Finally, the wastewater is split up in following 3 layers :-

  • The top layer belongs to oils and grease and stays afloat over all the waste. It is known as scum.
  • The middle layer belongs to the wastewater together with waste particles.
  • The bottom layer contains harder particles which are tougher as compared to water and develops a layer of sludge.


Inside the tank bacteria from the wastewater decomposes the solid waste quickly so that the liquids can be detached and discharged conveniently.

Septic Tank Cleaning

Septic tank cleaning is very important. A septic tank should be cleaned on a regular basis (within 1 year for smaller tanks) so that the toxins and antibacterial substances can't be accumulated to kill the bacteria that destroys the waste.