Humanure -- Safe Use

A simple bucket system, or a two-bin arrangement where one bin fills while the other processes, is the standard low-technology approach. Waste is collected in a covered container and, critically, a generous layer of dry cover material is added after every single use. Once a bin or bucket is full, it's set aside to process undisturbed while a second one fills, giving the first a full, uninterrupted processing period before it's ever touched again.

Cover material choices that suit a dry climate well include sawdust, wood ash and dry soil, all things that are reasonably available without relying on supply chains. The cover layer does three jobs at once: it controls odour, it absorbs excess moisture, and it adds the carbon that balances out nitrogen-rich material, much like the carbon materials discussed in Chapter 4.

As covered in Chapter 1, heat speeds pathogen die-off, and a pile that reliably reaches and holds a proper thermophilic temperature of 55-65 degrees C can process safely somewhat faster here than the same pile would in a cool climate. This is a genuine, real effect, not a myth.

But it comes with a serious catch that matters more here than almost anywhere else: moisture is needed for both active composting and for pathogen die-off itself, and moisture is precisely the resource under the most pressure in this climate. A pile that has dried out is not safely processing anything, regardless of how many months have technically passed since it was set aside. "Faster in theory" is not licence to cut corners in practice.

The genuinely responsible approach is to treat the shorter end of any processing-time range as something that can only be trusted if heat has actually been confirmed, ideally with a compost thermometer, and to err toward the longer, more conservative end whenever there's any doubt. A minimum processing period of a full year, with confirmed thermophilic heat sustained for an extended period within that year, is a reasonable and appropriately cautious standard to work toward, and longer is always safer than shorter.

• Never on or near root vegetables -- direct contact risk is too high regardless of processing time.
• Never on leafy greens eaten raw -- splash contamination and surface contact make this a genuine risk.
• Fine for fruit trees and ornamentals -- where there's no direct contact with edible plant surfaces.
• Fine for soil-building beds a season later -- fully cycled-through compost dug into a bed that then grows a further season of other crops before anything is eaten from it.
• Never used fresh, under any circumstance -- the entire point of the processing period is to make this safe, skipping it removes that safety entirely.