As part of a sanitation system that is in place, human waste is collected, transported, treated and disposed of or reused by one method or another, depending on the type of toilet being used, ability by the users to pay for services and other factors.
The sanitation systems in place differ vastly around the world, with many people in developing countries having to resort to open defecation where human waste is deposited in the environment, for lack of other options.
People in developed countries tend to use flush toilets where the human waste is mixed with water and transported to sewage treatment plants.
Human faeces pose a greater threat to the mountain environment than uncontrolled deposit of urine, due to the higher pathogen content of feces.
Human waste in the form of wastewater (sewage) is used to irrigate and fertilize fields in many parts of the developing world where fresh water is unavailable.