Lake Oswego Water Treatment Plant

Facility Description

The City of Lake Oswego has operated a drinking water treatment plant in West Linn’s Robinwood neighborhood since 1968. The Lake Oswego Tigard Water Partnership plans to upgrade and expand the treatment plant, located between Kenthorpe Way and Mapleton Drive, to meet current and future drinking water needs. The upgraded plant will supply Lake Oswego and Tigard, and will continue to serve as West Linn’s sole source of emergency and backup water supply.

History of the Water Treatment Plant

Built in 1968, Lake Oswego’s water treatment plant was originally located in unincorporated Clackamas County. The area was later annexed by West Linn. Through its 44-year history the plant has earned a reputation as a good neighbor. The City of West Linn has approved land use applications for upgrades and expansions three times since the plant was built.

It is not uncommon for wastewater and water treatment plants to be located in residential areas. South Fork Water Board’s treatment plant – jointly owned by West Linn and Oregon City – is located in Oregon City’s Park Place neighborhood. Extensive upgrading, expansion and treatment modifications have occurred there over the past several years to serve the two communities.

Water Treatment Plant – Good Neighbor Plan

Lake Oswego Tigard Water Partnership began discussions with the Robinwood Neighborhood Association in early 2010, sharing details of the water treatment plant expansion, listening to suggestions, and finding ways for the upgraded water plant to continue to be a good neighbor. Two years later, the Partnership has met with Robinwood neighbors more than 20 times, developing a Good Neighbor Plan (pdf, 308 kb) that contains the Partnership’s commitments for design–construction–operations of the new facility. Neighborhood input played a big role in design concepts with the addition of numerous plant layout changes and amenities requested by neighbors.

How to Get Involved

  • Click here for upcoming meeting dates.
  • Sign up to receive email notices.  Mark the ‘Water Treatment Plant' as your interest.
  • Click here to contact us by email.
  • Call the Water Hotline (503) 697-6502.

Additional Information

You can find regular updates on the Work Underway page.

Field Updates

Thursday - August 28, 2014

Water Treatment Plant Construction Update

The gravity thickener mechanism is now installed in the tank. It will thicken river sediments removed from the water.

Auger cast piles are almost complete for phase A of construction. The auger cast pile drill rig will remain on site until new piles are drilled in the parking lot for the new administration building elevator pit in September. Pile drilling will resume in February 2015.

Solids Storage Tank

Water testing of the solids storage tank is now complete. Coatings are now being applied and the area around the tank will be backfilled starting next week. During backfilling, neighbors close to the northeast of the site may experience some vibration.

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Thursday - August 21, 2014

West Linn Pipeline Construction Update: Horizontal Directional Drilling site (end of Mapleton Dr.)

The solids separation process separates material extracted during drilling. Gravel and rock is filtered and hauled off-site. Drilling fluid is recycled and reused during the HDD process.

A milestone was reached last week, with the successful completion of the pilot hole! Drilling has been ongoing for a few weeks from either side of the river, with both drills meeting in the middle to complete the pilot hole.

Crews have now started the process of upsizing the hole to 36”. More passes will be made with larger drill bits (or reamers) over the next few months until the hole is large enough for the pipe to be pulled through.

During drilling work, neighbors may hear noise from the drill rig and an increase in truck traffic. Work hours are 7 a.m. - 7 p.m. Monday through Friday, and Saturdays from 9 a.m. - 5 p.m. No work will occur over the Labor Day weekend, from Saturday, August 30 – Monday, September 1.

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Friday - August 15, 2014

Water Treatment Plant Construction Update

A large concrete pour occurred this week for the Chemical Building slabs

Over the last week, auger cast piles were drilled for the finished water pump station and concrete was poured for the chemical and electrical building slabs. Water testing of the solids storage tank also continued. Once the water test is complete and the coatings applied, the area around the solids storage tank will be backfilled.

Late next week, installation of the secondary power feed for the plant is expected to begin between the Kenthorpe Way plant entrance and the center of the site. This includes excavating, setting new vaults and an electrical meter slab. Neighbors close to the site on Kenthorpe Way may experience an increase in noise or potential vibration during the excavation.

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