Illustration: Permaplans
Compost toilet
A toilet without water: biochar and litter bind smells, after two years of decay it becomes humus.
Instead of flushing drinking water away, a handful of cover material (leaves, sawdust, chippings) and some biochar goes on top after every use. It covers, binds smells and adds carbon to the nitrogen-rich contents (C/N around 6–10).
The contents go onto a separate compost and rot there for at least one, better two years. Heat, time and soil life break down pathogens. The finished soil belongs under trees and shrubs, not on lettuce.
Per person and day about 0.3 litres of biochar and 1 litre of litter; around 2 litres of compost matter come out.
In Garden Survival the compost toilet feeds the compost every month for each person in the garden – as long as there is biochar and leaf litter. If one is missing, it stands still.