Thursday - September 10, 2015

Mayors Tour WTP in West Linn and Pump Station in Gladstone

Rebar cages used during auger cast pile drilling for the washwater basin foundation. More than 1,100 deep-reinforced concrete piles are being installed at the site to keep structures in place during an earthquake.

Water Treatment Plant Construction Update

New filters – northwest of site

Crews continue making good progress pouring the new filter walls. Electricians are getting ready to install the in-slab electrical conduit over the coming weeks. Concrete work for the filters and administration buildings will progress over the next few months. As part of the concrete work, several trucks are arriving and departing the site. A few days after each pour, the edges of the newly-poured concrete slabs and walls are either waterblasted or sandblasted. Neighbors close to the site on Mapleton Drive and Kenthorpe Way may experience an increase in intermittent noise during this activity.

New administration building – north of site

Last week crews placed 300 cubic yards of concrete for the foundation and main slab of the administration building, which took about three months to prepare. Edge forms are being removed this week. Soon, walls will also be poured and, later this month, structural steel installation will begin for the administration building.

Washwater recovery basin – northwest of site

Work is underway on the washwater recovery basin, which is being constructed next to the new filters. Last week, crews installed the first half of the “soldier piles,” as part of a shoring system for a sump on the south end, using a vibratory method. This work took less than a day and resulted in minimal noise and vibration. Next week, auger cast pile drilling is expected to begin for the first half of the basin.

After the first half of the auger cast piling is completed, the remaining portion of the excavation will take place, which is expected to take about two to three days. During this time, there will be an increase in two-way truck traffic on Kenthorpe Way as trucks haul away material and dirt. Once this is complete, additional soldier piles and auger cast piles will be installed for the second half of the basin.

After this series of activities are finished, a layer of gravel will be placed to create a working surface and crews will begin forming and pouring the slabs.

As a reminder, two-way truck traffic will continue on Kenthorpe Way during the pipeline work on Mapleton Drive.

Clearwell waterproofing – south of site

Crews are preparing the clearwell roof to be waterproofed. Waterproofing is expected to take about a week to complete, and will involve crews applying a layer of asphalt/tar over the roof. A gravel layer will then be placed over the asphalt, before final restoration occurs later next year. During this work, neighbors close to the site may notice a tar-like odor, similar to when new asphalt is placed on a roadway. This activity is weather dependent.

Mayors Tour WTP and Pump Station

Thank you to West Linn, Gladstone, Tigard and Lake Oswego mayors for attending a special tour of the treatment plant in West Linn and the new river intake pump station in Gladstone last week.



Along the tour, the mayors learned about the enhanced filtration process at the plant and witnessed construction efforts first-hand (pictured above). The mayors were also informed by operational staff about how the river intake pump station utilizes more energy-efficient technology and takes improved measures to protect fish in the Clackamas River.

Did you know?

There are several green design features and sustainable construction methods being implemented at the new water treatment plant, including a large solar panel array, garden roofs and energy efficient pump motors. Read more about the features here.

Neighborhood construction meetings – next meeting Sep. 15 at 6 p.m.

The next neighborhood construction meeting will be held at Robinwood Station on Tuesday, Sep. 15 at 6 p.m. Please attend to stay up-to-date on construction progress in West Linn and ask the project team questions.

Meeting schedule:

  • The first Tuesday of the month at 7:30 a.m., at Burgerville, 18350 Willamette Drive, West Linn.
  • The third Tuesday of the month at 6 p.m., at the Robinwood Station, 3706 Cedar Oak Drive, West Linn.

WTP construction tours

The next tour will be held on Sept. 24 at 10 a.m. Tours are held every two months on the fourth Thursday. Advance registration is required and space is limited. Please contact us and indicate in the subject line you would like to attend the next tour, along with your contact information.

Work hours

Work hours are 7 a.m. to 7 p.m., Monday to Friday, and 9 a.m. to 5 p.m. on Saturdays.

Site plan and glossary

Please refer to the site plan for locations of each structure or our glossary of terms for construction and operation of the WTP.

For more information, please email us, call the hotline at 503-697-6502, attend a neighborhood construction meeting.