Bio-char Toilet or Outhouse

My direct experience has been in a US context, so I'll stay there.

Dust has not been an issue. This issue most likely depends on your biochar source, particle size and moisture. Having slghtly moist biochar generally eliminates any potential dust problems.

I have been using a bucket toilet with biochar for 4 weeks. My goals are to greatly reduce water waste, eliminate the condition that causes excrement to be a waste, provide decayable and biochar-based organic matter for plantings of perennials. innoculate biochar, sequester carbon, run the experiment for under $30 US, spend less than 15 minutes design/setup time and to see whether indoor sanitary plumbing is necessary in a first world semi-urban setting.

I use the ubiquitous 5 gallon bucket available at big box stores in the US. The bucket is strong enough to support a removable toilet seat mounted directly on the top of the bucket. Four screws mounted under the seat keep it from shifting by potentially contacting the outside of the bucket. A fifth screw allows a second "spacer" bucket to be used and also not shift should you find the main bucket tipping to one side at any point.

A regular bucket lid covers the main bucket when not in use. I attempt to put a covering of biochar in the empty bucket to reduce sticking when emptying. After use biochar dropped in the top with a contain to cover and coat the excrement. This is about 1/2 cup per usage. I am male, of average size in the US, and have a fairly high amount of fiber in my diet.

Fiscally, I use a $10 wooden round holed toilet seat (seat only-hardware removed), 1 bucket for biochar holding, 1 "spacer" bucket and 4 buckets that rotate through usage, storage and emptying. Using brand new buckets and lids the total was under $30.

The biochar is made from assorted hardwood and softwood chips made in a DIY TLUD kiln that was water doused. The moist biochar is crushed in a third bucket using an impact technique and no dust resulted. The particle size ranges from sand to pea gravel size tending towards a 1/8" diameter.

The test is being run in an environment where objections are extremely likely so that less extreme environments will be even more successful. The bucket is used in a 10'x20' home office/bedroom with no ventilation other than a door that is mostly closed.

The full buckets are saved until there is a perennial planting to be made. This technique is used with non-edibles and edibles that yield food not in contact with the earth. Plantings are in locations where water resources are not threatened with contamination.

There is a slight odor, but much less than I expected. When I strictly deposited excrement, there was hardly any odor. After several buckets I relaxed and started adding some urine. The ammonia smell became stronger, but not so much that it was worth changing anything. In the same experiment I've been collecting urine in bottles and urine innoculating different buckets of biochar. Mostly now the urine goes in the bottles, but some goes in the bucket if convenient.

I've now used each of the buckets at least twice and haven't needed to wash them. The biochar keeps the smell down and aids in complete emptying when used as described above.

On the positive side, it's rather nice to only walk a foot rather than 30 feet to the western style flush toilet and I don't have to clean that toilet. I don't have the same perverse feeling I get when using drinking water to flush excrement. Psychologically, there have been a number of positive personal effects: visceral feeling of fertilizer creation-a primal creative feeling; fiscal satisfaction of saving money through avoided water and fertilizer purchases, emotional/satisfaction of helping people/planet and a perverse pleasure in defying conformity.

On the negative side, it takes 10 minutes extra per week to take the buckets outside to store. However, if you count the time saved by not getting fertilizer for plantings there is perhaps only 5 minutes extra per week spent over using the indoor flush toilet. Given how far outside of US mores this experiment was, I took time to cover the buckets when I had guests in the office.

These results are limited by having only having a single person. I am not at risk from my own pathogens. The "ick" factor is less for my own excrement. I probably notice the odor less because it comes from me, and I haven't brought in third party odor testers.

Also, there is enough land that I could continue this indefinitely. Once all the perennials are planted, burying the excrement would take care of the rest. With enough time in the soil, pathogens will not be an issue. There are theories that part of terra preta formation was through middens. If buried deep enough, I could get a soil profile similar to the classic terra preta picture from the Amazon. However, in an urban setting with much less space, disposal would be more difficult, although I believe that health inspectors aside, conscientious burying would work. Soil microbes would break down the excrement and water would leave, so the overall soil bulk increase wouldn't be very noticeable.

The microbe enhancing and water holding nature of biochar could reduce the risks of pathogens reaching the ground water supply. It's a long argument about the effects should everyone take this approach, but such an argument should consider animal excrement in the woods and in feedlots, the efficacy of traditional centralized sewage processing (not including things like Living Machines), the benefits of sewage elimination and the social effects of people directly with their own waste rather than it disappearing "somewhere else"..

Also, I didn't use controls in the perennial plantings, so I won't really know the effect of this on the plants. I have only been running this for 4 weeks and would really need a fully randomized double blind, controlled experiment run over a several years to give definitive results.

Another approach to this is "Terra Preta Sanitation" where biochar and lactofermentation of excrement are used to provide feedstock for vermicomposting. The worms eliminate the pathogens. See:

http://www.sswm.info/sites/default/files/reference_attachments/FACTURA%20et%20al%20Terra%20Preta%20Sanitation.pdf

For all its limitations, the experiment has shown that biochar bucket toilets can be easy, cheap and fun!

This is my longest initial post so far.

Well, that was a very detailed reply. Thanks for taking the time.

You mentioned the positive psychological aspect. As I sat on my freezing cold bucket, I was more likely to think "So it's come to this. I'm shitting in a 5 gallon bucket"

Along with the crap bucket, I used another for pee and a jug of water provided a cold water bidet. Hands were washed above the pee pail which was never allowed to stay inside for long.

You stated that " I am not at risk from my own pathogens. " and " I haven't brought in third party odor testers. "

We can definately be harmed by our own poop. Lots of e-coli etc. You'll need to lure unsuspecting odor testers. Invite them in for a movie. People don't usually line up for that sort of thing.

This seems to call out for a Monty Python 4 Yorkshiremen reference: "Well at least you had a bucket. We used to squat and throw sawdust behind us while looking in a mirror to hit the falling crap!"

It is not obvious to me that permaculture principles necessarily require a Puritan approach. If the bucket must be in as cold environment, perhaps it could be heated by humanure compost, or waste heat from Biochar making in a high thermal mass kiln, or though it be antithetical, perhaps and electrically heated compost toilet seat

You are correct point out my error. I got caught in Internet dogma. More accurately, from personal poop, I won't catch anything I've not already been exposed to.

As for third party testers, there have been third parties in the office, but not immediately after using the toilet. No complaints, however a showing of Soylent Green in the office might be in order.

Have you considered having the bucket in a heated bathroom with ventilation fan?

I think that's an excellent idea. Mixing biochar with manure helps to 'age' the char faster so it absorbs more nutrients, and char would probably help considerably with smell. You still need to add some sort of carbon (ie toilet paper, sawdust, etc) to balance out the nitrogen rich poo though (microbes can't use biochar as carbohydrates). It's also still safer to double compost humanure and/or make sure the temperature gets up as high as you can keep it while it's composting. "If I'm not exposed to it then it won't happen to me" is patently false, you have no idea what kind of horrible microbes might be living in your colon, where they normally don't reach large enough numbers to poison you. Once they leave your body along with a heap of bacteria food, then they start having a party.

Art Esarn wrote:

It is not obvious to me that permaculture principles necessarily require a Puritan approach. If the bucket must be in as cold environment, perhaps it could be heated by humanure compost, or waste heat from Biochar making in a high thermal mass kiln, or though it be antithetical, perhaps and electrically heated compost toilet seat ;

Have you considered having the bucket in a heated bathroom with ventilation fan?

My efforts have all been at jobsites where the utilities have been cut. In a household situation, I would construct an attached outhouse/greenhouse and there would be no bucket. In my climate little suplemental heating would be needed.

It looks like the terra preta was actually in unfired pots, but covered with green boughs in a reducing , slow burning fire to dry it , and possibly kill off some of the microbes.

Looks like drying actually helps it break down better, and reduces smell.

http://www.sunnyjohn.com/toiletpapers2.htm

The fact that it was found with crushed pottery mixed in was prob because there were no rocks in the rainforest, and they are in there to provide some airspaces.

My favorite theory was that the full pots were stacked next to each other in a line, and covered with wood, lit , then smothered with green boughs to create a reducing atmo.
They still do the smothering fires even today, in the open, to create charcoal.

Seems like they would abandon the village for awhile, due to wearing out the soil, and by the time they rotated back, they could crush the now decomposed potfulls of humanure, and mix it back in to the now overgrown , but slashed and burned , fields.

Morgan,

The purpose of the clay shards in the original (as best as we know) Terra Preta to me is unclear. Biochar when not pulverized to dust holds water, is lighter than clay and intuitively seems to have more surface area than clay. Why then would we need clay for air spaces when biochar serves that purpose?

Could the clay shards be a byproduct of Terra Preta creation through middens?

Why have all those pots (assuming the shards were from pots) when you could defecate in a hole? Perhaps the size of village makes temporary excrement storage and transport useful, and the washing of porous excrement filled pots just wasn't worth the time, sanitary, or ick factors.

The pottery sherds in TP were generally old, heavily used cooking pots. Since fish was the most popular "meat" of the time, that's generally what was cooked in them. The clay tended to absorb the phosphorous and other stuff from the cooking fish, making the shards into an interesting fertilizer.

interesting about the fish/phosphurus.

I know most of the TP was found in rain forest, and in beds above rivers.

Lots of arguments for years about whether is was river deposited or manmade.

As far as i know, everyplace they have found the biochar TP, there has always been pottery in it also.