Aug. 9, 2006
King County selects contractor to build Brightwater central tunnel
Construction will soon begin on six miles of underground tunnels
to serve the sewage treatment needs of people in south Snohomish
and north King counties. The tunnels for Brightwater treatment system
are part of the region’s largest clean water project in 40
King County recently awarded a $209.7 million construction contract
for the central portion of the Brightwater conveyance tunnel to
Vinci/Parsons RCI/Frontier-Kemper, a joint venture based in Montreal.
Construction of the 14-foot-diameter tunnels will begin Aug. 28.
Crews will use tunneling equipment that works long distances underground
without disrupting surface streets and neighborhoods.
This is the second of three Brightwater construction contracts to
build a 13-mile tunnel that will carry wastewater to and from the
new Brightwater treatment plant when it comes online in 2010.
The scope of work on the central tunnel contract includes building
two tunnels, one from Kenmore to the North Creek Business Park in
Bothell and another from Kenmore to Ballinger Way Northeast in Shoreline.
The combined length of the tunnels will be about six miles.
Crews will also excavate two deep shafts – one near the intersection
of 80th Avenue Northeast and Northeast 192nd Street in Kenmore,
and another along Ballinger Way Northeast in Shoreline – to
launch and remove the tunnel-boring machines.
The contractor will install six pipes in the tunnel ranging from
14 inches to 126 inches in diameter along with two fiber-optic cables
to monitor Brightwater facilities.
The North Creek to Kenmore tunnel segment will hold a 72-inch-diameter
pipe to carry treated wastewater through the system to an outfall
in Puget Sound, a 54-inch pipe to carry untreated wastewater to
an influent pump station where it will be pushed to Brightwater
for treatment, and a 24-inch pipe for reclaimed water.
The Kenmore-to-Shoreline segment will hold two 14-inch reclaimed
water pipes and a 126-inch-diameter pipe to carry treated wastewater
to the outfall.
Portions of the tunnel around the pipes will be filled with concrete
after those installations. In addition, the contractor will trench
a smaller 3,400-foot-long pipeline from the Kenmore portal to connect
the new Brightwater pipes to the existing local sewer system using
a combination of open-cut and microtunnel construction.
Construction on the central tunnel is scheduled to be completed
At $209.7 million, the winning bid is more than $20 million under
the county engineers’ estimate of $229.9 million. The county
and its consultants thoroughly reviewed Vinci/Parsons RCI/Frontier-Kemper’s
qualifications before awarding the contract.
The county has already selected Jacobs Civil to provide construction
management services for the conveyance facilities. MWH/Jacobs Associates
is designing the system as a joint venture, and CDM is providing
geotechnical work as part of tunnel design.
Brightwater tunnel construction on the east segment of the conveyance
system has been under way since March. Kenny/Shea/Traylor was awarded
the contract to build the Brightwater tunnel from North Creek to
the treatment plant site on State Route 9.
King County is currently seeking bids on the Brightwater west tunnel
contract, which closes Sept. 21.
More information about the Brightwater project, including the status
of construction-related contracts, is available on the project Web
site at http://dnr.metrokc.gov/wtd/brightwater/index.htm.
People enjoy clean water and a healthy environment because of King
County's wastewater treatment program. The county’s Wastewater
Treatment Division protects public health and water quality by serving
17 cities, 17 local sewer utilities and more than 1.4 million residents
in King, Snohomish and Pierce counties. Formerly called Metro, the
regional clean-water agency now operated by King County has been
preventing water pollution for more than 40 years.