WWF Update: Dry Toilets


8 February 2018

wwf water crisis toiletWhat will happen when we have no water to flush the toilet? WWF provides information on alternative dry sanitation solutions that you can start looking at now, both in preparation for Day Zero and to reduce your water use.

After Day Zero, what do I use to flush the toilet?

As long as the sewer systems are still functional, you should be able to flush your toilets with rainwater, greywater or groundwater. (Read an article sourced from the WWF website that answers your questions on groundwater). Do NOT flush with seawater. Doing so will increase salt in the wastewater treatment plants, and if the salinity levels get too high, the microbes that treat the sewage can’t survive and the treatment plants will stop working.

Will the sewer systems still work after Day Zero?

According to the City of Cape Town,  the sewer systems will continue to work after Day Zero. However, treatment plants or sewerage pipes could fail under these extreme conditions, therefore, be ready to make contingency plans.

So what are my options for preparing for Day Zero?

Dry Compost Toilets A dry toilet operates without any water to flush away poo or pee. A bucket is housed in a box to support your weight, with a toilet seat of your choice and organic material to cover the poo. The cover material can be sawdust or decomposed compost. These toilets have urine diversion mechanisms incorporated into their design. Separate the pee and the poo as much as possible, because if the mixture is too wet it will hamper decomposition.  The aim here is to keep the poo bucket, which is the highest risk, from filling up too quickly. Urine can be disposed of in a green space or in your compost heap.  If you can urinate (pee) in your (private) garden onto soil it will be absorbed and not present health problems providing the volumes aren’t too high.  Spread it around so that it doesn’t get concentrated and smell.

There are many websites with more information on how to construct your own compost loo and how to safely process the waste. A dry toilet can be used in a flat without a garden. Using a bucket system with cover material should prevent it from smelling. Separating out urine is even more important in this case. Speak to your body corporate about alternate methods of sanitation, including sourcing an alternate supply of greywater to flush the toilets, installing a commercial dry toilet system or chemical toilets in the grounds of your building, and also advising people on how to minimise blockages by putting toilet paper into a separate bin.

The features of a good compost toilet system at home include:

  • It should not be too wet because then it rots.
  • If the system is too dry, it doesn’t compost. Pee in the bucket for morning ablutions and to try to keep the rest separate.
  • It shouldn’t be soggy but rather have the consistency of good moist soil.
  • You should preferably use a 25-litre bucket with a lid as this is the easiest to carry, and won’t get too heavy.
  • Smell management is done with a dry organic material such as sawdust (anything that is reasonably dry and high in carbon can be used so you could also make use of garden clippings, compost or partially composted leaves and garden waste).
  • If your material doesn’t leak out of the container/bucket, if you can pick up the container comfortably, and if the container can be closed, your dry bucket is working properly. A composting toilet (which is bigger than a bucket) works well if it doesn’t smell. If it smells of ammonia, add more organic material. If it rots, there is too much liquid, this may be a design flaw, so if you go the compost toilet route, try having a way to safely remove some liquid with a tap at the bottom.

What other alternatives are there?

Commercial composting toilets: Invest in a commercial composting toilet system that uses the natural process of decomposition to break down human waste, yet it is self-contained. There are a number of commercial self-contained dry toilets available in South Africa but these are not always suitable for small dwellings. You would need to research the suitability of each of these options for your needs and reach out to the local authority to see if they might install these in communal spaces. Some of these toilets are already in use in public areas (such as on the top of Signal Hill in Cape Town) and in CapeNature rest camps.

Chemical toilets: Chemical toilets are often used by caravaners or at music festivals. These, however, will also need to be serviced so be sure to establish whether that is feasible.

Be sure to do thorough research on whichever option you may be considering.

This week’s prep for Day Zero – Bucket list activities                              

  • Work out what is going to be the best option for you depending on your circumstances – do you have a garden/ do you have alternate water sources to flush with/ how many people/ what can you afford?
  • Do some research now on your preferred method – there is a lot of information on the internet. Take a look at some sources below.
  • Think about doing a ‘dry run’ and testing your method (if it’s something simple like a bucket) so you know what you need.

Useful links



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