Saturday, September 3, 2011

For LG61820 (I like to call her "Anonymous")

The poop is still flying in the composting toilet discussion.  Really, the poop is now just being gently tossed in civil and genteel ways to avoid spatter.  Here's a commenter's honest questions, and my response.   

[Please don't feel that you must defend poop-flushing to me.  It's what most of us do in the developed world.  It's what I have done all my life.  It's what I taught my son to do.  Bye-bye, Poopie!  It's fast, it's easy, and it's fun.]

My last post was definitely off-topic and I'm sorry.

I do have some questions though:

1. Why would you consider a composting toilet in an RV when there are other sanitary waste disposal options available?

I don't know how long the composting process takes, but you would have to haul all that along with you until it's done. Weight is an issue with RVs. Where do you put it until that's done? Hauling around extra weight increases fuel consumption, which in itself is not good for the environment.

2. Assuming the composting process has completed, where would you dispose of it? What good would it do in a landfill somewhere, and aren't landfills themselves a blight on the environment?

3. Why would a composting toilet be preferable  to a sanitary dump station?

I don't know, maybe it's just me, but I would think that a composting toilet would be more efficacious if you were fixed in place where you could use the results to fertilize a garden to grow food. 

Hi T__ & R__,

I'm not positive you're asking me specifically, but I'll be glad to address your questions as best I can.

1)  There definitely are other options available, but I am far from convinced that they are superior (or even equal, but I'm not trying to impugn other people's motives).  The other options are conventional, and that's not always a compelling quality.

2)  "Completely composted" is hard for me to define.  Some people compost their manure to the point of using it on their vegetable gardens, and that process may be 2-3 years.  Composting in general begins within a week, and if you put your hand on the outside of the vault, you'll feel considerable heat being generated almost immediately, which is a sign of microbial action.  

To give you some perspective, two weeks' worth of continuously-composting manure from two people weighs about 15 pounds. How much would that much manure weigh mixed with water?  Urine is a consideration in the holding tank scenario, and so a conventional black tank's contents would likely weigh 15 pounds inside a day.  Most conventional RVers wouldn't travel to a dump site every day (and pay $5-10) to rid themselves of that weight, so overall, composting in an RV weighs much less than the conventional option.

[Let me say here that we look at this from an extreme boondocking perspective.  We don't camp in campgrounds generally.  We are also fans of an off-grid stationary life, although we aren't there yet.  This may help to explain why we find this a superior process.]

But, if we can reach some agreement on what "fully composted" is, and we can draw that arbitrary line,  I would put it on/in the ground.  There is no longer any reason to separate it in any way.  This is great for a homesteader, or anyone who is living stationary, as you said.  Because I am not going to carry our manure around for a couple of months, I settle for the less-perfect option of separating it to continue its composting in a landfill.  I  agree that landfills are a blight, but we all like to think that our household waste in general is going to biodegrade (rot) and go back to the Earth.  Not necessarily true ... except maybe for my lone bag of already-composting manure.

My poop is not doing any good in a landfill.  It will be a resource when we stop traveling, assuming we are in a place where we can "resource" it.  Now, my concern is "where will my poop cause the least impact?"  In a conventional (house) scenario, I might use the toilet six times a day (more if beer is involved).  Pooping and peeing into and flushing away about 10 gallons of drinking water.  After that, it is no longer really a resource (although farmers buy the heavy-metal-contaminated sludge as fertilizer for open fields).  For two of us, that's about 280 gallons of fresh water in a two week period.  As a couple, we have effectively created 1.1 tons of waste that must be dealt with, as opposed to 15 pounds of composting manure.

3)  When you gotta dump, you gotta dump.  A conventional RVer will have to travel to a dump station, and a boondocker will have to travel further.  This is not something that can be delayed for long.  When they get there, they'll have to pay a fee, understandably.  This fee feels small and totally worth it when the tank is dangerously full!  A composting toilet says "Relax!  Empty me tomorrow, or the next day, or on Thursday if you get a chance."

3a)  In our Nature's Head, the urine is separated from the manure mechanically, and we dump the urine onto the ground.  Under duress, we will dump it into a flush toilet.  This amounts to about 1.5 gallons every two days, with two people using it.  See above for beer disclaimer.

My re-disclaimer:  I'm not trying to knock conventional poop flushers.  Since you were interested enough, and so kind as to ask polite questions, I've tried to give you a sense of why we compost.  I'll admit to being strongly influenced by Joseph Jenkins' book Humanure (which you can download chapter by chapter here for free:

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Merikay said...

When, where and how do you dump your urine on the ground? Yes bears pee in the woods, but should ducks? I'm not prissy or critical, I have been known to pee behind a bush when on a hike, I was just wondering where.

If everyone dumped their pee on the ground would it be smelly like a city alley? Do you dig a hole? Do you leave a dead grass spot like a dog? 1 1/2 gallons of urine is a lot.

Annie said...

Merikay, Our toilet separates the urine into a 2-gallon container. When it's nearly full - nearly, because FULL is not fun - we just take the container out to a friendly bush, tree, or open green area. Remember, we don't stay in campgrounds, if we did then we'd have to empty it at a dump station or sewer hook-up. Right now, parked in Roxanne's mother's driveway, her mom encourages us to dump in her yard. Urine is really good for plants. No dead spots and once it has soaked into the ground, no smell.

We have a friend in NY who is big into permaculture. She lamented us living so far from her because she would have loved to use our urine around her house. Not that our urine is special, just that most folks don't collect it like we do.

Tesaje said...

Great response (see, you can do math!). Most people who compost their own manure use the finished product on ornamentals and not out of the eating garden to be absolutely sure there is no risk of disease transmission.

In my van, I favor the dry toilet method over the waste of my precious fresh water just to get my waste into the black water tank. I use cat pan liners (2 to protect against potential tears) in my toilet, then use a little pine cat litter in the bottom. Works great and is easy to pull out, seal, and dispose of. No worse than disposing of cat litter. But I admit, I use public toilets whenever I can.

I'm not keen on the plastic bag use but it is a lot less weight and cleaner to dispose of than black water. I would be happier if I could find those compostable bags in the cat liner size. This practice means that my gray water disposal is very clean too altho I have to be careful of the appearance of dumping sewage.

I thought the comment about how terrible it is that you carry around composting poop was funny considering that most RVs carry around a few hundred pounds of poop mixed in water.

The Good Luck Duck said...

Merikay, what Annie said. Plus, I would add that, if everyone dumped their pee onto the ground, there would be much less need for commercial fertilizer! Urine is very nitrogen-rich, which is one of the Big Three in plant viability. All three (phosphorus, potassium, nitrogen (PKN)) are found in poop (which is why people are glad to use other animal manure as soil amendments).

Thanks, Tesaje. When forced into it, I can work a number or two. May I ask how often you pull the bags out and dump? Is it an every-time thing, or is there a particular level you seek, or time period? We've settled on two weeks, because that's when it begins to get hard to crank.

We agree about appearances. I don't want to get into an angry discussion with anyone about how it looks like I'm dumping poo. I mean, are we going to settle it in the lab?

I think that most people who don't compost can't really know the proportions we're talking about, or the mechanics. He knows that if he poops into his RV toilet for two weeks, something's going to hit the fan, so it wouldn't naturally occur to him that our poop weighs 15 pounds after the same time frame. Which is why I try to always answer real questions, because the askers really don't know.

Annie said...

Tesaje, Roxanne is being modest. She's a freakin math genius. I'm the Barbie 'math is hard!' girl.

Sherry said...

This is a great informative post. The value system it reflects is admirable. You guys ROCK!


The Good Luck Duck said...

Thanks, Sherry! I appreciate that!

Merikay said...

I know that urine was (is) used for tanning hides. The indian women would work it into the deer skins to soften it. As I said in my first comment, I have been known to pee behind a bush from time to time. Are outhouses considered composting?

Tesaje said...

I dump my toilet bag daily when using it all the time. The reason is that the toilet bowl on my RV toilet is rather shallow. If it was deeper (like the 5 gal bucket type), I could just add some kitty litter and not have to empty it so often.

Outhouses can be composting depending on how they are built. Most these days are just tanks of chemical soup that they truck to a facility to dump.

The Good Luck Duck said...

Merikay, I'll bow to Tesaje's greater knowledge, because I really don't know about old-fashioned long-drops. Porta-Johns and chemical pit toilets, as she mentioned, are a whole 'nother pit of poo.

Gaelyn said...

Very interesting. Don't have anything poopy to say.

heyduke50 said...

two words.. clivus multrim (hope I spelled that right)

squawmama said...

Well this was all crappy... interesting!
Have fun