Friday, October 5, 2012

Composting toilets for RVs and simple homes

We've gotten a landslide of emails (3) asking us for more details about a composting toilet in an RV. You want details? You can't HANDLE the details!

[You totally can.]

WARNING: I am going to talk about human bodily functions and their results. I won't want to eat after I've finished this post, and that's my goal for you, too.

I've discussed this issue on public forums, and I've found that composting humanure in any way can make people really mad. I've warned you, now it's up to you to bring up toilets only very carefully as dinner party chatter.

Why compost?

An average RV toilet uses two quarts of water per flush, which is 4.2 pounds (plus the you-know-what you just did into that water).  
  • A couple might flush 10 times a day = 42 pounds/day (five gallons of previously-drinkable water)
  • In one month, that couple has created 1300 pounds of waste that must be treated (including a rather conservative estimate of the weight of the urine and feces involved). This also represents 150 gallons of drinking water.
Many RVers divert their gray water for flushing, which is certainly an improvement. Still, the weight and volume of the waste remain the same.

Our composting toilet is pretty forgiving in the poo-storage department. A full vault is not a de-camping emergency. It will begin to ask politely to be emptied, and will not become belligerent for several days when it won't allow itself to be cranked.

However, timely urine removal is not optional. Please don't ask how we know this. However, delay is not a catastrophe like Isaac or Katrina. It will be contained, you just won't enjoy clean-up.

If you're talking about the same couple in a stationary home with a common low-flow toilet (1.6 gallons), the amount of treatable waste is more than two tons (4000 pounds) in a month. That's about 500 gallons of drinking water. If you're mad when you look at your water/sewer bill, imagine turning 4000 pounds of your own dookie back into drinking water and the bill will seem cheap.

The takeaway point is that our waste doesn't cease to exist after we flush. RVers know that when they drop the stinky slinky into that hole in the ground, but even then, it still lives.

Maybe you're an intermittent flusher; I'm cool with that. You can customize these numbers just knowing that a gallon of water weighs 8.35 pounds.

What's in it for me?

If you're a campground kind of RVer, maybe not much. I can't deny the bliss of never thinking about where poo goes after it leaves me. This is an excellent set-up for boondockers and homesteaders, and people who are seeking simplicity. You can't get much simpler than we are.

How to compost poop

I'll talk about the Nature's Head composting toilet, just because that's what I know.

However, there are many approaches to RV waste management. Van dwellers tend to be very ingenious in this area (and in many others, too).

For two people, the Nature's Head poo-vault needs to be dumped about twice a month. The urine bucket in front (shown pristine white in the photo) must be dumped every two days, at least. Urine does not burn vegetation, and is safely dumped onto the ground. [Don't dump urine into a stream or other water body. Just because. A nice hole facilitates a contained dumping.]

If you feel you must occasionally flush something, take your urine bottle for a ride to a toilet and dump it there. This is just for you; your urine doesn't care either way.

We dump the poo into a garbage bag and throw it away. After two weeks in the vault, it weighs about 20 pounds. If we had our own stationary home, we would  compost it for a long time and become our own solid waste management system.

A new friend works for a sewage treatment facility in Tucson. He tells me that medication being dumped into the sewer system is a problem requiring a team of full-time lab workers. Untreated, the drugs are recycled into the aquifer and we get our diazepam for free. Nevermind the metabolites - he didn't even discuss that.

Drawbacks to composting poop

  • You can no longer deny you poo
  • After only two weeks, the contents of the vault will still smell a fair amount like poop
  • Sometimes there are "glitches" in the system. The toilet may smell, or you won't get a full two weeks/ couple out of the vault. Humidity bogs down the system.
The ultimate solution to the main wrinkles is just dumping and starting again. That's as drastic as it gets.

While I am typing away on my sanitary keyboard, Annie is implementing a vault dump. She is smiling, but it's not a happy smile. This has been a glitchy two weeks. We can't compare this to going to a dump station, since we've only done that once, for graywater. Luckily for us, that one time involved other people's turds laying all around the overflowed tank.

You will have gut reactions to what you have just read. Oh yeah, I said it. Hopefully I have addressed them, in snarky format, in this discussion. We're glad to answer questions. If you feel argumentative after reading this post and this thread, I'll respond depending on my mood at the moment.

As always, talking about a different way to do things is not meant to challenge traditionalists (much). Composting humanure has been a way to live the way we want to live, and it works. I'm not dissing conventional poo-management. Some of you may be looking for ways to get off-grid, and this is one of our Top Two modifications for off-grid living.

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Gaelyn said...

Love this! But of course my poo doesn't stink.

The Good Luck Duck said...


Merikay said...

But I've heard that vegan poo don't stink.

The Good Luck Duck said...

I don't want to smell omni-poo, then!

kim said...

well as one lucky recipient of your sage poop scoop insight, i'm all for disrupting a dinner party with composting toilet talk. I ignore all evil eye glares my my honey sends my way and blab on and on. I think composting toilets are an amazing and incredulous thing... and now i can add your stats above to further expound on the joys of composting our poo! yay

The Good Luck Duck said...

Yay, Kim! Way to GO! People eat too much, anyway.

Molly said...

Thanks for posting this! Mike & I have talked about possibly getting one if/when we get an Airstream.

heyduke50 said...

what a crappy blog this was... I mean it just plain stinks!!!

Pat said...

This reminds me of "The History of the Bathroom" over at It's a great read, just like this post.

Bonnie said...

As a county park manager, my daughter tried to get a barn on the property outfitted to use as an environmental classroom to use for summer camps and local school environmental education. The county and state health department both refused to allow them to install composting toilets and there was no existing well or septic nearby. The result was that kids could only be in there for an hour due to the lack of facilities. It was very frustrating to my daughter to have such narrow-minded people in control.

Rubye Jack said...

I can't believe I just read every word you wrote here when I don't have, and never will have, a RV. That's because this whole poop thing has always intrigued me, and sometimes when I flush I wonder how long it'll take the earth to fill up with poop as the population continues to increase. And forget the valium poop. What about all the meth poop?

Brenda A. said...

Out of curiousity...I swear!...where does the composting part come in? You poo, you empty it into a garbage bag and toss it. Am I correct? Or am I missing something?

And out of more curiosity....I promise!.....does the emptying process require a VERY strong stomach? Or am I imagining it to be worse than it is?

And with even more curiosity...which I realize may kill me at any moment....what about specifically FEMALE bodily functions? I'm just trying to imagine things I really can't quite wrap my head around. And I'm a VERY open-minded person. But....adding blood to the mix can't be as easy to dispose of as straight urine.

Desert Diva said...

If I ever sell everything and decide to go full-time, I certainly would make the investment.

Roxanne said...

Yay, Cheryl!

Brenda, here goes, as far as i'm able to answer: The poop starts composting right away (there's a starting matrix of coconut fiber or peat moss). There is a fan that helps to evaporate moisture in the vault, and there's a crank to turn it all. If you and your dear straight-out pooped into a bucket for two weeks, it would weigh a lot, and have a lot more volume.

Annie says there is nothing different about what she does, FEMALE bodily function-wise. Environmentally, I wouldn't be any more concerned about blood than about urine, but are you thinking of attracting sharks? Maybe bears. That would give me pause, but not serious pause.

Annie reports that normally, it does not require a strong stomach. Due to unaccounted-for glitches, today was worse. We don't know why.

Meth poop! I wonder how meth metabolizes? Probably there's not as much of that flushed unaltered, but who knows?? RJ, have you read the Humanure Handbook? If poop interests you, you'll enjoy it (I did).

Bonnie, that is so backward. I've heard of that kind of ignorant resistance elsewhere, though.

Pat, that's an awesome article! See, this stuff was in demand, baby!

Heyduke, I pulled rank on you. Get it? Rank?

Molly, what do you guys travel in?

Anonymous said...

ok... so what about dia-ree-ree poop?

you started it!

;o) nikothenomad incognitomad

Brenda A. said...

Yes....bears AND sharks AND assorted critters...OH MY! Hahahaha....thanks for the reassurances. Not that we have any immediate plans to invest is such a contraption, but always curious and wondering. :)

The Good Luck Duck said...

Dear Anonymous NikoTheNomad: I did a colonoscopy prep with this toilet, and it doesn't get more dia-ree-ree than that.

Brenda, you never know!

Rick Doyle said...

Your warning was absolutely correct - TMI!

Interesting though even if it is a bit of an appetite killer.

Michael Ultra said...

Well, that was a very interesting post about fate of the ever present stink pickle. To the very adult about it, most of us, after passing the 60 mark, have done it about 22,000 times. Quite honestly, after having two nurses his mates, I find nothing embarrassing about bodily functions. I found the concept of the composting toilet very interesting. Just one question, have you thought about a cathole? Or,in y'alls case, a duck hole. We will talk about these way back in Cub Scouts.

sierrasue said...

very interresting read. so, you mentioned that you only had to dump grey water once. Do you shower in your rv? and do dishes? and does that water just get dumped on the ground somewhere? I guess that is okay if are using natural products... I like the idea of the composting toilet. I guess there is a mix of compost stuff that you put in it that helps break down the poo???? Do you have to put some in everytime??
On my 9 day river rafting trip in the grand canyon , they used compost toilets that they then carried on board and out of the canyon. And we had 28 poopers in two boats !

The Good Luck Duck said...

Rick, I am the Jenny Craig of poo.

Michael, we have used (duck) holes in some areas where digging isn't disruptive. We have composting friends who dispose of poo that way exclusively. Now that you add the 22,000 figure, it seems pretty funny that we're still squeamish about our doody.

Very pertinent question, Sue. We use about 2-1/4 gallons of fresh water daily, about half of which goes to urine. A large portion of the rest is dishwater, which we collect in a dishpan and use to water a random flower. The rest is bathing, showering, and hand-washing, which we discreetly allow to trickle out onto the ground.

That is serious poo haulage!!

Sherry said...

So you removed the toilet that came with the RV and put in the Nature's Head? What does your black tank do now? Or did you take that out too. Hmmmmmm the way to get more storage space??

The Good Luck Duck said...

Hi Sherry. Yes, Annie removed the old potty, capped the pipe, then laid floor down. The new toilet just sits on top. We sanitized the black tank and repurposed it to hold extra gray water when we need it to.

Harriet said...

The new Outhouse sans lime, old things new again, just loving it, sustainable living at its best. Good post, carry on Ducks!

The Good Luck Duck said...

It's true! The new is more portable than the outhouse, and you get to poo indoors. Otherwise, yeah!

Russ Krecklow said...

Here's a breakfast link you might enjoy:

You probably already have it bookmarked.

The Good Luck Duck said...

Thanks Russ! The wine is better, but this is fun. Annie read me the latest "foil-wrapped leftover" post.

Steven said...

Can this thing sing to me? I often find it easier to complete my transaction that way.

The Good Luck Duck said...

Steve, you will want to invest in the Nature's Head-liners, an indie group included with the premium package.

shelly said...

Cool post. I've been using a humanure bucket system at home for the past 8+ years so I can see this product would be a great solution for an RV. Great job explaining the whole shebang...

The Good Luck Duck said...

Thanks, Shelly! What kind of system do you have? Is it like Jenkins' Loveable Loo?

Rojo said...

Very interesting post. There might just be another project added to the list.

Anonymous said...

OMG! I read this to learn what options we have for indoor toileting in our vintage camper... and ended up laughing out loud thru the entire post! Real life truly is funny! Excellent writing, Duck, and VERY informative! Thank you

Jillian Leigh said...

So interesting.... soooo. Say you are at an RV park. .. poo poo in the dumpster? And walk the urine to a toilet? Hmm... I should get a non see thru catch/bucket/separator for the peepee. Awesome post. Been wondering about how to dispose. But then I toss my kid's diapers in the trash. And Kitty poop. Why not human poop. Is it frowned upon at parks? We want to Rv but not deal with flushing holding tanks of black water. That actually seems ickier to me. I have nook idea why. Just does. Lol.

Jillian Leigh said...

So interesting.... soooo. Say you are at an RV park. .. poo poo in the dumpster? And walk the urine to a toilet? Hmm... I should get a non see thru catch/bucket/separator for the peepee. Awesome post. Been wondering about how to dispose. But then I toss my kid's diapers in the trash. And Kitty poop. Why not human poop. Is it frowned upon at parks? We want to Rv but not deal with flushing holding tanks of black water. That actually seems ickier to me. I have nook idea why. Just does. Lol. So is it easier to get a composting toilet or just make a bucket type toilet?

Good Luck Duck said...

Jillian, I would say some discreet poo-flinging would be in order. I've never had anyone, anywhere, ask me what was in the garbage bag I'm carrying. Maybe I just had that look.

I agree, dealing with gallons and gallons of poo/pee water feels grosser to me, too.

I haven't yet tried a daily-use bucket toilet, so I can't really say for sure. A bucket would definitely be easy to put together. You could get a ready-made toilet seat that's designed to click onto a bucket, and line the bucket with garbage bags. Maybe keep a little peat or sawdust next to it to put on each time? You try it, you don't like it, you tweak the system a little.

If you want to stay at RV parks, you can always start with the conventional method of hooking up when you get there. Then use your bucket when you want to. See how it GOES. You can bundle up an innocent bag of your experiment and toss it in the dumpster as you need to.

Good Luck Duck said...

The urine-separation is key to a long-term situation, too. When I've had to carry a urine bucket to the toilet, I've put it in an opaque, dedicated tote bag.

Anonymous said...

Thanks for your frank and funny discussion of humanure. I'm planning a trip through central and south america and hope to compost. You're an inspiration, if not just a bucket of giggles.

Good Luck Duck said...

Terrific, VK! I'm a bucket of something. I hope you'll share your experiences on your trip.

BH said...

Great post!

I travelled the US and Canada in my van for about 13months putting on over 40000km. I used a pee bottle and the bucket trick. You are so right that they must be kept separate! I used a yellow solid coloured bottle from wally world and a bucket from a restaurant I was passing by.
Using your in-house black tank is such a hassle. In my new dweller, a 31' class-A (moving up in the world) I will be continuing with my bucket (remove the standard toilet and then dump it into a 55gal barrel stored out back. With just me and how often I use it means that it will take probably 2yrs to fill it up.
Using peat and saw dust as a base.

thanks for sharing your experience!

Anonymous said...

Considering that the rv toilet dumps directly into a tank, it seems like one could convert it to a composting system with some clever ingenuity. The idea of keeping pee out of it and to somehow "mix" the compost could be incorporated. One could "glue" a divider that separates the pee. Instead of going into a little removable tank, like Nature's Head, it could go below the floor into a separate tank that could be drained typically. The "other stuff" would go where it usually does. Except with the addition of composting materials in the tank. The next step would be to somehow get it stirred up and decaying. The hardest part would be how to get it out. You could put a dumping port directly on the bottom to drop everything into a container. But how would you get it out if its stuck in there? I am shocked that someone hasn't already come up with a system like this for Rv's because it would sell like crazy. A simple conversion for any RV system. But without paying the outrageous $1000 price tag that Nature's Head doesn't mind charging. Robbery. They are capitalizing on a market that's overlooked.

Anonymous said...

How do you clean the bowl (bowel? jk…) after each poo use? Do you spritz water on it or just aim for the basin when going?

Good Luck Duck said...

On good days, it's a straight shot into the vault. Not all days are good, so you have to deal with it as it goes. Spritzing after peeing is a good idea, though.

Anonymous said...

Still trying to decide if the ultimate disposal is ethical or not, I am leaning toward not. You could consider a finishing area arrangement that would allow you to safely dispose of compost in flower beds or the like. From what I have read about systems such as Sun Mars a five gallon pail would probably be suitable, or possibly a vermiculture area would be better.

Anonymous said...

Great blog. Im building motorhome and seriously considering a composting toilet. Have to ask, what happens with the toilet paper. Do I assume it goes into the compost poop side. Does the paper create any problems.

Good Luck Duck said...

It can go into that side, or you can dispose of it in a trash can. We ultimately went with the trash can.

Anonymous said...

Thanks for composting that.

mrsd said...

Glad I found this post, very humorous and timely for me. I have an old tiny trailer we've been living in (14 ft.) and haven't used the toilet yet. We only have 1 waste tank and I have been looking for alternatives for poo disposal. Think I will use a bag and sawdust and trash can. Thanks for your take on this. On to read the Humanure Handbook.

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