Water Reclamation Facility Modifications

Project Description

This spring the City will begin two important projects at the Water Reclamation Facility (WRF): The EQ Basin and Digested Sludge Pump project and the Membrane Replacement and Optimization project.  

The City of Arlington will be modifying the Water Reclamation Facility (WRF) to meet requirements set forth in the WRF’s operating permit; known as its NPDES* permit. Please see Engineering Report for details on proposed plant modifications

(*NPDES - National Pollution Discharge Elimination System)  

The Membrane Replacement and Optimization project will replace the current membranes with the same Kubota RW400 style flat plate membranes.  The Kubota RW400 membranes typically have a 10-year life expectancy, these membranes are currently 12-years old and have provided exceptional service. The City replaced the membranes in MBR train #2 in 2021 and will replace membranes in MBR trains #1, #3, and #4 in 2022.  Once the membranes are all replaced, the MBR system and biological nutrient removal system will be optimized to ensure both systems are fully integrated and operating at peak efficiency.  

Project Benefits

  • Meets requirements of NPDES Permit  
  • Expanded reclaimed water production
  • Enhanced Biosolids Treatment Capacity
  • Increase life span of WRF facility

Project Cost and Funding

  • Engineer’s Estimate: (EQ Basin) $1.8 million
  • Engineer's Estimate: (Membranes) $3.8 Million
  • Funding source: City of Arlington Utility Fund

Project Schedule

  • Designed by: BHC Consultants
  • Construction Schedule: March 2022

Coordination with Residents

Progress updates will be provided by the City on this project webpage to keep local residents and businesses apprised of the project progress. 


If you have questions or concerns on this project, please contact the City Project Hotline at 360-403-3544 or cityprojects@arlingtonwa.gov.


Project Documents

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Projects Updates

  • July 15, 2021 - Bid opening for Equalization Basin Project.
  • Aug 2, 2021 - Bid awarded to McClure & Sons for the Equalization Basin Project.
  • March 28, 2022 - Construction start on the Equalization Basin Project.
  • April 14, 2022 - Bid opening for Membrane Replacement.
  • May 16, 2022 - Bid Awarded to McClure & Sons for Membrane Replacement.