Monday, November 1, 2010

out of the (water) closet

It happens, but it's not widely discussed.

I'm talking about making use of the perfect fertilizer - local, organic, easy to apply, free, sterile, with an NPK ratio of 18:2:5 and plenty of important trace minerals. It's a product of perhaps the best filtration device in existence, the human kidney.

Conveniently, our body places most (80% - 90%) of our excreted nutrients - the good stuff - in the urine. And all of the microbes and other bad stuff, but relatively little of the nutrients, end up in our feces. Diluted anywhere from 2:1 to 5:1 with water, urine is a perfect soil amendment. Undiluted, it speeds the composting process. Used as a soil amendment, one person's urine can provide the nutrients for one person's food consumption, more or less. A perfect circle.

And it gets better. Each flush uses precious water that has many higher and better uses. And each flush has its own carbon footprint from the energy used to pump, treat, and pressurize the water system and treat the effluent on the other end - a footprint that is tiny per-flush but large in the aggregate, especially when counting the energy cost of building and maintaining all of the associated infrastructure. Even more massive is the carbon footprint associated with the process of creating synthetic nitrogen fertilizer out of natural gas and the extensive loss of soil carbon that synthetic fertilizers have enabled.

So why doesn't it happen more? The "ick" factor? Cultural inertia? Just plain ignorance? All of the above, no doubt. Plus a large dose of what Wendell Berry terms the "rift" between body and nature in modern culture, creating a "dualism" that has caused "confusion about the body's proper involvement in the world."

But there are signs of change on a few fronts. A brand new gardening book, The Resilient Gardener, by Carol Deppe, addresses the subject boldly in a subsection titled "The Power of Pee," part of a longer chapter on "Soil and Fertility." Carol gives a quick rundown on collection, dilution and use. Steve Solomon's 2005 Gardening When It Counts tiptoes up to the subject, gives it a strong endorsement, then punts by sending the reader for details to Joseph Jenkins' The Humanure Handbook, a short how-to book available in print or downloadable free from a few web sites.

Globally, "pee-cycling" policies and technologies are advancing rapidly. Separate collection of urine and feces is being done on a large pilot scale in both Sweden and Germany. And a Swedish company, Separett (see manufactures a variety of source-separating and composting toilets, including an accessory urine tank ("Ejektortank 50 - For the green gardener") that facilitates dilution and garden application.

Outside of the western developed world, where soil enhancement needs are greater and the commitment to costly flush-it-away infrastructure less widespread - and perhaps the "disease of dualism" less advanced - both urine and feces are increasingly seen as resource, not waste. In China, a UNICEF/Red Cross program has installed over a million urine diversion dehydration toilets (UDDTs) over the past decade. UDDTs separate urine (for immediate agronomic use) and solids (for agronomic use after a year of composting). Similar programs are widespread throughout Africa.

Closer to home, an amazing non-profit organization called SOIL (Sustainable Organic Integrated Livelihoods, is working to rebuild soil resources and improve sanitation in Haiti through the recycling of human wastes.SOIL volunteers embrace a philosophy of "liberation ecology" with roots in "liberation theology." 

Liberating urine from the bounds of misconception and cultural prejudice - now there's a simple concept with far-reaching potential benefits.

Update: The Haiti project is featured by the New York Times here.
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