A waterless, composting toilet can save about 50 000ℓ of water per user per year, and return to the soil the nutrient-rich organic material we excrete.
It’s been called many names: outhouse, privy, jakes, little boys’ or girls’ room, cloakroom, restroom, powder room, bog, john, even the thunderbowl. Yet it’s “WC” – the water closet – that gets to the heart of the matter. The name stems from the days when sewage was washed away by a continuously running stream of water. But by the 1800s, increasing urban settlement made this prohibitively wasteful.
Now a growing shortage of water again sees us flushing with increasing guilt. The waterless or composting toilet is a modern application of a natural and low-tech sewerage treatment solution.
The flush toilet was not invented by Thomas Crapper (1836 to 1910), a plumber who founded & Co. Ltd in London – the myth is assisted by his surname. However, he did much to increase the flush toilet’s popularity. Most importantly, the new system drastically reduced the amount of water required to remove human waste. Save the waste, save the world In the early days it required about 50 000ℓ of water to carry away the 650ℓ of waste the average human produces a year. Today’s efficient bowl design requires only 9ℓ per flush, with some dual flush toilets offering a 3ℓ option for less demanding matters.
But still the demand for water grows. A lthough the concept of a waterless, composting toilet needs a bit of getting used to, the need is undeniable. At present human waste, an extremely rich and valuable fertiliser, is removed using pure drinking water, flushed underground to treatment plants where it’s separated into its basic components. water is then returned to the nearest river, lake or sea while the sludge (containing valuable plant nutrients) is dumped or burned. he solution seems simple: don’t flush, save the water, and recycle the decomposed waste. In the UK, US, Europe and China, dry composting toilets are attracting growing interest and increasing use. They’re low-tech, simple to use, odourless, non-polluting and return to the soil a lot of the organic material we excrete. Some units even accept organic kitchen waste. Ideally a dry unit should be incorporated into a building’s original design, but it can also replace an existing conventional system, whether for split-level or same-level use – only the location of the access hatch changes.
Odour is easily eliminated by sprinkling ash, lime or straw or dried leaves into the unit after each use. This provides both aeration and a source of carbon for the decomposition process. The final compost, a dry, dark, earthy-smelling material, is about 5% of the initial wet mass.
Although it’s quite safe, some local authorities recommend mixing it with conventional compost for a further 21 days. constant and sufficient flow of air through the unit is essential for quick decomposition. wind-powered or electric extraction unit works well. Getting your own unit C ompost toilets are available from companies such as African Sanitation, Ecosan and Enviro Options.
Use the diagrams above as a guideline to building a unit to your own specifications. These toilets have been installed across the country, from schools in Limpopo to rest sites and camp sites operated by various nature conservation authorities. he concept of groups taking responsibility for their own waste is old, and yet surprisingly novel for those concerned about the environmental impact of waterborne systems. At first we may baulk at the idea. But with greater understanding and deeper insight during those (hopefully) regular times of quiet reflection, all may not be entirely wasted. – Chris Nel Contact Auriel Mitchley on (011) 998 0796, or e-mail [email protected] |fw