Class | Quality | BMWP-PA index | Significance | Alert Signal |
I | Good | >120 101 - 120 | Very clean water |
|
II | Acceptable | 61 - 100 | Non-contaminated water |
|
III | Regular | 36 - 60 | Moderately polluted waters |
|
IV | Bad | 16 - 35 | Very polluted water |
|
V | Wretched | <15 | Severe contaminated water |
|