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

Friday - April 11, 2014

Water Treatment Plant Construction Update

Tying rebar and preparing for a concrete pour in the gravity thickener

The auger cast drill rig is continuing to drill piles for all new structures on site, including the mechanical dewatering building and electrical building - over half of the 1,100 auger cast piles have been installed to date!

Last week, work started on backfilling the access ramps into the south side of the clearwell near Mapleton Drive. The backfilling activity requires loaders to pick up and place gravel and rock, and then use a rolling vibratory compactor to compress the fill and gravel. The compaction in this area, and the northeast of the site close to the demolished lagoons will continue intermittently over the next few weeks. Form work and concrete pouring will also continue on-site over the next few weeks, for the clearwell and ballasted flocculation columns, walls and suspended roof.

Neighbors can expect some noise and potential vibration during the fill placement and compaction, auger cast drilling and concrete sandblasting, depending on locations or personal sensitivities. Truck traffic will continue during concrete and grout pouring for the auger cast piles and new foundations.

Work hours are Monday to Friday from 7:00 a.m. to 7:00 p.m. and Saturdays, from 9:00 a.m. to 5:00 p.m. There will be no work on Saturday, April 26.

For more detail about what activities are happening on site please see the table below.

We apologize for the inconvenience construction may cause and thank you for your patience as work progresses.

For more information, please contact us or call the hotline at 503-697-6502.

Construction Tour Reminder

The Partnership holds free WTP construction tours on the fourth Thursday of each month at 10:00 a.m. The next tour will take place on April 24. Space is limited so please sign-up in advance to register a spot by contacting us, calling the hotline or in person at the bi-monthly meetings.


Monday - April 7, 2014

Neighborhood WTP Construction Update Meeting:

Next Meeting Tuesday 4/15 at 6:00 p.m.

The 15th bi-monthly water treatment plant neighborhood construction update meeting was held on Tuesday, April 1, at Burgerville in West Linn. Neighbors learned about upcoming construction and asked questions of the project team. All meeting materials are available on the project website under the ‘Past Public Meetings’ page here. A link to the April 1 meeting summary, including discussion and action items can be found here.

The next meeting will be held on Tuesday, April 15, at 6:00 p.m. in the downstairs restaurant area at Burgerville, 18350 Willamette Drive in West Linn. Please come along to keep updated on construction progress and find out about upcoming work. Coffee and cookies provided by Burgerville.

For more information, please contact the Project Hotline on 503-697-6502 or contact us.

Friday - March 28, 2014

Water Treatment Plant Construction Update

The second tower crane is now assembled

The second tower crane is now assembled

This week was an active one on the site with the second tower crane being assembled. The tower crane will provide efficient, quiet and fume-free servicing of new structures on the west of the site as compared to a diesel crane.