Waterless sanitation – when will it take on?

“No innovation in the past 200 years has done more to save lives and improve health than the sanitation revolution triggered by the invention of the toilet. But it did not go far enough. It only reached one third of the world.” – Sylvia Mathews Burwell

By Mille Poulsen Jensen, Teodora Damian and Jørgen Erik Larsen

Sanitation rated as safe for people has only increased by 3% worldwide over the last few years and around 2 billion people still do not have access to basic sanitation facilities. Additionally, it is well established that waterborne sanitation in many areas is not the solution. Looking at the South African landscape, a survey conducted in 2018 revealed that the percentage of households across the country with access to improved sanitation increased from 62.3% in 2002 to 89% in 2018. However, there are still large variations between rural and urban areas when it comes to access to sanitation facilities; 5.6% of rural and 1.1% of urban households still lack sanitation services. Furthermore, there are still 100 000 South Africans that only have the option of open defecation.

What can be said is that there is a need for new solutions, ideally in the realm of waterless sanitation solutions, also known as dry sanitation. Communities living in dispersed rural areas rarely have the infrastructure necessary to support the well-known flush systems, yet they still deserve to be provided with dignified sanitation systems.

Over the last 50 years, a lot of effort and significant funding have been put into innovating waterless sanitation alternatives. Many solutions have been developed, but the reality is that the majority of people outside the serviced areas are relying on simple yet nonsustainable pit latrines.

The question is: why have the new innovative solutions not taken off at any scale?

Dry sanitation systems

The available types of dry sanitation systems today are classified as: selfcontained, single- or multilayered chamber tank, mixing device, urine-separating, electric or solar, and completely waterless or with low water usage. As an example, solarpowered, with a multilayer chamber

and waterless toilets will be selected for remote areas, while a self-contained, electric and single-layer system is used in a building within an urban setting.

Currently, the most common systems used in rural and peri-urban settlements in South Africa are long drops or pit latrines. The best attribute of this technology is that it does not require water to function, thereby saving water resources and eliminating the need for sewer pipes. Despite this, the long-drop solution is a temporary one that is difficult to manage, as the number of users is highly variable, and the latrines can fill quickly, so they require constant emptying.

At the same time, municipalities in South Africa still have limited feasible alternative options in use, and therefore have little choice but to implement costly solutions. For example, in 2013 in Cape Town, there were around 5 000 chemical toilets – these are expensive to operate due to the preferred contract mechanism being to rent the toilets from an operator, who then would be responsible for providing the unit and servicing it three times a week. Therefore, it is not sustainable for rural and more dispersed dwellings.

One of very the few waterless sanitation and sewage systems at scale is found in China. The system design here focuses on the separation of four main waste streams: faeces, urine, greywater and solid waste. The study, however, found that the dry sanitation system has a carbon footprint 13 times larger than the conventional system,

BACKGROUND

The South African-Danish Strategic Water Sector Programme (RSA-DK SWSP) has been under implementation since November 2015, when a memorandum of understanding on cooperation in the field of water, water use and water resources between the Danish Minister of Environment and the South African Minister of Water and Sanitation was signed.

The cooperation is headed jointly by the Danish and South African ministries, but further includes stakeholders from local government, water utilities, research institutions, industry organisations and the private sector. The programme is structured around groundwater management, urban water management, water efficiency in industries, research and innovation, and a project support facility.

The purpose of the programme is to support the South African government agencies and other relevant stakeholders in developing and implementing strategy, management and regulatory frameworks to contribute to the National Water Resource Strategy (2013), so that “water is efficiently and effectively managed for equitable and sustainable growth and development.”

Currently in its second phase, the programme has recently been extended to the end of 2022, with the third and final phase planned to run from 2023 to 2026.

resulting from a much greater diesel consumption of the dry system during operations. The study additionally found that the dry system was much more expensive than the waterborne one.

Barriers

This raises questions of whether waterless sanitation solutions actually are the way forward. As this analysis has shown, it can often be a costly solution that requires frequent maintenance and faces several societal barriers. Gisela Kaiser, former executive director at the City of Cape Town, notes that from a sustainability viewpoint, non-piped sanitation is the optimal solution, but it requires a behavioural change that cannot happen overnight. Crucially, there has to be an attitude shift before waterless sanitation can become widely accepted – especially in poorer areas, where the infrastructure does not support a conventional piped system.

Ongoing research in South Africa could point to solutions. Jay Bhagwan from the South African Water Research Commission points to decentralised minigrid systems with modular, containerbased wastewater solutions. Here, direct water reuse and the beneficiation of sludge create low-tech, nature-based solutions where constructed miniwetlands retain the sludge and treat the water. According to his research, this type of solution matches user preferences without the need for sewers, or a reliance on large quantities of water and/or energy supplies.

As it seems, even after more than 50 years of innovation, waterless sanitation is still not the better solution, compared to waterborne-sewagecollected sanitation and the pit latrine. However, it seems that more and better-fit solutions will be coming as research progresses. If one assesses the drivers of technological and energy source changes in history, one factor is clear: change only happens when we acknowledge and culturally accept a better solution. This must be better in terms of feasibility (affordability), in terms of convenience and, even more so now, in terms of sustainability. Therefore, as much as it is a matter of better innovation, it is also a matter of a mindset shift and willingness to adapt to new systems.