The primary objective of the study was to determine the efficiency of the free surface vortex chamber as a grit removal device for water treatment. The efficiency also includes a consideration of the effectiveness of this flow to retain the lighter organic particles in suspension as the fluid flows through the chamber. Related to the above aims was the determination of the appropriate orifice size, inlet channel width and vane configuration to give the optimum hydraulic conditions. An additional objective was to relate the heavy particle settling performance to the existing parameters characterizing vortex flows such as circulation, total head, flow rate and vortex number. The separation of settleable particles from flows in the process of treatment of waste and domestic water supplies is an area of continuing study and development.