Small scale poop-processing?

hey... i d like to have a system to safely process human poop. it s not for heavy use, just a few servings of brown stuff per week.
i can t do humanure-hot-composting. garden space is somewhat limited.

my ideas:
- worm tower. a pipe with holes dug into the ground, maybe with some earthworms and compost added to get things started faster. but what if the pipe will fill up?

- just using buckets and let them sit for 1-2 years

- making a flow-through worm bin. this would be fast processing and vermi-compost could be harvested. but what about temperatures in winter? maybe an insulated worm bin?

This is a link to a video with small scale humanure composting. I've heard of people having success with worms, but haven't gone that way myself. If you are looking to keep this to a small scale I would definitely put in a urine diverter and use it directly in the garden as you will end up using a lot less wood chips as cover material without mixing feces and urine. I've never collected in barrels like in the video but it seems to work well for smaller collections/smaller households.

hey daniel,

thank you. good video. but i checked where the lady lives. it s oakland california. i seldom get s below 6° Celsius there.

urine diversion is planned.

Why can't you hot compost? At least seasonally. Store it until summer and then run a hot batch to finish it off. A couple deposits a week will be 1-2 compost tumbler batches a year.

For infrequent use and a single person, a WPPU (worm poop processing unit ) is an oversized solution. If you have an outhouse and space below the outhouse (100 cm) , buy 2 trashcans (240 ltr) and prepare one of them: Place a false floor with a grid on the bottom of the can ( the bottom of the compost compile should remain sufficiently dry) , place some bark /wood shavings on the grid and let the show begin (but don't forget to place the can under the toilet seat). It will take a surprising long time, until the can fills up. After that, you prepare the next can and then switch. The filled can should stay for some time with an aereated lid. Then, you have compost. If the sump fills with water (very unlikely, if you divert the urine) the liquid has to be pumped out ( a foot-driven pump should do the work)

Worms need much humidity and this needs to be monitored. However, under ideal conditions, worms process poo very fast. The problem is the "under ideal conditions" . Fresh fecal matter can be toxic for worms (Ammonium).

This is what we use for 2 people in Oklahoma, zone 7, temperature lows between 5 and 20F. We separate probably 75% of the urine. We don't use a diverter but keep a separate urine bucket that we've just gotten used to using. No strict rules about urine separation. Each barrel fills up in 4 to 6 weeks, depending on how much company we've had. After 4 to 6 months of composting in the barrels we dump into an open compost area for a few months before using. When it's warm we get lots of soldier fly larvae in the barrels which really helps stuff break down.



Here's a link if the picture doesn't display.

webpage

thank you all.

hot composting: i thought that i would need a huge amount of stuff for it. maybe 1 cubic yard or so and that it needs to be somewhat the right ratio of carbon and nitrogen.

what about this... a barrell partially dug into the ground with holes in it. it get s charged with earthworms, half finished compost and some kitchen scraps. so the worms would have other food-options and habitat that fresh poop. i think, that they ll move towards the poop a some point in the decomposition process.
when it gets too cold for them, they ll move deeper into the soil. but they ll leave eggs behind. so in spirng a new population would start... and/or i could add new worms from indoor, worm bin after winter.

i think, i would need two barrels


what about that?


thank you and have nice and blessed easter-holidays

Don't mix the brown stuff with something else => it blows up the mass you have to deal with and it is contradictory to both mass reduction and pathogen destruction.
Additional carbon source: Toilet paper and some cardboard eventually. This stuff will decompose completely.

Read this: http://www.thermopileproject.com/wp-content/uploads/2014/06/Hill-and-Baldwin-2012-Vermicomposting-toilets.pdf
(A disaster for many existing composting toilet systems, additives like sawdust don't work well...)

I could locate an example with a wheelie bin: http://villagejournal.org.au/article_shell.php?page=n_e_compost_toilet.html&issue=252&group=2
(you could build it even simpler , but the mentioned 240 ltr waste bins are a good idea.) Never have an uncontrolled drain into the ground (pollution of ground water).
However , with an UDDT there is practically no drain water - it evaporates and you will not need enforced ventilation.

For a single person, it will take a very time long to fill such a bin. If you want to vermicompost both kitchen scraps and poo, build two vermicomposters. Kitchen scrap produces a lot of compost tea. Avoid contamination with fecal matter.

hey ... i ve not come to a decision by now.

i think, i ll start with a portable throne and try things out. i d like to cut the bottoms of a chair (just saved one from being burned at easter bon-fire), maybe add a self made toilet seat. i ll make diverter from a halved bucket and drain it into a watering can for direct use (diluted with water). i ll place a bucket with close fitting lid under the throne. i ll drill tiny holes into the bucket close to the upper rim. i hope, that will be enough ventillation and keep insects out.

i ll need some covering material so one would not see the mess in that bucket. maybe i ll shred cardboard or use leaves, grass-clippings or saw-dust.

when full, i ll write the date on the buckets and let them sit. so i ll have plenty of time until our place gets crowded with poop-buckets. until then, i ll know what to do.

later i d like to build a bench for that. kinda like a lovable loo, but built into an 80cm wide niche/toilet-room. i d like to have it in a way that it could double as a squatting toilet. maybe i could fit an urinal for males. i ll see how that all would fit into the space available.

Tobias,

I could locate the moldering toilet design based on wheelie bins on youtube



Two bins 240l each should do the work and you can see the modified bottom part with the grid. It will take two years to fill a bin...

Christoph,

thank you. the height of the room wont permit that kind of a setup and there is no space under the room to put the bins.

so i ll have to deal with smaller buckets. maybe i could put the buckets into a larger bin after a few months of rotting. and add worms to the larger bin in spring and empty that thing in late fall. that would add up to around 1 year of composting.

update:

i ve got the toilet working so far. not very convenient by now, but working.
the urine diverter works very well so far. ok, i need women to test it

i made a bucket for solids with 4 holes of 1 inch near the lid. i covered the holes with fly-netting, i glued it with acryl.

i use shredded carboard as covering material, but might go for more natural stuff.

when bucket is full, i ll write the date on it and let it sit ... just let the shit sit and that´s it
then i ll see how to go on from that ... but first get a few buckets filled

edit: ok, i just listened to podcast 213 and 214. there they suggest to keep the poop moist like a wrung out sponge to help the composting process. but not like submerged in water.
they say that poop has the right carbon/nitrogen-ratio for composting. but if you will add toilet paper and cover material, this will add too much carbon.

so should you from time to time wet the stuff with a bit of urine (maybe diluted) or use some greens as cover material?

update: ok, i tried it a few times. i did not use much cover material (shredded cardboard). the shit got all over covered by mold... yuck...

small scale poop processing can be a real pain in the ass ...

so i think, i ll change direction a bit. use a small bucket inside. empty it often into the bigger bucket (with ventillation holes) outside. keep the stuff in the outside bucket wet and add some urine to add N to the C to help composting.

any thoughts?

So...questions: Why not use a low-flow toilet or one of those camper toilets that use very little water, but still get stuff down with less streaks and the water-lock to keep the smell sealed out? As for vented bucket, why not have the holes in the bucket have a way to be closed off and an out-door vent be plugged in when in the receptacle area. Then, when it goes to stage 2 processing open those vents in a sort of compost tumbler method? what about anaerobic digestion or getting compost heat off this to heat the water to the sink? I have a spot that is probably easy for me to do this...but I need it to be pretty perfect. I'm putting the project 3 years out still, but something this big needs plenty of research.

Thanks!

hey amit...

my opinion: water + poop will create a very stinky mess. and the need to deal with contaminated water. you can t really compost water that well. so i would need to pour it over hot compost.
dry toilets make sense. but small and irregular amounts of poop will create problems.

an insulated all year flow through worm bin would make sense. add stuff from the buckets on top, harvest fertilizer from the bottom (pun intended). it needs to be slow enough to allow for a longer retention period to ensure better pathogen destruction.

or you could add a flow through worm bin below your toilet and just poop on top of it. harvest the compost and let it sit for another 6 month to 1 year...


philosophical lesson i learned: treat your shit well and it will become fertilizer and bring growth ... neglect your shit or treat it badly and it ll grow into a moldy mess...


i thought, it was called mouldering toilet ... not moldering toilet ...

The cheapest, easiest and most effective way that I've found for dealing with waste is a 5 gallon bucket. A lot of people will tell you to develop fancy grey water systems and composting toilets. They are right to a point, but if you are starting out and your situation is anything like mine was, then you'll be neck deep in leaking roofs and a need for money that will outweigh your well intentioned tree huggery.

As I was saying: 5 gallon buckets. I rotate between two. One is in the kitchen where I fill it half way with grey water by simply dumping things in it. Coffee grounds and water, water from dishes that soaked overnight, water that gets drained out of pasta, etc. When it is half full I move it to a private area where it is used as a toilet for a day or two. When I go I add junk mail, wood chips from the wood room, ashes from the furnace, anything organic garbagey that I have to clean out any way. The water plus carbon make the smell nonexistent. When the bucket is full I dump it out under a fruit tree for mulch and fertilizer. The trees love it. Then I rinse out the bucket and repeat.

Obviously this is not a good strategy around dogs and children, but for any young person long on desire and short on finances this is a viable option.

We have a simple, safe and easy humanure setup on our farm.

From 4 houses with 8 people total, we all use 5 gallon buckets and rice hulls. No diversions, nothing fancy. The magic trick to keeping a bucket of crud in your house without offending company is to *keep every deposit covered*. This applies inside the bucket as well as on the pile. Each bucket deposit needs to be fully immersed in rice hulls (or sawdust, there are many options), or itll get gross. Same with the compost pile outside (simple 3 bins system from pallets) - every bucket unloaded needs to be thoroughly covered in straw or some other carbon. This wards off smell, pests, nosy dogs and flies. Ive never ever smelled our humanure mound - and its fairly close to my front door. Rinse out the bucket with a hose, do a gentle vinegar rinse/wipe, and its good as barely-pooped-in.

The pile needs to be treated like a living volcano - scoop aside the top and add deposits there (thats the thermophilic area, deposits here will be hit with the most heat and biological action - rendering a safer product sooner) and again - cover well. In theory you make a new pile after a year, and once your third pile is built up - you can use pile #1 safely... even on food crops in *my* opinion. From the 8 of us using this system, each person fills roughly a bucket a week, and Ive been waiting over a year to flip over the current pile into another bin but... it just keeps cooking down. Its incredible to gaze upon an ever-shrinking 3 foot tall mound of humanure and imagine how many thousands of acre-feet of water that *wasnt* turned into sewage slurry.

Ive read quite a bit on the risks of moldering/dry compost toilets and various other methods - all tried and tested in harsh areas with pathogens running rampant, and from most everything I can find this seems to be the safest/easiest/best smelling method of turning sewage waste into valuable manure - and all thats required are a few buckets, a bucket-toilet seat and an income stream of rice hulls or sawdust.

Good luck, pooper!

I have seen the 50 gallon drums filled with poop set aside to compost for a couple of years. I would like a blow by blow description of the scenario when the lids are removed. Thanks much.

update: the system is outside the hut with a vented bucket (with lid) and a urine diverter. The bucket does not get many input, so i cannot tell how well it breaks down or how many buckets a person would fill per year.
but it works as intended for that scale of usage. No smell, no flies, some volume reduction/decomposition happening in the bucket. No cover material is needed (just for aesthetic resons, I use some shredded newspapers)

Ian, thank  you for sharing about your system. We're about to move off-grid + I don't want to have anything to do with flushing toilets ever again. So I'm glad to hear that 5 gal. buckets work well. Sounds like a very simple system, but effective!

Here's another Laura Allen video - from the lovely people at PeakMoment:

Published on May 30, 2010
Peak Moment 172: Laura Allen gives an intimate tour of a home-built composting toilet in her Bay Area urban home. The nutrient-rich composted "humanure" is used to enrich the lush, edible landscape, and doesn't waste precious drinking water like flush toilets. The co-founder of Greywater Action shows the throne-like toilet compartment whose distinctive feature is a urine diverter. Pee and poop are collected in separate containers beneath the toilet, and are accessed outside the house. Sterile pee is watered in at the base of plants, while poop is collected in barrels and aged for a year or more until it has composted fully. What a way to go!