EAGLE RIVER FLATS FY 00
46
Table III-2-3. White phosphorus concentra-
Sublimation/Oxidation Conditions
We installed sensors and dataloggers to
tions found in subsurface samples collected
monitor sediment temperature and moisture
at site #53 (Figure III-2-3) in Area C.
conditions using the same configuration of
White Phosphorus Conc. (g/g)
sensors as in 1997 for most of the stations. At
each station (Table III-2-4, Fig. III-2-3, III-2-5,
Depth
1992
1999
2000
III-2-8), sediment temperatures were moni-
Surface
9.83
1.43
0.0051
tored at 5- and 10-cm depths using Campbell
5 cm
179
1.16
0.060
Scientific (Logan, UT) Model 107B soil/wa-
10 cm
0.13
0.003
0.0009
ter thermistor probes. Sediment moisture con-
15 cm
198
0.020
0.0002
20 cm
0.116
not detected
ditions were monitored at 5- and 10-cm
25 cm
0.015
not detected
depths using Campbell Scientific Model 257
30 cm
0.016
not detected
(Watermark 200) soil moisture sensors. Out-
put from both sets of sensors was taken ev-
ery 10 minutes, and the hourly and 24-hour
averages were recorded by a Campbell CR10
terial remaining on the sieve was placed in a
Measurement and Control Module and an
septa jar and equilibrated at room tempera-
SM716 Storage Module.
ture. To determine if white phosphorus par-
Tensiometers provided another measure of
ticles had been retained on the sieve, we
s u r f a c e sediment moisture conditions.
SoilMoisture (SoilMoisture Equipment
performed headspace solid-phase micro-
Corp., Santa Barbara, CA) Series 2725 tensi-
extraction (SPME) followed by gas chroma-
ometers equipped with dial gauges were in-
tography (M.E. Walsh et al. 1995a).
stalled, one at 10-cm depth and another 20-
Discrete samples were subsampled by tak-
cm depth at most sites, and they were read
ing a 40-g portion of each soil and extracting
periodically by Dave Mitchell (Weldin Con-
the white phosphorus with 20 mL of isooc-
struction). A third tensiometer was equipped
tane. Subsurface samples, which were ob-
with a pressure transducer and wired to the
tained in the field with corers, were placed
datalogger where hourly and 24-hour aver-
directly in isooctane. After shaking overnight,
ages were computed and recorded on a stor-
the extracts were analyzed by gas chromatog-
age module.
raphy (EPA SW-846 Method 7580).
Table III-2-4. UTM coordinates and elevations of
dataloggers used to record sublimation/oxidation condi-
tions 5 June to 21 September 1999.
Datalogger
Elevation
Site
E (m)
N (m)
(m)
355,038.50
6,801,300.50
C 100m*
4.64
BT N 100m
354,536.42
6,801,826.00
4.74
BT S 100m
354,521.08
6,801,724.34
4.76
Pond 155
355,112.37
6,801,536.84
4.58
Pond 146
355,303.09
6,801,168.79
4.15
Pond 730 Station 2*
354,894.80
6,801,838.55
4.32
Pond 75
354,773.83
6,802,085.20
4.30
A Ponds - 1 (Pond 258)
353,990.20
6,800,707.95
4.61
A Ponds - 2 (Pond 256)
353,823.82
6,800,780.01
4.51
C (piezo site from '94)
355,013.18
6,801,196.88
4.78
*Tripods were moved by ice to the east of previous locations.
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