Table 5.45
Results of groundwater pollution evaluation of the Dachaidan Landfill
No Items
Unit Monitoring well#1
Monitoring well#2
Before the
landfill was
built
After the
landfill was
built
Grade
III
limits
P
Pollution
level
Before the
landfill was
built
After the
landfill was
built
Grade
III
limits
P
Pollution
level
1
NH
4
+
mg/L 0.06
0.02
0.5
−0.08 I
–
0.02
0.5
0
I
2
Cl
−
mg/L 28.33
32.61
250
0.02
II
68.44
85.59
250
0.07 II
3
SO
4
2−
mg/L 46.68
134.4
250
0.35
III
68.49
185.4
250
0.47 III
4
F
−
mg/L 1.29
1.61
1
0.32
III
–
0.46
1
0
I
5
NO
3
−
mg/L 2.96
1.91
20
−0.05 I
–
10.9
20
0
I
6
NO
2
−
mg/L
–
0.24
1
0
I
–
0.02
1
0
I
7
I
−
mg/L
–
0.001
0.08
0
I
–
0
0.08
0
I
8
Metasilicate
(H
2 SiO
3 )
mg/L
–
9.57
1000
0
I
–
9.46
1000
0
I
9
Chemical
oxygen demand
(COD)
mg/L 0.36
0.22
3
−0.05 I
–
0.88
3
0
I
10 Total hardness
(CaCO
3 )
mg/L 101
110.6
450
0.02
II
180
255.98
450
0.17 II
11 Cu
lg/L –
–
1000
0
I
–
3.02
1000
0
I
12 Pb
lg/L –
–
10
0
I
–
1
1 0
0
I
13 Zn
lg/L –
–
1000
0
I
–
10
1000
0
I
14 Cd
lg/L –
–
5
0
I
–
1
5
0
I
15 As
lg/L –
–
10
0
I
–
1
1 0
0
I
16 Hg
lg/L –
–
1
0
I
–
0.1
1
0
I
17 Se
lg/L –
–
10
0
I
–
1
1 0
0
I
18 Mn
lg/L –
–
100
0
I
–
0.35
100
0
I
19 Cr
6+
lg/L –
–
50
0
I
–
4
5 0
0
I
Comprehensive evaluation
Level III, moderate pollution
Level III, moderate pollution
5.2 Northwest China
181