Bi-Polar Bear wrote:
so that would not be a problem if stored in a cooll dark place?
Wrong. The contamination would occur at a slower pace. If you're building a bomb shelter; include ordinary bleach: 8 to 16 drops per gallon (depending on how nasty it looks), then wait 30 minutes and it won't matter how old the water is. Just like in your pool; bleach kills the crap, then rapidly evaporates. Like I said; glass is your friend if you want it to last and remain tasty… and rotation is your best bet with plastic.
For truly long term solutions; pack a shovel and a heavy smooth plastic tarp like a painter might use as well. Then, if you run out of water, dig holes a little smaller than the squares you cut out of the tarp. Place a water receptacle in the middle. Then cover the hole with the tarp, pulling it tight, and secure the border to seal in the air as much as possible. A stone placed on the tarp, directly over the water receptacle, will provide a drain point for your makeshift evaporator. This evaporation system would convert your own piss to tasty water in a pinch.
A more industrious water maker might dig a long trench and hang his plastic towards a gutter in the middle, to collect it in a single spot at one end. Such a system could collect rainwater when it rains, and use solar energy to produce clean evaporated water when it doesn’t.