Table 5.76
(continued)
Test items
Sampling position
Class III standard for
groundwater quality
1 m below the water level
1/2 of the well depth below the
water level
3/4 of the well depth below the
water level
Cobalt
<0.005
<0.005
<0.005
<0.005
<0.005
<0.005
0.05
Mercury
<0.00005
<0.00005
<0.00005
<0.00005
<0.00005
<0.00005
0.001
Arsenic
0.002
0.002
0.001
0.003
<0.001
0.001
0.05
Selenium
<0.0004
<0.0006
<0.0004
<0.0005
<0.0004
<0.0005
0.01
Cadmium
<0.0001
<0.0001
<0.0001
<0.0001
<0.0001
<0.0001
0.01
Hexavalent
chromium
<0.004
0.007
<0.004
0.006
<0.004
0.007
0.05
Lead
0.0029
0.0030
0.0028
0.0029
0.0028
0.0028
0.05
Barium
<0.01
<0.01
<0.01
<0.01
<0.01
<0.01
1.0
Nickel
<0.005
<0.005
<0.005
<0.005
<0.005
<0.005
0.05
Permanganate index
1.7
1.8
1.7
1.7
1.5
1.6
3.0
Total coliforms
Not detected
Not detected
Not detected
Not detected
Not detected
Not detected
3.0
Total number of
bacteria
26
37
24
32
24
34
100
Unit: mg/L (pH: dimensionless, turbidity: NTU, chroma: degree)
5.4 Southeast China
245