FEMA (the Federal Emergency Management Agency) recommends storing tap water in clean plastic, glass, enameled metal, or fiberglass containers. Once you have filled the container, it should be tightly sealed and stored in a dark, cool location. The water should be rotated out about every six months.
So, can drinking water spoil?
“Old bottled water isn't dangerous to drink but it can taste bad,” says Krogh, who thinks this is one of the reasons for expiration dates on water bottles. “If it has been stored poorly it's likely to develop a bad taste and this could dent the reputation of the bottling plant.
Can water expire?
Besides that, the expiration date on bottled water has certain benefits for the manufacturer. Although water, in and of itself, does not go bad, the plastic bottle it is contained in does "expire," and will eventually start leaching chemicals into the water.
How long is it safe to drink an opened bottle of water?
How long does bottled water last in the refrigerator once opened? Bottled water that has been continuously refrigerated will keep at best quality for about 4 to 6 days after opening. Is opened bottled water safe to drink after the "expiration" date on the bottle?