How do you know if your stored water is good?

[kemasa]

..or boil it if you have to.

If stored properly in a controlled environment in proper containers and given a sterilizing agent to keep it aseptic, you will be good to go for at least a few years, if not more. Rotating and re-sterilizing will keep that going.

Boiling water does not remove contamination in the water. Some filters will remove some things, but not everything.

Pool water, for example, is a problem due to the build up of heavy metals and such due to evaporation, pure water leaves, the rest remains.

You can make a solar still to get just the water, but pure distilled water can be an issue in terms of drinking, but can be mixed with other water.

It is a good idea to have a book on survival skills. Instead of storing water, you can use a clear trash bag and a rock to collect water from trees, but need to change branches or you will kill the tree.