Bottled Water vs. Filtered Tap Water
By volume, bottled water is often more expensive than gasoline; prices for water today range from less than $1 for a gallon jug of filtered water at the grocery store to more than $20 per gallon for high-end brands purchased in 9-ounce bottles. Tap water costs about a penny for every 4-5 gallons. So why do we drink bottled water? Tastes vary by location, but generally in taste tests people can't tell the difference between tap and bottled water. Scientifically, it has not been proven that bottled water is better (in fact, your dentist may recommend that you switch back to tap if you're not getting enough fluoride), and the contents of tap water are more heavily regulated than those of bottled water.
To put this information in a global context, according to the International Water Management Institute, for $1.7 billion a year in addition to what's already spent on water projects, everyone on earth could have access to clean water. For another $9.3 billion a year, everyone could have better sanitation (a major factor in preventing illness). In 2007, Americans alone spent $11.7 billion on bottled water (Masha, 2008). You do the math...
Home drinking water filtration units are clearly the economic and environmentally sound choice.