This is not about composting. This is about my composting toilet. There are plenty articles on the internet about the joys of composting - go read those! There are also many articles about other people’s composting toilets ... but this is about my composting toilet... Just for the record: I don’t believe in unicorns and fairies: I am a practical realist. The reality is: We can’t afford to waste water on sh*t.

No. There is no smell!

Well, it has only been a few days, but I don’t notice any smell. I am not telling my visitors and they haven’t noticed. My dogs most certainly have not noticed, and they can track sh*t a mile away! Today is 7 August 2017 and my compost toilet is 7 days old.

Yes, it is in my house.

It is not an outside toilet nor a long drop. It is a portable, composting toilet which uses no water and no chemicals. And it wont require any cleaning or scrubbing for at least 4 months... I am filling my bucket a lot faster than I expected. I may be throwing in too much sawdust and without the urine to add moisture, the system is too dry. I’ve added more green clippings to the sawdust mix.

Why bother? Is it worth the effort?

At the last forecast, Cape Town is set to run out of water by November 2017. And while I am hoping this will not happen, I don’t want to be caught ‘with my pants down’ when it does! And even if the municipality does manage to find an interim solution or even a permanent solution to the growing water scarcity, I don’t want to use potable water to flush away my waste, which will use even more water to process at the sewerage treatment plants.

Yes, it is a lot of bother, but can we really afford not to make the effort now? It’s too late once the water runs out!

But everyone else flushes!

Yes, they do. As the city densifies more and more people are using water to flush toilets. I can’t change the way other people live their lives, but I can change the way I live mine.

So! How much water could you be saving?

Last month I used on average 70 litres of municipal water per day. (Hell! That’s still a lot of water!) The estimates are that 30% of one’s water usage is accounted for by the bathroom.

Assuming you are very driven and you only flush twice per day (one poop flush and one for all that yellow mellowing fragrantly in the bowl) - that is still between 12 and 32 litres of water (depending on how waterwise your loo is). Do an experiment at home: keep count of how many times the toilet gets flushed.

This month’s bill arrived today, according to that, my water usage has dropped to 32 litres per day. That is probably the result of the urine harvesting and not so much the composting toilet. I have been urine harvesting for a month, the composting toilet is only a week old.

But what do I do with the sh*t?

Ideally you want to have a compost pile of your own in which you can bury the contents of the compost toilet once the container is full. There it needs to mature for at least 1 year. I am intending to process it through a dedicated worm farm. After which, the worm casings can be used in the garden as a natural fertiliser and compost. The worms will take about a year, so that should sort out the time factor but I may need to add another tier to the worm farm!

If you don’t have a compost pile or a friend with a compost pile, then admittedly, a compost toilet may not be feasible for you... yet.

Human waste is regularly used in agriculture (in the rest of the world and here) and already the solids from the sewerage works are processed for inclusion in soil conditioners and composts.  In the past, ‘night soil’ was collected and processed for use in the agricultural sector - before chemical fertilisers became big business. In the face of a water crisis which does not show any signs of ameliorating, perhaps local municipalities should start thinking ‘outside the box’ (or in this case “inside the bucket’) when it comes to waste removal and processing. Another added benefit could be job creation and investment in the small scale agricultural sector. But this needs a long vision and forward planning, it is not a quick fix. I’m not telling anyone what to do - I am putting my view into practice and on an extremely small scale.

So how does it work?

For the philosophy and practice of compost toilets read The Humanure Handbook - you can find it online. You can read or download specific chapters for free. Chapter 6 is the one about Composting Toilets and Systems. Also read Chapter 8: Tao of Composting. 

Making my compost toilet!

4 x 20 litre buckets with tight fitting lids

Sawdust/dried horse or cow dung/dried herbs/clippings etc

Old commode or a wooded box with a fitting toilet seat and lid - I used a commode I had bought at a flea market years ago!

The most complicated part of the production in my situation was making the alterations to the commode so that the bucket could fit snuggly in the cavity without moving about. It is probably simpler to construct the box for the compost toilet from scratch. Make sure that the bucket lines up with the toilet seat...

Line the bottom of your bucket (the one in the commode!) with the sawdust mixture so that the bucket is about a quarter full. This bottom layer acts as a sponge for liquids. The compost toilet is now ready to use. The sawdust should be fairly fine.

After making a ‘deposit’ you cover it with a good scoop of the sawdust mix so that the whole is well covered. I then replace the fitted lid before closing the commode - this shouldn’t be necessary if your toilet lid fits snuggly. Place the container with the sawdust mix next to the commode. If your compost toilet is not in your bathroom, remember to keep the loo paper close by!  If you are harvesting your urine separately, keep tabs on the moisture content in the bucket. If it is too dry, the bacteria can’t do its job. Add a cup of water (your shower water, not fresh water - that would defeat the purpose!).

When your first bucket is full, lift it out of the commode, firmly close the lid and put it outside to mature. If you have an active hot compost pile, you can bury the contents of the bucket into the pile straight away. I don’t, so I intend to leave the bucket to mature for a few weeks, before putting it in the worm-farm dedicated to the compost toilet. Strictly speaking, you only need two buckets in rotation, but it is not a bad idea to have a couple extra buckets for emergencies.

Urine harvest

Yes, you can pee in your compost toilet - the urine actually acts as an activator. Depending on how you are intending to process the contents of your compost toilet, you may decided to harvest your urine separately.

I harvest my urine separately because I am using it as a fertiliser in my garden. I started doing this well before I made the compost toilet and it works so well, that I am loath to stop. My garden seems very happy.

Composting etc

Main base ingredient: the sawdust with a little dried horse or cow dung. My friend Roy sourced three different types of sawdust for me: Port Jackson, Blue gum and Myrtle. He wanted me to test which type composted the best. I didn’t have enough sawdust of either to start that trial, so I combined the lot. So this is Trial 1:Sawdust Blend 1:1:1

You can buy compost activator at your local hardware or agricultural store if you don’t have access to dung. For a bit of pizazz, you can also add herb clippings and dried flower petals.

An old commode or home-made wooden box with a toilet lid that closes hides the bucket and makes the using of the compost toilet a little more comfortable.

Line the bucket with the sawdust mixture. It needs to fill between a fifth and a quarter of the bucket. This acts as a sponge. If you are planning to compost using your worm farm, you may need to separate the urine from the faeces. Urine can be too salty for the worms and they may not thrive.

Yes - here it is. In my house. Not outside in the garden. You don’t have to run out in the cold and dark. Plants help to filter the air and keep it fresh. That’s however not the reason for the fern. The fern came before the compost toilet.

The conventional flush toilet, rigged to urine capture. It couldn’t be simpler! A wide plastic bowl with a spout fitted inside your toilet bowl.
Loo paper needs to be thrown away separately (little green bin). When you’ve finished, decant the urine into a 5 litre plastic container and replace the bowl.