Pooping Green

No, we do not have weird jungle parasites that causes our poop to turn green. (Though we probably DO have weird jungle parasites doing other things...) But yes, this is a post about poop. It's even a post about green poop, but we're using it here as an adverb, not as an adjective. Today we'll tell you how to poop in a green (environmentally friendly) way.

This is not a green toilet :(
(C) Bickfords

Last week we told you about our latest Peace Corps project: the construction of five dry toilets in and around our community. We got a lot of good questions about this project (as well as some good jokes!)--so here are your answers! Let's start things off with a little science...

We call it "human waste," but really, it's a resource. People poop about a kilogram (2.2 lbs) a day. That's as heavy as a quart of water. And each little poop is chock full of nutrients. And urine is even better (of which you pee 1-2 liters a day, i.e. 1-2 Nalgene bottles worth of urine). Here is a nifty table to show you what percentage of your daily nutrient-release can be found in your pee and poop.

	Daily percentage released in...
	Feces	Urine
Nitrogen (N)	10%	90%
Phosphorus (P)	50%	50%
Potassium (K)	30%	70%

All you farmers should be saying, "Hm, that sounds a lot like the ingredients in my chemical fertilizers." Yup.

So why do we think that poop is bad? Well, it's smelly and squashy, for one thing. But it also causes a LOT of sickness around the world. For one thing, feces carry out a lot of the bacteria that live in our digestive systems. Where these might be good in your intestines, they can wreak havoc if they get into other parts of your body (like if you ingest them with your drinking water). Feces can also contain things like typhoid bacteria, hepatitis, and parasites. Urine, on the other hand, hardly ever contains anything harmful--only in very sick people with typhoid or paratyphoid or a few other even rarer diseases. We just don't like urine because it's smelly and comes out of down there.

What is this toilet thing?

The official name for the kind of toilets we built is Urine Diversion Dehydration Toilet (UDDT), though we generally call them "dry toilets." This isn't quite the same thing as a composting toilet, as the point of these dry toilets really is to dry out the feces in order to kill all of the bacteria and other bad stuff that lurks within. Since we're in the Amazon rainforest, humidity and rainfall make composting toilets difficult, hence we went with dry toilets.

How does it work?

The main point is to separate the urine from the feces. Urine is tasty food for all the germies that live in feces, so we send them their separate ways.

Poop goes in the back, urine in the front.

Instead of having one big pot for everything, there are two chambers. The urine falls into the front urinal (that we made from a recycled bottle), and the feces and toilet paper fall into the back chamber, often a removable bucket or box. We reused a feed bag because they're free here, and they breathe to allow air to carry away odors and extra moisture. After each use, the toilet paper and feces are covered with "dry material": sawdust, ash, mashed up leaves, dry dirt, or something similar. That way, bugs won't find it, any smells get covered up and absorbed, and it dries out quicker. There are lots of different designs, but this one was appropriate for this climate.

There's no flush... Where does it go?

Urine goes through to one of two places, depending on the design. 1) It goes into a long hose (ours were 10 meters) with holes poked in it. It's buried in the ground so that the urine can fertilize the nearby plants! 2) it goes through a short tube and then is collected to be diluted 1:10 with water and sprayed on leaves or poured around the plants. Remember: urine is an awesome fertilizer and is safe right when it comes outta ya.

The solids (the poop, cover material, and toilet paper) get stored in a dry place for six months. In our jungle climate, most to all of the bacteria die within four months, but due to the potential hazards of human waste, we store it an extra two months to kill the germies extra good. After the six months are up, it can be used as fertilizer, either directly (best on big plants like trees) or further processed by mixing it with urine and/or other composty things like kitchen scraps.

The urinal, made from reused plastic bottles, and the solids bag, made from a reused feed sack.

Okay, but seriously, a poop bag? What's wrong with you people?!

Think about this: Where do cats poop? They dig a hole in the ground. Where do cows poop? On the ground. Bears? Same. Now, where do fish poop? In the water. Octopuses? Water. See the trend? Just one more: where do people poop? In the water. Sometimes I feel like the humidity here is high enough that I need gills to breathe, but the fact remains that I am a land-dwelling creature that puts my waste into the water.

So really, the question is: why do we poop into the water? It's cleaner, right? Wrong! What do you drink? What do you bathe in? What do you use to clean with? Water. Those that live with the convenience of a modern water treatment system may think they're safe--the City cleans the water, right? Weeellll, you have to weight the pros and cons. For example, if you didn't poop into the water in the first place, then no one would have to clean out all of your fecal coliform, something that costs a lot of money and often uses chemicals and other practices that are unsustainable or even harmful.

Our municipal water takes a stop to settle out some of the sediment before it heads to the treatment center where it will be settled some more before being shot with chlorine.

In our community, almost all children who go to the local clinic have bacterial infections or intestinal parasites caused by contaminated water. The City does treat the water, but it's unregulated and untested, and many people still use water from the rivers for things like washing and cooking. Building dry toilets is one way we can help combat the problem of water contamination.

So, like everything, you have a choice: you can poop in your water if you want. Or you can make free fertilizer in a bag.

..Kirstie and Isaac..

Edit ;) Apologies to everyone who came here via a search engine looking for information about what parasites are turning their poop green. Maybe we'll do a future post about our experiences with such things, but for now you're stuck with toilet talk.

This post is part of the Rethinking High Tech series.