My thoughts as well. From the in-line tank start, you could add an in-line filter/treatment system, a bypass/shut off, a pump, a check valve (so the water you collected can't backflow), and a monitoring station of your own. I wanted to stimulate some thought processes with the initial idea.

This brings to mind another issue. Everyone using a municipal water supply puts a lot of faith in the maintenance of that system by someone else. If we don't exercise a little due diligence on our own part, aren't we as much to blame if something happens and we are adversely affected? I've seen enough "bad" and "very bad" practices in municipal water treatment systems maintenance to know I am ALWAYS suspicious of the end product.