This is the view from our loo.
It is one of the advantages of rural life, that you can have a loo with a view. Figs are now in season, and you can sit on our loo and spot the ones that need picking. Which is a useful thing because figs don’t ripen well when picked green (the main reason they’ve never made it into the standard supermarket array), they ripen daily, and they’re best eaten straight away.
Our loo is a red manure worm processing system, and the resulting worm castings end up in an underground trench that the fig tree’s roots can get into. That may, or may not, have something to do with the fact that this year is turning into a very good year for fig harvesting. It’s a relatively new system – we’ve given up on the imperfectly designed composting toilet that always required a bit too much attention and maintenance to work properly on the cool south side of the house in our sub-tropical climate. The new worm processing system should, in theory, work much better.
I always think that “composting toilet” is a bit of a misnomer. Compost by rights is a compound that contains big, stable molecules of humic acid created by a particular kind of thermophilic bacteria. The particular bacteria that make it like about three times as much carbon in their diet as nitrogen, an environment that is moist but not wet, batch not incremental feeding, and nice insulation to keep warm. Manure (human and other animals) is nearly all nitrogen rich compounds, much too wet, and you don’t get a batch of it all at once. Most of the designs I see work on the principle of drying and aging rather than true compost making.
Anaerobic bacteria, the kind that make biogas, like a nitrogen rich wet environment. I see a few designs around these days for household scale biogas digesters and I suspect that could be the technology of the future.
But the other creature, and the one we’ve targeted, is red worms – Eisenia foetida and Lumbricus rubellus species, commercially used to process pig manure. We were seeking a design that used no water – we’re on tank water, and in a drought year it is always a toss up whether to conserve water for possible fire fighting, spend it keeping trees alive or the garden producing, or let it go to environmental flow. Flushing a toilet doesn’t get a look-in.
We were also seeking a design that used no or very little power. Nowadays we now have 4.5 kva of off-grid solar power and most of the time we can be completely profligate with spending it – put the electric bread oven, the slow cooker, the stereo, the washing machine, the pool pump and every light in the house on all at once. But I am so used to being frugal with power I can’t bear the idea of wasting it!
It had to cope with urine, cycle nutrients, take virtually no maintenance, and be salubrious enough for visitors used to white porcelain.
All that, and, very importantly, a view.