Onsite and Decentralised Systems: A Sanitation Revolution
According to the latest WHO-UNICEF Joint Monitoring Programme for Water Supply, Sanitation and Hygiene Report (2021), 1.9 billion people globally lack basic sanitation services. While access to safe water made progress in the MDG and SDG-to-date era, sanitation and hygiene remain laggards. This has been further accentuated by the impact of COVID-19.
The World Bank estimates that an investment between 171 and 229 billion US dollars is needed to achieve SDG 6. Today WASH practitioners, professionals, service providers and government entities continue to research the latest innovations and strategies to achieve universal access to WASH globally.
Being a water sector insider, it is my conviction that business-as-usual or traditional approaches will have to give way to innovative, local, and more site-specific solutions, such as non-sewered and decentralised systems. The traditional sanitation value chain incorporates 5-6 steps from the capture of faecal matter to its reuse/disposal. To add to that, most urban centres have capital-heavy, energy-guzzling centralised sewage treatment plants (STPs). While these may have served the yesteryears, the systems of tomorrow will have to be nature-friendly, less energy consuming or reliant, possibly including elements of resource recovery and circular economy.
Since times immemorial pit latrines have been prevalent in most parts of the world. Now they are mostly relegated to rural or underdeveloped areas. Studies have shown that if implemented without the right precautions, pit latrines can contaminate groundwater. In recent years, many improvements and alternatives have been explored to make on-site and non-sewered systems more efficient, giving way to the decentralised sanitation revolution.
Numerous innovative solutions are being implemented across continents every day. Our bioloos treat the faecal matter in a multi-chambered bio-digester tank, in the presence of naturally-inoculated bacterial culture. Similarly, the faecal sludge treatment plant (FSTP) provides re-usable water and biosolids. Sanergy in Africa has delivered container-based Fresh Life Toilets in urban slums, wherein the faecal matter is collected, safely treated and is ultimately reused. Sanivation transforms faecal sludge into biomass fuels at treatment plants. In Tiger toilet, the faecal sludge is converted to vermicompost using worms. EcoLoo is another onsite solution, where the faecal sludge is decomposed onsite.
If we keep looking, we can find hundreds of such onsite treat & reuse sanitation systems. Innovative, decentralised and non-sewered systems such as these are the way forward for sustainable sanitation in emerging economies. They don’t need big capital investments as required for centralised systems, have none to low energy requirement for treatment, can be managed effectively by the user (without external support), and, very importantly, provide solid, liquid or gas output that could be used to enhance agriculture, as fuel, or meet other social needs. In my opinion, this is the type of revolution we need for achieving universal and sustainable sanitation worldwide.
The IWA World Water Congress & Exhibition will provide a space for discussion on relevant themes such as WASH and community-scale water management, small-scale/decentralised sanitation solutions, and decentralised treatment and non-sewered sanitation. Registrations are now open! For more information including delegate registration, please visit: worldwatercongress.org/register