SR 520 Pontoon and Floating Bridge Construction

Client: Kiewit-General-Manson
Design Build Team
Permit lead for all design-builder permits and consulting support around environmental constraints during the replacement of the SR 520 floating bridge construction.

Overview of Floyd|Snider Contributions

Facilitation of design-builder and agency environmental task force meetings
Acquisition of design-builder permits
Support for construction change approvals
Preparation of Environmental Compliance Plans
Tracking of environmental commitments

Project Summary

Kiewit-General and Kiewit-General-Manson (KGM) were awarded two separate design-build contracts by the Washington State Department of Transportation (WSDOT) for the replacement of the SR 520 Floating Bridge across Lake Washington.

The Pontoon Construction Project involved designing and building a new pontoon casting basin in Aberdeen, Washington, designing and constructing 33 new floating bridge concrete pontoons, and storing the pontoons for ultimate transportation to the SR 520 floating bridge location. The Floating Bridge and Landings Project included construction of a new six-lane floating bridge, demolition of the existing floating bridge, a new east approach connection, and a bridge maintenance facility and dock. The combined value of the construction contracts was $953 million. Completion of the work was achieved in August 2017.

Kiewit-General and Kiewit-General-Manson (KGM) were awarded two separate design-build contracts by the Washington State Department of Transportation (WSDOT) for the replacement of the SR 520 Floating Bridge across Lake Washington. The Pontoon Construction Project involved designing and building a new pontoon casting basin in Aberdeen, Washington, designing and constructing 33 new floating bridge concrete pontoons, and storing the pontoons for ultimate transportation to the SR 520 floating bridge location. The Floating Bridge and Landings Project included construction of a new six-lane floating bridge, demolition of the existing floating bridge, a new east approach connection, and a bridge maintenance facility and dock. The combined value of the construction contracts was $953 million. Completion of the work was achieved in August 2017.

Our Approach

Floyd|Snider provided environmental consulting services to the Design-Build teams.

Floyd|Snider was permit lead for acquisition of all design-builder permits and supported the project team’s interpretation of environmental constraints and new potential effects from KGM’s design. Floyd|Snider worked closely with the design-builder, as well as the design engineers for both projects, HNTB for the Pontoon Construction Project and KPFF Consulting Engineers for the Floating Bridge and Landings Project, to strategically prepare permit application submittals that maintained flexibility as the project designs were finalized, while ensuring that project impacts were consistent with design-builder and WSDOT environmental requirements. In addition, Floyd|Snider developed all design-builder Environmental Compliance Plans; monitoring and protection plans under the 401 Water Quality Certification; acquired NPDES stormwater permits, building permits, noise variances, and PATON navigation permits; and coordinated provision of design information to WSDOT for NEPA re-evaluation and JARPA permitting for the projects. Floyd|Snider also facilitated and documented weekly Environmental Task Force meetings for both projects.

In addition, Tessa Gardner-Brown, now Floyd|Snider’s Permitting Specialist, supported WSDOT as a key planner on the team preparing the final NEPA Environmental Impact Statement, acquiring all in-water permits, and responding to public concerns. Ms. Gardner-Brown was responsible for preparation of numerous NEPA re-evaluations and memoranda to the file, in collaboration with Floyd|Snider, to document changes proposed by the design-build contractor.

Project Milestones:

Pontoon Construction Project:
2011. Casting basin construction begins in Aberdeen
2015. Pontoon construction completed

Floating Bridge and Landings Project:
2012. Bridge construction begins
2016. Bridge opens to drivers
2017. Removal of old floating bridge complete

Floyd|Snider provided environmental consulting services to the Design-Build teams. Floyd|Snider was permit lead for acquisition of all design-builder permits and supported the project team’s interpretation of environmental constraints and new potential effects from KGM’s design. Floyd|Snider worked closely with the design-builder, as well as the design engineers for both projects, HNTB for the Pontoon Construction Project and KPFF Consulting Engineers for the Floating Bridge and Landings Project, to strategically prepare permit application submittals that maintained flexibility as the project designs were finalized, while ensuring that project impacts were consistent with design-builder and WSDOT environmental requirements. In addition, Floyd|Snider developed all design-builder Environmental Compliance Plans; monitoring and protection plans under the 401 Water Quality Certification; acquired NPDES stormwater permits, building permits, noise variances, and PATON navigation permits; and coordinated provision of design information to WSDOT for NEPA re-evaluation and JARPA permitting for the projects. Floyd|Snider also facilitated and documented weekly Environmental Task Force meetings for both projects.

In addition, Tessa Gardner-Brown, now Floyd|Snider’s Permitting Specialist, supported WSDOT as a key planner on the team preparing the final NEPA Environmental Impact Statement, acquiring all in-water permits, and responding to public concerns. Ms. Gardner-Brown was responsible for preparation of numerous NEPA re-evaluations and memoranda to the file, in collaboration with Floyd|Snider, to document changes proposed by the design-build contractor.

Project Milestones:

Pontoon Construction Project:
2011. Casting basin construction begins in Aberdeen
2015. Pontoon construction completed

Floating Bridge and Landings Project:
2012. Bridge construction begins
2016. Bridge opens to drivers
2017. Removal of old floating bridge complete

Project Team

Floyd|Snider
KPFF Consulting Engineers