How to Make a Vermicomposting Flush Toilet

How to create a composting toilet system with a flush toilet, a worm-composting bin and a filter bed. Nothing is wasted and the garden is given nutrient dense organic matter.

Full details here.

Brilliant ! I have always seen the benefits of vermicomposting, and composting toilets...
...but, I had never even imagined the concept of combining the two systems.

For more info, see Anna Edey's two sites:
http://www.solviva.com/wastewater.htm
and the new blog site http://www.solvivagreenlight.com/

This is great. Thanks!

Just wondering if you have considered Paul's problem of overwintering any grey/black water, with the lack of microbes and all.

But I'm guessing in Portugal there is still soil activity in the winter months, or no?

Willliam

As a city living plumber I would like to try this on the down low, or in other words, inside.
I am seeing a first chamber much like the one pictured, maybe smaller. The second would have a reservoir at the bottom, a wicking soil on top of that and be planted with poopbeasts.
I could see putting the poop beasts outside in a Intermediate Bulk Comtainer (IBC), with a green house cover for the winter, but I would rather avoid any pump in the system.
So any ideas on indoor poopbeasts? I am thinking very shade tolerant fruiting edibles, salable flowers, and something that grows a TP substitute or rocket stove fuel.

Some searching and I have not come up with much of anything.
Most low light indoor plants grow slowly and are often poisonous to man or beast.
So a pump is probably in the works, and I have several sump pumps to do the job...

Hi William,

in the late 80's/early 90's on PBS there was a show called "The New Garden" on PBS
hosted by John Dromgoole http://www.naturalgardeneraustin.com/john-dromgoole.html
one segment was on "Indoor Greywater system" #707
it featured a scientist from NASA who had done research for poo recycling in space
I can't remember his name
but he built a system in his house that flushes thru a long tank with typical low light indoor plants
his reasoning is that even though they may not be growing much, the roots are very active
he also installed a system at a Mississippi Jr. College (in the student union I think)
I don't know if the video is available
but I still have a VHS of it (no working VCR however)

I also have one entitled "Swales and Spirals" #805
featuring someone named Bill Mollison

I don't know anything about copyright on these
but if anyone wants to convert them to whatever it is that plays in the internet
I'd be glad to send them for cost of shipping

Nice in South America, but how well would this work where it freezes deeply in the winter. Are there any options?

William I didn't really understand your post due to the abbreviations, but one thing stuck my mind: greenhouse.
Somehow the poop could heat a greenhouse, fantastic!!!

Angelika, I was thinking of something like this:
http://sanitygarden.files.wordpress.com/2011/11/img-20111109-00742.jpg

Looks good. Would build the upper part a bit better, it will fall apart in the first windstorm. Maybe an old window a bit tilted would do the job.
HOw do you get the compost out in your design (that is what it's all about)?

Yeah it does look flimsy doesn't it?
My design would be a giant sub-irrigated planter, so black water would be pumped into a porouse reserve tank at the bottom of the 250 gallon tote (IBC) and wicking soil would deliver the water/nutrients to the roots. I would pump the black water waste outside to this mini green house or I would put the IBC tote in the basement and use grow lights.
The basement is crowded and I think an on demand sump pump might use less energy than 8 plus hours a day of grow lights.
Also I have a used sump pump already (I work as a service plumber).

Only just saw this post! The OP is linking to an article I wrote for Permaculture Magazine back in 2014. Since then, the system has performed so well I introduced it to my local municipality here in Portugal. It's now approved for use under the provisions for 'septic tank with drainage', and is being installed by the council where septic tanks have failed or are non-existent. Many people in the area are also adopting it as a solution for their off-grid sanitation. I've open-sourced the system and there's now a website devoted to it. I'm gathering case studies of installations and encourage people to join the forum. The more experience gained, the more potential weaknesses are discovered and ironed out, the better the system becomes.

Greetings,

I'm looking to build a vermicomposting flush toilet on my research farm.  The local government never heard of such a system and won't approve unless I can submit documentation showing that it is safe and it works.  

Does ANYONE have any documentation for the use of a vermicomposting toilet that has been approved by their local government?  

Can I please have a copy to submit to my local government?

Thank you very kindly.

Sincerely,

-  Paul

We built a system in rural south west Oregon, based on Wendy's post. 2.5 years in and it is working perfectly. When it freezes, the worms just move to the interior of the bin and activity is slow. In early spring I toss in more worms, just to help handle any stuff that has collected over winter. Granted, we don't get 'deep' freezes.  So far we have only one hiccup; in the initial build I did not pay enough attention to screening the exit, and the thing got clogged, resulting in too much liquid retention that killed the worms.  I had to dig into it (it was not too awful) and create a guard around the exit that keeps the mulch out. Then we have a secondary screen right at the exit pipe (similar to Wendy's build). Anyway, once that was cleared it has been working like a charm ever since. It was installed  for my parents house on my off-grid property (my house still uses composting outhouse) and is used by 2 people. However, we had 13 people use it for a week and the system handled the fluxuation just fine. I ordered and installed low-flow Toto toilets for this system - they rock.

Wendy- thank you so much for sharing this work! It has been a blessing for my older parents to have an indoor toilet as they age.

Wendy Howard wrote:Only just saw this post! The OP is linking to an article I wrote for Permaculture Magazine back in 2014. Since then, the system has performed so well I introduced it to my local municipality here in Portugal. It's now approved for use under the provisions for 'septic tank with drainage', and is being installed by the council where septic tanks have failed or are non-existent. Many people in the area are also adopting it as a solution for their off-grid sanitation. I've open-sourced the system and there's now a website devoted to it. I'm gathering case studies of installations and encourage people to join the forum. The more experience gained, the more potential weaknesses are discovered and ironed out, the better the system becomes.

Zenais Buck, thank you for your reply.  

Did you get local approval?  

Can you share your documentation with me?

Thank you very kindly.

Sincerely,

-  Paul

Hi all,

thanks for this interesting post and idea.

I was thinking about ways to develop clean toileting system for urban situations and thought of the following system. I haven't yet experimented it so I'm sending out the idea maybe some of you thought of this already or would be curious to develop and experiment with it.

(Maybe I should create a new thread for this so if this picks up, I'll do so not to spoil this specific topic if need be.)

I was reading Tradd Cotter's book on mushroom growing and mycoremediation and thought of the following system.
Could we used inoculated woodchips and sawdust to use in a dry composting toilet so that the fungi (ultimately antibacterial fungi that will eat up bacterias such as salmonella and e.colli) starts eating up the matter as soon as it gets in contact with it. Then, once fructified and stabilized by the mushrooms (less ammonia for instance), the matter will be fed to worms (which love the enzymes produced by the mycelium). Then used as compost.

I think this would be a small and intensive system which could fit in a small urban flat (or cellar) if one was willing to have it.

What do you guys think, any thoughts and comments on that?
I'm posting this rather quickly and can develop, links, sources, drawings, and give species precisions if need be.

Best,
Lennan

I haven't built one of these myself because we are very happy with the dry composting toilets at our school, but I want to reassure people who wonder if it would work in a cold climate.

Will it work in a cold climate?
I visited Anna Edey's original one at her house on Martha's Vineyard, an island in the Atlantic off Massachusetts. It gets a cold winter there: I used to live just 5 miles away over the water, and we'd get some 0*F (-18*C) weather every year, and there were months of skating on ponds, to give you an idea of the temperature.

Anna Edey's worm chamber was buried in the ground so that the top was flush with the ground. The top cover was insulated with styrofoam, and maybe the sides had buried insulation too. The frost line there is probably 3 feet, so I think if you are in a cold climate, just make sure that the top is insulated and that the depth is enough for the worms to migrate below the frost line. Maybe insulate the sides at least partway down. Don't insulate the bottom, so that the warmth of the deep earth can come up into it.

Will it fill up or need to be emptied?
It was wonderful and inspiring. She opened the lid and poked with a stick. There was one visible poop on top with some paper, and the rest was big box full of beautiful chunky black compost teeming with happy worms diving among the decomposing wood chips. Normal healthy compost smell. The one we saw had been in use for 11 years and doesn't fill up. She dumps in more wood chips from time to time, and when they compost down, she adds more. So you never have to remove the compost or wonder if it's safe to use.

What about cleaning products or toilet paper?
Everyone always asks if you have to use special biodegradable soaps or toilet paper, and Ana Edey helpfully answered that question for you by intentionally using the popular brands from the supermarket and NOT using special materials, and her system still worked fine. For decades. You may still want to use gentler or biodegradable products, but you don't have to worry that your visiting mother-in-law or house-sitters might kill everything if they use standard products in your system.

Will the worms starve to death if we go away?
I don't have experience of this, but I think they'll survive for several months and then leave eggs if they do die, so I believe this system could recover after a few months of disuse.

At our school, the "straight to the surface" greywater system has become a bit yucky now that we have a hundred people living and cooking here most of the time, so we are about to install these for the greywater. The effluent will still go straight to the surface to irrigate trees, but I hope it will be less offensive now.

Rebecca Norman wrote:Will the worms starve to death if we go away?
I don't have experience of this, but I think they'll survive for several months and then leave eggs if they do die, so I believe this system could recover after a few months of disuse.

You can take the guesswork out of this very simply. Many people installing my version of Anna Edey's system here in Portugal have holiday homes, so I recommend they simply add animal manures - horse, goat, etc - enough to keep the worms happy while they're away. I don't recommend cow manure as it's too liquid and a large quantity could tip the tank into anaerobic conditions.

Zenais Buck wrote:We built a system in rural south west Oregon, based on Wendy's post. 2.5 years in and it is working perfectly. When it freezes, the worms just move to the interior of the bin and activity is slow. In early spring I toss in more worms, just to help handle any stuff that has collected over winter. Granted, we don't get 'deep' freezes.  So far we have only one hiccup; in the initial build I did not pay enough attention to screening the exit, and the thing got clogged, resulting in too much liquid retention that killed the worms.  I had to dig into it (it was not too awful) and create a guard around the exit that keeps the mulch out. Then we have a secondary screen right at the exit pipe (similar to Wendy's build). Anyway, once that was cleared it has been working like a charm ever since. It was installed  for my parents house on my off-grid property (my house still uses composting outhouse) and is used by 2 people. However, we had 13 people use it for a week and the system handled the fluxuation just fine. I ordered and installed low-flow Toto toilets for this system - they rock.

Wendy- thank you so much for sharing this work! It has been a blessing for my older parents to have an indoor toilet as they age.

Sweet! Thanks so much for letting me know! Could I ask you to PLEASE send me a write-up and some images for the case studies section on the website (email address on the website)? Be sure to document the initial problems as well! Everyone who installs this system promises me faithfully they will do this but I'm still waiting for the first one.

I want to start raising the profile of the system and am considering either a crowdfunder or applying for some environmental prize competition or another to raise funds to make a series of instructional videos and get professional translations for the website done (friends keep promising but the same thing happens as happens with the case studies ...). Having some good case studies on the site is going to make all the difference in being able to demonstrate uptake and effectiveness. And documenting all the various problems and their solutions is going to make for a much more robust system. That outlet is the weakest point. I've been designing a tank attachment which makes it much less prone to accidental blocking, but the problem at the moment is that the tap area profiles of IBC totes vary from manufacturer to manufacturer so making a universal fitting isn't so straightforward. Watch the website for developments though ...

Am I to understand that NONE of you have local permission to build and operate these vermicomposting toilets?

I would like to build one, but the local government won't allow it unless I can provide evidence that it is safe.  The easiest way to do that, they say, is to provide documentation that has already been approved somewhere else.

So, does ANYONE have any documentation showing that their system has been approved as an alternative to septic/sewer or the few commercial composting toilets available?

Thank you for your assistance.

Sincerely,

-  Paul

This is a great idea!  Vermicomposting.net... what a fantastic site.

The design uses flush toilets and that seems reasonable. I wonder if this could be used with dry toilets?  I'm building from scratch and could locate the IBC tote in a basement directly under the toilet.  Distance from the bottom of the toilet to the top of the IBC would be about five feet.  If I cut off the top of the IBC, the waste could drop directly (like an outhouse toilet.)  Could even have a wood shaving "flush" handle to account for the natural reflex to flush.

The benefits I see are:

Expense (no need to buy toilets or run plumbing)

Maintenance (no chance of a clogged toilet or having to deal with that fiddly balloon float thingy that always gets stuck)

Sanitation (solid waste would rarely touch a wall)

The disadvantages:

Need to build a toilet alternative that is removable for access to the drain walls

Squicky factor (users are probably more comfortable with a flush toilet)

Sanitation (if waste did touch walls, would need to clean with a mop or something else weird)

Smell? (since there is no top on the IBC)

The reason I'm asking these questions is I'm pairing with some local reuse organizations and the city to try to create as low cost and sustainable a home as possible that can pass code in this area.  Bathrooms are one of the most expensive rooms.

You could have a vermicomposting treatment system underneath a dry toilet, yes. You don't have to remove the top of the IBC either - you could just enlarge the central hole to fit the walls of your toilet. But bear in mind you need to keep moisture levels in the tank at around 60-75% and you would still need to drain off liquid (urine mostly) which, if it's the only liquid going into the tank, is possibly going to create some problems for the worms through build-up of inorganic salts. Having handwashing water going into the tank will help. As will the water used to clean the toilet (and drop toilets can get really horrid - it's amazing where solids can end up!).

While a properly functioning vermicomposting system doesn't smell bad at all, fresh deposits will provide a welcoming aroma for the next user for sure, especially if it's a straight drop into the tank. The worst nose offender with normal drop toilets though is urine. Many people who run them ask people to pee elsewhere for this reason. If you're not diluting urine with flush water, I can imagine this will also apply with a vermicomposting system.

The expense of a flush toilet is pretty insignificant if you source toilet bowls from the waste stream. You don't have to have a conventional cistern - mine uses a 50-litre wooden wine barrel with a tap so you use exactly the amount of water you need for each flush and there's no waiting around for the cistern to refill for the next person. Again, water containers can be sourced from the waste stream and a proper ball and brass float valve is much more reliable in my experience than these plastic units you find in modern cisterns. So that only leaves plastic piping, which is not exactly expensive. But the biggest advantage besides user-friendliness is the flush water ensures optimum hydration levels in the worm tank and dilutes the urine.

Wow. Thank you, Wendy. I can completely picture what you're saying. Thankfully i can't smell it! You've convinced me. Im also much happier about this once i heard about using grey water or rain water to flush toilets. That makes good ecological sense to me. Is there any issue with using grey water in vermicomposting toilets?

About screening the drainage hole, my friends and I here came up with an idea recently. In the wood chip chamber we recently made to filter our institutional kitchen greywater, we put a piece of rigid metal mesh welded to a frame, vertical about 6 inches back from the drainage hole, but I'm sure it will rust out soon. Later I got a brainwave, we can use one of the many slightly broken plastic crates we have around here as the rigid non-degradable vertical holder for whatever mesh we decide to put in after the metal mesh rusts out. Otherwise I was stumped.

By the way, don't use wood shavings! We asked our students to collect wood chips from around our construction site, but they filled the tank with wood shavings instead, so for the first week or two it smelled great and the water coming out was quite clear, but then the shavings clogged up so the water was backing up a bit in there, and it went anaerobic and started smelling bad in the whole area including the kitchen and dining hall. So I dug out all the wet stinky shavings and we filled it up with wood chunks from construction (no, nobody uses any pressure treated or chemical treated wood here, and minimal plywood was used in this project so the chips seem pretty clean). It's only been going another 2 weeks so I don't have anything meaningful to report yet.

I really need to get my grey water system going!

I've considered building a vermicomposting tank in line with my conventional city sewage system,as a catch all for nutrient capture.
I would even add a garbage disposal, since the food scraps would no longer be going to waste.
But given the monetary return on investment its a project way down there on "the list".

Rob Lineberger wrote:Wow. Thank you, Wendy. I can completely picture what you're saying. Thankfully i can't smell it! You've convinced me. Im also much happier about this once i heard about using grey water or rain water to flush toilets. That makes good ecological sense to me. Is there any issue with using grey water in vermicomposting toilets?

No issue with grey water. You can retrofit these vermicomposting systems to septic systems. In these instances, you just need to ensure you have a well-mixed matrix of organic material that's coarse enough to allow the higher water throughput volume to drain off fast enough.

Rebecca Norman wrote:By the way, don't use wood shavings! We asked our students to collect wood chips from around our construction site, but they filled the tank with wood shavings instead, so for the first week or two it smelled great and the water coming out was quite clear, but then the shavings clogged up so the water was backing up a bit in there, and it went anaerobic and started smelling bad in the whole area including the kitchen and dining hall. So I dug out all the wet stinky shavings and we filled it up with wood chunks from construction (no, nobody uses any pressure treated or chemical treated wood here, and minimal plywood was used in this project so the chips seem pretty clean). It's only been going another 2 weeks so I don't have anything meaningful to report yet.

I've found a proportion of coarse wood shavings are OK provided they're well mixed up with other material. Wood chunks are great but I'd also mix in some fast carbon sources like dead leaves, bracken ferns, straw, etc. The microbial part of the ecosystem uses carbon to neutralise any nitrates and it takes much longer to break down woody material.

Good idea, thanks. I'll go back and throw some other compostable stuff in there along with the wood chunks.

Rebecca Norman wrote:Good idea, thanks. I'll go back and throw some other compostable stuff in there along with the wood chunks.

Just make sure there's little or no fresh green material amongst it or the temperature will get too high for the worms!

We are in Cusco, Peru, starting a new build off-grid.  I am very excited about this possibility of a flushable toilet, as much good that I’ve heard about “loveable loos”. It all seems doable but we do have some concerns.  Our lot is flat and we only have 435sq meters total.  Right now it’s a cornfield.  A pump is a no-go.  We know that we will have to put the tank in to the half meter limit.  Also the green filter will be in hard clay.  I understand that we will need to fill in with quite a bit of mulch.We also want to keep most of the yard as grass and not shrubbery so that the kids can run and play.  Thus, we are concerned about the water not soaking in enough, especially during our rainy season.  Because of this we will divert laundry and kitchen, at least, greywater to another system.  

Should we be concerned or is there anything else we can do to prevent standing water?  How deep have people successfully dug for the greenfilter? Any thoughts or suggestions in this area would be greatly appreciated.  If these concerns can be addressed a new project will be started in Peru within the next couple months.  

Sandy Wise wrote:Should we be concerned or is there anything else we can do to prevent standing water?  How deep have people successfully dug for the greenfilter? Any thoughts or suggestions in this area would be greatly appreciated.  If these concerns can be addressed a new project will be started in Peru within the next couple months.  

Hi Sandy

Sensible in your situation to divert greywater elsewhere. You have a lot of options as far as the green filter is concerned. It doesn't have to be a bed. You could also use a swale as a soakaway/greenfilter (if you have any sort of gradient at all) or pipe to mulch pits around trees and shrubs. The more you can spread the water, the better. You don't say how many of you will be using the toilet but using it for black water only is not a significant amount of water. You can also limit the number of flushes per day if you're really concerned.

Good luck! And if you go ahead with the project, please send me a case study for the website!! I'm hearing of people installing them, all over the place but still have yet to receive any documentation!

For those looking for documentation, check out the post https://permies.com/t/83986 about vermicomposting systems for blackwater in Switzerland.

Rebecca Norman wrote:About screening the drainage hole, my friends and I here came up with an idea recently. In the wood chip chamber we recently made to filter our institutional kitchen greywater, we put a piece of rigid metal mesh welded to a frame, vertical about 6 inches back from the drainage hole, but I'm sure it will rust out soon. Later I got a brainwave, we can use one of the many slightly broken plastic crates we have around here as the rigid non-degradable vertical holder for whatever mesh we decide to put in after the metal mesh rusts out. Otherwise I was stumped.

By the way, don't use wood shavings! We asked our students to collect wood chips from around our construction site, but they filled the tank with wood shavings instead, so for the first week or two it smelled great and the water coming out was quite clear, but then the shavings clogged up so the water was backing up a bit in there, and it went anaerobic and started smelling bad in the whole area including the kitchen and dining hall. So I dug out all the wet stinky shavings and we filled it up with wood chunks from construction (no, nobody uses any pressure treated or chemical treated wood here, and minimal plywood was used in this project so the chips seem pretty clean). It's only been going another 2 weeks so I don't have anything meaningful to report yet.

Hi, any guidance as to the size of the mesh used would be appreciated, thank you!
Some people using this system have mesh around the tap outlet,   cover the bottom of tank with gravel and then put a different size of mesh on top of the gravel?
, if the mesh( I can use plastic / nylon) is to fine, it will clog and cause liquid to back up and drown the worms?
Also, I can obtain black  ibc tanks?
Would this provide better natural insulation, or cause it to become to hot for the worms?
My plan is to wrap the tank in insulation and build a wall around it, with a fitted, insulated lid .so maybe colour of the tank is less crucial?
All advice appreciated!

Hi John, I don't have an informed suggestion for you about mesh size. Yes, I think that a fine screen, maybe 1 cm (half inch), would risk clogging, backing up and drowning the worms and other creatures. But I don't know, as I haven't tried it.

I'm not very keen on using gravel, because at some point the gravel will clog up, and I don't look forward to pulling out stinky gravel and trying to scrub and wash it. Nor to spread stinky gravel somewhere in the hope that rain and traffic will clean it. The appealing thing to me about wood chips rather than gravel is that they decompose and dissolve instead.

About your container (IBC), I think a lot depends on your climate. Most climates have times that are too hot or too cold for compost worms, so it is ideal to enclose or bury the container to moderate the temperature. Black doesn't insulate more than other colors. Its effect on temperature mainly happens when hit by direct sunlight. Insulation, burying, or building an enclosing wall as you suggest would be more effective at keeping the temperature stable.

Many thanks for your prompt reply and useful comments!

Just to clarify, please?
Does anyone use somekind of mesh filter to   prevent the outlet from becoming blocked?
If so, what size mesh?
Or, just rely on woodchips remaining either yo6 big to cause a block, or so small as not to worry about?
Many thanks.

Lots of work! What was the total cost?

Hi, dont know whereabouts you are, I'm giving the cost from U.K perspective.
Toilet pan and cistern ( new) £50 ( can be obtained second hand on recycle.sites when people upgrade?)
IBC tank £80 ( perhaps less , depending on location and supply)
£70 pipework
Quite a lot of muscle work digging in pipes and drilling holes.etc through wall for soil pipe from toilet.
Hoping i can source some wood chips for free
Good luck!

John Middleton wrote:Just to clarify, please?
Does anyone use somekind of mesh filter to   prevent the outlet from becoming blocked?
If so, what size mesh?
Or, just rely on woodchips remaining either yo6 big to cause a block, or so small as not to worry about?
Many thanks.

We used a metal mesh, maybe low grade steel, with about 1 inch gaps. I'm sure it'll rust out, and then we'll find out if the wood chips can work without a mesh. Or we'll put in a plastic crate as the next mesh, since it will be protected from sun so it should be long lasting, I hope.

There is a company manufacturing a system which is compliant in NZ:

https://www.naturalflow.co.nz/

I have a friend (mentor, really) who has installed one of these on his farmstay cottage. Works like a charm, and the water flows down through a food forest.