WSDOT: Pontoon Cracks Will Push 520 Bridge Completion to 2015

The Washington State Department of Transportation announced Tuesday it will need to spend tens of millions of dollars in contingency funds to repair pontoon cracks and modify design plans for the new 520 Bridge.

Speaking at a news conference in Seattle, outgoing state transportation secretary Paula Hammond said the repairs and modifications will likely push the bridge's completion into 2015. 

“The most important thing to us is to make sure the pontoons are safe, sound and serve the public,” she said.

The changes are the result of findings by an expert review panel that was formed in 2012 to address cracking and spalling on the first batch of pontoons constructed in Aberdeen. Based on the panel's recommendations, WSDOT plans to incorporate additional post-tensioning—a process that uses steel tendons to compress and strengthen the concrete—to the construction of future pontoons, as well as retrofit the pontoons that have already been built.

Hammond said the exact cost for the repairs is not known at this point, as WSDOT is currently negotiating change orders for the work with contractor Kiewit/General/Manson. But the transportation secretary said she is confident the state will not exhaust its remaining $200 million in contingency funding for the project.

Hammond blamed much of the problem on design mistakes within WSDOT and said some of the agency's structural engineers failed to run models that would have highlighted the flaws. "It's possible," she said, that some WSDOT personnel will lose their jobs because of the errors, adding that managers are currently examining the findings of an internal review on the matter.

Originally scheduled to be completed in December 2014, the new six-lane SR 520 Bridge is part of a $4.65 billion plan to improve SR 520 from Seattle to Redmond. The bridge has been designed to last at least 75 years and must open to drivers by July 2015 in order to adhere to the state's contract.

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