Geology Reference
In-Depth Information
TABLE 14.2 Concentration of Mercury and Chromium in the Top 2 Centimeters (1971) and 3 Centimeters (1997/98)
of Bottom Sediment in Lake Erie and in Local Municipal Drinking Water
1971 Core Sites*
Chromium
1971
(ppm)
Mercury
1971
(ppm)
1997/98 Core
Sites (approx.
1971 locations)*
Mercury
1997/98
(ppm)
1997/98" Core Sites
(nearby locations)
Mercury
1997/98
(ppm)
1
143
2.1
97
0.94
96
0.22
—
—
—
2
87
2.0
3
88
1.4
0.69
4
47
1.0
81
0.46
82
0.37
5
141
2.8
88
0.08
6
80
1.4
86
0.69
7
75
0.71
85
0.64
8
48
0.82
84
0.23
9
37
0.44
79
0.24
80
0.21
10
60
0.3
73
0.13
110
0.03
11
18
0.12
74
0.24
12 Cleve Harbor
143
0.93
92
0.02
68
0.25
13
53
0.46
111
0.30
66
0.18
14
47
0.18
98
0.16
69
0.20
63***
0.17***
15
5
0.01
51
0.01
16
24
0.45
99
0.07
47
0.22
17
44
0.19
43
0.09
42
0.07
—
18
0.12
107
0.05
19
103
2.3
35
0.13
109
0.01
—
—
20 Buffalo Harbor
103
2.3
—
—
"A"
61
102
0.16
105***
0.05***
Municipal water
Detroit, Ml
0.0015
Toledo, OH
0.0037
Cleveland, OH
0.0035
Buffalo, NY
0.0028
* The approximate match of 1971 and 1997/98 sites is given by location on the same line.
** Nearby locations, 1997/98: locations near the 1971 sites and their mercury concentration.
*** Secondary nearby locations and their mercury concentration.
Concentrations for some sites have been plotted on Figures 14.1, 14.2, and 14.3.
9.
With reference to Table 14.2 and Figures 14.1 and 14
.3,
b. at the sites of the four highest 1971 values of mercury in
briefly describe the changes between 1971 and 1997/98:
the West Basin
a.
in the areas of high and low mercury distribution
high mercury values in the West, Middle, and East
Basins
low mercury values in the Middle Basin
