Basic information to be obtained in the census is whether housing units have or do not have a piped water installation, in other words, whether or not water is provided to the housing unit by pipes from a community-wide system or a private installation, such as a pressure tank or pump. The unit of enumeration for this topic is a housing unit. It is also recommended that countries should indicate whether the unit has tap water inside or, if not, whether it is within a certain distance from the door.