Backyard Aquaponics
A place to discuss aquaponics

Much better if it's composted, then there are no worries about catching pathogens by eating uncooked veggies.

Manure is really good fertilizer though. If from warm blooded animals it is always best if it's composted first though.

Agreed... an important point...

Ok, this could provide me with a solution. I am wondering, if I have eight people using the compost toilet, (And they live on almost exclusively chicken and maize meal. How the don't get scurvy I don't know!) More people more crap would I need to make changes to the size of the compost containers or would one just have more compost piles going, or would two 1 cubic meter heaps do it? We also have very wet winters and hot dry summers here. Should I roof the bins over so as not to have them getting sodden in winter? I also have masses of sawdust here but of unknown origin, some of which must be from treated wood, can I use this if I use it only for lawns, trees and ornamentals? I already have a dedicated compost pile from cow chicken straw and grass clippings for the veg patch.

When you ask about the size of containers, I'm not sure if you mean the buckets for the sawdust toilets or if you mean the actual compost pile.

I would probably stick with regular 5 gallon buckets for the sawdust toilets.
The compost pile. Well perhaps a bit bigger would be appropriate for 8 people but you don't want to make a compost pile so big that it is difficult to add to as it starts getting full. The author of the Humanure Handbook generally recommends a bin of 5' by 5' for a family. At least I think 5' by 5' works well for his family of 5. And you need a minimum of two bins since you fill a bin for a year and then let it age for at least a year. Of course you can have more bins if you fill them up too quick but I've found that a bit will get to about 1/2 to 2/3rds full pretty quickly and then as we keep adding it keeps shrinking so it seems like we spend most of the year adding to a 2/3rds or more full bin but by the next addition its shrunk back down again. Just keep track of the date at which you stop adding to a bin and be sure to let it age properly.

Pressure treated sawdust is generally not recommended but you will have to make your own call as to if you are gonna use it, if it is only a very small portion of what is in the sawdust, then well it's a judgment call.

Joseph Jenkins does have a forum on his web site for more in depth discussion on Humanure Composting.

Well, I have presented the humanure idea to my Malawian work force and it has been met with great skepticisms. Almost blunt reluctance and complete refusal. They are convinced that it will be flies (a 'different' kind of fly they tell me) and stink and then of course who is going to empty the buckets and deal with the compost etc etc. At first I thought it was a cultural African type thing but Now realize that it has more to do with the notion that their poop is somehow completely personal and they wish to see it washed away with copious quantities of water in a very western way. I guess that the use of a bucket represents, for them, a backward movement in their desire to be modernized or 'civilized'. I wish I could have recorded the discussion! Very funny. They would be happy to create a smelly, festering, fly infested open long drop out in the field though, and I guess they have seen plenty of those in their rural African homesteads. I also explained that even if it was 50 meters away, with no composting happening the flies would come from there to their kitchen or wherever and the pathogens would seep into the ground water. After a long discussion and explanation of the whole process of composting and how it will work, we came up with a compromise. The toilet and compost heap will need to be one unit where the toilet is above the heap and the dwang falls directly on the heap followed by a spade or two of sawdust and then once a week the whole thing could get a covering of straw. Take away the bucket and they are happy! They do have toilet facilities but they are about 200m from the workshop so it takes time to get there and wastes valuable work time you see.

So I have in mind building a double raised toilet /compost heap that has a door on the front with steps going up and then once inside there would be a toilet on each side and a space in the middle for a wash basin for hands. Access to the compost heaps would be on ground level from behind and the space in the middle could house bales of straw for cover material. I also thought that if I had a hopper on the back with sawdust then they could almost 'flush' the thing

Would this work or is it a problem that deposits would be small and frequent as apposed to large and less frequent? Would the hand washing water be able to go directly on the heap for moisture for the composting or would it get too wet? Any ideas

Just an interesting side note... I mowed the lawn on the weekend and piled the clippings (a decent amount of clippings as it is a big lawn) on one side of my existing cow manure and straw compost heap and today the grass clippings where very hot while the cow manure and straw parts of the pile where only a little warm. What's up with this? This is perhaps something I don't get... if you have a pile and the pile has a concentration of nitrogen in one place and carbon in another do the microbes move about from place to place 'munching' what the need when they need it, or how does it work?

High nitrogen content can definitely hot compost. The need for a good balance with carbon material actually has a lot more to do with keeping the pile aerated and keeping the odor from becoming a problem. Hence why we often call the carbon material "cover material"

And, There are instances where a humanure composting outhouse type toilet/compost bin can work. Trick is to keep them from using up way more sawdust than is needed for each "flush".

Now plenty of westerners ask those same questions and have those same issues with the idea of a sawdust toilet with the buckets. Many people need to observe the lack of smell and fly issues to believe it. So, build the first one out of the way and manage it really well so in a season or two, maybe they will let you move it closer. (In the mean time, maybe you can set up a bucket toilet for yourself somewhere and later after you have been using it for a while and no one notices a problem with it, you will have even more proof.)

As to the who will empty the bucket, well that is a job that some people have a real problem with. I feel it is actually a good thing for people to learn to take care of and deal with their own waste because this world can't handle flushing much longer.

I've seen some methods on the Humanure site where they use big wheeled trash bins for the compost for big music festivals and stuff so then the people managing the compost wheel out the full bins to let them age and put empty bins in place. The contents are left in the bins to compost and age so some extra thought to aeration of the bins is needed but seems quite reasonable.

Good luck with it all.

Wow thanks Tcl. some really good advice. I really like the idea of the wheelie bin parked under the toilet. then I could just build one toilet and have two or three bins going. It would mean flexibility in terms of how quickly the bins get full. One could use a small hole saw and drill holes all over the bins to provide aeration. Possibly one would need to build a kind of ramp basement so as to avoid the toilet being too high. Sadly it is totally flat here so no naturally elevated spots to make use of I also thought of some kind of hopper containing the sawdust with a kind of flush dose so that the sawdust covering is regulated. How exactly to do this I don't know.

I had an idea the other day regarding the dumping of the bucket into the bin. Line the bucket with newspaper so that when you tip it in, you can pull the whole line out.

People have talked of lining the buckets over on the Humanure forum. But remember that whatever is in the bottom of the bucket is gonna get very wet and may try to stick to the bottom of the bucket more than make it easy to empty and clean.

I'm also not that interested in spending a lot of time carefully trying to line buckets for this purpose. It really isn't that hard to dump a bucket, Give it a little rinse to get most of the paper/sawdust to come out, then wash with a little drop of dish soap and a toilet brush. Then let dry in the sun, ready for next use. Chances are even if you line the buckets, you will still have to go through the rinse, wash rinse, anyway so the lining isn't really saving you anything.

Oh, and about putting holes in a plastic trash bin to compost in place. I don't know that it would be all that effective. I highly recommend http://www.jenkinspublishing.com/messages/ then you can perhaps get a look at pictures of what some other people have done. Anyway, using the bins under the "outhouse" I think you might need a slightly different method of keeping it aerated since as people use the "toilet" from above it might not be possible to make sure all the contents stay to the middle while the cover surrounds the outside to keep things from stinking or attracting flys etc. I've seen pictures of the bins used at some music festivals and I don't think the put holes in them, they install some perferated drainage tubing down into the bin from the top to allow air flow even after they close up the bins to age. (tubing installed before the bin is used under the toilet.)

I have tried to manage a humanure compost pile on a 9' by 9' patio in large trash bins with holes. It made the management much harder. (if you can do a compost bin on ground of at least 3' by 3' but often better at 5' by 5' it is so much easier to get the proper moisture and cover and avoid the smell problems that so commonly cause people to give up composting and their little plastic compost containers.)

I think you are right there about the wheeliebins. Those plastic jobbies, about the same size as a wheeliebin, built for composting that they sell in the garden shops are useless. Whenever I see them I check what is going on in there and I can say that it is always absolutely nothing! The compost heap we built here two days ago with cow manure straw chicken manure and green grass clippings is big and I stuck my hand in there tonight and it is HOT! Very HOT I have never felt such a hot compost pile. With compost bigger is definitely better. Dumping the wheelie bin option...

BSF larva are naturally occuring in our deer camp outhouse which is nothing but a Port-o-let with the bottom of the tank cut out and mounted over a hole in the ground. All winter during deer season deposits build up... in the spring The BSF larva move in during turkey season and by summer there is a deep hole again. Been there 6 seasons so far. We figured we would have to move it every year or two initially. Pleasently surprised. Smell isn't bad and the girls don't mind using it! Their only apprehension is spiders that lurk in there!

Hi Brian:
Maybe something like this design could be used with humanure composting and without the people being grossed out. The pits would be composting with sawdust scooped into the toilet with each addition?

http://www.dwls.org/sustainability.html

Thanks Dave. That looks cool. I wonder how well it would work on extended cool rainy winter periods we have here which can go on for weeks.