• Grade I: With low level of chemical components, the groundwater is suitable for
various uses;
• Grade II: With relatively low level of chemical components, the groundwater is
suitable for various uses;
• Grade III: With moderate chemical content, the groundwater is suitable for
centralized drinking water supply and agricultural and industrial uses based on
the Standards GB5749–2006;
• Grade IV: With relatively high level of chemical components, the groundwater
is suitable for agricultural and industrial uses when meeting corresponding water
quality requirements, and after appropriate treatment, it can be used for drinking
water supply based on a certain level of human health risks;
• Grade V: With high level of chemical components, the groundwater should not
be for drinking water supply, but for other purposes where appropriate.
Table 5.40 Background
values of groundwater
indicators in the Dachaidan
Landfill
No. Items
Unit Background values
1
K
+
mg/L 1.96
2
Na
+
mg/L 34
3
Ca
2+
mg/L 27.58
4
Mg
2+
mg/L 7.84
5
NH 4
+
mg/L 0.06
6
Cl
−
mg/L 28.33
7
SO 4
2−
mg/L 46.68
8
HCO 3
−
mg/L 113.37
9
CO 3
2−
mg/L 0
10
F
−
mg/L 1.29
11
NO 3
−
mg/L 2.96
12
NO 2
−
mg/L –
13
I
−
mg/L –
14
H 2 SiO 3
mg/L –
15
Total soluble solids
mg/L 257
16
Chemical oxygen demand mg/L 0.36
17
Fe
mg/L –
18
Total hardness
mg/L 101
19
Cu
lg/L –
20
Pb
lg/L –
21
Zn
lg/L –
22
Cd
lg/L –
23
As
lg/L –
24
Hg
lg/L –
25
Se
lg/L –
26
Al
lg/L –
27
Mn
lg/L –
28
Cr
6+
lg/L –
174
5 Application Cases