compost toilet
[NOTE: this is a note on compost that almost made it into my book. It is meant to allay any concerns and provide more details regarding the toilet designs.]
I have traveled for decades among hippies, permaculturists, organic farmers, and professional self-sufficiency experts. I got to see and use many composting toilets. Most were inspired by The Humanure Handbook by Joseph Jenkins.
The most advanced was the Sunny John moldering toilet, designed by an associate, the late John Cruikshank. Poop composts composts where it is first deposited, without further handling till it is perfect fertilizer.
The system I liked the most for handling buckets of compost brought from inside a house was in a guy’s suburban backyard. It was three plywood bins under an awning. Two had hinged lids and were lined with plastic. They were 1 m3. One in the middle, about half as wide, held plant debris (leaves, etc).
We emptied 20L buckets of poop and food scraps into a big bin, then covered it with debris. We also wiped the buckets out with debris. This instantly stops the smell.
It only smelled while emptying a bucket. Poop and food scraps are proteinaceous. The nitrogen in protein makes it smell. Debris is carbonaceous. Carbon absorbs and neutralizes odor. Decaying leaves, for example, smell pleasant.
The carbon stuff combines rapidly with the nitrogen stuff to make humus, the black fertile component of soil. It happens by chemical reaction, microbes, and enzymes, and fungi and worms from outside.
Food scraps smell mild compared to poop. Mixing the two made the piles legal in Oregon. That law is old. It passed before indoor plumbing was common.
When the first bin was full, he would seal it off for about a year. He would empty the other, spreading it onto the yard and garden. Then we would start filling it.
I liked this system because of its overall simplicity, adaptability, and economy. It was easy to use. It just worked. I saw plenty of fancy, complicated systems that smelled or required regular maintenance. Who needs that?
Some systems are solid state, require no handling of raw waste or maintenance except emptying the perfect compost. Decomposition occurs inside. They are usually big, expensive, require 2 floors in the building, and require a permit.
Millions of people died in Europe due to poor sanitation. Once they realized this, poop terrified them. But poop was not the problem. Mixing it with water was. Poop is safe if it remains dry. Carrying it away with water in sewers and flush toilets is to blame, not proper composting systems.
It’s nearly impossible to screw up compost. There are a million ways to do it. I met a guy who had gotten a degree in ecology. He did his senior thesis on compost. He found that only one liquid or soft substance in a typical American home cannot be composted: chlorine bleach.
Chlorine bleach is a persistent toxin. It kills life wherever it goes and for a long time. It simply should not be used. Color-safe bleach (sodium percarbonate) works well and is non-toxic. Regular cleaners are sufficient elsewhere.
Everything else—detergents, pesticides, motor oil, expired medication—will break down. Any complication you ever hear about compost is simply false. Citrus and banana peels are fine, even meat scraps as long as they are covered immediately with plant debris. High temperature is unnecessary (it actually means: add more carbon). Whatever it may be, compost it.