The setup for the lawn/garden should be a piece-of-cake. The drinkable version is a bit more involved, but I intend to work up to it.
The author of the book I recommended gives a comparison-chart of her rainwater (after mostly filtered) vs the city water in her Austin, TX-area town. The rainwater was many times cleaner and safer than the city stuff - AND that was the reading before she put it through her Berkey filtration system (the water dept requested the test be done on her MOSTLY-filtered PRE-Berkey rainwater).
So do any of you out there have any ideas or experience in this arena?
Here are some interesting links/vids:
This is a short video of one man's lawn/garden system: