Brightwater emergency - TunnelTalk
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Brightwater action to limit costly delays Feb 2010
King County news release
A change in the contractor building a problematic section of the Brightwater tunnel system in Seattle is being called for by the client. King County Executive Dow Constantine is proposing the action to protect the best interests of King County and its regional ratepayers.
"While most elements of the Brightwater project are on schedule," said Constantine, "I am extremely concerned about construction delays on a remaining 2-mile segment of the Central tunnel contract and am not confident that the current contractor can complete its construction in a timely manner. We have an obligation to our ratepayers to pursue alternatives, and that is what we are doing." The Executive has issued a declaration of emergency that will enable the County to waive procurement requirements and hire the project's West Tunnel contractor, the Jay Dee/Coluccio/Taisei JV (JCT), to complete the remaining 2 miles of the central BT-3 tunnel. The current Central tunnel contractor, the Vinci/Parsons RCI/Frontier-Kemper JV (VPFK), would remain under contract to complete the eastbound BT-2 tunnel.
p1

Fig 1. Plan of the Brightwater tunnel conveyance project

The tunnel drives are part of the 13-mile Brightwater conveyance system to carry treated wastewater from the treatment plant to a new outfall in Puget Sound (Fig 1). JCT is working on the 4-mile West tunnel contract and its Lovat EPBM is expected to complete a successful breakthrough into the Ballinger Way shaft in the coming few weeks. Construction on the two central BT2 and BT3 tunnels in opposite directions from the North Kenmore shaft by VPFK was suspended in May 2009 after inspections revealed extensive damage to the cutterhead rims on the two 5m diameter Herrenknecht Mixshields.
The damage has required complex repairs before additional tunnelling could proceed. VPFK successfully repaired the BT2 machine and tunnelling resumed last week (mid-Feb 2010). The BT2 machine has completed about 1.5 miles of the 2.2-mile drive to the North Creek shaft.
For the second machine, VPFK estimates that an additional $98 million will be required for them to repair its damage and complete the BT3 tunnel. As a result, King County staff estimates the project would not be completed until December 2013 resulting in a cost increase and a significant schedule delay, which the Executive has deemed unacceptable. "We believe JCT can complete this portion of the BT3 tunnel at substantially lower cost and in significantly less time," said Christie True, Director of the Wastewater Treatment Division of the King County Department of Natural Resources and Parks.
"Timely completion is critical to ensure our regional wastewater system has enough capacity to serve population growth, protect public health and the environment, and support economic recovery as we emerge from a serious recession," True said.
The BT3 machine began tunneling west from the North Kenmore shaft in fall 2007. The machine is currently under a cover of about 330ft and has completed about 1.9 miles of the nearly 4-mile drive to the Ballinger Way shaft.
King County project managers do not yet know the extent of the costs associated with the delays and repairs, or who will ultimately bear responsibility for any additional costs. Both issues will be subject to negotiation with the companies involved.
The King County Council must approve the extension of the waiver of competitive bidding for the change in contractor. While repairs have delayed the tunnel project completion by up to two years, the treatment plant contract remains on schedule to open in the fall of 2011. It will operate using existing sewerage infrastructure until the conveyance tunnel construction is complete and on-line.
TunnelTalk is awaiting the return of calls to bring further details of the situation as it develops.
References
Dewatering assists Brightwater TBM repairs - TunnelTalk, Oct 2009

           

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