Composting Toilet — Report on 8 months full time usage

DiploStrat

Expedition Leader
Some interesting comments by a gentleman who rolled his own:

Composting Toilet Update

So several asked for updates on the homemade composting toilet. I have to say I am really, really pleased with it!

It has not been without its learning curve but I’m a fan. The first issue we had was when somebody put the lid back on without making sure the funnel lined up with the milk jug. This caused a bit of a flood the next time it got used. Spill #1.

The second issue was with overflow. This has happened twice (spills #2 and #3) and will not happen again. I didn’t put in the sight gauge that the C-head has and I’ve paid the price. I fixed that this morning by cutting a slot in the front of the outer container so you can see the urine level. Turns out two adults and two kids per more than a gallon a day. I guess I should have known that, but nothing like learning science by doing


On the #2 side of things...this thing is AWESOME! I emptied it for the first time today a week into our trip. I think I started with too much sawdust in it. I think we could ha e kept going but there was a free sawdust source right next to our campsite so why not. Emptying it was odorless and easy. It was last used probably 10 hrs before.

Not to be vulgar but let’s talk about smell. I have a confession to make...I know I’m probably the only one...but my poo stinks. Having a composting toilet doesn’t change that. So when you make a deposit, it’s gonna stink just like it does at home. However once you crank the handle and get the poo sawdust coated the smell dissipates. I just have a normal plastic toilet seat without any sort of gasket. However, when it’s closed and the handle is in there is very little odor. I never got to installing the vent and computer fan that I had planned on installing so I leave the exhaust fan in the bathroom on low. This has proved to be quite sufficient.

Anyways...I’m very pleased!

Post 179, here: https://www.expeditionportal.com/forum/threads/beefcakes-build-a-roll-your-own-earthroamerish-family-expo-rig.190647/page-12

Now Beloved Spouse is after me to fabricate a composter for our XP. Hmmm. Time for me to put my money and time where my mouth is?
 

Coachgeo

Explorer
... I never got to installing the vent and computer fan that I had planned on installing so I leave the exhaust fan in the bathroom on low. This has proved to be quite sufficient....
only speculating.. but would think the vent fan pulls smells OUT of the toilet and up to your nose..... before it exits out the top. For that reason would assume once you put in the vent connected straight to the box holding poo bucket...... you will have ZERO smells for it will then be bypassing the space in the bathroom..... and the nose on your head.
 

Neil

Observer
On the #2 side of things...this thing is AWESOME! I emptied it for the first time today a week into our trip.
I am sorry each to their own and all that, but if it being emptied after a week because of the smell, then this is in no way a composting toilet. Its a bucket full of S#*$.

If they work correctly you should be able to go months without emptying and no smell.

Sounds horrendous to me

Sorry I sound so negative.

We go three weeks no problem, never smells , powered by gravity, no stocks of medium and cannot be easier to dispose of.

I must be missing something



Neil
 

DiploStrat

Expedition Leader
I am sorry each to their own and all that, but if it being emptied after a week because of the smell, then this is in no way a composting toilet. Its a bucket full of S#*$.
...
I must be missing something
You are.

He did not empty due to smell, but rather because he had a free source of sawdust.

And Coachgeo is right, if he has a vent that is pulling out of the bathroom, as opposed to a fan pulling air INTO the feces box, then he is giving it the acid test. I used to demo our Nature's Head by doing exactly that - turning on the roof vent and then opening the flap. There was little odor and what odor there was was that of soil, as opposed to the normal smell of toilet. Still would not leave the flap open as the exhaust fan was much larger than the tiny computer fan on the toilet.

With daily use with two people we typically got between one and two weeks between emptying. But you empty because of volume, not smell. The stuff doesn't smell, even when you empty it, and that is a great, esthetic advantage over the cassette. After three days the contents of a cassette smell vile. Not a great issue at a dump station, but I would hate to have to use a public restroom. You would NOT be popular. And, FWIW, it usually takes about three flushes with water to get the cassette clean.

Your two stage, decanting system is neat, but you still have to rinse it from time to time and the smell from the contents of the cassette is gagging. I realize that it would only be an issue if you went the full twenty days, but the prospect of dumping a cassette a half a dozen times in a row is daunting.

About the only ways you can get a composting toilet to smell are:

-- Put a lot of urine directly into the feces chamber. This, of course, defeats the design of the system.

-- Put a lot of shower water directly into the feces chamber. I did this before I learned how to set up the seal properly. The cure is simply, an early dump, but in this case, the contents WILL have an odor as they are wet.
 
Last edited:

Neil

Observer
I am still missing something.

So if two people can get two weeks

Is that compost or or that 2 week old s@#% in a bucket.

I am not anti composting toilets in any way. I think they are fantastic if used correctly and safe compost is produced.

I have met lots of ioverlander with them. They will all tell you its the best thing in their life. They will also tell you that they are empryingvthem every few weeks. It feels to me like the emporers new clothes syndrome.

I would love to hear from someone who has actually used them correctly and made real compost. . The sort you can put in a bag and put on your roses.

It takes months to do this not weeks.

Each to their own , I just get a bit frustrated when people suggest they make compost in 2 weeks. They can't.

Neil
 

DiploStrat

Expedition Leader
No one is claiming to make finished compost in two weeks. You can't ask for a product to do the impossible. You can ask for it to perform as advertised.

Everything that I have read indicates that it takes about six months to render human feces completely safe. We are talking about a composting toilet, not a time machine. According to the common literature, you would have to leave the contents in the toilet for six months or so to complete the process. This is, of course, what many people who install composting toilets in weekend cabins do - with weekend use, they typically only have to dump once a season.

An overland vehicle (or a boat) is a much more intense use and the best we ever got was three weeks before the bucket was getting full.

If you don't want to call it a "composting toilet," call it a "Urine separating, desiccating toilet." Got no rhythm and you can't dance to it, but that is technically what it is. These beasts owe their magic to several factors:

-- Separating the ammonia in the urine from feces completely prevents the normal sewage smell. The nasty odor is actually the result of a form of fermentation, only it ain't makin' wine.

-- Keeping the feces chamber under negative pressure means that a composting toilet actually has less odor than a normal water filled toilet in a house. (Something we always noted with a bit of chagrin after a trip.)

-- The composting medium facilitates the access of oxygen to the feces by increasing the surface area. This causes it to dry out much faster and, yes, starts the composting process.

-- Drying out the feces greatly reduces the volume of the material so that the chamber fills much more slowly than you would expect - literally more goes in than comes out. Remember that 85% of what you produce is urine - take that out of the mix (literally) and things get a lot easier.

-- When it comes time to dump the material smells like garden dirt and completely lacks the sharp odor of the discharge from a conventional black tank or a cassette.

Ironically, the nastiest task with a composting toilet is dumping the urine bucket, a task which gives you a strong dose of "Nursing Home Aroma."

On the road we have dumped our composting toilet in a trash dumpster (the same place that people dump diapers and that the garbage men do their business), a dry, drop toilet in a campground, a cow pasture (watching where we stepped), and even at a conventional dump station that had water. (The material is so dry that you have to flush it down, bit by bit, to avoid clogging the pipe.) About the only place that you can't dump is in a conventional toilet.

With a cassette or a black tank, the first thing you do when you get home is to dump and clean. With the composting toilet we take out, dump, and wash the urine bucket. The rest of the material we leave in the truck. Why? Because it is composting and the longer it stays in, the more benign the output. And since we do have a rather large compost heap anyway, we dump it there before we set out on our next trip. After six months that does go on my roses.

No one is claiming that composting toilets do anything that they can't. I think that part of the issue may be that you still associate the contents of a composting toilet with the wet, smelly slurry that comes out of a black tank. It is not the same. And now having worked with both, I know which I prefer.

Again, I have never met anyone who had actually used a composting toilet who did not prefer it.

As they say, YMMV.
 
Last edited:

Neil

Observer
Good explanation.

Now that it established that nobody in overland vehicles actually ever uses them correctly and makes compost its easier to understand.

I think "alternative toilet" would be a good title.

Thanks for the clarificatoon.

Cheers

Neil
 

DiploStrat

Expedition Leader
Neil, boyo, we are really splitting infinitives! We are certainly using the beasts correctly and they are certainly composting the contents. No you are not going to leave the stuff in the truck for six months to produce final compost, but believe me, the stuff is transformed.

FWIW, the Swedish company, Separatt sells biodegradable bags for their toilets. You fill the bag, and then toss the bag on your compost heap to finish the process.

You noted that everyone you have met who actually uses a composting toilet loves it. There are many reasons, which I tried to enumerate. I think I am qualified having now lived with both systems. But it comes down to your original discussion of what you have at the end of a few days. Note as well the first pages of this thread - the original poster was reporting on his positive experiences.

With a cassette, at the end of three days, you have several gallons of $h*t mixed with urine. And dealing with this is a nasty chore. Lord help you if you spill the stuff!

With a alternate reality, unicorn powered, urine diverting, desiccating toilet, at the end to two weeks, you have a few pounds of what is essentially garden soil. No, it is not finished compost and I'm not going to run my fingers through it, but I certainly don't need to wear gloves dealing with it as I never have to touch it. It doesn't smell bad, is hard to spill (and easy to clean up as it is dry, and can be disposed of many ways, just not in a common flush toilet.

Done both and I know which I prefer. To that end, just got back from a two month trip and guess what I have to go dump!

Now, enough of this, get thee to Potosi and start enjoying Bolivia! Have a Singani sour for me!
 
Last edited:

Recommended books for Overlanding

Vehicle-dependent Expedition Guide
by Tom Sheppard
From $136.99
Motorcycle Messengers: Tales from the Road by Writers who...
by Lois Pryce, Mark Richardson, Carla King, Sam Manic...
From $9.99

Neil

Observer
Agreed. Each to their own. I think both sytems are good if it suits your needs.

We lefy Potosi this morning and took incredible drive to Sucre. We will stay here a few days

Its great to Discuss

Neil
 

Neil

Observer
Yes. Wasn't expecting it. We took some pictures very similar to your one.Amazing country.

Neil
 

Coachgeo

Explorer
...FWIW, the Swedish company, Separatt sells biodegradable bags for their toilets. You fill the bag, and then toss the bag on your compost heap to finish the process. ...!
you can find several companies that make biodegradable bags. Many can be purchased on Amazon
 

Victorian

Approved Vendor : Total Composites
I'm in the early stages of Composting toilet ownership. Haven't hooked up the "fan" yet, but have to say that I like the operation and 100% lack of smell (when the lid is closed). I wish the pee bottle could be removed without opening the whole thing.... Other then that, it's a complete game changer for us.
 

DiploStrat

Expedition Leader
… I like the operation and 100% lack of smell (when the lid is closed).
Plug in the fan or connect the hose to a solar roof vent and the lid won't matter. The essential is that there be negative pressure in the box. That is, the air flows in, not out.
 

Victorian

Approved Vendor : Total Composites
Yep will certainly do this the next couple days. My biggest challange is time....

Cheers,
 
Top