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About the Water Treatment Plant

City of Lake Oswego Oregon Official Website

Construction is underway to upgrade the Lake Oswego Tigard Water Treatment Plant (WTP) located in West Linn. Lake Oswego’s original water treatment plant was constructed in this location in 1968, in what was then unincorporated Clackamas County. The facility has treated Clackamas River water to high-quality drinking water standards for almost 50 years.

The plant had an initial treatment capacity of 10 million gallons per day (MGD) and was expanded to 16 MGD in the 1980's. Although the facility has been updated over the years, it was too old and undersized to meet the current and future demand in Lake Oswego and Tigard.

As part of the Lake Oswego Tigard Water Partnership project, the plant capacity was expanded to 38 MGD and began supplying water to both Lake Oswego and Tigard customers in the summer of 2016.

The current treatment process used at the plant is conventional filtration. In 2017, ozone will also be added to the treatment process.

The WTP is staffed with nine full-time operators, keeping the plant running smoothly every day of the year.  Our operators all hold water treatment certifications from the Oregon Health Authority and continue to upgrade skills and learn the newest treatment techniques through continuing education opportunities.