centerline) perpendicular to the road. Twenty or more increments were taken to build
each composite. Transects were fixed with the help of the Global Positioning System
(GPS). The GPS locations are reported in Table I. The linear transect samples
corresponded to the % of the distance between the range entrance and the target. As
an example, at 20% of the distance, we collected on each side of the road by walking
perpendicularly to the road using a GPS to keep on a straight line. A minimum of 20
surface sub samples at 0-2 cm depth were collected to build each composite sample
with A and B corresponding to the right and left sides of the road. The composites
were built by walking 100-200 meters. In some occasions such as hot spots or other
artefacts of interest, we used composite sampling that consisted in building the
sample using discrete samples around the hot spot (20 minimum). This strategy was
also used in the strafing area of Jimmy Lake Range except that the 40 %
corresponded to the target area (Fig. 2). Three to four sets of poles held targets for
strafing in this range as illustrated in Figure 3. Composite soil samples were collected
behind three targets in transects that were split into A and B sections as illustrated
(Fig. 2). Transects were parallel to targets at distances of 20, 40, 60, 80, 100, 120,
140 and 160% of a 150 m range. The soil samples collected in this range were
comprised of fine grained sand and were collected in transect 0 to 100 %. Samples of
vegetation were taken at 20 to 60 % and at 120 to 160% beyond the 150 m length of
the range.
In the Bombing area of Jimmy Lake and in Shaver River ranges, the circular
sampling strategy developed during Phase I was applied and consisted of sampling
around targets by compositing samples taken in a circular pattern. This strategy, based
on the circular sampling used at CFB Shilo, was used for specific target evaluation.
The strategy was modified to adapt to the specific context of air-to-ground targets and
was designed to allow a comparison of the relative concentrations in front of and
behind a target. A semi-circular pattern was used to collect composite samples at
specific distances from the targets (Fig. 4). Twenty-six soil samples were collected
around targets, one within each of the cells around the target. Three circles located at
10, 30 and 50 m radius of the target define these cells. Two composite samples (A1 &
A2) were collected in hemispheres of the first 10-m diameter ring (Front and Back of
Target). Eight equal-sized rectangles were sampled between 10 and 30 m (B1-B8),
and 16 between 30 and 50 m (C1-C16). Twenty or more increments were collected to
build 800 g to 1.5 kg composite samples. In Jimmy Lake Range, an old Truck was
used as the target, while a tank was used as the center of the circular strategy in
Shaver River Range (Figs. 5, 6). In this range, air dropping of 250, 500, and 1000 lbs
high explosive (HE) bombs at a stationary target is done on a regular basis and
significant explosive concentrations had been measured during Phase I. For this
reason, the circular approach was used to verify that the concentrations were of the
same order of magnitude even with the range tilling performed regularly. As for the
other ranges, the surface was covered with fine grained sands. In front of the target in
Shaver River Range, sampling designed for a statictical analysis was conducted.
The purpose of the sampling experiment conducted at the Shaver River Range was to
understand the distribution of energetic residues at an Air Force bombing range in
order to optimize the sampling strategy for collection of representative surface soil
samples at these types of ranges. The emphasis was on surface soils because residues
of energetic compounds are deposited as particles at the surface. These surface
residues are the largest source of residues for potential migration of these compounds
9
DRDC Valcartier TR 2004-204
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