tion of micro- and macroencapsulation. Because
METHODS AND MATERIALS
of the low permeabilities and hydrophobic, wa-
ter-repelling nature of the compacted materials,
Initial RMA waste soil characterization
water cannot easily penetrate the soil body
Four separate 15-gal drums containing repre-
(Pamukcu et al. 198990). In Europe, such DCR-
sentative soil samples were transported under full
treated soil bodies have been compacted (with
chain of custody to SOUND/epic Environmental
permeabilities in the range of 106 to 108 cm s1)
in Encinitas, California, on 9 March 1995. Upon
initial receipt, each sample was further homog-
into unlined landfills, roads, berms around tank
farms, and subgrade for industrial sites. Data from
enized and examined to assess handling and
adjacent monitoring wells have verified the ab-
physical characteristics (Table 1). An aliquot of
sence of any significant off-site migration of or-
each was removed for hexane extraction and gravi-
ganic components for over 16 years (Boelsing
metric determinations of oil and grease and total
1994).
petroleum hydrocarbons (TPH). The extracts were
This report summarizes the results of DCR test-
then further characterized by flame ionization de-
ing of soil-amended Basin F sludge from the Rocky
tector (FID) gas chromatography (GC) to deter-
Mountain Arsenal. The report is divided into sev-
mine total resolved hydrocarbons and the approxi-
mate molecular weight range (distillate cut
eral sections dealing with waste characterization,
fraction) of any petroleum-type constituents in
selection of a "worst case" sample for further test-
the sample. Electron capture detector (ECD) gas
ing, initial DCR treatability testing (scoping ex-
chromatography was then used to screen for pes-
periments) on the worst-case sample, and bench-
ticides.
scale (13 kg) batch preparation of DCR-treated
Figure 1 presents the chromatograms obtained
material for independent, third-party laboratory
from the FID GC analyses. Of the four samples,
analyses. The results of the independent chemical
the "soil-amended Basin F sludge from above the
testing are then presented, followed by overall con-
liner" is clearly the most contaminated, with five
clusions and recommendations for further study.
Table 1. Initial characterization of four selected waste/soil samples from the Rocky Mountain
Arsenal Basin F area.
Waste sample
Below the liner,
Soil-amended Basin F
Below the liner,
Below the liner,
sample no. 41238
sludge from above the
sample no. 24093
sample no. 41249
liner, sample
no. 24216
Waste description
Lt. brown, dry, and
Med. brown soil/silt.
Wet, saturated gray
Lt. tan/brown
slightly plastic and
Very dry and friable;
clay/silt sludge.
clayey soil. Com-
sticky soil. No
not plastic. Yellow-
Surface and inter-
pressible. No
crystals present.
green crystals present.
stitial water, light
crystals present.
tan/brown.
Odor
Mild, sweet
Rotten (like old gym
Light petroleum
Moderate
socks or shoes) and
hydrocarbon-
"pesticide" or
trace of ammonia.
like smell
organic smell.
Peak OVA in drum
headspace (ppm)
430
N.A.
100
400
Stable OVA in drum
headspace (ppm)
35
N.A.
2
15
Moisture content (%)
15.8
11.7
27.2
16.3
Gravimetric oil and
grease (mg/kg dry wt.)
365
10,700
4,110
634
Total resolved
hydrocarbons (FID
GC) (mg/kg dry wt.)
726
2,420
82
943
Total resolved
pesticides (ECD GC)
(mg/kg dry wt.)
1,010
3,270
110
1,280
N.A. = Not analyzed
2
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