CI | Water Quality Class | Water condition |
>83 | I | No or very low pollution |
73 - 82 | I - II | Low pollution |
56 - 72 | II | Moderate pollution |
44 - 55 | II - III | Critical pollution |
27 - 43 | III | Severe pollution |
17 - 26 | III - IV | Very severe pollution |
<17 | IV | Excessive pollution |