Thursday - May 7, 2015

Treatment plant enters new phase of construction

Micro-sand pumps.

Foundation of the new administration building.

Crews installing yard piping on the east of the site.

Water Treatment Plant Construction Update

The new ballasted flocculation system is now up and running and the plant is producing water with the new process! Ballasted flocculation is one part of the new conventional filtration system, which helps remove more material from the water before filtration. It involves adding aluminum sulfate and micro-sand to the water, which helps particles in the water stick together and settle to the bottom. Sediment is then transferred to the solids handling system.

The startup of ballasted flocculation kick-starts a new phase of construction, which also 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

Auger cast pile drilling resumed on the site this week to support the foundation of the new administration building. Over 60 piles will be installed for the new building, and this is expected to be complete next week. Once the auger cast piles are installed, work will begin on forming the elevator pit and pouring concrete for the foundation. Neighbors close to the site or on Kenthorpe Way may notice an increase in noise or potential vibration during this work.

Sedimentation basin demolition – northwest of site

Solids are now removed from the existing sedimentation basins, and some of the concrete has been saw-cut to prepare for demolition. Starting today, excavators with concrete processors or hydraulic hammers will begin breaking up the concrete. Crews will be working Monday through Saturday. 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 be excavating, forming, pouring concrete and placing piping from the newly installed finished water pipe to connect to a new surge tank. The surge tank is expected to be installed in late May. Neighbors close to the site on Mapleton Drive may notice an increase in noise or potential vibration during this work.

Neighborhood construction meetings

The May 19 meeting will be a special “Meet the Mapleton Drive pipeline contractor” session from 7 – 9 p.m. at the Robinwood Station, 3706 Cedar Oak Drive, West Linn. The next neighborhood construction meeting with the plant contractor will be held on June 16, 6 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 attend a neighborhood construction meeting or contact us