What area of a basin provides the calm area necessary for the suspended material to settle?

The settling zone is designed specifically to allow the suspended solids in water to settle out due to gravity, creating a calm area where sedimentation can occur effectively. In this zone, the velocities of the water flow are reduced, which enhances the opportunity for the heavier particles to settle to the bottom of the basin. The settling zone is crucial in water treatment processes, such as in sedimentation basins or clarifiers, where the goal is to remove particulates from the water before further treatment steps occur.

In contrast, the sludge zone refers to the area where the settled solids accumulate, requiring regular removal. The influent zone is where water enters a treatment facility or basin, and the distribution zone pertains to the area where treated water is distributed to various locations. While these zones play important roles in the overall water treatment process, the settling zone is uniquely responsible for creating the calm conditions necessary for effective sedimentation to take place.