% Na | Quality of water | Samples |
<20% | Excellent | 12 (CTd, IT1a, IT1b, IT1c, IT1d, IT2a, IT2c, IT2d, IT3a, IT3b, IT3c and IT3d) |
20% - 40% | Good | 3 (CTc, IT2b, SWa) |
40% - 60% | Permissible | None |
60% - 80% | Doubtful | 1 (CTb) |
80% | Unsuitable | 3 (CTa, SWb, SWc) |