• 4 high capacity and 2 low capacity pumps.
  • Inlet structure to divert flow at 45 degrees from the influent sewer.
  • Flow Science developed an innovative layout of the pump inlet piping and pumps.

Columbia Boulevard Wastewater Treatment Plant (CBWTP) Headworks Design

City of Portland
Portland, OR


Flow Science developed the basic headworks layout for the 319 mgd pump station including four high capacity and two low capacity pumps. The design required an inlet structure to divert flow at 45 degrees from the influent sewer, and the layout of the bar screens and the pump inlet and pumps to provide an additional 45 degrees of direction change. This latter change was accomplished within the pumps by an innovative layout of the pump inlet piping and the pumps.By carefully designing the approach flow to the pump inlets and paying particular attention to the NPSH requirements of the pumps a very smoothly operating pump station was developed without hydraulic modeling. The system has now been in operation for more than a year.