Anybody here with experience with composting toilets?

[Grandpa Shooter]

Been trying to read up on alternative means of disposing of human waste.  Before anyone else beats me to it: Yeah its a really crappy subject!  One of the problems I will have using my remote location will be disposing of humanure (that is the technical term) without pollution.  The old days of the one holer are long gone and with the trailer sitting on a stone shelf, the feasibility of digging down to put in leach lines is doubtful.

The commercially available units I have been reading up on cost from $850 to $2,000 plus and all seem to have significant drawbacks.  Without stirring up the poop, it seems they work kind of when the traditional septic systems are not feasible.  Anyone on here have actual hands on experience with the systems?  I hope you own good plastic gloves

[AJ Dual]

I've thought about this as a "compost in place" scenario for a long term SHTF in urban situations.

The four biggest challenges as I see them are

- Venting unwanted/potentially dangerous odors/gasses.
- Separating the liquid waste to promote drying and over nitrating/ammonia formation, or sufficient filler bulk (sawdust etc.) to absorb the urine etc.
- Churning/aeration to keep the waste composting aerobically.
- Hauling/moving the compost when the initial house/outhouse receptical is full.

The venting is probably the easiest part, standard vent pipe plumbing up through the roof gets you most of the way there. Unfortunately you don't have water or the "P-trap" to block waste gasses like you do in traditional plumbing. So you might want a seal on the toilet seat when it's closed and not in use, You could even provide constant negative pressure (during the day at least) with a small solar panel and a DC fan. Or you just use "traditional" outhouse construction that's just enough to keep the rain off your backside while doing your business and the breeze carries the rest away.

The separation of liquids could be as easy as just having two toilets. One for number one, and one for number two. The ammonia from concentrated urea can be nasty, but it's not a bio-hazard issue at least. Piping and a minimal amount of flush-water could wash it away to a gravel pit or a leach field of some kind. You could even go waterless with a mineral oil-filled P-trap to prevent backflow of gasses for the urine seat. The oil will always float on top of the urine blocking any odor backwash.

Or you just go super simple, a 5gal bucket, a toilet lid and see if there's a ready supply of sawdust somewhere like a lumberyard in town or whatever that will let you grab a truckload every few months. Sprinkle it in each use to keep things acceptably dry, and cover each new deposit with a fresh layer to keep the smell down.

Keeping things aerated, and moving the humanure to the final composting location (with minimal handling) seems to be the hardest part. I envision a system of plastic drums for the collector, and you close a hatch when it's full, and the full drum rolls down a hill away from the house/outhouse and gets aerated at the same time. Then you just dump the oldest drum  out, drag it back up to the toilet (with a quad-runner ATV and a tow strap, hey... I'm lazy...) and roll all the others over once a day with a good swift kick, or a rope or or maybe even a solar DC motor and a timer set to go once a day to keep everything turning and the oxygen going.

[MillCreek]

When reading about installations in the Pacific NW, Clivus Multrum seems to be the most popular choice by far.  Several years ago, with stricter environmental regulations, our county health department changed the requirements for a septic tank perk field.  This made countless property lots unbuildable if you were not on a local sewer system.  The local Clivus Multrum installer has been doing a great business ever since. 

[Grandpa Shooter]

AJ,

You pretty well summed up the problems as I see them also.  Venting of gases and aeration of the material are certainly the easiest to accomplish.  A toilet positioned over a tank, or a bucket under a seat are easy enough.  The kind of cedar chips which are sold as pet bedding nicely absorb the fluid and keep the smell almost non existant.

I have thought of building or finding a metal box which I could build settling trays for.  Dump the waste in and the liquids run through the top tray.  Some of the smaller particles go through the top tray and settle in the next one down.  About four trays with increasingly smaller drain holes would capture the solids and allow the liquid to drain off into a barrel.  What little was left of decaying material would settle into the bottom of the barrel and the remainder could drain off into a dry well.  With only two people, the solids should not accumulate all that quickly.  When a tray gets full, pull it out and set the whole thing into a solar dehydrator.  Plexiglass walled box with metal roof and turbine on top.  When it is dry incinerate it, and you are done.

Obviously bugs to be worked out, but I think it is doable.

[Headless Thompson Gunner]

What advantage does a composting toilet system have over a good ol' outhouse?

[AJ Dual]

What advantage does a composting toilet system have over a good ol' outhouse?

Outhouses are illegal in many areas. And IIRC, Grandpa Shooter's location has a lot of rock ledge, so there's nowhere for the liquids to leach to, much  less the drilling and dynamite to create the outhouse pit in the first place. 

Grandpa,

The settling tray idea is nice, it's what many muncipal water treatment plants do, but it sounds like an awful lot of parts and work to get it cleaned, or unclogged etc. Your idea has me visualizing lots of reaching inside to fiddle with the trays and well... yech. 

I was thinking more along the lines of a bunch of those big plastic barrels, the kind soft drink syrup or industrial quantity cleaning soaps come in. Have a few in rotation, one collecting under the privy, and the others composting. Once the oldest barrel is sufficiently composted into dirt, it's dumped over to empty it and put under the privy.

[Grandpa Shooter]

If I remember the stuff I have been reading, the time to decompose humanure is 3-5 years if left with the composting process intact.  There needs to be a way of speeding up the process to make it more efficient.  I have some experience with settling tanks from the service and am trying to rack my old brain as to how to make it work for me.  The icky part is no worse than being the one to empty the porta pottie.  When left for 3 days when using bio friendly TP and a citrus accelerator all that is left is a running brown "gravy" if you will.  If you sift in half a cup of cedar chips before dumping it, the smell is not all that bad.  Of course having bad sinuses helps a lot in that department.

Believe it or not, about the only thing this county will get after you for is an outhouse.  Just runs down the neighborhood

[AJ Dual]

If I remember the stuff I have been reading, the time to decompose humanure is 3-5 years if left with the composting process intact.  There needs to be a way of speeding up the process to make it more efficient. 

More air/oxygen? How about a big old drum of some kind with an old clothes dryer belt drive to make it rotate? A scoop of quicklime?

I have some experience with settling tanks from the service and am trying to rack my old brain as to how to make it work for me.  The icky part is no worse than being the one to empty the porta pottie.  When left for 3 days when using bio friendly TP and a citrus accelerator all that is left is a running brown "gravy" if you will. 

Oh yummy... 

If you sift in half a cup of cedar chips before dumping it, the smell is not all that bad.  Of course having bad sinuses helps a lot in that department.

Believe it or not, about the only thing this county will get after you for is an outhouse.  Just runs down the neighborhood

[Scout26]

A half of a 55 gal drum and a jerry can of gasoline.  Ignite and stir with a big stick......

[Bogie]

About 30 years ago, we had a client who listed a house with a clivus multrum... Sucker was UGLY... But it didn't stink...
 
It may be a thought - check out the web sites, and see what they say. Choice #2 would be a large-capacity mobile RV dumper...
 

[Grandpa Shooter]

About 30 years ago, we had a client who listed a house with a clivus multrum... Sucker was UGLY... But it didn't stink...
 
It may be a thought - check out the web sites, and see what they say. Choice #2 would be a large-capacity mobile RV dumper...
 

What we have on the property now is a 33 foot travel trailer.  The holding tank is only around 40 gals.  We can't just tow it into town to dump because there are no RV dump sites anywhere around.  Even if I can time it right, I still have to dump it somewhere.  That is the whole problem.  There is no dirt out there other than what little decayed rock is on the shelves.  We can't dig down and put a leach field in without destroying the nature of the land.  What we are trying to do is avoid the $2,000 fancy toilet and devise a working alternative system.  I am pretty good at rigging things from all of the years of fixing things others said couldn't be fixed and should just be thrown away.

I have always told people the easiest way to get something done is to tell me I can't or shouldn't do it.  Aside from that what has kept me going all these years is work.  The more the better, especially if I have to invent something to get the job done.

[Boomhauer]

The state hunting campground just down the road from me installed composting toilets about six or seven years ago. They seem to work OK...but they spent a hell of a lot of money on them (typical for gov't controlled stuff, though)

[WhiteTiger]

I'd suggest having a look at some of the systems that have been built for use on small farms. I have hazy recollections of one in use on a pig farm that powered and heated the whole barn complex by storing the methane and using it to power a modified generator. Plugging terms like bio methane into google should get you lots of info.



Tiger

[Grandpa Shooter]

http://www.duntonfarms.com/projects/2006_toilet.htm

Check this one out.  My Lady and I just went through it and figured out how to reconfigure the existing bathroom in the trailer to accomodate this method for humanure treatment.  The solar chamber will be up on the next shelf where it will catch more sun to speed decomposition and wind for the stack for ventilation.  Adding the worms is a touch I would not have thought of.

Amazing thing this "google".

[Bogie]

Now, do you also have a different property within a drive? If you can plumb an outside sewer connection, you could use one of the "tanks on wheels" that Camping World sells, and just take with... One of my old neighbors had a (probably not allowed by the city) "sewer cleanout" set up next to his drive... All he had to do was drop a short hose.
 

[Vile Nylons]

I have a Sun-Mar non-electric composting unit that we [wife and I] have used for about a dozen years. It has a stainless drum inside it that you hand crank to tumble and aerate about three times per week. It is vented by a 4" PVC pipe. It does not smell because the composting process is aerobic. Typical sewer smell comes from anerobic decomposition. We do get minor flying insect hatches on occassion but they are more of a nuisance than a real problem. Urine assists in the composting process and should not be seperated. The venting works well enough that we usually have to supplement liquids to keep the compost moist. We have a 20 ' stack which draws well. This can be supplemeted with fans or an increase in vent pipe size. Getting it to work right requires a good understanding of the composting process and how to accelerate it. Media such as sawdust tends to clump and does not break down fast enough. Chips last forever, especially cedar which might smell nice but actually hinder composting since it contains natural anti-fungals and anti- bacterials. It's why cedar lumber does not rot readily. What Sun-Mar recommends and we use is peat moss. Especially the long strand type. Sort strand type used in landscaping and bought in bales works but it still does not provide enough voids for good aeration. Long strand is used in flower shops to fill around the stems in flower arrangements. Long strandy stuff that doesn't even look like peat. A bale is about $ 30 bucks which last us a year. There are microbe accelerants and starters that can be used to accelerate or heat up the process but we usually use concentrated protein in pelletized form. Pet food works but we have been using pelletized alfalfa to keep the process going since our output is insufficient to keep the process going continuously. We also add urea in the form of purchased pelletized nitrogen. We also add diatemaceous earth for insect control. This is all premixed dry and a cup is added on top of each human deposit.
Compost toilets are not the same. Some are just plastic buckets under a fancy shell. We chose Sun-mar because it has the stainless tumbler which I was used to in garden compost acceleration. Cost was just under a grand for our unit which was designed as a weekender cabin unit for two persons. They have fancier, better, and more money. Our unit needs no excavation underneath as does a Clivus, but it is rather high off the ground requiring a step up deal that is provided. Uncomfortable and requires sitting down.
How does it work? Not that great but better than any alternate I can find other than a full water based individual septic system. It takes some work and daily visual monitoring. And you have to offload the compost from a secondary treatment shelf under the tumbler maybe four times a year. The more you use it the more you have to monitor and keep things working right. Kind of like running your own little sewage treatment plant at home. If the process goes bad it takes some rather nasty hands on stuff to clear it and restart. It really helps if you are science/bacteria minded and interested. Most normal folks would probably see it all as a giant p.i.a. Flushing a toilet is soooo much nicer, but when you don't have a choice you make do.     PM me if you want more of the gory details and good luck.

[Harold Tuttle]

There is a Chinese composting trebuchet
called a whoflungpoo...
 

The only composter i have seen is the Chesapeake Bay foundation HQ's clivus

http://greenlineblog.com/clivus-multrum-composting-toilets/

[roo_ster]

GS:

How about a chemical toilet:
http://en.wikipedia.org/wiki/Chemical_toilet

Or, if you have a heat or energy source, an incinerating toilet:
http://en.wikipedia.org/wiki/Incinerating_toilet

[roo_ster]

http://www.duntonfarms.com/projects/2006_toilet.htm

http://www.solartoilet.com/

http://www.longbrancheec.org/pubs/composting_toilet.html