JWC Water Treatment Plant Expansion Project

Increasing Water Capacity, Strengthening Water Infrastructure & Ensuring Clean, Reliable Drinking Water for Customers

In response to the need to provide additional water for growing communities in western Washington County, the Joint Water Commission (JWC) —owned in partnership by the Cities of Hillsboro, Beaverton, Forest Grove and the Tualatin Valley Water District — are working to complete a multi-year water treatment expansion, improvements project, and facility plan for the JWC Water Treatment Plant.

The project, a result of nearly four years of water supply planning, addresses long-term water capacity and strengthens seismic resiliency while bringing the capacity of the plant from 75- to 85-million gallons (of water) per day (mgd) by 2019.

In addition to new and enhanced water treatment capabilities increasing the plant’s treatment capacity and reliability, the project also involves strengthening water infrastructure and planning for a future plant capacity of 105-mgd. A facility plan has been developed to lay the groundwork for the immediate plant expansion as well as phased seismic improvements and expansions until ultimate plant build out.

The JWC currently treats, transmits and stores drinking water for more than 365,000 customers, and is the largest conventional water treatment plant in Oregon.

For additional information on how the project will help provide safe and cost-effective drinking water to the water service partners for current and future needs, contact City of Hillsboro Project Manager Erika Murphy at 503-615-6720 or by e-mail.

Project Details

  • Project Status: Currently under construction
  • Completion: Summer 2019
  • Total Project Value: $35 million
  • Delivery Method: CM/GC
  • Project Manager: Erika Murphy, City of Hillsboro
  • Contractors: Jacobs (formerly CH2M) and Slayden Constructors

March 2018 Updates

  • All improvements to the existing rapid mix are complete and the expanded capacity of the rapid mix is now 85 million gallons per day (MGD).
  • The 30”-thick surge basin concrete walls are complete and in place.
  • The 36”-thick concrete slab for the new filters continues to be poured in sections.
  • Earthquake Resistant Ductile Iron Pipe (ERDIP) and corrugated HDPE pipe have been delivered to site for installation.
  • A new 12” sludge line has been installed to assist operations when draining the existing sedimentation basins.

Additional Resources

  • Joint Water Commission Water Treatment Plant Expansion to 85 MGD – Package 2 – GMP Submittal: The GMP is available for review at the partner agencies: Cities of HillsboroForest GroveBeaverton and the Tualatin Valley Water District (TVWD). For questions, contact Tacy Steele at 503-615-6732.