o Septic tank is one of the simplest and cheapest natural methods of wastewater treatment, which performs mechanical treatment (settlement of heavy wastewater) and biological treatment (breakdown of wastewater with the help of anaerobic bacteria) simultaneously.
o Septic tanks are mostly used in places where there is no sewage piping or for small communities and single industrial and residential units. The operation of the septic tank reduces the pollution of the underground aquifers and the soil, and the water recycled from it is used for agricultural purposes.
The septic tank must be emptied periodically.