A composting toilet is a device whose purpose is to recycle human excrement. In its simplest form the composting toilet consits of a hole into a collection bin. Instead of having human waste flushed through the local sewer or septic system to become a waste product (we humans are the only species that crap exclusively into our drinking water) the excrement is saved for further breakdown by natural composting agents (bacteria, worms, etc) thus becoming a useful byproduct which can be used for fertilizer.

The collection bin may be emptied on a regular basis into an external composting site, or, in the case of more complicated composting toliets, the composting can take place within the bin itself. The second method eliminates the need for continual maintenace and reduces the emptying of the collection bin to once every 6 months to a year.

If the composting is to be done within the bin (and not emptied regularly) some secondary devices should be employed to increase hygine and reduce smell. A fan system which draws air from within the bin and vents externally will create negative pressure at the deposit hole and prevent air from escaping from the toilet itself. A system which allows excess liquid to leave the collection bin is also desireable to allow oxygen to reach the composting agents. The third, but by no means final, device is a mecanical mechanism to turn the compost, again with the idea of increasing the oxygen flow to aerobic composting agents.

At the end of the composting period, what previously would have been treated as waste and flushed into the nearest body of water now becomes a rich substance by which to make your garden grow. For those who are squeamish about gardening with the compost (even though it's no more harmful than good soil), it can be dug into a shallow trench anywhere in one's yard to fertilize whatever happens to be growing there. And grow it will! The finished compost will be full of all sorts of rare vitamins and minerals as well as high in nitrogen. Every year we flush away tonnes of valuable fertilizer and nutrients. Just think how many resources would be saved if we recycled all of our crap back into our gardens to make more food for ourselves.

This device ties in neatly, practically speaking, with broader philosophical concepts such as bioregionalism, permaculture, sustainable development, off-the-grid living and recycling.