work. From an engineering standpoint, we know what works, but from a biological standpoint, there is nOt much known. I nave always been leary about use of sodiwn-based detergents, because the sodium competes with other cations for the active exchange sites on the clay particles. Too much Na means less space for the other beneficial cadons, and pH problems. Tom J avitts suggested the use of gypsum to flush out the Na periodically, but checking with soil scientists, I have found that this may compound the problems rather than helping them. That may work better Out West, but in the East the 40-plus inches of annual rainfall dbes a better natural flushing (maybe). My study of soils and biological agriculture suggests that the reuse of nutrients in greywater is highly site-specific. What works well some places may not work other places. A lot of it depends on management-in terms of what crops are grown, what methods used to install, what volume, concentration and nature of wastes disposed, what ultimate disposal intended, soils, climate, length of use, etc. I could go on at lengths, but fear this might already have overloaded you. Let me know. To pass along a method that we found very workable for outhouses: the traditional method of using lime to cut the smell was uncomfortable to us, because you had to buy the lime and it renders the material unusable. So we decided to compost the material by effectively balancing off the C:N ratio and adding wood ashes for pH control. Our routine was to throw in a generous handful of spoiled hay each time we took a dump in the outhouse. This did several things- covered over the active sites where flies breed, absorbed the moisture build-up, inoculated the system with more microbes, gave the decomposer organisms a more balanced food, and prevented compaction (thus also increased air volume). Periodically, we added some wood ashes for the potash content and to raise the pH. About once a month we moved the top layers <maybe about 15-18"} toward the front of the outhouse pit because the pile was building upwards towards the throne, and also because it seemed like a good idea to let it compost without the additions of fresh material daily. We turned it .. ~ ... o" .s:... i c 'go '2 oS til E .g simply with a long stick stuck down the throne. The most surprising thing about this operation was the clean, spring-like earthy smell that was emanating from the pot after the top layers were pushed forward. The bottom layers obviously were composting well. It was amazing to walk into the outhouse in the middle of the summer to nave it smell so fresh and pleasant! We often used hay that I made after cutting the lawn, letting the clippings dry out a few days, and then gathering them up, storing in a feed sack next to the toilet. The volume reduction in any good composting operation is about 80-90 percent, so there was not much yield. The main advantages (\f this method are: pleasant outhouse, cheap, and most of all, you don't have to move the outhouse so frequently because the pile builds up so slowly. Of course, you could also shovel June 1979 RAI Page 2l the stuff out and usc it on your bushes, flowers, trees, elC., and reuse the same spot again. In your update, I hope you find instances of solar outhouses; I think they have lots of application in the future and are cheaper than composting toilets with the same benefits. We need [0 get public approval of attached outhouses, since they are perhaps the most environmentally sound systems of dealing with human manures, and attaching them would take the hassle out of going outside in the middle of the winternasty especially when you're sick and in a hurry. Patti Nesbitt Route 2, Box 374 Strasburg, VA 22657 ~ ~ " :E o it c c '0 is .~ Vl E o J:: Rainpeople .. . The basic design of the compost unit is similar to a Clivus Multrum and is just about identical to designs in Stop the Five Gallon Flush. Construction was very easy-a good example of low-skill appropriate tech. We cut 1-112" beadboard insulation to the shape needed, stapled chicken wire to it, and covered it with cement plaster. Cement was fairly rich- 5:1 I think- and contained an admixture of glass fibers for extra strength. The glass is a particular alkali-resistant type designed for use with cement by Dow Corning. About one small handful til a wheelbarrow of mortar is all that's used. We set up the beadboard with plywood forms [0 hold it in shape and plastered the inside. After that cured, we removed the forms. Meanwhile we laid the top of the ground and plastered the inside of that. When the [Op cured, we put it in place and plastered ule ()utside. The inside was later painted with Blockbond to be watC!Tproof. It all seems very strong and quite waterproof. Installing the chute requires careful attention to detail-'otherwise it leaks odors into the house. My total costs were about $400- including $300 to Ron, who supplied some fiberglass parts. I Lhink anyone else could build one for half that. Use 3" plastic pipe ripped in half for the U-tube ventilators. The baffle at tbe high end of the tank could be made from sheet plastic, the interior ha tch could be plywood or whatever. Details on a homebuilt Clivus from a Ieuer from David Robison 19593 Desantis Ln SE Silverton, OR 97381 Tom : For your Compost Toilet update. If you don't have the World Bank's studies on " Health Aspects of Excreta and Sullage Management" and related work, you might write: John Kalbermarten, EWT/ Rm. D- I036, World Bank, Washington, DC 20433. It's probably the best stuff out. Also, for your information, we're initiating a program [0 develop employment from solid waste at the Bank with Niel Seidman Institute for Local Self-Reli3 nce. It's a narr<HVline but the Bank does have the resources t<) put a.t. on a technically sound base. Bill Ellis TRAN ET
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