Don't use tap water. Set up a barrel to catch rain water.
I wouldn't be too positive about rain water anymore either....this isn't 1922 anymore, Industrial pollution and chem trails have ruined the sky
I USED to have a underground pure spring on other property, about 2 years ago, had the water tested, fecal bacteria level was @ a all time high in it, I no longer use it...
PS: Interesting note, the towns OLD sewage treatment plant was about 1/2 mile from that spring, back when they WERE using this facility, everything seemed ok. But now after they abandoned it and made a new one elsewhere, is when i started having the water problem