There Are 6 Basic Septic System Types

A septic system moves raw effluent from your home and distributes it over a drain-field so that it can be cleansed by the natural processes in the soil. There are 6 basic types of septic systems.

Gravity
Gravity systems use gravity to assist the effluent through the tank into the drain-field. Gravity flow systems are probably the most common type of system in use today. They are also the simplest and the most cost effective way of treating your household waste.

Pressure
Pressure distribution systems make better use of the whole drain-field by ensuring an even distribution. The effluent is pumped to the entire field.

Mound
Mound systems, as the name implies, have the drain-field built above ground level to ensure there is a sufficient depth of soil for effective filtration.  Mounds are used in areas that have soil or ground water issues that prevent the drain field from being buried.

Sand filter
Sand filter beds are utilized to filter the effluent and when gravity does not allow, a pump to disburse the effluent more effectively. These systems are for use where there is not enough depth of soil for effective and safe treatment of the effluent.

Aerobic
Aerobic treatment plants use oxygen to break the effluent down to produce a cleaner waste. These systems are used in areas where there are environmental issues to contend with or the soil does not allow for the effective and safe treatment of the effluent.

Closed
Closed septic systems deliver the effluent into a septic tank that must be emptied at regular intervals to be taken elsewhere for treatment.  You will find this on many RV vehicles and seldom at a residence.

Septic systems are used where sewer main hookup is not available and if you have one you should be aware of how it works and where it is.