Just like you or me, water companies would rather mindlessly repeat the same task over and over. Since water is packaged in the same plant as soda and juices, it’s just easier for, say, Coca-Cola to label Dasani bottles the same way it would Coke and Sprite bottles instead of having a whole separate process. So whatever expiration date your bottle has on it is the same as bunch of soda and juice bottles that were made on the same day.
