In the News

Water-less toilets: Solution to a sustainable future?

Features 23 Dec 2019

Did you know that in Temasek Shophouse, therein lies some untold stories about toilets? The beautiful and Instagrammable spiral staircase at the back of the Shophouse had a much different purpose back in the day. Its primary function is for a group of people, night soil labourers. Night soil, better known as human faeces, was collected in buckets in the silence of the night and sometimes, soil was used as a cover. At night, a night-soil labourer would enter the alleys behind the shophouses and climb the very same spiral staircases to each storey, to collect the bucket of human faeces and replace it with a clean one.

Where does this collected ‘night soil” go? These labourers would carry the bucket filled with waste on their shoulders using a pole, and load it onto a 32-door wagon. The buckets were emptied into a big concrete tank, washed and loaded back into the wagon at the same time. The waste would then be pumped to the various sewerage stations in Lorong Chuan, Tiong Bahru Road and Ulu Pandan for treatment, before it is processed into fertilizers.

Sustainable toilets of the future

Before you think that ‘recycling human waste’ is a thing of the past, it is now making a come-back in the name of ‘sustainable lifestyle’. EcoLoo, a startup co-founded by a Malaysian and Swede, have managed to successfully market waterless portable toilets. Using microbe solution to break down human waste, EcoLoo claims that it is less energy-intensive than a regular toilet as there is no waste water to separate and treat. The bacterial process also prevents bad odours from building in the tank. This invention has already clinched several awards and is currently being deployed in countries all over the world; most notably at Petra, the UNESCO World Heritage Site in Jordan.


EcoLoos being deployed in Petra, Jordan (Source: CNN)

The drive towards sustainability is gaining prominence, especially after the United Nation’s Sustainable Development Goals (UN SDG) was announced in 2015. Big companies are lending their support towards one of the 17 goals, “Clean Water and Sanitation For All”. The esteemed Bill and Melinda Gates Foundation recently issued a challenge for global innovators, to reinvent the toilet to improve sanitation for the developing countries. At the same time, the foundation hopes to create sustainable sanitation markets that drive progress toward global water and sanitation goals. One of the inventions that they have invested in is the “Tiger Toilets” by the London School of Hygiene and Tropical Medicine. Another form of waterless toilet that uses Tiger worms to help compost the faeces. The toilet looks like any other pit latrine, without the stench. Instead, it comes with a built-in population of tiger worms whose natural habitat is faeces. Tiger Toilets involve no traditional flushing and are not hooked up to a sewer system. Instead, the worms contained in a container below the toilet feast on the faeces, leaving behind a mixture of water, carbon dioxide, and a small amount of wormy compost. The resulting water will go into the ground and be filtered naturally.


Tiger Toilet in India (Source: Business Insider)

Researchers in Cranfield Water Science Institute have also found out a way to filter water away from faecal matter, creating a water-less nano-membrane toilet that works by using a process called “pervaporation”. Liquid from faeces is separated by vapourisation through a membrane, leaving the solids to be used as fertilizers or fuel. The vapour collected is drained into a vessel, which can be used for irrigation, washing, or even consumption. The collection tank below will collect the solids as sediment, and passed through a gasifier to convert it into gas and energy. This self-sustaining system is currently being trialed in Ghana, and hopes to be commercialised in the near future.

An inconvenient truth

While circular economy is all the rage currently, how open are we to water-less toilets? Other than the convenience factor, are we willing to build up additional infrastructure for these composting toilets? Are you willing to give these water-less toilets a try?


The iconic spiral staircases at the back of Temasek Shophouse.
Photo credit: Surbana Jurong Consultants Pte. Ltd.

So, the next time you visit Temasek Shophouse and marvel at the quaintness of the black and white spiral staircase, remember… there was no ‘flush’ in the 1920s. Who knows? Maybe night soil labourers will make a comeback.

Cover Image: Night soil labourers in action (Source: National Archives of Singapore)