Design Procedure of a Rectangular Sedimentation Tank

The topic of this tutorial highlights on the design method of a rectangular sedimentation tank which is also called settling tank.

Before we move on straight to the tutorial; we need to know what actually a sedimentation tank is? A sedimentation tank is run by a separation method in which a suspension is separated into two stages - (1) overflow and (2) underflow.

Purpose of Settling

  • To eliminate coarse dispersed phase.
  • To get rid of coagulated and flocculated impurities.
  • To extract precipitated impurities after chemical treatment.


In the design calculation we will provide solution to the following problem.
Design a rectangular sedimentation tank for a population of one lakh people. Rate of water supply is 150 lit/no/day. Water will stay for 2 hours in tank (detention period)

Go through the following exclusive video lecture to get the details:

Video Courtesy : SL Khan


Rectangular sedimentation tank design