Water class | Variation %Na | Number of samples | % of samples |
Excellent | <20 | 2 | 6 |
good | 20 - 40 | 4 | 12.2 |
Eligible | 40 - 60 | 12 | 36.4 |
Doubtful | 60 - 80 | 14 | 42.4 |
Unsuitable | ≥80 | 1 | 3 |