My week at CAT, part 3, Compost Toilets

10 May

Two chambers underneath

Where are we flushing away a large amount of drinking quality water? Down the loo of course! Hence the beauty of compost toilets. Get one of those bad boys and you can really start to become more water efficient. However they are not always a possibility for many and they do have their own requirements such as space and social acceptance.

I always though compost loos were pretty straight forward but there are a whole host of products on the market that aim to make compost loos adaptable for the ‘modern home’. The basic premise is the same though – that human excrement falls into a composting chamber beneath the loo and all the organisms below have a feast. Bacteria, worms, fungi and others use this organic matter as a food source and break it down into humus or compost.

Another of CAT's compost loos

A ‘soak’, such as sawdust or other carbon rich material is scooped on after one has done their business, to help achieve optimum composting conditions. Urine is ideally separated out to control moisture levels and most compost loos have some kind of ventilation system, whether that’s a proper fan or panels missing for air circulation.

The composting process kills the pathogens in the excreta and the finished compost should be safe and free from odour. This ‘humanure’ can be removed every year and used to help nourish plants.

Important things to consider are:
- location – things like height and so forth
- access
- removal – how do you get the damn stuff out?
- drainage
- urine separation
- soak materials availability
- aesthetics – the most pretty compost loo I’ve ever seen was at Karuna, with a gorgeous driftwood cover, shells, poetry you name it.. I didn’t want to leave!

The aquatron (it's the business)

There’s a whole bunch of resources out there that detail the different compost toilets on the market and how to build your own. Some good books that explore all of these points can be found here.

One Response to “My week at CAT, part 3, Compost Toilets”

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