I couldn't agree more with bogey21. If one would research the profit made from selling bottled water, some of which is only purified water and not spring water, one would be amazed. Working in the water/wastewater industry, I can attest that drinking water and wastewater facilities treat water to an extremely pure state. A portion of our tax dollars as well as, our water/ sewer bills (and incorporated some way into maintenance fees) pay for water treatment. Well water should be regularly tested for quality and content of minerals, etc. We take the small Brita pitcher & filter and always use timeshare tap water.
I'm not so convinced... I am always concerned with
Cryptosporidium . At least in the midwest a lot of the bottled water came from Lake Michigan which I consider to be a relatively good source but not immune from all impurities that could get into bottled water.
Cut and paste:
The cover story of the June edition of the Nutrition Action Health Letter is “Water, Water, Everywhere...but is it safe to drink?” The article describes the different categories of elements that can be found in water, and what the hazards are for each one.
The categories include disinfection by-products (like chlorine), turbidity (caused by items like soil run-off), lead, arsenic, asbestos, and parasites (like cryptosporidium, which can actually be deadly). The likelihood of any of these items being present in your water depends on where you live; contact your local public water utility for more information.
The Brita pitcher filter reduces levels of lead, copper, mercury, chlorine, and zinc, but it does not protect you from asbestos or cryptosporidium. Note that the Brita faucet filter, however, reduces levels of other harmful elements, including cryptosporidium, giardia, and asbestos
All of the cold water should be softened, with the exception of the outside faucets and the sprinklers. The hot water tank input should bypass the water softner; hot water in the house is not softened. Not sure how your house is plumbed. 
