How we deal with our sewage is one of the most basic issues for humanity but one which we have still spectacularly failed to come to grips with. As soon as we mix our excrement with the 7 litres of fresh drinking water the average toilet uses to flush it away we have 7 litres of highly polluted water to deal with. In towns this is either very expensively treated with chemicals and large energy inputs, or, for those towns ‘lucky’ enough to be by the coast, pumped straight out into the sea. In rural areas the usual approach is a septic tank, which often cracks and can contaminate groundwater.
The ideal solution is to keep the water and the solids apart from each other in the first place. Although there are systems for treating ‘black’ water (the liquid from your toilet) using reed beds, which are very effective, they could be seen as a bit of a ‘using a sledgehammer to crack a walnut’ – they can be expensive and are a lot of work to install.
The approach to dry composting that most inspired us is the ‘Humanure’ method, pioneered by Joseph Jenkins in his book ‘The Humanure Handbook’. The basics of the approach are this; your toilet is a bucket inside a wooden box, with a toilet seat on top. Every time you use the toilet you cover your ‘deposit’ with a handful of sawdust, which effectively prevents problems with flies and odours, and, if you can get some nice fresh pine sawdust, acts as an air freshener too! When the bucket is nearly full you empty it onto your compost heap, constructed in such a way, with layers of alternating ‘dry’ materials (straw, bracken, newspaper), kitchen waste, garden waste, leaves, animal manures. A compost heap structured in such a way should get so hot in the middle that all the pathogens in the humanure are killed (indeed, Jenkins asserts that aside from the use of some very unpleasant chemicals, such composting is the only way to kill them off). Once the composting is complete. The fine, crumbly, sweet smelling compost is completely safe to use on your vegetable and fruit garden. For an excellent guide for how to build a humanure sawdust toilet go to www.rdrop.com/users/krishna/sawdust.htm
Our Experience
When we arrived at The Hollies, it had no running water, no septic tanks, no toilets. The old house had only an old hand pump and no water in the house at all. Also, when we built the new wooden house we wanted a low-impact toilet system which was easy and quick to install. We therefore used humanure systems in both buildings. The toilet system itself was easy enough to put together using left over bits of wood from building the house. The main expense was the toilet seat and lid. One good tip here, particularly if you have young male children, is to fit some kind of rim around the inside of the toilet seat which fits inside the bucket, thereby preventing any misdirected wees going over the top of the bucket. Jeavons doesn’t mention this in his book (maybe he doesn’t have young children!), but it is suggested on the website mentioned above, where they recommend buying two buckets the same size and cutting the rim off one, and affixing it to the bottom of the lid so that it fits snugly into the bucket. The next tip is the sawdust. The kinds of sawdust you can get make all the difference between a smelly toilet and a smell-free one. Very dry very fine sawdust isn’t much good, the best stuff we have had so far is fresh macrocarpa (a kind of cypress) sawdust, which is still a bit damp and has a lovely perfume to it. Leaves are ok but you need a lot to be effective and the loo fills up very fast, requiring emptying more often. We also tried moss, which was alright but gave the bathroom a sort of damp forest smell which I didn’t really like. It seems like a sawdust which is already a bit moist is somehow more absorbent than one which is dry. We have had (provided we have decent sawdust) no problem with smells or flies, and our children easily got into the habit of putting a handful of sawdust in after they finished. We’ve used this system for 8 years and have used our 2-year old compost on all parts of the garden with good results and everybody very healthy.