Dry latrines

The problem of human waste disposal is as old as sedentary living. Once humans stopped moving and started staying in one place—around 10,000 BCE with agriculture—waste accumulation became a threat to health. The dry latrine emerged independently wherever settlement density crossed a threshold: dig a pit, position a seat, let gravity and earth do the work.

At Skara Brae in Orkney, Scotland, around 3180 BCE, Neolithic villagers built small cell-like rooms over communal drains. Egyptian elites had limestone seats over sand-filled pits by 3000 BCE. The Harappan civilization of the Indus Valley (2600-1900 BCE) engineered covered drains connecting private toilets to municipal sewage systems—a sophistication not matched in Europe for another three millennia.

The dry latrine's logic is elegantly simple: separate humans from their waste, let soil microbes do the decomposition, return nutrients to the ground. This is precisely what nature does without human intervention. Cats bury their waste. Dung beetles roll it underground. The forest floor decomposes fallen leaves. Dry latrines harness the same microbial processes—aerobic bacteria break down organic matter when mixed with carbon-rich material like soil, ash, or sawdust.

For most of human history, dry latrines coexisted with open defecation and crude chamber pots. The Roman foricae (public toilets) and medieval garderobes were improvements in convenience but not in principle—waste still accumulated in cesspits, periodically emptied by "night soil" collectors who sold the contents as fertilizer.

The systematic application of dry earth came in 1860, when an English vicar named Henry Moule filed a patent for the "earth closet." Moule's Fordington parish had suffered through cholera epidemics in 1849 and 1854, and the Great Stink of 1858 had made London's cesspools unbearable. He filled in his own cesspool and instructed his family to use buckets, burying the contents in his garden. Within weeks, no trace of sewage remained. The earth had consumed it.

Moule's earth closet mechanized this discovery. A hopper stored dry earth; after use, a lever released enough to cover the deposit. The floor sloped to separate liquids from solids. Some designs included a rotating screw to mix waste and earth for faster composting. Queen Victoria installed one at Windsor Castle. By 1868, 148 earth closets served 2,000 soldiers at the Wimbledon Volunteer encampment without producing any detectable odor.

For decades, the earth closet competed with the water closet. The EC had clear advantages: no plumbing required, no water consumption, and it produced usable fertilizer. But the WC had convenience—no need to manage earth supplies or compost removal. As municipal water and sewer systems expanded in the late 19th century, the flush toilet won. The earth closet retreated to rural areas, military camps, and places without running water.

The dry latrine never disappeared. It remained standard in much of the developing world and survived in Western contexts as the outhouse. In the 21st century, it's being reinvented. The Bill and Melinda Gates Foundation has funded dry toilet development since 2012, seeking off-grid solutions for the 2 billion people without adequate sanitation. Urine-diverting dry toilets separate liquid from solid waste for pathogen reduction. Van-lifers and off-grid homesteaders have embraced composting toilets.

Moule's insight—that properly managed decomposition eliminates waste rather than merely relocating it—is gaining new relevance as water scarcity intensifies. The dry latrine's 5,000-year history may be prologue to its next act.