My feeling is that I will keep the bottled water for as long as the bottles stay sealed, but after a few months in storage I will add bleach or iodine tabs before drinking just to be sure. Reason being that old bottled water is still going to be better, in theory, than what you might scoop out of an unknown source, because at least it started out safe and clean.
Regards, Alan K.
Available for Cabinet level positions, consultation on matters of foreign policy, weddings and bar-mitzvahs. Will work for gold or guns.