The Dangerous Couple: Illegal Mining and Water Pollution—A Case Study in Fena River in the Ashanti Region of Ghana
Table 3
Nemerow’s pollution index and water quality index.
Month
Pb
Cd
Fe
Cu
Zn
pH
Temp.
Turb.
TSS
Cond.
TDS
Nemerow’s pollution index (NPI) for Fen 1
Jan.
33.1
110.33
7.57
0.06
0.18
1.08
1.18
2.60
5.99
1.20
6.03
Feb.
15.5
51.66
8.22
0.06
0.17
1.06
1.17
2.51
6.07
1.10
6.42
Mar.
0
0
6.66
0.01
0.09
1.08
1.19
2.68
6.10
1.30
5.12
April
12.3
41
6.76
0.03
0.16
0.98
1.19
2.84
5.85
1.21
6.63
May
81.1
270.33
6.02
0.04
0.17
1.12
1.18
2.37
4.27
1.30
6.34
June
34.1
113.66
6.50
0.04
0.17
1.06
1.19
2.80
4.08
1.31
6.42
July
1.2
4
6.60
0.04
0.12
1.00
1.17
2.24
4.36
1.20
6.61
Aug.
2.1
7
6.07
0.04
0.17
0.98
1.20
2.12
4.23
1.20
6.58
Sept.
1.1
3.66
5.52
0.07
0.18
1.07
1.18
1.97
4.14
1.28
6.41
Oct.
2.2
7.33
6.01
0.03
0.16
1.11
1.20
2.51
4.02
1.24
6.40
Nov.
31.2
104.00
5.61
0.06
0.18
1.07
1.19
2.33
4.62
1.26
6.40
Dec.
16.5
55
6.09
0.07
0.18
1.06
1.18
2.19
4.24
1.22
6.62
WQI
=23.70
Nemerow’s pollution index (NPI) for Fen 2
Jan.
87.60
5.33
7.05
0.01
0.18
1.03
1.19
2.68
5.85
1.25
6.03
Feb.
103.30
10.33
5.82
0.06
0.20
1.20
1.18
2.81
6.10
1.30
6.42
Mar.
102.10
4
6.04
0.07
0.20
1.06
1.21
3.08
6.10
1.28
5.66
April
86.60
7.33
6.72
0.06
0.15
1.06
1.18
2.52
5.85
1.27
6.62
May
56.10
3.67
6.57
0.04
0.16
1.20
1.19
2.76
5.87
1.25
6.24
June
43.20
4
6.61
0.12
0.16
1.19
1.21
2.59
5.88
1.24
6.42
July
81.20
7
6.71
0.06
0.16
1.25
1.19
2.51
5.90
1.26
6.36
Aug.
51.10
10.67
6.52
0.03
0.16
1.05
1.20
2.49
6.07
1.29
6.42
Sept.
32.10
7
6.58
0.01
0.14
1.03
1.19
2.25
5.89
1.27
6.62
Oct.
23.10
4.33
6.63
0.02
0.17
1.19
1.19
2.56
5.86
1.25
6.71
Nov.
93.20
10.67
6.05
0.03
0.18
1.10
1.19
2.45
6
1.27
6.41
Dec.
104.10
13.67
6.77
0.04
0.16
1.15
1.19
2.39
5.95
1.28
6.42
WQI
=20.33
Nemerow’s pollution index (NPI) for point A
Jan.
5.2
3.33
2.24
0
0.11
0.97
1.17
1.89
0.24
0.14
4.25
Feb.
4.1
3.33
2.45
0.01
0.1
1.04
1.14
2.13
0.21
0.14
3.68
Mar.
10.3
3.33
2.4
0.01
0.11
1.03
1.17
1.37
0.23
0.12
3.04
April
6.2
3.33
2.56
0.01
0.15
1.02
1.15
2.08
0.26
0.15
2.05
May
5.1
3.33
2.39
0.01
0.13
1.04
1.15
1.95
0.25
0.17
2.00
June
3.2
3.33
2.24
0.06
0.13
1.03
1.17
1.97
0.21
0.14
2.82
July
3.1
3.33
2.28
0.02
0.11
0.99
1.17
1.91
0.23
0.16
3.43
Aug.
2.1
3.33
2.61
0.02
0.11
1.00
1.17
1.41
0.21
0.18
4.20
Sept.
2.2
3.67
2.44
0.01
0.15
0.97
1.15
1.40
0.25
0.13
3.74
Oct.
3.6
3.33
2.56
0.01
0.13
1.04
1.17
1.79
0.22
0.15
2.59
Nov.
5.6
3.67
2.37
0.02
0.13
1.06
1.17
1.63
0.25
0.12
2.65
Dec.
4.2
4.33
2.31
0.06
0.13
1.05
1.17
1.76
0.22
0.13
2.41
WQI
=55.05
Nemerow’s pollution index (NPI) for point B
Jan.
5.2
10.67
3.41
0.01
0.21
1.2
1.18
5.13
1.2
0.21
6.02
Feb.
4.1
67
3.17
0.01
0.25
1.17
1.18
3.49
1.46
0.23
6.50
Mar.
10.3
34.33
3.61
0.01
0.2
1.24
1.19
5.73
1.17
0.23
6.82
April
6.2
34
2.94
0.02
0.2
1.17
1.18
5.93
1.55
0.24
6.24
May
5.1
68.33
3.06
0.02
0.21
1.22
1.18
5.77
1.4
0.27
6.22
June
3.2
10.67
2.52
0.02
0.25
1.17
1.19
4.28
1.35
0.26
6.11
July
3.1
10.33
2.58
0.01
0.35
1.24
1.18
5.77
1.25
0.25
6.02
Aug.
2.1
7
3.43
0.01
0.35
1.19
1.18
5.49
1.09
0.28
6.33
Sept.
2.2
4
3.36
0.01
0.16
1.13
1.18
4.60
1.25
0.27
6.6
Oct.
3.6
12
3.44
0.02
0.18
1.11
1.18
4.85
1.31
0.28
6.44
Nov.
5.6
18.67
3.53
0.02
0.19
1.25
1.18
4.43
1.33
0.24
6.22
Dec.
4.2
14
3.67
0.03
0.11
1.27
1.18
4.09
1.47
0.25
6.31
WQI
=30.81
Nemerow’s pollution index (NPI) for point C
Jan.
0
40.33
0.08
0
0.21
1.22
1.18
2.4
0.35
0.21
6.22
Feb.
0
43.33
0.27
0
0.20
1.22
1.19
2.16
0.19
0.18
6.1
Mar.
0
30.67
0.27
0
0.18
1.27
1.17
2.27
0.24
0.20
6.32
April
0
43.33
0.29
0
0.15
1.28
1.18
2.24
0.46
0.20
6.01
May
0
47
0.18
0
0.15
1.26
1.2
2.41
0.37
0.19
6.42
June
0
57
0.18
0.01
0.17
1.19
1.18
1.71
0.21
0.19
6.21
July
0
36.67
0.21
0
0.16
1.27
1.18
1.63
0.20
0.21
6.3
Aug.
0
31.67
0.15
0
0.13
1.17
1.18
2.4
0.29
0.21
6.24
Sept.
0
26
0.17
0.01
0.16
1.15
1.18
2.27
0.22
0.20
6.13
Oct.
0
25.33
0.18
0
0.19
1.24
1.18
2.19
0.21
0.18
6.33
Nov.
0
40.33
0.12
0
0.17
1.22
1.17
2.24
0.20
0.19
6.2
Dec.
0
44
0.17
0
0.19
1.23
1.18
2.07
0.23
0.19
6.62
WQI
=56.81
Nemerow’s pollution index (NPI) for Fen 3
Jan.
12.9
20.67
5.53
0.03
0.12
1.07
1.19
4.85
4.05
0.32
6.02
Feb.
12.4
13.67
6.04
0.05
0.10
1.06
1.18
4.19
4.18
0.31
7.04
Mar
13.1
14
5.56
0.03
0.09
1.12
1.18
2.40
5.85
0.32
6.23
April
12.2
11.67
5.49
0.02
0.10
1.13
1.19
4.67
3.30
0.37
6.80
May
10.2
18
5.50
0.03
0.15
1.05
1.20
4.20
4.02
0.34
7.40
June
8.1
19.67
6.02
0.03
0.13
1.06
1.17
4.08
4.08
0.31
6.64
July
8.8
15.33
5.51
0.04
0.11
1.07
1.18
4.19
4.26
0.37
6.41
Aug.
8.2
20.67
5.87
0.03
0.12
1.05
1.17
4.35
4.82
0.32
6.60
Sept.
12.1
21
5.62
0.03
0.16
1.01
1.18
4.15
4.26
0.30
6.24
Oct.
12
18
5.53
0.03
0.12
1.03
1.19
4.20
2.30
0.35
7.23
Nov.
11
21
5.53
0.03
0.12
1.11
1.18
4.13
3.16
0.37
6.02
Dec.
12.1
14.33
5.58
0.03
0.15
1.10
1.20
4.13
2.04
0.31
6.18
WQI
=26.57
All values in italic show absence of pollution. Jan. = January; Feb. = February; Mar. = March; Aug. = August; Sept. = September; Oct. = October; Nov.= November; and Dec. = December.
