Toilet Systems

Parts of Nicaragua still have a reasonably efficient way of dealing with human waste—the outhouse. Those systems, however, does have some drawbacks. In particular: it is not a good system for a heavily populated area and, well, it doesn't appeal to many. The "solution" was to create centralized sewage treatment systems that depend on lots of water and lots of pipes to remove the "problem" of human waste to someone else's neighborhood. The result is that you now have gallons of contaminated water to deal with for each bowel movement. It seems there must be a better way. We can learn a lot by looking at how an outhouse is supposed to work. The idea is that it will do the following:

• Separate liquid from solid waste. This is done by liquids evaporating and also sinking into the ground.
• Compost the solid waste. To be efficient (and not smell), this generally means adding straw or sawdust.

There are many composting toilets available that attempt to move this natural process from the outhouse into an indoor, upscale solution. They vary from the Nature's Head to a house-wide Clivus Multrum system. All of them attempt to do the same thing:

• Separate liquid from solids. Most systems then try to evaporate them. Natures Head is an exception where you just end up with a separate container of liquid to dispose of.
• Compost what is left.
• Offer an odor-free system.
• Offer a "hands clean" disposal method.

While all these systems seem to work, they tend to involve too many "operational issues" (things you must do with each use, for example), high costs, and/or electricity use. As an outhouse only needed the "it smells, let's toss some straw into it" operational issue along with low cost and no electricity use, it seems like there is room for improvement. I have been reading the Earthship books by Michael Reynolds. In Volume III he introduces what he calls a "solar toilet". He has two different designs. This book was written 15 years ago and I don't see what he offers as the last word but I do think he has a concept that can evolve into an indoor toilet that is more in line with appropriate technology than any commercial product I have seen. His designs basically combine the concept of a solar oven with a more traditional composting toilet. The heat from the sun quickly evaporates liquids and also turns solid waste into dry power quickly. He likens it to what happens when you leave a casserole in the oven overnight. I leave this idea here for someone to carry to "an indoor outhouse for Nicaragua".

Resources

Commercial manufacturers

• http://www.biolet.com/
• http://www.compostingtoilet.com/ big systems, not for homes
• http://www.envirolet.com/
• http://www.natureshead.net/
• http://www.sun-mar.com/

Do-it-yourself and general information

• http://www.cityfarmer.org/comptoilet64.html in-city composting toilet
• http://www.jenkinspublishing.com/sawdustoilet.html $25 home-made composting toilet book
• http://www.oikos.com/library/compostingtoilet/ How they work