Composting Toilet

Posted by on Nov 12, 2008 in Life Support Systems | 5 Comments
Composting Toilet

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We guess that the final straw for the last people who lived here was when the long drop toilet filled up. That meant that when we arrived there was no toilet.

 

This quickly became a priority in our lives, and I have learned that we live in the best possible climate to compost our own humanure. This is further reinforced because we collect our own water, making us conscious of this valuable resource and how we can save, and reuse it.

 

The average home mixes 30,000L of water with solid excrement a year. This creates sewerage! A disgusting difficult to use waste product that must be treated with chemicals and then dumped further down the line into the systems that provide habitat for marine creatures and eventually water again for us.

 

Dry composting of humanure is a safe, natural and healthy way to break down the organic solids, kill the bacteria and parasites that may be there and then return the nutrient rich humous back to the soil where it can be used by plants to grow. In an area like ours with very old soil that was farmed, this is a vital top soil layer that will make it possible for us to complete our loop and move closer to full sustainability.

 

Our main considerations in choosing a site for the composting toilet were:

  1. Convenient access; not to close, not to far.
  2. Pleasant walk, rain, hail and shine
  3. Easy access for removal of compost
  4. An open air aspect that can be private
  5. A view
  6. Flattish to minimise excavation work

 

The site we eventually chose was close enough to the house, without being too close. And more importantly, already pretty flat. The fallones type batch composting toilet chamber was our final design choice and is no small undertaking.

 

We chose the double chamber design for its durability and minimal maintenance. The batch design means the pile is left to compost where it falls for at least a year. No moving of half finished goods. Recommendations from other owners/builders encouraged us in our decision.

 

For more information on the planning aspect of this composting toilet project see Toilet Planning in Work.

 

Here is part of the site, this had to be leveled with dirt from the deck and cut into the hill a bit:

 

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We had the materials delivered by on a truck from Lismore.

 

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A neighbour in our community had just lost his concreting job and it seemed like an ideal fit so we payed him to begin digging the foundations. We fit steel reinforcing under the chamber walls.

 

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Our next blessing came along shortly after that. A friend came to live with us in the hut and he had concreting experience. The next phase the chamber floor slab and the walls went up so quickly I didn't have time to get process photos!

 

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Our very productive friend had to leave again at short notice and the composting toilet project stopped dead in it's tracks.

 

 

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The chamber walls were up and next we wanted to do the floating concrete slab. I found the whole concept a little baffling and the double chamber toilet didn't move forward for over six months. It wasn't until we met Bec at the Permaforest Trust that things resumed.

 

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Bec grew up concreting and had all the enthusiasm we needed to things started again. She came out for an inspection and we decided with the PFT to have a working day finishing the slab.

 

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The many hands made short work of the job that had seemed incomprehensible for so many months.

 

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It was all done in a day.

 

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With the floating slab out of the way it seemed like smooth sailing from there. I worked on the designs for upstairs portion, that process can be seen at the Toilet Planning Page in Work.

 

The next step was to create the pedestals. There is a divine proportion here that puts your rectum below your knees allowing a complete clearing of the bowel without requiring you to support your entire weight in a squat.

Further reading is available in Ray Flanagan's Plans. They are made by using chicken wire wrapped around a plastic bucket.

 

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At this time we got enthusiastic about getting on the loo and built a temporary privacy shelter. It was never used though, and shortly after collapsed in a big storm.

 

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I also built a door for the chamber made of flooring, this quickly warped and opened gaps. A big no-no for this kind of system.

 

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After the roof collapsed we decided to get real about a permanent shelter on our permanent toilet so we had some branches that were overhead pruned off.

 

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Kirrah & I set to work making wall frames.

 

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We had a very large snake come and hold things up again.

 

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Once most of the frames were together, we had some local carpenters come and put them together.

 

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Professionals can make a job seem very quick.

 

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With the permanent frame together. I put the roof and wall cladding on.

 

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I replaced the earlier attempt at making a door with a sheet of ply wood.

 

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And we started using the toilet.

 

2010-03-17 at 18-20-08

 

Once everything was functional, we got to work on the finishing. Fly screens & mesh.

 

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After some use we discovered that rats had eaten their way into the chamber through the ply door!

 

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I haven't heard of this happening before. But now i would recommend for durability to use a thin sheet of galvanised steel. I had this one cut to the exact dimensions I needed for $50.

 

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2010-07-07 at 08-14-21

 

Impenetrable!

 

2010-03-30 at 18-19-20

 

The view of the loo as it stands today.

 

Here are some more fantastic local resources about composting toilets: An Introduction

 

Model Comparison The wheely bin model Building another Double Chamber in Nimbin. Part 2 Part 3

http://milkwood.net/2011/04/18/compost-toilet-specifics-the-bins/

 

5 Comments

  1. Wholistic » Blog Archive » Grey Water System
    November 27, 2008

    […] three tier design after the scope of the project day was also expended to float the slab on the composting toilet. April […]

  2. Wholistic » Blog Archive » Unusual Patterns
    November 27, 2008

    […] The composting toilet now has its slab floating. […]

  3. B R Best
    November 28, 2008

    How is the composting toilet? I would love to see some pictures of the finished crapper and the finished product. How have you been managing the daily deposits and what do you do when you fill it up?

    Take care.
    Brian

  4. WholisticDesign » Blog Archive » Wholistic
    January 25, 2009

    […] Humanure composting and Living Organic Soil production. […]

  5. brother nick @ maqai surf camp - fiji
    April 27, 2009

    guy…

    how you going brother?!

    i am at a surf camp here that would seemingly like to live closer to its marketing name ‘eco resort’. they are on tank water collected only from just large structure. rainfall is limited and yet they have numerous flush toilets. i checked your site quickly but cant see any photos of the dual chamber composting toilet you’ve built, but would love them to see it. they desperately need some encouragement and direcion with limited rainfall and the everpresent threat of running out of water.
    hope all is well mate. see you in a few weks when i return.
    you coming to the dreaming festival this year?
    i’m vollying again. all set. stunner of a festival mate, cant recommend it highly enough.

    my love to kirra (and yourself)

    n’k