Humanure is not traditional sewage that has been processed by waste-treatment facilities, which may include waste from industrial and other sources; rather, it is the combination of feces and urine with paper and additional carbon material (such as sawdust). A humanure system, such as a composting toilet does not require water or electricity, and when properly managed does not smell.

By disposing of feces and urine through composting, the nutrients contained in them are returned to the soil. This aids in preventing soil degradation. Human fecal matter and urine have high percentages of nitrogen, phosphorous, potassium, carbon, and calcium. It is equal to many fertilizers and manures purchased in garden stores. Humanure aids in the conservation of fresh water by avoiding the usage of potable water required by the typical flush toilet. It further prevents the pollution of ground water by controlling the fecal matter decomposition before entering the system. When properly managed, there should be no ground contamination from leachate.

Humanure may be deemed safe for humans to use on crops if handled in accordance with local health regulations, and composted properly. This means that thermophilicdecomposition of the humanure must heat it sufficiently to destroy harmful pathogens, or enough time must have elapsed since fresh material was added that biologicalactivity has killed any pathogens. To be safe for crops, a curing stage is often needed to allow a second mesophilic phase to reduce potential phytotoxins.

Humanure is different from night soil, which is raw human waste spread on crops. While aiding the return of nutrients in fecal matter to the soil, it can carry and spread a vast number of human pathogens. Humanure kills these pathogens both by the extreme heat of the composting and the extended amount of time (1 to 2 years) that it is allowed to decompose.

From Wikipedia