Composting Toilet — Report on 8 months full time usage

762X39

Explorer
C-Head: http://c-head.com/index.html Smaller, less expensive, less capacity, but some interesting ideas. Like the use of common containers. (I didn't want to say disposable.)

Some churn on this subject on a sailing forum: http://www.sailnet.com/forums/gear-maintenance/58601-composting-toilet-report.html
Nice find. Thanks for this link. I have experience with composting toilets and have a cassette toilet in my trailer. I have found the cassette to be good for 2 days with 2 of us and it is fairly easy to empty in a regular toilet or pit toilet but I have never tried to empty it at a dump station (of course we typically camp on crown land so there are no dump stations) .I may replace our cassette with this composting toilet.:coffee:
 
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dwh

Tail-End Charlie
Like a lot of subjects, there are a lot of phanbois and an equal number who insist that it simply cannot work. :Wow1:
<raises hand>

That's me.

I never said "it cannot work". What I said was, "It's not compost."

My gripe is that they really shouldn't call these things "composting" toilets, since they don't actually COMPOST the waste. It's grossly misleading because the solid waste that is being dumped is NOT harmless compost.


"Waste separating"; True. "Easy disposal"; By all accounts, certainly. "Damned handy"; No doubt.

"Composting"; Not even close.


It has nothing to do with being a phanboi or not, it has to do with the process of composting - which these small units DO NOT DO.


And, unlike a lot of hotly debated subjects - there is no mystery here; Composting human waste is a well known process.







There are composting toilets that actually do compost the waste. The basic design generally looks something like this:



Note the hatch near the top for adding organics like sawdust or peat moss, the crank handle for stirring the heap, and the pull out tray at the bottom for removing whatever has worked its way from one end of the bin to the other, becoming compost as it goes.

Note also the electric wiring for the exhaust fan and/or the heating element.



The "Humanure" guys build small toilets that use a 5 gallon bucket and sawdust, or they show you how to build your own.:

http://humanurehandbook.com/humanure_toilet.html



BUT...they don't claim that what comes out of the toilet is compost.

BECAUSE...

The waste then has to be put in to an actual compost heap before it becomes compost. They take a year to fill a compost bin, then let it sit and compost for ANOTHER YEAR before it's fully composted and ready for use:

 

DiploStrat

Expedition Leader
<raises hand>

That's me.
Actually, no, I was refering to folks on the sailing forum. :)

(They were mostly claiming that it would leak/smell/etc. Sailors don't care about whether it is finished compost, whatever it is, it is going over the side once they pass the three mile limit.)

Shall we call it a desiccating toilet? Your point about not producing finished compost, even in a month, is exactly right.

But that brings up an interesting question - what DO you do with the desiccated waste? For a one month trip that brings you home, you dump in your own compost pile. In the third world, you dig a hole. But in the world of dump stations, can you dump peat moss and waste at an RV dump station? You can dump it in an outhouse, but clearly it is too dry and absorbent to go in a conventional toilet.

And were do you get peat moss in the third world? Oh, the thinks you can think!
 

762X39

Explorer
Ok, I know what a composting toilet is and as previously stated, have experience with them.The solids that come out of this unit would then go into my compost heap and in a year or so it will feed the flowers.Makes it a compost starter toilet then.Whatever it is, sh$t goes in, something a bit more pleasant comes out.I'm good with that.:coffee:
 

Entropy

Observer
Since I've got three kids and I'm planning to do a year in Europe and would like to avoid hookups whenever possible, I'd be interested in any opinions for this kind of high-use situation. So far it seems like a large tank and dumping every couple of days can't really be avoided. I like the idea of cassettes, but the capacity seems too small - same for composting. I haven't really looked at incinerating toilets yet.
 

dwh

Tail-End Charlie
Ok, I know what a composting toilet is and as previously stated, have experience with them.The solids that come out of this unit would then go into my compost heap and in a year or so it will feed the flowers.Makes it a compost starter toilet then.Whatever it is, sh$t goes in, something a bit more pleasant comes out.I'm good with that.:coffee:
In one of the vids from the Lovable Loo guys, the fellow narrating says that the Lovable Loo is a collection device for a composting system. He then states that if the user is not equipped to compost the waste themselves, that there are composting companies which run collection services.

What Nature's Head, AirHead, C-Head, etc. sell is the same thing - a "collection device" for a "composting system". They just don't include the rest of the system. :D


(Fine for boats. As Diplo said, "over the side". What the hell, the oceans that cover 70% of this rock are quickly becoming corrosively acidic - an acid bath will break down the waste for sure.)
 

dwh

Tail-End Charlie
Since I've got three kids and I'm planning to do a year in Europe and would like to avoid hookups whenever possible, I'd be interested in any opinions for this kind of high-use situation. So far it seems like a large tank and dumping every couple of days can't really be avoided. I like the idea of cassettes, but the capacity seems too small - same for composting. I haven't really looked at incinerating toilets yet.

Jay, with the Eco Roamer vehicle, used one of these waste seperating toilets, and travels with a wife and kids. I seem to recall he did something like run the urine line to the exhaust somehow to burn off the liquid.

No idea how he handles the solid waste. Probably just tosses a bag of it in a handy dumpster.

Incinerating toilets have been discussed here - there is a thread somewhere I think.

Basically, they come in electric, propane or diesel fired.

The electric ones use about a kilowatt per cycle. Good luck powering that sucker without running a generator.

The propane unit I've seen is designed for full-time use for a family of 4, and costs I think around 3 grand.

The diesel fired...there is one that is for installation in a trucker's sleeping berth - it has a 1/2 gallon chamber and takes 40 minutes for an incineration cycle - and then another half-hour to cool down from 1200 degrees F before you can sit on it again. [EDIT: Now that I think about it...that one might be 24v electric...probably is...oh, lament the failing memory...]

The only other diesel fired I've seen, is designed to handle a job site crew of 20, weighs 200 lbs. and costs around 5 grand.

Both the propane fired and the larger diesel fired come from the same company, and they can both have an optional catalytic converter (with forced flow fan) fitted into the 8" chimney to trap the odor of incinerating waste. That option I think runs another grand or so. (But the neighbors will thank you. Or at least not kill you, which they would do if they had to deal with the smell.)


And then, there was the Thermasan system installed as an option on the old GMC motorhomes. It used a single grey/black water tank, and used a pump to inject the waste into the exhaust pipe just aft of the engine, where it would get incinerated by the heat of the engine exhaust.

It used both speed and vacuum sensors, so the pump wouldn't come on unless the vehicle was moving at 35 mph or more AND the exhaust gas was over 900 degrees.

Developed with the co-operation of the EPA, it was fully approved for use in the U.S. Too bad they don't make it anymore...

http://www.gmcgreatlakers.org/GMCGreatLakers/Technical/Livingarea/Thermasan-System/Pages795-800 from X7425.pdf
 
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DiploStrat

Expedition Leader
Thermasan

That is simply brilliant! (And not all that different from diesel particulate filters!)

Couple it with a macerator pump and you are in business. Do you know what the disposal rate was? Liter per minute? Per hour?
 

grizzlyj

Adventurer
Since I've got three kids and I'm planning to do a year in Europe and would like to avoid hookups whenever possible, I'd be interested in any opinions for this kind of high-use situation. So far it seems like a large tank and dumping every couple of days can't really be avoided. I like the idea of cassettes, but the capacity seems too small - same for composting. I haven't really looked at incinerating toilets yet.
Hi

Europe is mainly set up for casettes though. Most of the emptying points cannot be used by draining from a black tank via gravity. A macerator would be a good idea, although we have managed with a 70l tank and a 2m drain hose for the two of us.

I wouldn't set off on a long trip without being sure a composting toilet was really suitable having trialled it. Personally I think I would stick with cassettes and a SOG, but carry two extra reservoirs as many campers do.

:)

Edited to say thank you to DWH, nice extra info :)
 

kerry

Expedition Leader
Hi

Europe is mainly set up for casettes though. Most of the emptying points cannot be used by draining from a black tank via gravity.
That was my experience in European campgrounds also. No hookups for a hose directly from the black tank to the sewer at campsite and no means of draining a black tank. Everyone I saw was using a cassette or a porta potti. You could be in a ****load of trouble (literally) if you planned to empty a US black tank system in Europe.
 

762X39

Explorer
We have decided to install a C-Head in our trailer in the spring. We compost both at the cottage and at home so it won't be a problem to finish the cycle. The Thetford cassette we currently use only lasts 3 days max in the bush and I am totally unhappy with it but it is way better than the old system with black and grey-water tanks.
At some point we will be installing a composting toilet at the cottage to reduce the load on our septic bed. I had a Sanmar composting toilet at the old studio 25 years ago and it worked great and the clients never had a problem with it. Once the toilet has been in use for a year I'll post comments on how happy we are with it and after that, how the compost turned out.:coffee:
I just emptied the cassette from our last trip, it's funny that Katherine didn't offer to do it....
 
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User113

New member
Kitty Litter

As asked by DiploStrat:

Do you know what the disposal rate was? Liter per minute? Per hour?
See page 1 (i.e., 24M-1):

Rate.png

Also, for the dessication, do you think you could use kitty litter in lieu of peat moss?
 

RonaldPottol

New member
To get good compost, you need the right mix of carbon and nitrogen, the point of the wood chips or moss is to add more carbon to balance out the nitrogen in urine.
 

chromisdesigns

Adventurer
**edited** somehow the quote didn't show up. Original post was that people had to empty a cassette unit every other day with only 2 people using it.


Every other day seems excessive for two people. When we rented in Australia and New Zealand, we were able to go several days before emptying the cassette unit. Definitely less often than every other day. And emptying is quick into any dump facility or toilet. The only problem with a cassette, it seems to me, would be if you were dry camping for a long period of time away from a place to dump it. Blackwater holding tanks obviously have the same issue.

Now we were not using the cassette exclusively; where there was a toilet we used that during the day, or in remote areas I don't worry about peeing in the woods, but we used it a lot. We are looking hard at a Bengal Tiger, and will go with a cassette unit on that if we do order one.
 
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