Friday - April 24, 2015

WTP reaches another milestone

Sedimentation basins (upper left corner).

Shoring support for the elevator pit.

Water Treatment Plant Construction Update

Work at the site is successfully transitioning to a new phase, as the eight new structures that have been constructed are progressing through their startup and commissioning stages. The yellow tower crane has been removed, and the red tower crane will remain in order to service the major work occurring in the center and west of the site.

An exciting milestone is expected to be reached next week with the startup of the ballasted flocculation system, which is a major step in the water treatment process! Ballasted flocculation is one part of the new conventional filtration system, which helps remove more material from the water before filtration.

The next phase of major work includes building the new administration building, demolishing the existing sedimentation basins, as well as excavating and installing the washwater recovery basins and the new filters.

More information about onsite work includes:

New administration building – north of site

During the last few weeks, crews excavated the foundation for the new administration building and placed shoring support for the elevator pit. Next week, Dewitt’s crane and drill rig is expected to arrive and begin installing auger cast piles for the foundation of the structure. This is expected to take about a week to complete. Neighbors close to the site on Kenthorpe Way may notice an increase in noise or potential vibration during this work.

Sedimentation basin demolition – northwest of site

Next week, solids will be removed from the existing sedimentation basins, and some of the concrete will be saw-cut to prepare for demolition. Starting in mid-May, excavators with concrete processors or hydraulic hammers will begin breaking up the concrete. The concrete will be stockpiled and crushed on-site as the work continues. Crushing the material on site for later reuse reduces truck traffic in the neighborhood. The crusher will be located in the middle of the site, with the fan facing inward, to reduce noise. During this work, there will be an increase in noise, depending on neighbors’ locations. This demolition work is expected to take about a month to complete.

Finished water pump station, chemical and electrical buildings –center of site

Some architectural (roofing) and structural siding remains for the finished water pump station, chemical and electrical buildings, although this is weather dependent.

Miscellaneous piping work– east and center of site

Over the next few weeks, crews will begin excavating, forming, pouring concrete and placing piping from the newly installed finished water pipe to connect to a new surge tank. Neighbors close to the site on Mapleton Drive may notice an increase in noise or potential vibration during this work.

New meeting location and frequency - neighborhood construction meetings

Starting in May, meetings will be held once a month, at the Robinwood Station, 3706 Cedaroak Drive, West Linn. Meetings will be held on the third Tuesday of the month at 6 p.m. The May 19 meeting will be a special “Meet the Mapleton Drive pipeline contractor” session from 7 – 9 p.m. at the Robinwood Station.

WTP construction tours

The next tour will be held on May 28, 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 Monday to Friday from 7 a.m. to 7 p.m. and Saturdays from 9 a.m. to 5 p.m.

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 contact us or attend a neighborhood construction meeting.