You should purchase bottled water that is certified by New York State Department of Health. This certification will be printed on the label of each bottle. The FDA considers bottled water to have an indefinite shelf life if it is produced in accordance with regulations and remains sealed and unopened. Therefore, expiration dates on bottles are voluntary and may reflect concerns for taste and odor rather than safety.
If you bottle up public drinking water from your faucet prior to toxins being identified in the public drinking water, use only clean, food-grade plastic or glass containers that seal tightly and replace the supply every six months.