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King Street Center
201 S. Jackson St., Suite 505
Seattle, WA 98104-3855
Phone: 206-684-1280
Fax: 206-684-1741
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Puget Sound shoreline next to the West Point Treatment Plant, Seattle
 

Hidden Lake Pump Station Replacement and Sewer Improvement Project

Construction Photos - Underground Storage Tank and Boeing Creek Park

The new underground storage pipe will temporarily store up to 500,000 gallons of wastewater during large storms and help reduce overflows to Puget Sound. Click on thumbnail to view larger image.

July 2008 | October 2007 | May 2007 | Sept. 2006 | Aug. 2006

July 2008. Boeing Creek Park update.

PermeablePavers1
Permeable pavers were installed at the 3rd Avenue NW entrance to allow support for maintenance trucks accessing the underground odor control facility.

PermeablePavers2
Plants in the Pacific Northwest wildflower mix used to restore the area will continue to vegetate the pavers.

PermeablePavers3
Soil and vegetation will allow rainwater to sink into the ground below, reducing storm water runoff.

CircleCedars
Circle of Cedars -
Natural-looking rock walls were installed to protect the slope by the "Circle of Cedars" that once surrounded a hunting cabin.

Snag2
The only above ground structure in Boeing Creek Park is an odor control stack disguised as a tree snag.

Snag1
Birds have been sighted perching on the "branches" of the tree snag.

COSParkProject
The City of Shoreline is making additional park and stormwater improvements in Boeing Creek Park in summer 2008.

Trails
Trails running through construction areas were restored and the adjacent areas seeded with a wildflower mix.



October 2007. Storage Facility now complete! View photos from Boeing Creek Park neighborhood celebration, Oct. 20, 2007.

Boeing Creek Park Celebration

May 2007. Progress to date:

  • Construction of a channel in the bottom of the 12' diameter storage pipe in Boeing Creek Park
  • Construction of a new sewer in 10th Ave NW by microtunneling and trenching

Channel
Workers installed a channel at the bottom of the underground storage pipe to convey normal wastewater flows.

Channel2
Another view of the channel along
the bottom of the pipe.

stormwater pond
Work in the City's stormwater pond.

manhole installation
Workers install a manhole in 10th Ave. NW

underground odor control
The underground odor control structure should be completed by fall 2007

Dust Control
Street sweeping to control dust.

Carrier pipes
A carrier pipe was installed by the microtunneling machine. A smaller sewer pipe will be installed inside.

Microtunneling machine Microtunneling machine
A microtunnelling machine was used to install a
new sewer under 10th Ave NW.

Support and Equipment
Microtunneling support and equipment.

setup along 10th ave nw
Staging of materials and equipment along 10th Ave NW



September 2006. Progress to date:

  • About 650 feet of the underground storage pipe has been installed in Boeing Creek Park
  • Excavation of two of three underground structures is complete.
  • Construction of a microtunneling machine access shaft to install a new sewers in the streets near the park has begun on 6 th Avenue NW.

Trenches
Trenches for the underground storage pipe and deepening of the city's storm water detention pond.

Signs and fencing to protect trees
Signs and fencing protect trees in the park. Small trees were transplanted in neighboring Shoreview Park . Suitable older trees were kept in the park for use as habitat logs.

Pipe sections
Pipe sections are either straight or curved so the pipe can go around a corner. Each piece is 12 feet in diameter and weighs about 30 tons.

Laying pipe requires many workers
Laying the underground storage pipe is a complex process that requires a team of workers.

New pipe meets old pipe
The new section of pipe will be fit into the existing pipe in the trench.


 Suspension is attached to pipes Suspension is attached to pipes Suspension is attached to pipes
Crews attach suspension systems, or rigging, to pipes.

Rubber gaskets being stretched across the pipe collar.
Workers stretch two rubber gaskets across the collar of the pipe. The pipe end is greased to allow the pipe sections to slide together easily.

0609_172_100
Each section of pipe is lowered carefully into the trench with a crane that can lift 240 tons.

Two sections of pipe sliding together.
Sections of pipe are slid together. Once sealed, the pipe is inspected.

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August 2006

Shoring the trench
Steel beams and sheets are installed to shore the trench where the storage pipe will be laid.

Pipe is stabilized in place.
Storage pipe sections are stabilized in place before additional sections are added. The wastewater storage pipe in Boeing Creek Park will require 69 sections of pipe.

Pipes are 30 tons, 10ft long, 12ft diameter.
Pipe sections are made by Hanson Pipe & Precast manufacturing plant in Tacoma and hauled to the Boeing Creek Park construction site. Each piece of pipe is at least 30 tons (60,000 pounds), 10 feet long, and 12 feet inside diameter. As you can imagine, they are shipped as oversize loads!

The crane can lift up to 240 tons.
A large crane capable of lifting 240 tons (480,000 pounds) is required to move pipe sections from the truck to the trench.

Even with a crane, these pipes are hard to lift.
Crane operators require special training and certification to work with such large material. Experience, skill, and timing are critical for proper placement of pipe sections. Sections of pipe that have bends are even more challenging to handle because of their off-balance center of gravity.

Workers grease the end of a pipe for fitting.
Workers grease pipe ends so they join together smoothly.

Workers have to guide the hanging pipe.
A team of workers guides the pipe section to keep it from rotating as the crane lowers it into the trench.

The pipe is manouvered between steel reinforcing beams.
The pipe section is slowly and carefully maneuvered between steel reinforcing beams in the trench.

Secondary suspension cables are now used for the rest of the work.
The primary suspension cables used to lower the pipe into the trench are removed. A secondary suspension system is used for fine manipulations to fit the new pipe section into the already installed segments.

Bedding and backfilling the new pipe
Once pipe sections are assembled, the new section of pipe is bedded and backfilled with Controlled Density Fill (CDF), a self-compacting, self-leveling material that hardens into a strong backfill material with minimal settlement.

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