The digested sludge from the tank is periodically removed approx at periods of 6 to 12 months and removed.
A Septic tank is an outstanding form of primary sedimentation tank with a higher detention period of approx 12 to 36 hours against the duration of 2 hours in an ordinary sedimentation tank, in which digestion of settled sludge also takes place.In other words, a septic tank is a joint sedimentation cum digestion tank. The septic tank has a larger capability than an ordinary primary sedimentation tank, to adjust and hold the settled sludge for its subsequent digestion.
