Murray Morgan Bridge Remedial Action

Floyd|Snider assisted the City of Tacoma with environmental engineering support for a focused sediment dredge and cap remedial action under the Murray Morgan Bridge, which spans the Thea Foss Waterway within the boundaries of the Commencement Bay Nearshore/Tideflats Superfund Site. The Thea Foss and Wheeler-Osgood Waterways remediation construction was completed in 2006, under a Consent Decree issued by USEPA in 2003. In 2011, rehabilitation of the Murray Morgan Bridge commenced, and was conducted to restore traffic to the bridge without load restrictions. It consisted of the design and rehabilitation of the three truss spans over the Thea Foss Waterway, including the lift span and the approach structures. Post-construction surface sediment sampling under and adjacent to the Murray Morgan Bridge identified elevated concentrations of lead, copper, and zinc.

These metals detected in surface sediment at concentrations greater that Sediment Quality Objectives were believed to be the result of the Murray Morgan Bridge rehabilitation construction activities that were conducted from April 2011 to May 2013 and, therefore, the City's bridge contractor was responsible for the remedial action. Floyd|Snider led USEPA agency coordination and prepared a Removal Action Work Plan, including dredge and capping design, project Best Management Practices and specifications, a Water Quality Monitoring and Protection Plan, a Post-Dredge Confirmational Sampling Plan, and a Health and Safety Plan. The team also coordinated with environmental agencies, such as the USEPA and the Services, to ensure that the substantive requirements of environmental permits and approvals were met. Floyd|Snider provided construction management oversight, assisted the marine contractor conducting the remedial action, and performed the post-dredge confirmation sampling, as well as data analysis, management, and review, and prepared the Removal Action Completion Report.    


  • Dredge and Capping Design
  • Remedial Action Work Plan Preparation
  • Agency Coordination and Negotiation
  • Post-Remedial Action Sediment Confirmational Sampling
  • Marine Contractor and Water Quality Monitoring Support
  • Construction Management

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