Water Treatment Plant

Plant Location and Capacity

Construction of a new, seismically resilient water treatment plant (WTP) is an important component of the new water system. It will be located in the Tonquin Employment Area, currently in unincorporated Washington County, near the intersection of SW 124th Avenue and Tualatin-Sherwood Road. The WTP will be sited on a parcel within the southern portion of a nearly 100-acre planned industrial development. The WTP will occupy about 20 acres. Approximately 20 additional acres are earmarked for roadway improvements, setbacks and habitat preservation.

The WTP site is within the Urban Growth Boundary, is zoned industrial, and will eventually be part of the City of Sherwood (see map). The new WTP will initially produce up to 60 million gallons of water per day (mgd) but will be designed for a maximum of 120 mgd.

Water Treatment Process

The new WTP will be designed to utilize similar processes as the existing Willamette River Water Treatment Plant, which has been delivering safe and reliable water to Wilsonville and Sherwood residents since April 2002. Steps for the new state of the art Willamette Water Suppy System treatment plant will include enhanced coagulation sedimentation, ozone and ultraviolet treatment, granulated activated carbon filtration, sand filtration, and chlorine disinfection (learn more here).

Water Treatment Plant Fact Sheet

Our Reliable Water

Program Timeline

Developing the new Willamette water source will take over a decade.

Willamette Water Supply Program

Willamette Water Supply Program