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

January 2018 Updates

  • JWC WTP Expansion Project - January 2018Auger cast pile installation is complete for the new surge basin and is in progress for the new filters. These piles provide stability for the structures in a seismic event.
  • The surge basin base slab was completed on Jan. 16, 2017. The 3’ thick concrete slab was poured in two sections. Rebar ties the auger cast piles to the surge basin base slab. 
  • The next step in construction is to pour the concrete walls for the surge basin and to begin installation of Earthquake Resistant Ductile Iron Pipe (ERDIP), up to 48” in diameter.

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.