Dry toilet

A dry toilet is a toilet that operates without flush water, unlike a flush toilet. The dry toilet may be a raised pedestal on which the user can sit, or a squat pan over which the user squats in the case of a squat toilet. In both cases, the excreta (both urine and feces) falls through a drop hole. The urine and feces can either become mixed at the point of dropping or stay separated, which is called urine diversion.

A dry toilet can be any of the following types of toilets: a composting toilet, urine-diverting dry toilet, Arborloo, bucket toilet, pit latrine (except for pour flush pit latrines), incinerating toilets, or freezing toilets.

Nomenclature

There are several types of toilets which are referred to as "dry toilets". All of them work without flush water and without a connection to a sewer system or septic tank:

Composting toilet

A composting toilet is a type of dry toilet that uses a predominantly aerobic processing system to treat human excreta, by composting or managed aerobic decomposition. These toilets generally use little to no water and may be used as an alternative to flush toilets. They have found use in situations where no suitable water supply or sewer system and sewage treatment plant is available to capture the nutrients in human excreta. They are in use in many roadside facilities and national parks in Sweden, Canada, US, UK and Australia. They are used in rural holiday homes in Sweden and Finland.

The human excreta is usually mixed with sawdust, coconut coir or peat moss to facilitate aerobic processing, liquid absorption, and odor mitigation. Most composting toilets use slow, cold composting conditions, sometimes connected to a secondary external composting step.

Composting toilets produce a compost that may be used for horticultural or agricultural soil enrichment if the local regulations allow this. A curing stage is often needed to allow mesophilic composting to reduce potential phytotoxins.