Septic tank
In the United States, the 2007 American Housing Survey indicated that about 20 percent of all households rely on septic tanks, and that the overwhelming majority of systems are located in rural (50%) and suburban (47%) areas. Indianapolis is one example of a large city where many of the city's neighborhoods still rely on separate septic systems. In Europe, septic systems are generally limited to rural areas.
Autonomous building
Electric incinerating toilets turn excrement into a small amount of ash. They are cool to the touch, have no water and no pipes, and require an air vent in a wall. They are used in remote areas where use of septic tanks is limited, usually to reduce nutrient loads in lakes.