Simple methods of collecting and composting humanure are sometimes called cartage systems or bucket systems, as the manure is carried to the compost bin, often in buckets or other waterproof vessels. People who utilize such simple techniques for composting humanure simply take it for granted that humanure recycling is one of the regular and necessary responsibilities for sustainable human life on this planet.
How it works is a model of simplicity. One begins by depositing one's organic refuse (feces and urine) into a plastic bucket, clay urn or other non-corrodible waterproof receptacle with about a five-gallon (20 liter) capacity. Food scraps may be collected in a separate receptacle, but can also be deposited into the toilet receptacle. A five-gallon capacity is recommended because a larger size would be too heavy to carry when full. If a full five-gallon container is still too heavy for someone to carry, it can be emptied when only half full.
The contents of the toilet are always kept covered with a clean, organic cover material such as rotted sawdust, peat moss, leaf mould, rice hulls or grass clippings, in order to prevent odors, absorb urine, and eliminate any fly nuisance. Urine is deposited into the same receptacle, and as the liquid surface rises, more cover material is added so that a clean layer of organic material covers the toilet contents at all times.
A lid is kept on the toilet receptacle when not in use. The lid need not be air-tight; a standard, hinged toilet seat is quite suitable. The lid does not necessarily prevent odor from escaping, and it does not necessarily prevent flies from gaining access to the toilet contents. Instead, the cover material does. The cover material acts as an organic lid or a biofilter; the physical lid or toilet seat is used primarily for convenience and aesthetics. Therefore, the choice of organic cover material is very important and a material that has some moisture content, such as rotted sawdust, works well. This is not kiln-dried sawdust from a carpenter shop. It is sawdust from a sawmill where trees are cut into boards. Such sawdust is both moist and biologically active and makes a very effective biofilter. Kiln-dried sawdust is too light and airy to be a 100% effective biofilter, unless partially rehy-drated. Furthermore, kiln-dried sawdust from wood-working shops may contain hazardous chemical poisons if "pressure-treated" lumber is being used there.
During a cold winter, an outdoor pile of sawdust will freeze solid and should be covered or insulated in some manner. Otherwise, feedsacks filled with sawdust stored in a basement will work as an alternative, as will peat moss and other cover materials stored indoors.
The system of using an organic cover material in a toilet receptacle works well enough in preventing odors to allow the toilet to be indoors, year round. In fact, a full bucket with adequate and appropriate cover material, and no lid, can be set on the kitchen table without emitting unpleasant odors (take my word for it). An indoor sawdust toilet should be designed to be as warm, cozy, pleasant and comfortable as possible. A well-lit, private room with a window, a standard toilet seat, a container of cover material and some reading material will suffice.
Full buckets are carried to the composting area and deposited on the pile (you'll know that a bucket is full enough to empty when you have to stand up to take a shit). Since the material must be moved from the toilet room to an outdoor compost pile, the toilet room should be handy to an outside door. If you are designing a sawdust toilet in a new home, situate the toilet room near a door that allows direct access to the outside.
It is best to dig a slight depression in the top center of the compost pile in the outdoor compost bin, then deposit the fresh toilet material there, in order to keep the incoming humanure in the hotter center of the pile. This is easily achieved by raking aside the cover material on top of the pile, depositing the toilet contents in the resulting depression, and then raking the cover material back over the fresh deposit. The area is then immediately covered with additional clean, bulky, organic material such as straw, leaves or weeds, in order to eliminate odors and to trap air as the pile is built.
The bucket is then thoroughly scrubbed with a small quantity of water, which can be rain water or graywater, and biodegradable soap, if available or desired. A long-handled toilet brush works well for this purpose. Often, a simple but thorough rinsing will be adequate. Rain water or wastewater is ideal for this purpose as its collection requires no electricity or technology. The soiled water is then poured on the compost pile.
It is imperative that the rinse water not be allowed to pollute the environment. The best way to avoid this is to put the rinse water on the compost pile, as stated. However, the rinse water can be poured down a drain into a sewer or septic system, or drained into an artificial wetland. It can also be poured at the base of a tree or shrub that is designated for this purpose. Such a tree or shrub should have a thick layer of organic material — a biological sponge — at its base and be staked or fenced to prevent access by children or pets. Under no circumstances should the rinse water be flung aside nonchalantly. This can be a weak link in this simple humanure recycling chain and it provides the most likely opportunity for environmental contamination. Such contamination is easy to avoid through considerate, responsible management of the system. Finally, never use chlorine to rinse a compost receptacle. Chlorine is a chemical poison that is detrimental to the environment and is totally unnecessary for use in any humanure recycling system. Simple soap and water is adequate.
After rinsing or washing, the bucket is then replaced in the toilet area. The inside of the bucket should then be dusted with sawdust, the bottom of the empty receptacle should be primed with an inch or two of sawdust, and it's once again ready for use. After about ten years, the plastic bucket may begin to develop an odor,
YARDS AND GARDENS: TRANSLATING AMERICAN INTO ENGLISH
In the United States, a "yard" is a grassy area surrounding a house; the term is equivalent to the English term "garden." That grassy area may contain trees, shrubs or flowers. If it is located in front of the house, it is called the "front yard." Behind the house, it is the "back yard." Beside the house, it is the "side yard." An American "garden" is a plot of vegetables, often located within the yard. An American garden can also be a flower garden or fruit garden; some American gardens contain flowers, fruits and vegetables. In the UK, the green area around a house is called the "garden," whether it contains vegetables, flowers or nothing but mowed grass. English homes do not have "yards." So the term "back yard composting," translated to UK English, would be "back garden composting."
Was this article helpful?