Rainwater is said to be twenty times cleaner than the cleanest groundwater of any kind.

If you know you'll have to harvest rainwater, the next very first thing you need to do is get up on the roof and clean it off. Sweep off the leaves and conifer needles. Take careful note of where the bird poop is -- there's actually very little on most of the roof, isn't there?. Birds mostly poop where they perch: on trees overhanging the roof (cut them off for firewood), on your TV antenna (take it down), on wires stretching across your roof (see what you can do to remove them), and on the ridgeline of your house. Remove the perches and you'll remove the major source of rainwater contamination.

Since you carried two eye-bolts and a hundred feet of thin wire with you when you went up on the roof, once it is cleaned off, screw an eye-bolt into each end of the ridge of your roof (if you've got one of those fancy, multi-sectioned roofs, it gets more complicated). Fasten one end of the wire securely to one eye-bolt and then stretch it tightly down the length of the roof to the other eyebolt. It has to be very thin (too thin for even a sparrow to perch on) and tight. This will prevent birds from perching on your roofline.

If you do this, you've just eliminated probably 98% of your rooftop contamination sources. And, if things got bad, I wouldn't really hesitate to drink the water that comes from the roof without purification. I know that everyone says, "Oh, no, you can't drink THAT! It's got asphalt in it!" Well, how much residue really comes off the roof as the water quickly runs over it? Do you think you would be ingesting as much of the petroleum product as you're already eating in your food now, or less? I know what I think!

Grocery stores will be stripped before you even think of breaking into one.

Those plastic underbed storage containers are great for storing more food where it isn't in the way, or obvious.

Sue