Bottled water companies fill the bottles with water that has been heated to just below boiling then piped to the bottleing mechine and sealed in the bottles,
They are then treated with high intensity UV light.
http://www.ultraviolet.com/lamp/sterlra05a.htm
This is why they use clear plastic bottles for water.
warning to anyone that finds the old cans of survival water at gun shows or surplus stores.
http://www.olive-drab.com/images/rations_lifeboat_400.jpg
If you find any of these shake the cans.
If it sounds and feels like there is water in the can don't buy them the water is bad as the seal has leaked.
If it feel and sounds like there is a chunk of bread dough in the can the seal is still good.
I use to have to test them in the navy and we got rid of all the one that sounded like water.
I have yet to find any good cans at gun shows or surplus stores and i have tested hundreds that i have seen.