SUSTAINABLE SANITATION:
HOW GREEN TECH AND A PARADIGM SHIFT CAN BRING THE CHANGE WE NEED
Dr Valerie Naidoo is the Executive Manager of the Water Research Commission (WRC), which works together with global experts to have highly informed water decision-making through science and technology at all levels, in all stakeholder groups, and innovative water solutions through research and development for South Africa, Africa and the world. She spoke to Positive Impact magazine about the green technologies and programmes that are helping to shape a sustainable future.
“It is now well-recognised that South Africa and its neighbouring countries are high climate-risk areas, with drier, hotter conditions predicted to continue an upward trajectory in line with global warming statistics,” says Dr Naidoo. “Water stress is a priority problem across the country, and so the issue that really needs to be addressed relates to the fact that across South Africa, water that is perfectly safe for human consumption is used for flushing.” In urban homes, full flush toilets use at least nine litres of potable water, contributing to around 30% of household water use. “While the flush toilet connected to a sewer system is a global strategy that has resulted in a significant reduction of waterborne illnesses, the approach is not viable over the long term, given water scarcity and the fact that high urbanisation trends and population growth will require even more people to be connected to a system which is costly to operate, maintain and implement.” There is also the reality that the condition of South Africa’s municipal waste water treatment works is declining, with many ranging from a poor to a critical state.
On the opposite side of the technical spectrum are on-site sanitation systems. By far the most common system used in rural and per-urban informal settlements is that of pit latrines, commonly known as “long drops”, with faecal waste dropping into a hole in the ground. While the advantage of these latrines is that they do not require water or sewer pipes to function, chemical toilets were an emergency measure. They are difficult to manage, filling quickly and requiring costly disposal of the faecal sludge.
Filling the gap
Clearly, there is a need for a product that is able to perform its function without the disadvantages of aspirational flush toilets and rudimentary pit latrine toilets. This is the gap that the WRC has been seeking to solve through its South African Sanitation Technology Enterprise Programme (SASTEP), involving national and international partners. Over the past ten years, SASTEP has supported and accelerated the uptake of the latest, cutting-edge toilets through policy adjustments, demonstrations, testing and science-based improvements towards localisation and industrialisation. Systems manufactured by SASTEP’s commercial partners, such as Enviro-Options and WEC Projects, can provide off-grid waterborne sanitation that is non-sewered with net-zero water. Filled with water on start-up, the system allows for the recovery of water used for flushing and requires only periodic top-ups to compensate for losses. The water used to fill the system does not have to be potable, as treated stormwater run-off can be used for flushing.
Many nonsewered sanitation systems are prefabricated and modular, and can be deployed faster and more easily than civil-work-intensive waste water treatment works. In order to fast-track adoption, support from the Department of Water and Sanitation (DWS) and other government stakeholders is needed. The WRC has been working with several sanitation industry stakeholders to develop a mark scheme that would allow for local ISO 30500 accreditation and certification. This voluntary, international product standard, published in October 2018 and adopted as is by the South African Bureau of Standards (SABS) in 2019, provides general safety and performance requirements for the product design and performance testing of nonsewered sanitation systems.
G2RT: Time for a paradigm shift
Given the necessity for a transformative technology to address the challenges of the globally accepted “gold standard” of sanitation (the flush toilet), in 2011 the Bill and Melinda Gates Foundation launched the “Reinvent the Toilet Challenge”, to co-create sustainable solutions for people worldwide who don’t have access to safe, affordable sanitation. In 2018, at the Beijing Toilet Expo, grant recipients demonstrated the breadth of different technologies. In 2019, Phase 1 was embarked on for the Generation 2 Reinvented Toilet (G2RT), a design and planning phase, with the down-selection of technologies and development of the engineering design packet. Between 2020 and 2021, development of individual modules and core concepts, integration of the processes and the realization of SURT (single user reinvented toilet) systems took place, with 2022 marking the deployment of the systems into the field, and the optimisation, simplification and development of systems through phase 3, a testing and evaluation phase. Field testing took place in South Africa and India, with South Africa having become a testbed for developing and demonstrating technology solutions.
An important part of getting these solutions in circulation is having appropriate process performance standards to ensure that the new toilets are able to meet a specific public health and environmental standard. Globally, process standards for these technologies have been adopted by the International Standards Organisation (ISO), with many countries adopting the new standard. The current prototype was shipped to South Africa in May this year and the first installation in a home in South Africa took place on 10 June 2022.
The revolutionary toilet systems have water-saving or water-recycling features, are aspirational in design, and, most importantly, eliminate pathogens and sludge production at point-of-source, without the need for sewers. For informal settlement areas, or areas with constrained water supply, these solutions could revolutionise the world’s sanitation services, at a time when it needs it most. G2RT is also being designed to be powered by renewable energy or with a very low energy consumption.
Global collaboration
“The whole process is about a global collaboration of turning what was previously an infrastructure, into an appliance,” says Dr Naidoo. “It requires a shift in thinking and for people to embrace G2RT as ‘normal’; in the same way as communication infrastructure transformed from telephone towers and lines into distributed communications, with forecasters estimating that sub-Saharan Africa will have nearly 1 billion mobile phones in 2023.”
Dr Naidoo is excited by the opportunities that this “sanitation revolution” will present for local entrepreneurs and small and medium-size (SME) businesses. “If there is a complete conversion to G2RT toilets, the product volumes will be enormous; and there will be economic opportunities throughout every stage of the process, from the manufacturing of units and components, through to the distribution, transportation and installation of each and every toilet. At a time when economic growth is sorely needed, this green technology can lead to service-related industry development.
