It just feels right to poop in a dry toilet. It’s such a profound way to fix a broken system and create a closed loop (poop → soil → food → poop). It’s been three months since we started to exclusively use a compost (dry) toilet in our home. In the following, I documented our family’s journey of using a dry toilet system.
Needs
We were looking forward to having
- a simple and safe method for converting poop to soil,
- a system that is friendly for people who are not familiar with this setup,
- a covered area for pooping, and
- nearby water access to wash our butts and treat the black water safely.
Design
- We use a dry toilet system, sometimes referred to as a compost toilet. It’s not a composting toilet, since the composting process doesn’t happen in the loo. We follow the design and recommendations of the book The Humanure Handbook (Shit In A Nutshell) by Joseph C. Jenkins. It’s a wonderful resource to understand the process of composting poop and designing a dry toilet system.
- We have an outdoor, yet covered toilet space in the poly-tunnel where we live
- We use three 20-liter buckets as the loo (one at a time). Urine and poo go together. Initially, we imagined a urine-diverting toilet, but it seemed a much more complicated system with little benefit in the end. Therefore we discarded this idea. We also thought about having a separate bucket for washing our butts, but again, seemed a lot of trouble. We have soap and a portable shower at reach, and the black water goes into the loo.
- We have set up two compost bins in the backyard. This is where the actual composting takes place. Both kitchen scraps and toilet materials go there. We top up the loo buckets with the kitchen scraps before sealing them. We decided not to mix animal dung in the compost bins. It was solely to avoid the bins filling up too quickly. We have a separate corner in the land where we collect animal manure.
- We bought a 50 cm thermometer to monitor the temperature of the compost pile
Maintainance and observations
- A bit humid, fine sawdust is the best material to cover poop. Fortunately, we have free access to it from a closeby lumber mill. We tried wood shavings, but they weren’t good, they are too airy and odor escapes. The loo bucket usually smells sawdust. In rare cases, when it smells unpleasant, just need to add more sawdust.
- We wash the buckets with soap and vinegar. The liquid goes into the compost pile. It takes less than an hour to clean all buckets. I use about 8 liters of water. We have a Decathlon portable shower that comes in very handy for the job.
- For our family of three, a loo bucket fills up in 2-3 days. With three buckets in place, we clean the buckets once a week.
- In two months, one of the compost bins filled up (80cm x 100cm x 100m). The pace obviously depends a lot on the cover material. We use some sawdust and woodchip, but mostly fern cuttings that we get from the land. The fern is very airy, I expect it to shrink significantly over time.
- With mild outdoor temperatures (15-20 ℃), the compost pile burns at a temperature 50-60 ℃. This is great because, per Jenkins’ book, pathogens are then destroyed within a day. Since the weather turned cold (5-10 ℃), the compost pile’s temperature dropped to 30 ℃.
- Our two-year-old child understands the system. With some support, she can transfer the poop from the potty to the loo and cover it with sawdust. We often do the weekly bucket cleaning together.
Tweaks
In our region autumn typically brings some heavy rain. In the last month, we decided to cover our compost bins with a transparent plastic sheet to avoid the pile cooling down too much and prevent from their content leaking out.