNDWATER SAMPLING,
tions of various energetic materials that are deposited
FORT LEWIS, WASHINGTON
from high-order detonations of various military muni-
tions, and assess the potential for transport of these
Fort Lewis is located approximately 10 miles west
materials to groundwater. Other issues, such as off-site
of Olympia, Washington, and adjacent to McChord Air
transport in surface runoff, or as a component of air-
Force Base. Fort Lewis, part of Forces Command, is
borne dust, are also important, but are beyond the scope
the home of First Corps, one of 15 U.S. power projec-
of the project.
tion platforms. The Corps' primary focus is Pacific Rim.
The study will be executed in two parts: range char-
Fort Lewis includes 115 live fire ranges and encom-
acterization, and fate and transport parameters for explo-
passes 86,000 acres. Soil sampling was conducted at
sives residues. To characterize ranges, heavy artillery
Fort Lewis, Washington, on 7 and 8 July 2000. Three
impact and firing points, and hand grenade ranges will
distinct functional areas at Fort Lewis were chosen for
be sampled. Where possible, groundwater associated
soil sampling. The three areas sampled were a hand
with the ranges will also be sampled. Chemical resi-
grenade range impact area, a firing point for artillery,
dues from live fire or demolitions of specific rounds
and an artillery impact area.
will be assessed by detonations on snow cover. To fill
Hand grenade range
data gaps in transport parameters, such as dissolution
kinetics and partitioning coefficients, laboratory scale
The grenade range at Fort Lewis is divided into four
batch tests will be conducted.
separate launching and impact areas separated by con-
crete and wooden walls and has been actively used for
at least 30 years.* It is estimated that about 6,000 to
OBJECTIVES
7,000 grenades are thrown on the range each year, or
The major objective of the research reported here
about 1,500 to 1,750 grenades per launching area per
was to determine the magnitude and variability of explo-
year.
sives residues in surface soils resulting from training
Currently about 95% of the hand grenades detonat-
activities at several types of training ranges at major
ed on this range are M67 fragmentation grenades, which
U.S. Army training facilities. It is hoped that this type
are the type of hand grenade currently used by the U.S.
of information will help assess the potential for con-
Army. The other 5% of the grenades used at this range
tamination of groundwater with explosives-related con-
are of Canadian and British manufacture and used by
taminants. A long-term objective of this work includes
Canadian and British troops who train regularly at Fort
the development of a protocol that can be used to deter-
Lewis. The Canadian hand grenade is model C7, but is
mine the nature and extent of surface soil contamina-
manufactured to the same specification as the U.S. M67.
tion around impact areas that will include the sampling
The current British hand grenade is the Model L2, which
strategy and analytical methods best suited to this applica-
is based on the older U.S. M26 hand grenade.
tion. Data generated with this protocol can then be used
The M67 and C7 grenades contain 186 g of Compo-
to estimate a source term for post-blast residues based
sition B as the main charge. Composition B is com-
upon the extent of surface soil contamination at a spe-
posed of 60% military-grade RDX and 39% military-
cific site. To address these objectives, ranges were sam-
grade TNT. Military-grade RDX generally contains
pled at Fort Lewis, Washington, and at Fort Richard-
HMX as the major impurity, with concentrations rang-
son, Alaska. At Fort Lewis, we investigated surface
ing from 8 to 12% (U.S. Army 1984). Military-grade
contamination at two types of ranges: an artillery range
TNT is about 99% 2,4,6-TNT with the remainder made
and a hand grenade range. On the artillery range, we
up of other isomers of TNT, the various isomers of dini-
sampled in front of a 105-mm howitzer firing position,
trotoluene (2,4-DNT being the most abundant), 1,3-
and in the main impact area. In the hand grenade range,
dinitrobenzene, and 1,3,5-trinitrobenzene (TNB) (Leg-
we selected one of the four test ranges and sampled
gett et al. 1977, George et al. 1999). Thus, each gre-
surface soils and soils collected at several shallow
depths in the subsoil. We also analyzed a set of ground-
* Personal communication, Del Larson, Range Control, Fort Lewis,
water samples collected from monitoring wells and
Washington, 2000.
2
To contents
Previous Page
