Paul Kurtz wrote:Orin,
I certainly don't understand why urine is separated from the solids. For nearly two decades I've been keeping a sawdust bucket toilet (Jenkins, Joseph. The Humanure Handbook, 2nd edition, 1999) with excellent results. Urine is integral to the composting process.
The toilets here are not the composting type as Jenkins described. There are many ways to deal with humanure safely: contained black fly larva; a human manufactured process to provide clear
water, pure water with bio-systems(fish&snail tanks,then reed beds and other plants); and the willow bank version.
I will admit by using the word "compost" in my post, I confused the fact that our toilets are a willow bank method and not composting toilets. You will notice I also show how to
compost kitchen scraps; since we have no
chickens and we don't want squirrels, composting is what I do with the kitchen scraps here. Wheaton Labs is about pushing the envelope on techniques on what we do know and trying things no one has tried before.
Also at Wheaton Labs, we are trying to come up with methods that are as fool proof as possible; a willow bank which sucks up all the surface fluid instead of putting it in the ground water is one solution we are promoting. Paul believes this method is superior to the composting method and is always looking for ways to better solutions to humanure handling.
Urine makes our willow feeder carts too heavy for a human to move. Urine can also carry black water and makes large batches very sloppy (this could be addressed by more sawdust but new people don't know what is the correct quantity and might not care to really learn). When you have the general public showing up in large quantities, then concern about black water going places you'd rather not have it is clearly important (especially when people unfamiliar with the processes are also showing up in large quantities).
I've always thought the only thing integral to composting is the correct mixture of nitrogen and
carbon; urine can be a part of that process. Urine separation is one approach to humanure composting, Jenkins way is the most popular but not the only method in existence (albeit thanks to him, you and I can actually have this conversation). For instance, urine is a great liquid fertilizer and can be diluted with 8 to 10 parts water to one part urine and spread on
trees and bushes: great for an area which is very dry.
This is by no means a simple
answer topic. Paul's book lists 10 different methods to deal with
poop on page 19. Here are some links for you to explore and comment there if you'd like others to respond in more detail:
sewer treatment podcast
humanure
willow bank
Please direct further questions and comments here:
https://permies.com/t/47814/permaculture-projects/willow-feeder-wheelie-bin-pooper