The Horizontal Overflow Screen is a cylindrical shaped screen barrel mounted on an overflow weir. Overflowing sewer flows through the cylindrical barrel and out of the chamber. The perforated mesh keeps screenings on the sewer side of the weir. 

A brush-tipped screw is mounted inside the screen barrel and rotates during operation to move captured screenings off the screen. In an emergency relief sewer or inlet works overflow installation, the screenings on the sewer side of the weir are conveyed continuously on to the inlet works of the wastewater treatment plant. In a pump station application, the screenings typically recirculate within the pump well during the overflow event, and then once the overflow event has finished a pump draws the screenings out of the pump station and conveys them on to the wastewater treatment plant.