Both responses are slightly off.
The water has been treated by passing O3 through it from an ozone generator (basically an electrical arc in air). The half life of ozone in water is quite short so no dissolved ozone will remain.
The purpose of the treatment is to kill any bugs in the water before it is packaged.
One problem with ozonation is that if there is any appreciable bromine in the water it will react with the ozone to form bromate which is a health hazard. If the water was adequately deionised in the first place this is not a concern.
The water has been treated by passing O3 through it from an ozone generator (basically an electrical arc in air). The half life of ozone in water is quite short so no dissolved ozone will remain.
The purpose of the treatment is to kill any bugs in the water before it is packaged.
One problem with ozonation is that if there is any appreciable bromine in the water it will react with the ozone to form bromate which is a health hazard. If the water was adequately deionised in the first place this is not a concern.