Whole Life Times: Loo sans l'eau

January 2007 | Mindful Living

Loo sans l'eau

Why we need waterless potties

By Jeff Conant

When it comes to human impact on the environment, there is perhaps no clearer point of encounter than the toilet.

Worldwide, illnesses related to poor sanitation and hygiene kill more than 3 million people a year. With water resources growing scarcer and the high cost of sewage service, variations on the composting toilet are, of necessity, on the rise.

One important outpost of the eco-toilet trend is the Mexican town of Tepotzlan. Long a bastion of radicals and freethinkers, the town is home to a diverse community of indigenous peasant farmers, New Age expats, artists and a small group of global health professionals who have dedicated themselves to perfecting the waterless loo.

How Dry Am I
When American expat Ron Sawyer found his way to Tepotzlan after years of service for UNICEF’s Child Survival campaign in Kenya, he was surprised to find more than 100 waterless toilets already in use. It was a head start to establishing an ecological sanitation (eco-san) pilot program with support from the Swedish International Development Association (SIDA) and the UN Development Programme. The program, known as Tepotz-eco (a play on Tepozteco, a nearby Aztec pyramid), is one of three SIDA-funded eco-san pilot programs worldwide.

Sawyer recognized a kindred spirit in Cesar Añorve, a local architect who had developed an innovative toilet that separates liquids from solids to facilitate safer handling. He took Añorve’s design to the next step by closing the nutrient cycle and preserving the dried solids for use as soil conditioner. Urine, which carries no pathogens, is collected separately and used as fertilizer, with no risk of spreading disease.

Another colleague, Francisco Arroyo, brought a further development, which he calls orinoponics (or the less technical but far more fun “peepee-ponics”). Arroyo found that mixing a handful of compost into a few gallons of urine causes it to breed a microorganism that digests carbon. Adding this “fermented urine” to a pile of dried plant matter causes the plant matter to be transformed, relatively quickly, into rich soil.

The system is not technically “composting,” but a dry toilet system, using dessication rather than biological decomposition. This simple, low-cost technology could play a crucial role in conserving and protecting water, reducing germ-transmission and returning precious nutrients to the soil for farming.

Arno Rossmarin, communications director of the Stockholm Environment Institute, believes that ecological sanitation may be the only way to avert a global phosphate crisis. In nature, nitrogen, potassium and phosphate are all returned to soil in animal wastes. But a century of sewage has diverted vast amounts of these essential elements to the bottom of the oceans, from where they can never be recovered. While phosphorous is essential for agriculture, its build-up in aquatic ecosystems causes eutrophication (the elimination of oxygen from the marine environment). Meanwhile, the world’s known reserves of mined phosphorous are growing dangerously scarce.

In the high, dry and rapidly overpopulating reaches of Northern New Mexico—where my household water supply regularly runs out—I am acutely aware of the absurdity of using precious, life-giving water to flush my waste. At five gallons per flush, three flushes per day (minimum), the US, with a population of 296,000,000 flushes, well, a lot of water down the toilet. After witnessing the innovations in Tepotzlan, this habit now seems as absurd as using champagne to hose down the sidewalk.

As project coordinator for the Hesperian Foundation’s Environmental Health Book Project, Jeff Conant develops popular education materials on environmental health for low-literacy audiences. His new outhouse is a humble attempt to practice what he preaches.

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