Thursday, April 8, 2010

Special Compost

Now, out of the first hundred people who read this entry, I predict that:
20 of you will stop in the middle of it, go to the sink and wash your hands obsessively,
40 of you will finish reading and say "That's nuts."
25 of you will read it and say "I couldn't do that."
10 of you will file it away in your minds in case of emergencies.
4 of you will give it serious thought but not do it.
1 of you will do it.

Yes, that is right. I make special compost. Out of rice hulls even. Although sawdust would work too. We used to use cedar sawdust, but ended up with compost that wouldn't rot and nothing would grow in. I recommend hardwood, failing that, pine.

My special compost closes a lot of the nutrient loss in our little circle of life up here. We grow vegetables, we eat vegetables, and we make the special compost to grow more vegetables.

If haven't guessed it yet, we compost our humanure (this is the cue for the first 20 to go and wash your hands obsessively) Joe Jenkins style. We got the idea from his wonderful book- The Humanure Handbook" and his excellent webpage manual.
Now it is not as disgusting as you may think. It doesn't look like you might imagine. It looks like a 5 gallon bucket of sawdust. It doesn't smell either. Think of a cat litterbox. Cats cover their "deposits" and it keeps the smell down. Same principle. Cover your deposits, and everything is fine.
Our toilet is a plywood box with a hinged lid that we put over a five gallon bucket. It has a regular toilet seat on it as well. We keep another bucket next to the toilet to provide the covering material. When the bucket is full, I open the lid, take out the bucket, and bring it outside to the composting area. Then I dump it on the pile, wash out the bucket- dumping the wash water on the pile as well. Finally, I put a layer of soil and some more clean rice hulls on the pile. It takes about two minutes all told, and we go through about four buckets a week on average. (This is the cue for the next 40 to think "That's nuts" - and indeed there are some, probably corn too! :)

We let the compost age like a fine wine for at least a year after we stop adding to it, and then it is ready to go.


  1. Hi Eric;

    You are right about the numbers! I love talking people through how disgusting a conventional flush toilet can be by dissolving
    human waste and directing it into the potable water in your area. It doesn't matter if you have a well and septic tank or a municipal system the results are the same. We use the truck tires with part of their sidewall removed to compost our crap in two of our homes here at Woodhenge. In fact, we just spread about 500# of composted material around to start grass in an area we'd just landscaped...I'm curious as to how it will work. I wonder how bad it will get in urban and hyper-suburban areas if the water supply is ever cut off? Thanks for your input! -Jim-

  2. Hi Eric
    We are seriously considering this option for our inaka house. Do you soley use this system or do you have a septic? What do your kids think? Are they used to it? My daughter has just got the hang of washiki since going to yoichien but with a lot of persuasion.

  3. This is the only thing we use. We don't have a septic tank, just a "big old greywater pipe" where our washwater drains to a big bed of rice hulls as a biofilter. Our kids grew up on this and don't give it a second thought.

  4. Hi Eric,

    Rob here from Inaka House. We have been studying composting toilets in some detail. I am sure they are better than the fearful "boton" type Japanese hole in the ground toilets. They always seem to smell dreadful. I was getting ready to order some sawdust but was concerned to hear it didn't work for you here. Is this the type of wood here? Was it cedar? I'd like to try rice hulls but not sure where is the best source. Called "momigara"? Probably those rice washing stations I need to hang around in Yonezawa to get them for free. I also found rice hull charcoal like you made for sale. Would this be good for a compost toilet? I bet it would absorb smells and moisture well. Would leaves and plant cuttings work? Knotweed LOL? We will have lots of that.

    Also, do you separate #1 and #2 into different toilets? I read that if you do this, then the solids size is reduced by a factor of 10 and much less cover material is required. Also it apparently smells much less. I understand urine can be diluted and poured on your plants as it contains no pathogens. There are separating toilets but these seem to be difficult to clean. Better to have two separate ones it seems. I am weighing different ideas. I could have 20 litre bucket I empty onto a larger pile every couple of days, or directly use an enormous 500 litre plastic lorry tank with a seat to compost in that would last years. Do you think such a tank would allow enough air to circulate? I slightly worry about the authorities with an "open" compost heap (they seem red hot on septic tank regulation - the long arm of government) which could have run-off though I am sure there are no practical problems. Interested in your experiences! Cheers in advance.

    1. The sawdust we used was cedar. I shouldn't say it didn't rot, it just took a longer time. Rice hulls (momigara) also take a long time to decompose due to the high silica content. You can usually get it from the rice-milling stations for free. Rice hull charcoal would work, but I would definitely worry about charcoal smudges all over the bathroom and hallway. I don't recommend it for indoor use. You can use shredded leaves no problem. Put dry fall leaves in a barrel and plunge a brush cutter with a nylon string head on it. They will be shredded in 2-3 seconds.

      We don't separate, and don't think it is necessary. Of course our boys have notoriously bad aim, so I am thinking of making a urinal outhouse for them to use. Urine is an excellent fertilizer, just keep it off the leaves.

      I can't believe the solids size is reduced by a factor of 10. Our "solids" seem to dissolve in the bucket by the time I empty it on the pile. Definitely go with the 20L bucket. The other one is just a botan toilet.

      You bought your house with a pre-approved toilet in it. The authorities don't need to know that you aren't using it but are composting humanure. Don't tell them or neighbors and everyone is ignorantly happy. When you empty the buckets, just put a few centimeters of dirt, leaves, or more rice hulls to keep the smell down, and everyone thinks it is just another yard waste composter. And it will soak up immense quantities of liquids- water or other, so runoff is not a problem.
      Hope that helps!

  5. My husband and I just built some compost bins and are about to build a loveable loo. Thanks for sharing info about yours! It's good to see someone doing exactly what we want to do. I like the wooden seat and the bookshelf behind it. Love your blog!

  6. Great to meet a fellow composter and one who follows the Jenkins book. No need for fancy separators and the like, keep it simple I say. We use pine saw dust from the wood mill and whilst it adds a slight orange hue to the end compost it does break down over a years cooling down time. As you say hard wood is reputed to be the best, but it's not that easy to come by.