Composting in the desert and some thoughts on designing a compost protocol for human waste.
(2/2) on composting in the desert.
The last time we spoke, I was at a residency in the desert called A-Z West. Part of the work I was doing there was designing a new compost protocol that would include management of the property’s human waste. This was particularly exciting for me, a composter, because managing our own shit is probably one of the more enduring challenges of building truly sustainable waste management systems. I’ve read lots of books on the subject, but I’d never had a shot at hands-on experience with real people. (“Real people” being the primary sticking point in widespread adoption of these practices.)
A-Z West is an 80-acre property located in the high desert of Joshua Tree, with a smattering of small buildings at its mouth. Most of these buildings are serviced with simple, one-bucket compost toilets. Collective output, when the property is fully occupied, is in the realm of 7-8 buckets of waste per week. This is a modest amount, by most measures, so the real challenge was going to be how to design the system to work when managed by a rotating cast of resident artists who might know next-to-nothing about how to compost.
The first step was working out the absolute minimum amount of information that anybody would need in order to successfully work the compost, and then designing that information into the system itself. Residents would have to understand how to collect material, how to add that material the pile, and then when and how to turn the compost—all without relying on access to any one individual for specific training. Signage was going to be critical. Not just at the compost itself, but at strategic points around the property wherever waste would be regularly generated. The obvious placement of materials and tools, like wood chips and shovels, would also be important.
A-Z West already had concise and informative labels on their composting toilets, visible in the photo above. Each toilet stall also had a small bucket of wood chips inside, neatly labeled for proper use. (“Use to cover solid waste.”) Missing was instructions on the receiving end. The four-bin compost system that lived on the property had no labeling, and it was often unclear to residents where and how they were meant to dispose of the contents of their buckets. That was one of the first recommendations I recorded.
Another issue was aeration.
Maintaining oxygen flow throughout a compost pile is necessary for creating productive decomposition, but is a major challenge when dealing with human waste. Materials are moist and gloppy, and thus prone to compaction. A-Z West was lucky to have a consistent supply of sawdust from their on-site wood shop, but sawdust wasn’t sturdy enough to create air pockets in a big pile of poop. To address this, I recommended maintaining a bin of thick-cut wood chips—at least 3/4”—directly next to the compost bins, and marking it with clear instructions to add three big scoops with each bucket. (The proximity of the bin is critical for encouraging its actual use, as even well-meaning people, slightly put off by dealing with human waste, are likely to take any shortcut that presents itself.) Twigs and other heavy materials could also be collected from around the property and put to use.
Turning was the last major obstacle to consider. More traditional management practices for a pile like this would require fastidious temperature tracking and a base understanding of the phases of decomposition, but that seemed both unfair and highly unrealistic for this particular scenario. I needed a solution that favored simplicity over complex perfection. It also had to be very easy to communicate. Therefore, I made the trigger for turning the pile as straight-forward as possible: whenever the first bin was filled to the top, flip all the bins. This wasn’t bulletproof (if the first bin filled too fast, the bins would get turned too quickly), but based on the average amount of material being added each week, it felt like a reasonable gauge for readiness.
I loved the opportunity to design this protocol. It let me put my skills to use in a new way, while collaborating with an entire organization. People were smart and interested, and I got to practice what sorts of things made their eyes light up with understanding, in addition to being able to explore the land and space around me in deep and considered ways, as I strove to build something truly integrative. We’ll see if I succeeded sometime next year!
The entire protocol is viewable here, for those interested.
For further reading on composting toilets and sanitation, I highly recommend The Humanure Handbook. It’s available in its entirety online, for free. Essential Composting Toilets is also invaluable, although a more expensive option. Lastly, I recommend the book Waste by Catherine Coleman Flowers, a sanitation activist who hails from Alabama, and has spent her life fighting to improve the living conditions in the rural community where she grew up. She doesn’t talk directly about compost, but she illuminates a little-seen and very-big issue that we have in America, which is that—outside major cities—many of our communities do not have functioning waste management systems. It is worth reading this book to understand the scope and urgency of the problem that human waste composting can help to address. You can also check out organizations like Our Soil, who are doing this type of work in other countries.
Okay, back to regularly scheduled programming next week.
I have upcoming editions on bear prevention, single-bin systems, prepping your inputs, gardening with compost and soil health, plus more that’s relevant to the individual and at-home composter.