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.
Flush toilet
A toilet need not be connected to a water supply, but may be pour-flushed. This type of flush toilet has no cistern or permanent water supply, but is flushed by pouring in a few litres of water from a container. The flushing can use as little as 2–3 litres. This type of toilet is common in many Asian countries. The toilet can be connected to one or two pits, in which case it is called a "pour flush pit latrine" or a "twin pit pour flush pit latrine". It can also be connected to a septic tank.