APPENDIX E: BASIN SEDIMENT CHARACTERIZATION
DATA AND ANALYSIS
The tables in this appendix contain data and
basin from the 1996 season as well as the basin
analyses from work done to characterize the
liner. Organic content of the sediments is indica-
dredge spoils in the retention basin. Table E1 con-
tive of the material dredged and is directly
tains moisture content data for the spoils pumped
related to the amount of time required for drying
into the basin during the 1995 dredging season.
to occur. The organic content of the liner is impor-
These data are indicative of the overall effective-
tant for the sorption of colloidal white phospho-
ness of the basin as a remediation tool for contami-
rous, which may percolate through the liner, as
nated sediments removed from the Flats.
well as the susceptibility of the liner to freeze
Although reduction of moisture content was only
thaw deconsolidation.
measured over the winter season, significant dry-
The overall average organic carbon content of
ing of the less organic material found farther from
the sediment samples is 5.4%, the median 5.0%,
and the standard deviation 2.2. Eliminating the
the outfall is a positive outcome. The more organic
outliers brings the average to 4.6%, the median to
(and thicker) deposits nearer the inlet pipe outfall
4.8%, and the standard deviation down to 0.98.
will require a more extensive drying period before
This is comparable to previous analyses of sedi-
the required reduction to approximately 45%
ments from the Flats.
moisture content can be achieved.
Tables E3 and E4 contain survey data for the
Table E2 contains data and analyses of the
test locations in the retention basin. Table E3 con-
organic carbon content of the sediments in the
Table E1. Moisture contents of basin sediment samples (June 1996).
Soil + Tare
Soil moisture
content†
Sample
Depth
Wet
Dry Water wt. Soil wt.
Location
number
(cm)
(g)
(g)
(g)
(g)
(%)
Inlet
P-00:10
0
to
10
49.27
30.37
18.90
21.23
89.02
Pipe
P-10:20
10
to
20
41.75
26.02
15.73
16.56
94.99
P-20:30
20
to
30
39.31
23.99
15.32
14.51
105.58
P-30:40
30
to
40
46.73
29.66
17.07
20.47
83.39
P-40:45
40
to
45
28.90
20.40
8.50
11.34
74.96
Fence
F-00:10
0
to
10
51.33
33.39
17.94
24.31
73.80
Corner
F-10:20
10
to
20
44.08
28.03
16.05
18.58
86.38
F-20:30
20
to
30
46.02
28.61
17.41
19.51
89.24
F-30:37
30
to
37
33.75
22.99
10.76
13.83
77.80
5 m out *
5-00:10
0
to
10
50.24
33.37
16.87
24.01
70.26
5-10:20
10
to
20
38.68
25.72
12.96
16.31
79.46
5-20:30
20
to
30
48.94
31.02
17.92
21.90
81.83
5-30:33
30
to
33
21.31
16.43
4.88
7.13
68.44
10 m out *
10-00:10
0
to
10
41.73
28.65
13.08
19.45
67.25
10-10:20
10
to
20
41.50
26.67
14.83
17.21
86.17
10-20:24
20
to
24
34.04
24.60
9.44
15.54
60.75
15 m out *
15-00:10
0
to
10
45.59
30.06
15.53
20.67
75.13
15-10:20
10
to
20
42.93
28.59
14.34
19.27
74.42
15-20:28
20
to
28
41.23
29.59
11.64
20.14
57.80
20 m out *
20-00:10
0
to
10
44.47
31.48
12.99
22.20
58.51
20-10:18
10
to
18
40.42
28.41
12.01
18.95
63.38
25 m out *
25-00:10
0
to
10
48.44
36.59
11.85
27.23
43.52
25-10:13
10
to
13
23.54
19.08
4.46
9.74
45.79
30 m out *
30-00:10
0
to
10
32.30
28.44
3.86
19.14
20.17
Station 1
S1-00:05
0
to
5
25.14
23.67
1.47
14.25
10.32
Station 3
S3-00:10
0
to
10
54.28
38.16
16.12
28.70
56.17
S3-10:16
10
to
13
27.65
20.44
7.21
10.99
65.61
* Distance from fence corner on splash pad to Station 1.
†
As a percentage of dry weight.
31
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