The Humanure Handbook
This is the definitive source on composting crappers, from why to how, and yes, the scatological humor abounds. Yet this is a serious issue. Biosolids are recycled and used in the U.S. and around the world by governments and municipalities, and not always in the most responsible ways. Jenkins gives you the knowledge to do it yourself, and do it responsibly. The entire contents of this comprehensive guide are available as a free PDF download, and the Jenkins Publishing site offers up instructional videos, too.
[See the Humanure Handbook's lessons actualized in the bucket toilet Erik made here.-- es]
Available from Amazon
“We don’t want to eat shit!” they informed me, rather distressed (that’s an exact quote), as if in preparing dinner I had simply set a steaming turd on a plate in front of them with a
knife, fork and napkin. Fecophobia is alive and well and running rampant. One common misconception is that fecal material, when composted, remains fecal material. It does not. Humanure comes from the earth, and through the miraculous process of composting, is converted back into earth.
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That’s also why humanure and urine alone will not compost. They contain too much nitrogen and not enough carbon, and microorganisms, like humans, gag at the thought of eating it. Since there’s nothing worse than the thought of several billion gagging microorganisms, a carbon-based material must be added to the humanure in order to make it into an appealing dinner. Plant cellulose is a carbon-based material, and therefore plant by-products such as hay, straw, weeds or even paper products if ground to the proper consistency, will provide the needed carbon. Kitchen food scraps are generally C/N balanced, and they can be readily added to humanure compost. Sawdust (preferably not kiln-dried) is a good carbon material for balancing the nitrogen of humanure.
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A wide array of microorganisms live in a compost pile. Bacteria are especially abundant and are usually divided into several classes based upon the temperatures at which they best thrive. The low temperature bacteria are thepsychrophiles, which can grow at temperatures down to -10°C, but whose optimum temperature is 15°C (59°F) or lower. The mesophileslive at medium temperatures, 20-45°C (68-113°F), and include human pathogens. Thermophiles thrive above 45°C (113°F), and some live at, or even above, the boiling point of water.
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If a backyard composter has any doubt or concern about the existence of pathogenic organisms in his or her humanure compost, s/he can use the compost for horticultural purposes rather than for food purposes. Humanure compost can grow an amazing batch of berries, flowers, bushes, or trees. Furthermore, lingering pathogens continue to die after the compost has been applied to the soil, which is not surprising since human pathogens prefer the warm and moist environment of the human body. As the World Bank researchers put it, “even pathogens remaining in compost seem to disappear rapidly in the soil.” [Night Soil Composting, 1981] Finally, compost can be tested for pathogens by compost testing labs.
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Allow me to make a radical suggestion: humanure is not dangerous. More specifically, it is not any more dangerous than the body from which it is excreted. The danger lies in what we do with humanure, not in the material itself. To use an analogy, a glass jar is not dangerous either. However, if we smash it on the kitchen floor and walk on it with bare feet, we will be harmed. If we use a glass jar improperly and dangerously, we will suffer for it, but that’s no reason to condemn glass jars. When we discard humanure as a waste material and pollute our soil and water supplies with it, we are using it improperly, and that is where the danger lies. When we constructively recycle humanure by composting, it enriches our soil, and, like a glass jar, actually makes life easier for us.
Favorite (15)
Davey
This will always be the subject of, um, dirty jokes, but addresses a profoundly important issue that could determine the survival chances of millions of people worldwide. Anything that helps overcome the Ick factor with good info is more than welcome.
However, the excerpts leave me wondering about the book's credibility. The temperature conversions are way off, and the claim that some bacteria thrive at temperatures above 450 C -- or anything close to that -- are unsupported by any reference I've found. There seems to be a certain sloppiness elsewhere in the excerpts as well.
The rather cavalier claims about the built-in safety of humanure would be more convincing in a more credible context. I'd like to think the conclusions are correct, but won't be betting the health of the household and the community on this source, unfortunately.
elon
Davey: Good catch on the temperatures. That was a cut-paste issue, and degree symbols had turned to zeros. The error has been fixed. Temperatures and credibility are intact. -es
Zwack
My biggest concern would be if you are using ANY form of pharmaceutical products, and they are excreted, surely using that manure (composted or not) will put the pharmaceuticals back into the environment.
Z.
Davey
Zwack, those pharma chemicals are going to get into the environment no matter what you do with them, short of shooting them into outer space. It seems possible that composting could break at least some of them down into less noxious substances, compared with just putting them into the water supply like we do now.
Elon, thanx for the corrections. Good to know I can take the book more seriously than I'd imagined.
Athios
Pharmaceutical drugs usually get degraded in your body, or used up over time, which is why people need to take their medications everyday to maintain the levels of the drug in their body.
As Davey has said, any residual drugs would be further degraded during the composting process.
Finally, as the book excerpt says, if you are worried, you could use the products horticulture instead.
Tom Sackett
I started to use this system recently for a small off-grid cabin in the Northwest U.S.. So far, I can highly recommend it. Here's the quick version of how it works: you use a toilet made up of a case containing a bucket. There is sawdust in the bucket, and every time you use it, you add more sawdust to cover. A full bucket is actually mostly sawdust. You empty full buckets into the center of a large compost bin that is mostly filled with straw and cover the contents with more straw. You wash and rinse the bucket with a small amount of water, which you dump into the bin. You put a few inches of clean sawdust into the bucket and it's ready to use again.
This procedure might sound a bit nasty, but it's not. Anyone who has emptied a portable toilet, or an RV holding tank, has dealt with much worse. The buckets, even when full, smell like sawdust. The compost bin smells like straw. I left full buckets sitting, covered, for two summer months before I got around to building the compost bin. When I emptied the buckets, there was only a slight ammonia smell, which disappeared as soon as I covered the bin with six inches of fresh straw.
Commercial composting toilets cost a lot, have very limited capacities, and often require electricity. If you read on-line message boards, you will find many people trying one thing after another to get their commercial units not to smell. The humanure system is cheap. It can even be made and maintained using salvaged materials. Its capacity is limited only by how many buckets you have, or how often you empty them. It requires a small amount of water for cleaning buckets, but no utilities. If it ever smells, add more sawdust or straw and it stops smelling instantly.
Though Jenkins recommends monitoring the temperature of the bin to confirm that it is reaching temperatures that kill pathogens, I don't think this is entirely necessary. In my case, it's not really possible, given that we only visit the cabin for a few days at a time, for part of the year. I plan to wait until the bin is full (which will take at least three years, at the current rate) then let it sit for a year, as Jenkins recommends. After that I will send samples to a lab to confirm that it is safe, then use it as compost for non-food plants.
Davey
For those with personal experience of such things, I'm curious: it seems like the Ick Factor to all of this would center on dumping other peoples' production. So do people tend to make it mandatory to take care of their own mess, or does it devolve down to a designated dumper? IOW, does this mostly work well only for solo use and for highly responsible groups? Or are there people willing to do for everybody?
Matt
What a bunch of crap!
Tom Sackett
Davey-
I think most groups will have one person responsible for emptying the buckets. It's not difficult, but there are a few rules you want to follow closely, like always dumping the buckets in the middle of the bin, and only using a small amount of water to clean and rinse the buckets. It's okay to let the full buckets sit for a while, so you only have to empty them once a week. If you have a cabin that's being used by guests, they can just leave the covered buckets for you to empty later.
The Ick Factor is more psychological than actual. I was surprised the first time I emptied a bucket into the bin to find that there wasn't much recognizable in it. The clean sawdust starts out moist and brown (You use damp, slightly rotted sawdust from sawmills, rather than dry sawdust from woodworking, though this can be used if you moisten it with water. In our case, we use peat moss.) As I mentioned before, a full bucket is mostly sawdust, and it absorbs the moisture from human waste so that everything ends up being roughly the same crumbly consistency and brown color. The toilet paper is more noticeable, but it's mostly covered in sawdust so it's not too bad.
It takes a little bit of strength to lift and dump the buckets. That might limit who can take on the chore.
Charlie
People who've raised kids are usually pretty blase about dealing with feces, regardless of how revolting.
This is unfortunately changing, as more and more people are able to move themselves away from the reality of infant excretions through the use of "disposable" diapers, wipes, etc. No washcloths or diapers to launder!
Once you've washed a few loads of diapers from a sick baby, adult excretions are ho-hum yawn moving on now. I recommend the experience to anyone who wants to be fully involved in physical reality. But you won't actually like it.
Nancy Baumeister
Humanure works! I have been doing it for 5 years. My piles routine heat to 120 to 140 degrees F. The compost it makes is the best I have ever made. This method is highly recommended to reduce human impact on the environment. By not mixing your own excretions up with all the nasty industrial and chemical waste that people and businesses flush down the toilet, the resulting compost is as free of noxious and persistant chemicals as your own diet is. GIGO revisted (Good stuff In, Good stuff Out). You water usage will be almost halved. The energy required to pump all that water to your toilet and to "treat" the resulting sewage is saved.
Hub
Does a compost tumbler work for dumping in the excrement? I am looking for a good way to protect from the critters here in the mountains and have seen no mention as to whether a tumbler would reach the appropriate temperatures.