A settling tank, also known as a vertical settling tank, is a sedimentation tank in which wastewater flows vertically. The flat shape of the tank body is circular or square, and water enters the tank from top to bottom through the inlet pipe located at the center of the tank. Umbrella shaped baffles are installed below the pipe to evenly distribute wastewater in the tank and slowly rise along the entire water flow section. Suspended solids settle in the conical sedimentation hopper at the bottom of the tank, and clarified water flows out from the surrounding overflow weirs around the tank.