Does a compost bin have to be in contact with the ground? I'm thinking using a 3-foot-wide round composter on top of a palette, so that I can move the compost, if necessary. Some of the things I've read in this forum (and, I think, in the book) suggest that the sponge in the bottom of the pile should be in contact with the soil. Would it be enough to "prime" the bottom of the composter with a little dirt mixed into the sponge, and then sprinkle in a little additional dirt with each deposit?
Here's the background: My wife and I have built a tiny camping cabin on a small piece of land. The land has water, but no existing septic system, and we don't want to tear up the land to install one. We've been using a small portable toilet. The nastiness of transporting, emptying, and cleaning this thing makes handling a sawdust toilet and compost pile sound positively pleasant. However, the cabin is not very isolated, and we need a fall-back plan in case anyone complains. We figure we would still be able to use the sawdust toilet, as it matches what the county actually requires of people who camp on their own land, but the compost pile would have to go. If it's on a shipping palette, the whole thing could be lifted on to the back of a pickup truck and moved to our backyard in the city. We would then just bring the buckets back with us after every visit to the cabin.
The composter itself is one of those cylindrical plastic ones. The bottom is a plastic pan, and I think I can put a small drain in it and collect any leachate in a drawer that slides into the palette.
We'll be using peat moss in the toilet and straw in the composter for cover materials. I'd prefer sawdust over the peat moss, but it sounds like most of the sawdust in Washington state is less than ideal.