According to Frank Overton for HealthGuidance.org, the main methods of sewage disposal, which are also the safest and most effective, are the use of cesspools, also known as underground septic tanks, settling tanks and disposal plants. Cesspools are self-contained and are not connected to public sewage disposal systems. Settling tanks have a drainage pipe that leads the waste into a reservoir every 12 to 24 hours.
Overton explains that there are several accessories available for these methods of sewage disposal depending on the layout of a plot of land and its various water locations. These accessories become a necessity according to the location of a home and its access to city drainage systems. Some homes do not have proper soil strength to support these methods alone.
For example, large country houses can have ground water that is very close to the surface of the soil, which requires the use of a subsurface irrigation system to supplement the functioning of a cesspool. These systems serve to bring the waste from a cesspool closer to the soil surface through the use of several pipes laid approximately 1 to 2 feet under the soil. This allows the bacteria present in the waste to be treated through processes known as oxidization and nitrification.