Settling/Sedimentation modelling approach?

Hello,
Please, where can I find a description about the settling/sedimentation modelling approach used in WEST?
Thank you,
Kind regards,
João

In the Models Guide - which you can access via the Home / Help / "?" menu of WEST.
Or, if you are located in an existing WEST layout, you can select a block (in this case a primary or secondary settling tank) and hit the "F1" key: this will take you directly to the description of the selected model.