Humanure - Two years of living with a dry toilet

For over two years now we have been using our home-made dry toilet and have just been able to start using the compost from our first bin which has been lying idle for over eighteen months. Idle perhaps isn't the correct word for in that time a whole host of activities have been occurring within it.

   Hands on Experience - Paying dividends after eighteen months.

Humanure is like death and taxes it's something we all know about but as the elephant in the room, are most loath to mention it. It is this inability to cope with our own waste which has led us down the path of least resistance, removing  it as far away from our dwellings as possible and leading many countries literally to the brink of overflowing. What we need to do is face up to the problem as individuals and stop flushing this precious resource along with equally valuable water down the pan. We need to stop being afraid.

Changing language - changing attitudes

The word humanure is an interesting one in that it seeks to redefine what was once perceived as waste and place it in the context of a resource. Along with chicken, horse, pigeon and cow manure, etc., humanure becomes no longer a waste material which needs to be disposed of but a useful product to be composted and recycled for reuse. 

So how does it work. Firstly, in order to run a dry toilet system efficiently and ensure a quality breakdown to a rich compost without pathogens, one needs two basic 'cover' materials to provide carbon, with which to balance the nitrogen in the humanure. These also have a role in absorbing moisture and preventing the escape of odours from both the dry toilet recipient and compost bin. The most popular cover for the former is sawdust and the latter straw. In our case we recycle the certified organic hay and triticale straw used in nest boxes, hen house floors and our hen-powered propagator. The further important function of the cover material once in the compost bin is to provide the tiny interstitial air spaces for the necessary aerobic thermophilic microbial reaction to take place.

Everything pivots around language and nomenclature, once the concept of humanure can be explained 'scientifically' rather than in the old 'muck and mystery' ways of the organic and ecological movements of the early 1920, many more people begin to feel comfortable with it. It is also important to remember that these systems are as removed from the old chemical toilet outhouses as they are from the modern flushing wc.

  

The aerobic decomposition of the humanure, or thermophilic composting includes a hot stage of 45 degrees C or hotter. There is no exact timing for this stage because it is dependent on a number of variable factors. These include, the mass and composition of the mix, ones geographical location, the ambient temperatures, changing seasons and humidity levels both inside and out. One of our reasons for including the lid on our bin is to prevent the excessive humidity caused by the ingress of Normandie rain! 

Human Pathogens: -  viruses, protozoa, bacteria and intestinal worms

There has been a great body of research carried out on the efficiency of the thermophilic environment in eradicating the above, with the conclusion that when composting has been carried out efficiently there are no pathogens detectable even in cases where the initial level has been a heavy one. It is after this initial hot stage that the next part of the process, the cooling stage begins, after which comes the work of nonthermophilic microorganisms and our old friends the compost worms, wood lice and fungi. Then follows a stage known as 'curing', which allows time for all the work to be completed.  This last stage leaves you with the dry friable mix and a valuable resource for your garden.
For a comprehensive essay on the above:
http://www.agrowingculture.org/2011/08/humanure-part-iii-thermophillic-bacteria-composting-stages-the-sanitization-of-compost-joe-jenkins/
and a well presented factual short article:
http://compost.css.cornell.edu/microorg.html

Facts and Figures: Our own system

 
Water Consumption: prior to installation 80m³ per annum.
Water Consumption: post installation  36m³ per annum.
Volume of  sewage:  which would have been sent for re-treatment in a year: 44m³ (over 99% of this would have been potable water!)
Volume of dry waste: actually produced per annum 0.24m³

From the above, the benefits of installing a dry toilet are great both to the pocket and to the environment. Furthermore, the astounding difference is in the amount of 'waste' or rather resource engendered by the process. This is particularly important to highlight because many people believe erroneously that only country people with land can use this sort of set up. Interestingly Sue and I gave several demonstrations over this Summer of all things repurposed, including dry toilets and I had a great conversation with guy from central Paris who has exactly the same set up as ours. His only problem is sourcing the sawdust! It is worth pointing out too that we also have a liquids only toilet within the bathroom, which we can remove when visitors come to stay and give them the choice which toilet to use.

Our system was designed and made for and from repurposed pallet wood and a minimum of fixings and comes out at a cost of under 10 $/Euros/£. The three films showing how to make the compost bin, cabin and toilets are all on this blog as well as on my Youtube site*. There are obviously a multitude of designs both to make and purchase and many of which are specifically tailored for an urban environment. 

*http://www.youtube.com/user/Organikmechanic 

Conclusions

 

The Industrial Revolution removed vast numbers of ordinary people physically from the land. However, it did more to them mentally, holding them captive in a system, where they no longer had dominion over the management of their own lives. Further generations would be taught to look down upon the provision of food and composting 'waste' until World Wars obliged governments to force them back to it. The rallying cry of the post war period was about spending,  consuming and throwing away and the scale of its repercussions are only just beginning to be openly realised on our personal health, happiness and our one and only Planet. In the present economic climate, more and more are moving back to the land by choice and finding joy in the rediscovery of old skills and autonomy. Dry toilets are just a leitmotif for this paradigm shift. It is up to personal choice where you put the resultant compost. It is also an individual choice as to what you include in your mix. We are purists and have a dedicated bin just for the contents of the dry toilet. When we raise a glass of kir containing home-made crème de cassis this New year we will be drinking to the success of another year of thermophilic microbial reaction or rather the toast will be: "To Muck and Mystery!"

Now sit back, if you will and watch our dry toilet 'reveal' and find the answer to the questions that decades of flushing can no longer keep from you. The film still below is of our current working bin just to show the 'cover' materials and the worm activity - nothing to worry about!

 

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© Andy Colley 2014

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