Even if its quantity equals kurr, mixed water becomes impure if a particle of an impurity comes into contact with it. However, in the event that it is poured from above onto an impure object, the amount that comes into contact with the impurity is impure, and the amount that does not come into contact with it is pure.
For example, if rose water is poured from a rose water bottle onto an impure hand, the amount that makes contact with the hand is impure, and the amount that does not make contact with the hand is pure.