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Three Categories of Natural, No-flush Toilets
For people living in the developed world, having a flush toilet to carry away their human wastes is not a big deal. Having the water readily available with which to flush and having the electricity readily available with which to operate the pumps that deliver water under pressure to their toilet just seems ordinary. Also seeming ordinary is the massive, mostly out of sight, sewage handling infra structure that carries away the entire neighborhood’s waste to a treatment facility where it is processed and made ready for reuse. Most flush toilet users have heard that our fresh water supply is getting scarce, but few have felt the serious pinch yet.
In the undeveloped world, electricity, if available at all, is often rationed, and even the rationing schedule can be unreliable. Water is scarce too. Having a flush toilet is out of the question for these people—even if they could afford it, and most can’t. Some say, in a world where water is scarce and we have shortages, it is almost criminal that the flush toilet has been spread so widely and has become synonymous with wealth and luxury—a status symbol in much of the world. It has become idolized as the premier way to handle personal waste. How unfortunate that the flush toilet is so wasteful of a scarce resource and yet so desired. There are ways to handle our waste that are not nearly so dependent upon costly infrastructures and valuable resources.
There are three major categories of natural and no-flush toilets. They use neither water nor electricity. They are: 1) compost/aerobic, 2) anaerobic digester and 3) bio-mass/biofilter. Within each category there are several types and many models. There are electric or gas incinerating toilets too—but they need electricity or gas to operate. Even when electricity or gas are available, they are expensive energy compared to natural alternatives available. There are low flush toilets, but they still use water and require water and sewage infrastructures. Let’s look at the three categories of natural no-flush
We begin with the bio-mass toilet. The most common bio-mass used is worms. They eat the fecal material. Often the urine is diverted and allowed to simply evaporate. Urine is pathogen free, unlike fecal material, so simple evaporation is fine. The worms greatly reduce the volume of solids and the end product (worm poop) is not very smelly. At this point, it is pathogen free. It can be used for fertilizer, as can the residue of evaporated urine. For those who have experience at taking care of a worm colony this could be a good choice.
But the worms are animals and must be cared for in terms of temperature, nesting materials, protection from toxic materials and so on. I am told they don’t like urine—so it often is put through a diversion apparatus. It takes effort and knowledge to keep a worm bio-mass toilet in operation. Shock loading events (have a party and all the guests use the toilet) can play havoc with the worm colony. They need stable living conditions to keep happy and growing. Toxic liquids accidentally put in the toilet can kill the worms. This will cause the toilet to fail. Most people in the world lack the experience to manage a worm colony. Bio-mass toilets seem inherently fragile and require experience most toilet users don’t have and likely are not interested in acquiring.
Compost (aerobic) toilets have the support of many in the “green” community. And the odor one might expect from the end product is simply non-existent. It is great at producing safe to use fertilizer. However it takes time and storage for the excreta to turn into fertilizer. This is the drawback to human waste composting. Outside the green community, most people do not want to take the time required to deal with the composting process. And many find it even more unpleasant because it requires working
close to human excreta. There are a few expensive models that eliminate much of the care composting human waste requires.+ For the affordable models, these steps apply:
1) Cover the excreta with sawdust or peat moss after each use, 2) carry it outside once or twice a week, 3) put it in the compost bin, 4) cover the excreta again, 5) possibly check the temperature to ensure proper compost operation, 6) turn the pile and cover edges well. 7) You will have waste composting bins and piles of wood shavings, which you either produced or had delivered, setting in your back yard.
Composting storage. The first outdoors bin you build is to hold the first year’s waste. The second bin is for the second year’s waste while the first bin composts for a year. The third bin will be for year three’s waste while bin number two is composting. During year three you can safely use the compost from bin number one for fertilizer. You will use these three bins in yearly rotation.
Compost enthusiasts perhaps won’t mind that it is human waste with which they are working. Nor will they mind doing the maintenance steps just described. But because it is human waste and because of the effort required to carry out the maintenance steps, the aerobic compost toilet will not be favored by the majority of toilet users.
The anaerobic digester toilet has not been popular because of the bad smell that is a natural by-product of anaerobic digestion. The older toilets do have this odor. To date they have not been very popular.* But when the odor is eliminated the anaerobic toilet is the favorite of this writer. Here is why. Stated briefly, the anaerobic digester toilet is a toilet that: 1) uses no water, 2) is pleasant to use because it is odorless and 3) and avoids the required composting steps and working with human waste. Proper design and powered venting remove the unpleasant odors (methane, ammonia, etc.) from the bathroom area.
The design and venting of a recently invented anaerobic toilet offers features 1, 2 and 3 mentioned above. Such a toilet is the first choice of this writer. Electricity is not required. A small solar panel, with 12 V battery back up, powers the exhaust fan atop the vent pipe. After initial filling, no additional water is needed. The system has two tanks, each installed at ground level. The effluent discharged from tank number two is odorless and pathogen free. This small amount of discharged liquid can be used for fertilizer.
Anaerobic digester toilets produce very little sludge and, depending upon use rates, would need to be pumped out every two to five years. They dispose of human waste straight away and on site—no handling required. The hydraulic flush moves solids away from user view. There is one more step needed than there is in a fresh water flush system. It is a simple 3 to 4 second additional step—take the brush from the cleaning solution in the near by pale, swish it around the bowl, then return it to the pale. That’s it.
System failure due to human taboos against working closely with human waste or unwillingness to keep up the composting chores, are unlikely with the anaerobic digesting toilet.
+ Here is a system Dr. Owen Geiger likes, in his words. “Another option is 'wheeled trash bins'. They hold about 32-45 gallons. No cleaning necessary. The biggest drawback is cost. The family would have to buy multiple trash bins and store them somewhere for two years or so. But this is offset by ease of use. Simply move the trash bin every 6-8 weeks or so and park in an out of the way place.”
*Biogas, which an anaerobic digester automatically produces, is good for household use in cooking and heating IF there is a regulation and delivery system installed and there is sufficient animal and human manure introduced into the digester. For one or two toilets the biogas produced will not be sufficient to supply a home. For farms with sizable enclosed animal lots it would be worth while.
About the author.
Dr. Jerry Epps lives in Marietta, Georgia, USA and is co-partners with Mr. John Hunter-Hardy, Francistown, Botswana, in the business of selling and promoting the Eppivent toilet. Mr. Hunter-Hardy is the inventor of the Gendarme toilet—a self-flush anaerobic toilet that uses no fresh drinking water, which is the forerunner of the odor free latest model, the Eppivent. Dr. Epps’ website: www.teachdemocracy.org and Mr. Hunter-Hardy’s website: www.gendarme.co.za
Jerry Dean Epps, Ph. D.**
Marietta, Georgia, 30062, USA
February 27, 2012