UV, sorry for the lapse in thought location. UV is a natural method used to kill bacteria. I understand <-- (have not tested or verified) that you can fill a clear plastic/plastic container and set it in the sunlight. A day of light is said to kill all of the bacteria/diseases in the water. You will still have all of the non living issues in the water.

Socalman, there are many methods of water collection. Have researched the majority since I live in CO (little water to locate)
Rain Barrel 1" of rain water collected from a 1000sqft area = 600 gallons of water.
Hot water heater and the average size house in water lines = ~60 gallons of water (40 gallon hot water heater)
And then if it gets really ruff dew harvesting. http://inspiringfuture.org/wordpress...rinking-water/