To work properly, a composting toilet must maintain the right moisture, temperature, airflow, and balance of materials. The system must keep waste aerobic (oxygen-rich) so it can decompose safely.
Key operational factors:
Moisture control: Waste must stay moist but not saturated. Excess liquid (leachate) should be collected and removed so the compost pile doesn’t go anaerobic.
Temperature: Composting works best between 68°F and 113°F. The system may generate heat on its own, but ventilation air should stay between 41°F and 65°F so bacteria can thrive.
Ventilation: Continuous airflow is needed to move air down the chute and through the composting chamber, venting gases out through the roof.
Aeration: Add organic bulking material—like sawdust, coconut husks, or popped corn—to keep the compost porous and oxygenated. Aeration can be done manually or mechanically.
Plug flow: The composting chamber should allow older material to be removed separately from new waste, ensuring all waste is fully treated before removal.
Following these principles keeps the composting process aerobic, minimizes odor, and ensures safe, effective decomposition.
For technical specifications, see OWTS Manual Section 21 – Waterless Toilets.