In chapter 22, we talked about the different levels of wastewater management one might achieve. And we talked about some ways of treating greywater – almost all of which are theoretically possible with an urban lot. But we intentionally left the discussion of what to do with blackwater until here in Part 5 because it’s generally easier to deal with appropriately when you live on a homestead.
Most of us have been taught that pee and poop are waste and must be removed from the premises with the utmost expediency, lest we all die of an unfortunate illness. While there is good reason for caution, something else to consider is that our urine and feces are loaded with all of the extra nutrients from our food that our bodies did not use – nutrients that could eventually help grow more food. To send those nutrients “away” is a waste. In other words, it is a waste to call this material a waste. I want to keep these nutrients on my land – but I want to do so safely.
Creating a Magnificent Jungle with Your Urine
Even if you have some kind of crazy infection, fresh urine is still sterile for all practical purposes.1 In rare cases, urine can contain pathogens – but then those pathogens will survive no more than seven seconds outside the human body. Medical professionals do not require the use of gloves when dealing with human urine.
There are some people who, for their own reasons, drink urine. Just like with brussels sprouts, I am constantly baffled by what people choose to put in their pie holes. But I think this makes a good point that brussels sprouts, despite their horrible flavor, are considered safe to consume. And urine falls into that same category.
Urine contains a very particular mix of nitrogen, phosphorus, and potassium (N,P,K) that happens to be a really good fertilizer.2 And using our urine to feed some growies is a great way of recycling our nutrients back into our gardening systems. It’s as if people are meant to be gardeners!
Some people will capture their urine in some sort of container, dilute it with water, and then use it to irrigate the base of their plants. Urine has a lot of nitrogen, so diluting it helps to prevent “burning” the plants.3 Urine can also contain a fair bit of salt, so dilution helps keep the concentration at a manageable level for soil organisms.4
Another approach is to pee at the base of the plants instead of fussing with a container filled with pee water. If it has been raining or is about to rain, I will pee near plants that love a lot of nitrogen like rhubarb, grasses, cottonwood, willow, or poplar.5 And if it is currently raining, I might just pee near any plant – the rain will take care of dilution. But if it hasn’t rained for a couple of days and won’t rain for a couple more days, then the urine needs to be diluted or even the most nitrogen-loving plants might get sad.
The trick is to pee in one spot – let the plants take what they want. If you pee everywhere around a plant, then it is left with no choice. Another way of thinking of it: add diversity to the soil rather than making the soil homogeneous. Some spots have more pee than other spots – so plants that like lots of pee can have more of it. And plants that don’t like pee so much can opt out.
Peeing on good soil works about a hundred times better than peeing on dirt. Pee and dirt makes for stinky mud. Most plants are just not into that sort of kink. Rich soil is loaded with carbon and micro-organisms – this team of about 400 trillion beasties has been craving some good urine, and their new slogan is “WE’RE RICH! WE’RE RICH! IN ALL OF OUR DEEPEST FANTASIES, WE NEVER IMAGINED SUCH AMAZING WEALTH!” This is the part where you can tell this massive population “Yes, I am a generous god.”
At this point, I expect that a number of you reading this will say “BUT Paul, I’m a woman! We can’t just pee outside!” In response, I will say that I know plenty of women who choose to pee outdoors on a regular basis. I hear that for some women it just takes a bit of practice and ingenuity. And for others it takes a bit of practice, ingenuity, and determination.6
To be fair, regardless of what body parts you might have, peeing outdoors can lead to some uncomfortable conversations with neighbors and, potentially, officers of the law. If you live near other people, you may wish to stick with the urine diverter and container approach. Just don’t tell the neighbors what’s in the watering can…
Before moving on, I want to quickly include a few words of caution. While urine is usually just fine when fresh, it starts to get pretty rich with bacteria if you let it sit. After roughly 24 hours, urine will start turning into ammonia and develop a powerful stink! After being stored long enough, the ammonia kills off any bacteria…but you also lose a lot of the nitrogen (which is the smell – the nitrogen escaping into the atmosphere). It’s best applied fresh.
An Exploration of Pooping Contraptions
In chapter 20, we explored the idea of NOT composting.7 The same can be said for composting toilets – that’s a lot of carbon and nitrogen that we want to keep in our soils rather than sending it up into the atmosphere. But, poop from sick people can contain dangerous pathogens that can make other people sick. So we need to remove the pathogens while keeping the carbon and nitrogen.
To explore “better” or “best,” we need to parade out the options and metrics.
The nominees for the best place to put your poop are (in no particular order):
Poop on the ground: in tropical areas, the poop will generally be gone in a few hours – but it can still make people sick. In colder climates, the danger lasts much longer.
Poop in a hole: dig a hole, poop in it, and cover up the hole. The worst part of backpacking.
Outhouse: a big hole in the ground with a little structure built over it.
Septic tank & drain field: a standard flush toilet connected to a septic tank and drain field in your yard.
Sewage treatment plant:8 a standard flush toilet connected to a municipal sewer system.
Humanure:9 fill a five-gallon (~20 liter) bucket with poop, pee, and sawdust and twice a week put it in a compost pile outside.
Composting toilet:10 the poop goes into a chamber. Fresh material is added on top and finished material is pulled out the bottom. The contraption might have something that attempts to speed up the composting process.
Poop cooker: a composting toilet with an electric heating element inside of it that heats the poop for ten minutes to sterilize it.
Willow feeder:11 poop is stored for two years to eliminate pathogens and then placed at the base of willow trees. More on this later.
Dry outhouse:12 like an outhouse except with a urine diverter and placed on a hill where rain doesn’t reach the pit. Nutrient-loving trees are planted around the structure to drink up the nutrients. More on this later.
There are several more options to add to this list, but this is enough to make my points.
For each system, there are several possible metrics. Of course, there’s a lot of “it depends” involved, but I am going to make up a number for each metric for each system to try to paint a picture of how each performs relative to the others without going too much into the nitty gritty. Each factor will be ranked from 0 to 10, with “0” representing “worst” and “10” representing “best.”
The six metrics under consideration are:
The stink factor: can we just make a system that doesn’t stink? Something that people like to use more than the modern bathroom?
The fly factor: a fly lands on poop and then lands on your food and you get sick.
The poop-flavored water factor: poop finds its way into the groundwater and you get sick.
The poop handling factor: how much gross poop handling is involved in the operation?
The fertilizer factor: how much of the nutrients are repurposed as fertilizer?
The price factor: it would be nice to have a good solution that doesn’t break the bank.
And now for the comparison (remember, “10” is best):
Of these options, I think the willow feeder and the dry outhouse are the best bet. Let’s take a closer look at each of them.
Making Poop Jerky and Saving It for Later
On my property I have several willow feeders.13 Mine are all in skiddable structures, but this design could also be used for an indoor toilet. The design is that there is a big, watertight garbage can that receives the deposit in a chamber underneath the seat. The idea is that the garbage can is really close to the hole so there is no chance of anything ending up outside of the can…no matter how much digestive distress the supplier might have!
When poop and pee are mixed together, it makes things stinkier. And when pee is included, there is a lot of extra moisture that often needs to be taken up, usually with sawdust. A big part of my design is that a urine diverter is included to catch 90% of the pee (that wasn’t already deposited elsewhere) and send it outside. The bins fill up much less quickly and are much less smelly.
At the same time, air needs to be able to move from the sitting room, through the seat, into the garbage can chamber, and then up a vent pipe, which pulls excess stink and moisture out of the system. The vent is attached to a fly trap so that any flies that somehow make it down the hole and get covered in poop bits can’t get out and transfer those poop bits onto people.
In my experiments, I have employed both a solar-electric fan and a trombe wall to vent the space. The solar-electric fan generally works, but it involves using a battery which will need replacing roughly every five years and involves moving parts – not ideal. On the other hand, a trombe wall does not require active components. Sunlight passes through glass and strikes a thermal mass made of cob (a mix of clay, sand, and sometimes straw) with the vent pipe embedded in it. An air gap between the cob and the glass helps to hold the heat in. And since the pipe will be warmer inside the thermal mass than in the poop chamber, the air is drawn up the vent pipe by convection. This technique has been successful, even in the cold of a Montana winter!
Once the bins are full, they are sealed off so that no one opens them and they are allowed to sit for two whole years. After this point 99.999% of the pathogens in the bin will be dead – if there ever were any pathogens. To be clear, this is NOT designed to be a composting toilet that composts all of the materials – I’m trying for “poop mummification” or “making poop jerky” where most of the carbon and nitrogen is still in the bin at the end. But so far we have found that a can appears half full after sitting for two years, so the material has broken down a little anyways. Still, when the bin is opened after two years, you will see poop jerky and the accompanying toilet paper…but the pathogens are dead so it’s now safe to use.
Some people would feel just fine with placing the finished material in their garden around all of their food crops. After all, the idea is to cycle the nutrients back into the food. I prefer to play it extra safe by placing the contents of the can at the base of willow, cottonwood, or poplar trees (that is, away from edible plants) and covering them up with sawdust. I refer to these tree species as “poop beasts” – plants that thrive in nutrient-rich environments.14 They will happily eat up all of the nutrients provided by the finished material, bringing them back into the ecological system. Maybe someday they’ll get cut down and put in a hugelkultur bed.15 And then the nutrients will have come full circle.
Feeding Poop Beasts, Killing Them, and Building Stuff out of Their Bones
I think that the best solution is the dry outhouse. Let’s take a regular outhouse and pimp it out so that we might score a 10 in the first five poop management metrics:
Include a urine diverter.
Use a vent system like the one for the willow feeder. (Remember, this also keeps the stink and flies under control.)
Place the dry outhouse on top of a ground swell that effectively sheds water and doesn’t allow rain or ground water to reach the pit.
Plant poop beasts around the structure such that their roots will make their way into the pit and eat up all of the nutrients. The roots will also drink up any excess moisture.
How do those metrics look now?
The stink factor: the regular outhouse might be one of the most horrible experiences a person could have. But the dry outhouse will keep air moving from the “people chamber” through “the hole” and up above the roof – so there will be less odor than a conventional bathroom.
The fly factor: a regular outhouse could host fly conventions. A dry outhouse has no more flies than any other outdoor structure.
The poop-flavored water factor: this is the main reason that the regular outhouse was made illegal. And while there could possibly be a tiny speck of liquid that might someday find its way to the groundwater, the odds are very near zero. And if any does, it would still be less than a septic tank or a sewage treatment plant.
The poop handling factor: Some old-school outhouses were emptied. But the dry outhouse would never be emptied.
The fertilizer factor: Regular outhouses did not typically feed plants, but the primary function of the dry outhouse is to feed the poop beasts.
With so little moisture, it might be possible that the hole will never fill up – the poop beasts will just gobble up everything that gets put in there. If it does, or if there is any other reason, it’s a skiddable structure – you can just move the structure to a new location and drop a few seeds in the old hole. No poop handling required!
Of course, in some locations, the roots of the poop beasts will go dormant for winter. Fortunately, during this time the poop will freeze, and since there’s so little moisture, the chances of groundwater contamination are very low. Then when the poop beasts wake up in the spring, they have a lot of poop-beast food ready to help them put on a lot of growth.
The only downside is that the seat might be a bit chilly in winter. But if you have an outdoor dry outhouse, you also have a great place to dump the contents from your indoor willow feeder! The best of all worlds!