Table 3 Standard of surface water quality classification (WHO, 1996)
Comprehensive pollution index (P) | Water quality level |
|---|---|
≤< 0.20 | I cleanness |
0.20 to 0.40 | II sub-cleanness |
0.41to1.00 | III slight pollution |
1.01 to 2.00 | IV moderate pollution |
 ≥ 2.01 | V sever pollution |