The existing toilet use paradigm is water intensive and designed to use a high volume of flush water to transport human waste away.

Reduced-flush water toilets are possible and will contribute to decreased water use; however, with water-efficient flush toilets, there is poor uptake in public and private sectors.

The Water Research Commission (WRC) has pioneered various initiatives to reduce flush volumes in toilet systems, resulting in innovations such as the pour-flush and low-flush toilets.

Low-flush, water-efficient toilets are designed to use low amounts of water for flushing between 1 to 2.5 litres a flush, which, if upscaled, would result in significant nett water savings on a country scale, where nearly 30% to 40% of all domestic water supply is used for flushing.

Furthermore, the locally manufactured low-flush toilets hold potential to create new employment across the value chain and contribute to reducing capital expenditure on greenfield projects, while also improving the capacities of burdened existing sewerage and wastewater systems.

A large volume of South Africa’s water consumption is used for flushing toilets. Water-efficient toilets minimise the amount of water used to convey the waste collected in the bowl to the back-end treatment, conveyance and collection system.

“Close to 11 million households have access to a flushing toilet – using mostly 9 to 12 litres per flush. If we can reduce the amount of flush water used by 50%, we could potentially save up to 400 Mℓ of water per day. It is imperative that we all learn how much water we are using, especially regarding sanitation. If we can manage the amount of fresh water that goes down the drain, we have a better chance of securing water for other uses,” explains Akin Akinsete, programme manager, WRC.

Challenges

Despite the overwhelming advantages of low-flush/water-efficient toilets, acceptance and uptake are hampered by various factors:

  • Many plumbers do not stock or fit low-flushing toilet pedestals because of the perception that they do not work.
  • There is concern that low flush volume is insufficient to transport waste from the toilet to the conveyance system, and human waste coats the conveyance pipe, causing odours and obstructions. Recent studies and those emanating from the Cape Town drought have proven otherwise.
  • There are also concerns around the impact of low flush volume on wastewater treatment plants (WWTPs); however, with new technology, there are now examples where low-flush toilets have been installed with a sewer at standard gradient and no additional blockages have been noted.
  • User concerns centre around noise, high installation and maintenance costs, and the lack of readily available parts, especially in rural areas.
  • There is a lack of financial incentives for people to use low-flush systems. Rebates, grants and retrofits should form part of municipal pricing.
  • Another challenge is the general lack of data relating to the uptake of low-flush toilets and further studies are needed, especially in low-income households.
  • The public is not exposed to this technology.
  • Very few low-flush toilets are already on the market and available for purchase.

Gaps in policy, regulation, standards and by-laws

A recent WRC study explored South African policies, regulations, standards and municipal by-laws that governed low-flush or water-efficient toilets. This was done to identify any gaps and make recommendations that would facilitate the uptake and implementation of low-flush toilets in South Africa.

The study findings indicated that:

  • Terminology is not standardised. This creates a disconnect and confusion. Low-flush terminology should be standardised across all literature, standards and documents. There are also ineffective rating systems and there is no clear, leading authority to manage the process forward.
  • Most policies do not make provision for low-flush water toilets. Low-flush toilets are not included in the National Building Regulations and the Guidelines for Human Settlements and Planning (Red Book). They need to be more specifiC and defined. Critically, SANS 10400 needs to be expanded with part XB – ‘efficient water use in buildings’ – which will then form part of the national building regulations.
  • Most small to medium municipalities have developed their by-laws from generic ones made available from the Department of Water and Sanitation in 2005 that do not accommodate low-flush technology or water efficiency. Fortunately, most metros have by-laws that do accommodate low-flush technology.
  • Non-compliant products can be legally imported and manufactured – this gap must be closed. National standards are required to assist manufacturers and a labelling system on products can provide guidance on rating and the rate of water consumption.
  • Unprofessional plumbers must be held accountable for the products they fit.

Recommendations have been put forward that the National Building Regulations be revised to accommodate toilets that use less than three litres per flush, as well as use greywater in those flushes. Waterless toilets and urinals need to be included.

Performance testing protocol

Developed to accelerate the standardisation of low-flush toilet technology development in South Africa, the WRC has conducted a study to create a performance testing protocol that evaluates the impact of low-flush pedestals on water consumption at household and municipal levels, and determines which ones perform optimally.

It also assesses the effect low-flush toilets have on internal and external piping and reticulation systems, as well as
the WWTPs.

The performance testing protocol is not designed to replace SANS1722:2011 – it is built upon the main performance tests within the standard. It provides an overview of the performance of the pedestals (eight low-flush pedestals were tested).

The performance testing protocol can be used as a starting point, where pedestals can be tested against different attributes under different contexts. This will assist municipalities and developers to identify the most suitable pedestal for a specific environment.

Tests included:

  • Flush volume – measuring water used per flush.
  • Full flush performance – clearing the pan in a single full flush.
  • Paper removal performance – clearing of toilet and newspaper from the pan.
  • Mixed-media flush performance – clearing simulated faeces and toilet paper from the pan.
  • Bowl-washing performance – removing the surface coating of sawdust from the pan.
  • Dye test performance – diluting dye in the water trap.
  • Splash performance – ensuring that flushing does not result in water splashing on to the floor.
  • Drain line transport performance – ensuring simulated faeces do not block drainage pipework.

A traditional water-intensive toilet was included in all the tests as a comparison, and it performed poorly in some of the tests. No pedestal managed to pass all the tests. It was therefore apparent that poor performance was not always
linked to the reduced volume of water
for flushing.

Three low-flush and one international vacuum pedestals all performed well and passed six out of the eight tests. This demonstrates that the low-flush pedestals on the market and in late-stage development are able to perform well – if not better than the existing pedestals on the market.

While the development of the testing protocol can be viewed as holding low-flush pedestals to higher standards than the existing water-intensive pedestals, they can also be used as a driver to encourage new innovations and outperform existing systems.

Changing the narrative

There are a number of locally designed and manufactured pedestal toilets available in South Africa and we need to buy local and support these businesses in the sector.

The WRC’s low-flush, water-efficiency study adds that there needs to be a mindset reset. “We need to reintroduce water-efficient concepts, making sure that they are inclusive, systematic and organised. Information needs to be readily available.”

The WRC believes that the following plan of action should be adopted in order to facilitate the effective uptake and implementation of low-flush, water-efficient toilet technology in South Africa.

1) The availability and benefits of water-efficient pedestals must be promoted to the public.

2) SASTEP must co-create a strategy with government where water-efficient toilets are included in national programmes.

3) Promote standardisation and certification of water-efficient pedestals – making sure that they are all able to perform.

4) Promote South African manufactured pedestals.

While the early transition from high-volume flush toilets to water-efficient toilets is positive, there is also a dire need to consider decentralised sanitation and waterless toilets, since South Africa’s wastewater treatment plants are largely dysfunctional and nutrient pollution (eutrophication) is a huge problem.

SASTEP

SASTEP was established by the WRC in partnership with the Department of Science and Innovation, the Bill and Melinda Gates Foundation, and with the support of the Department of Water and Sanitation.

The South African Sanitation Technology Enterprise Programme (SASTEP) seeks to fast-track the adoption of innovative and emerging sanitation technologies in South Africa through fostering local manufacturing and commercialisation.

SASTEP aims to create jobs, contribute towards the economy, minimise pollution, beneficiate waste, and promote health, safety and water security. It further seeks to be a global leader in the application of alternative sanitation technologies, providing everyone in South Africa with access to dignified sanitation.

The core strategy of the programme includes supporting and empowering sanitation innovators (technology partners) and sanitation entrepreneurs (commercial partners). The programme’s approach is hinged on the formation of collaborative partnership with these partners to ensure the transition of suitable and appropriate sanitation technologies to the marketplace.

The programme is an operational vehicle of the WRC’s sanitation transformational vision, SANiTi: Sanitation Transformation Initiative.

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