Our 4000 sq. ft. roof captures 2,500 gallons of pure rain water for every inch of rain. We store it in large tanks.
When we turn on the faucet our pump delivers pristine water through triple filters down to .2 microns. Our filters remove giardia, cysts, bacteria, and inorganics. Our UV light then zaps any organizims that might have passed through the filters.
Most folks consider .5 micron filters good enough for safe water. We don't. We want to be super safe.
We don't need chlorine to make our water safe. Because we don't want to drink floride ... we don't put any in our water.
Check out this video link: Listen to this about floridated water.