Filtered water: Municipal water is filtered through a five-micron barrier that captures dirt, rust and sediment, particles smaller than the eye can see. Reverse-osmosis systems and charcoal filters are also used to acheve "Filtered water" A note about water: More and more evidence shows the benifit of being well hydrated. Studies show that 75% of Americans are chronically dehydrated (likely applies to half the world's population), leading to possible health problems such as fatigue. In 37% of Americans, the thirst mechanism is so weak that it is often mistaken for hunger, leading to over-eating. And even MILD dehydration will slow down one's metabolism as much as 3%. Bottled Water: Some types of bottled water are not subject to the same regulations as tap water. These are regulated as food products, and their regulations are largely related to sanitary food handling and processing practices. Bottled water manufacturers will provide a detailed report on the quality of their product to consumers who call to request it.