Thursday - October 23, 2014

Water Treatment Plant Construction Update

Crews working on the decking and steel for the electrical building.

Attendees at the WTP construction tour last week – tours will resume in the New Year.

Finished water pump station and clearwell – south and center of site

Concrete blocks are being placed and walls completed for the finished water pump station. The water test is progressing for the clearwell – the tank is now filled about halfway and will be complete next month.

Ballasted flocculation – center of site

Crews have started installing steel and grating for the deck of the ballasted flocculation. Water testing continues on the two tanks in the south of the structure. Once the water test is complete, work will begin on applying coating to the outside of the structure.

Solids storage and mechanical dewatering buildings – northeast of site

Mechanical equipment including pumps and piping are being placed in the solids storage tank. Installation of structural trusses and roof systems will continue through the month.

Tomorrow, a large 90-ton mobile crane will arrive to install screw presses in the mechanical dewatering building at the northeast corner of the site (photo to the right). Screw presses will remove water from the solids, and the cake that results will be trucked offsite for disposal or reuse. The crane will be removed once the equipment is placed in the building. Neighbors located on the northeast of the site can expect to see the crane and screw presses and experience some noise during the crane operation.

Chemical & electrical buildings – center of site

Work is almost complete on installing the concrete blocks for the chemical building. Crews will then begin installing the structural steel. Forming the decking, roof slab and installing structural steel continues for the electrical building.

Miscellaneous piping– center of site

Installation of the 30” – 48” piping across the site continues, including excavating, placing the pipe, encasing it in concrete and backfilling the trench. Backfilling of the corridor where piping has been installed north of the clearwell and south of the ballasted flocculation is rescheduled until early-mid November. This is expected to take about one week to complete. During this time, neighbors located close to the site on Mapleton Drive or Kenthorpe Way may experience an increase in vibration, as the large compactor compresses fill. Once the backfilling is complete, auger cast pile drilling will resume for the liquid oxygen storage tank and manholes.

Work hours

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.

Site plan and new glossary

Please refer to the site plan for locations of each structure o our new glossary of terms formore information on construction and operation of the WTP.

Neighborhood construction meetings – first and third Tuesday of the month

The next meeting will be held on November 18, at 6 p.m. in the downstairs restaurant area at Burgerville, 18350 Willamette Drive, West Linn. There will be no meeting on November 4. Please come along to stay updated on construction progress in West Linn and ask questions of the project team. All meeting materials are posted online under “past meetings and events.” 

For more information, please email lotwater@ci.oswego.or.us, call the hotline at 503-697-6502.