5 Conclusion
In August 2002 DRDC Valcartier and CRREL conducted Phase I to characterize the
soil, vegetation and surface water for metals and energetic materials at Cold lake Air
Weapons Range (CLAWR). A total of 193 soil, 16 vegetation and 4 surface water
samples were collected during Phase I in Alpha, Bravo, Jimmy Lake, Shaver River,
open detonation and rifle ranges. A few surface water samples were collected in
Primerose Lake, Jimmy Lake, the Shaver River and in a pond containing ammunition
in Shaver River Range. In August 2003, DRDC Valcartier and CRREL conducted
Phase II of the study to complete the characterization of the soil, vegetation, surface
water and sediment for metals and energetic materials. 324 soil, 69 vegetation, 19
surface water and 28 sediment samples were collected during Phase II. Efforts were
mainly in Jimmy Lake and Shaver River ranges, and also in Primerose Lake and
Jimmy Lake.
Two strategies were used to collect samples across the ranges. The first consisted in
using a linear sampling pattern. This approach was used during Phase I to evaluate
whether the level of contamination by metals was following a pattern with distance
from the target. The same approach was used in Alpha Range to collect vegetation
samples and in Jimmy Lake Range where we modified the strategy by fixing the 40 %
transect at the target position. The concentrations behind and in front of the target
were then determined. This proved to be a good approach since the results showed
that metals accumulated mainly in front of the targets. The second sampling strategy
was the circular approach also developed during Phase I and applied to targets in
Jimmy Lake and in Shaver River ranges. The strategy consisted of compositing
samples taken in a circular pattern around targets. Twenty-six (26) soil samples were
collected, one within each of the cells around the target. These cells are defined by
three circles located at 10-, 30- and 50-m radius of the target. Two composite samples
(A1 & A2) were collected in hemispheres of the first, 10-m diameter ring (in front of
and behind the 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. Furthermore, in Shaver River
Range, a one hundred 1-m x 1-m minigrids were constructed and 100 discrete
samples were collected to evaluate the dispersion and the heterogeneity of the
explosives in front of the tank. This statistical evaluation revealed again the great
heterogeneity encountered with explosive contamination, and emphasized that
compositing with 20-30 increments is the best approach to collect soils for explosive
analysis. In all other ranges such as in the remote areas, simple composite sampling
was done around targets or existing infrastructures that were used as targets.
Generally, as observed during Phase I, results from Phase II showed that the
concentrations of metals in soils in all of the ranges were quite low. Most of the time,
the metals detected at concentrations higher than the BGL were only 1 to twice the
BGL value. Most of the time, concentrations were far below the ASQG except for
some metals such as cadmium, copper and zinc, which were present at higher
concentrations. These metals can be related to firing activities. Nevertheless, most of
the values were quite low. Only copper in Jimmy Lake Range exceeded the ISQG.
The fact that metals concentrations were low is the direct result of good management
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DRDC Valcartier TR 2004-204
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