Every house does not require a septic tank. Homes that lack sewer service systems require septic tanks, and determining if the home uses a septic tank requires identifying if the property uses municipal water. Homes that rely on well water, rather than municipal water, typically require septic tanks.
Homes in major metropolitan areas rarely have septic tanks, as a result of using municipal water and designated sewer systems. Homes outside the city limits, usually in rural areas, need septic systems to manage the waste water from the property. In some cases, large properties with several acres, such as farms or ranch properties, require septic systems.