Requirements of drinking ( potable) water:
                                      i.      Free from colour, odour, bacteria, dissolved gases
                                    ii.      Should have pleasant taste
                                  iii.      Dissolved oxygen should be below 10 ppm
                                   iv.      Chloride content should be below 250 ppm.
                                     v.      Flouride content should be below 1.5 ppm.
                                   vi.      Hardness salt content should be below 500 ppm.
                                 vii.      PH  should be in the range of 6.5 – 8.0
To get these properties, the water is treated properly.