Today, there's a fascinating op-ed in the NYTIMES. RTWT.
Basically, it shows that water is dirtier than ever, and that we need to treat it before we drink it, but that it is foolish to treat the ALL water before it goes into the general mains and pipes because there are so many leaks (most repeat MOST of it leaks), and because most of the water we use is not for drinking.
I'm not sure he has the right solution, but it's worth debating. If everybody/every building bought and used good filters, then we wouldn't have to redo the nation's pipes. Makes sense. The thing is - still and always: WHO PAYS? If water is a utility than the utility pays. But maybe it'd be better if this was a private and personal responsibility. Something landlords and homeowners are required to do.