Hikemor, you are correct if you are bugging out from a snowstorm or other event that does not compromise the utility's pipes or filtration plant. Such a compromise of a water utility is all too common in any situation causing flooding and in some involving a blackout or plant failure or a chemical spill into a reservoir. Just think how many times the media transmit boil water advisories after a storm or flood. Heavy flooding also brings about chemical contamination from vehicles, businesses and factories. Conjure New Orleans water, post-Katrina. Finally, the Seychelles purifiers and other comparable backpack purifiers are rated for a fair amount of chemical and viral elimination.