Past innovations and future challenges
Earth closets
LATE 19TH CENTURY
(Picture: Musphot, CC BY-SA 3.0, via Wikimedia Commons)
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In this model of Moule’s earth closet from 1875, a handle pull released soil from the hopper behind the seat to cover the waste. It needed no water supply or sewerage connection
Though piped water supplies and integrated sewerage systems began to be installed in some cities from the mid-19th century, water closets were still unsuitable or unwanted in many places. Instead, old cesspits were replaced by ‘dry’ solutions such as this earth closet.
(Picture: Patent, courtesy of British Library)
This diagram from the first patent for an earth closet granted to Henry Moule and James Bannehr in 1860 shows how lifting a handle lowers the floor of the pan (b) to drop the mix of faeces and dry earth into a container below. When the handle is released, the floor of the pan returns to its original position, and a small amount of dry earth is released from the hopper (j) onto the floor (b). So each time the toilet is used, fresh dry earth is already waiting to receive excrement. The floor slopes forward, to separate urine from the solid waste.
Moule, and others, produced a number of variations on original design. One was included in his 1860 patent (shown here): a rotating screw is set within a trench beneath the seat, which when turned mixes the waste and earth together to improve composting. Some designs featured troughs on wheels that could be easily removed from the wooden cabinet, or were installed over larger vaults that needed emptying less frequently.
(Picture: Patent, courtesy of British Library)
Reverend Henry Moule, vicar of the village of Fordington in Dorset, was moved to improve the sanitation of his parishioners following outbreaks of cholera in the mid-19th century. He felt that in many situations, a closet that covered faeces with dry, sifted soil was preferable to one flushed with water.
Earth closets were easy to maintain, didn’t require the expensive installation of water supply and sewerage systems, and didn’t result in sewage being discharged into rivers from which drinking water might be drawn. And mixing human waste and soil led to decomposition of the faeces, resulting in an ‘earth manure’ with minimal smell and potentially high value as fertiliser. Moule’s dry closet was a commercial success: many were sold, installed and used into the early 20th century.
Today, the idea of composting human waste to create an innocuous or useful by-product, either at source or at a separate site, is an important element in what’s known as ecological sanitation or ‘eco-san’. It’s ideal for places where, as in Moule’s village, water supply or sewerage system aren’t available or adequate. To work, it needs dry waste – so urine needs to be separated and disposed of separately. But it has the potential to provide an affordable, sustainable solution in providing safe, healthy sanitation in both urban and rural environments.