'"Moldering" means slow, relatively cool, continuous composting in which native soil microorganisms decompose human waste in the presence of oxygen, over time. A bulking agent, such as shavings, bark, or leaves, is added by users to the waste pile to aerate it and prevent compacting. Redworms may be added to the pile to accelerate composting, where authorized. Oxygen/airflow is the key ingredient (missing in many pit privies) that allows composting to occur.

In contrast to a traditional pit privy (a riser and outhouse structure over a hole dug to varying depths), a moldering privy is built on a screened crib located above ground. '