Testing tomorrow’s toilets today

Prepared by Dr Rebecca Sindall, Operations Manager, Pollution Research Group

In Sub-Saharan Africa, only 28% of people have access to basic sanitation facilities that are not shared with other households. That means that over 776 million people in sub-Saharan Africa do not have a safe and dignified place to urinate and defecate without leaving their home. This is a problem for everyone. Even if you have a flushing toilet in your own house, you will still be exposed to disease-causing pathogens that enter the environment when the human waste of others is not safely captured, collected and treated.

The traditional Western solution to sanitation is the flushing toilet. The wonderful thing about a flushing toilet is that it immediately separates us from our waste and transports that waste away to be treated and made safe before it enters the environment. The terrible thing about a flushing toilet is that it takes kilometres of underground pipework, huge volumes of water and lots of skilled people and money to make sure that the whole sanitation system from toilet to treatment works functions well. It also needs a reliable electricity supply.

A sewer system does not work well in a changing climate. When a city experiences droughts and water shortages such as those seen in Cape Town in 2018, pouring water down the toilet to get rid of human waste is, at best, foolish. In addition, conventional sewer systems do not cope well in flood situations either, when human waste is often washed into the environment untreated. On a rapidly urbanising continent where flooding and water scarcity will both become more common with the effects of climate change, it is clear that providing every home with flushing toilets linked to a sewer system is not the ideal sanitation solution.

Sustainable Development Goal 6 calls for access to clean water and sanitation for all people by 2030. However, at the current rate of progress, it will take until the end of the century to provide everyone with a safe toilet. That is too long to wait, when inadequate sanitation leads to approximately 432 000 deaths due to diarrhoea around the world each year, alongside many more deaths from other water-borne diseases.

The sanitation of the future not only needs to safely separate us from our waste and treat it before it is discharged into the environment, but it also needs to be climate-smart – it needs to use minimal water and it needs to safely contain waste during extreme weather events. The biggest challenge is that with the current gaps in sanitation service provision, we need the sanitation of the future ready today.

Globally, scientists and researchers are designing innovative sanitation systems that treat human waste at source, reduce water usage and generate useable products that may include electricity, fertilisers and treated water for reuse. Not only do these systems fulfil the needs of sanitation for the future, they also provide a way to capture and reuse the valuable energy and nutrients in human waste.

The Pollution Research Group, based at the University of KwaZulu-Natal, with its partners, the School of Built Environment and Development Studies at the University of KwaZulu-Natal, eThekwini Water and Sanitation and Khanyisa Projects, are testing prototypes of some of these sanitation systems in informal settlements and rural households in and around Durban. Although technology provides part of the solution to the future of sanitation, it is vital that communities are consulted during the development of that technology. This is an important part of the testing that takes place in Durban – not only are these toilets evaluated on how well they perform, they are also evaluated on what users think of them.

Testing prototypes early allows changes to be made before they reach a commercial market. The communities that are testing these prototypes are expected to be future customers. By engaging with the communities and getting their input early, this testing allows technology developers to be sure that they are producing a toilet that provides customers with a safe and dignified experience.

As Africa is such a diverse continent, there will not be a single sanitation system that is the right solution for every situation. Some of the systems being tested require electricity to run, which can be a challenge in some areas, while others require no electricity or even allow you to charge your mobile phone with electricity generated from urine. Some systems capture nutrients for use as fertilisers, which is beneficial if you have a garden or farm but less useful if you live in the middle of a densely populated city. Finally, most of the systems are low-flush systems or are designed to treat, clean and recycle the water for flushing the toilet. This means that you can have the experience of a flushing toilet, without wasting large volumes of water.

The sanitation of the future can be so much more than just a toilet. It can be a source of renewable energy, a fertiliser factory to improve access to sustainable food production and a water treatment system, as well as making human waste safe in the same place that it is generated. We have the technology to build these systems, and by testing prototypes early and in real-world settings, engineers, communities and governments are working together to make these promising sanitation solutions a reality.