Table 4 Summary statistics of pollutant concentration in samples and potable water standard specifications given by the WHO.
Heavy metals | Wet season (g/l) | Samples exceeding DW. standards (%) | Dry season (g/l) | Samples exceeding DW. standards (%) | WHO standard (µg/l) | EPA standard (µg/l) | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| Â | Min | Max | Mean | Min | Max | Mean | ||||
As | 0.3 | 2.44 | 2.23 | 0 | 0.33 | 8.8 | 1.6 | 0 | 10 | 10 |
Cd | 0 | 10 | 0.31 | 2.4 | 0 | 9 | 0.29 | 2.4 | 3 | 5 |
Pb | 0 | 9.89 | 2.66 | 0 | 0.67 | 9.89 | 4.22 | 0 | 10 | 15 |
Cr | 1.6 | 42 | 24.99 | 0 | 0.75 | 24 | 13.97 | 0 | 50 | 100 |
Cu | 1.12 | 560.33 | 4.54 | 0 | 0 | 96 | 11.35 | 0 | 2000 | 1300 |
Zn | 4.31 | 368.83 | 69.7 | 0 | 5.8 | 730 | 140.62 | 0 | – | 500 |
Mn | 4 | 163 | 44.14 | 0 | 13 | 92 | 97.29 | 0 | 400 | 500 |
