I hate to break it to you, but tap water has been altered by a company... for the better. Even local ground water has to be filtered to some extent by the local municipality. Only time you're getting untouched water is if you have a well on your property. And even then, a lot of people have discovered that local farm and industrial activity can drastically change the quality of that water. And even if you're lucky enough to have well water that isn't filtered and isn't affected by anything outside your control... you could have old lead pipes in your house... or the water could be affected by radon or many other things. Basically... I wouldn't fret too much about who touches your water unless it presents an actual danger to your health.

"Altered by companies" is such a tinfoil hat way to say it