Clarification, sedimentation or flotation, are physical water treatment processes using gravity or buoyancy to remove suspended solids from water. Solid particles entrained by the turbulence of moving water may be removed naturally by sedimentation in the still water of lakes and oceans. Settling basins are ponds constructed for the purpose of removing entrained solids by sedimentation. Settling basins are built with mechanical means for continuous removal of solids being deposited by sedimentation. Dissolved air flotation clarification systems are considered high rate clarifiers which introduce water saturated with air to float.