Thea Foss Waterway

Collectively, Floyd|Snider staff have participated in the Thea Foss and Wheeler-Osgood Waterways cleanup activities since the early 1990s, from initial area-wide master planning and presumptive remedy negotiation to environmental compliance construction oversight of the final sediment remediation project.

From 2002 to 2006, Floyd|Snider served the City of Tacoma (City) on the environmental component of the construction management team that oversaw sediment remediation activities for the Thea Foss and Wheeler-Osgood Waterways Remediation Project, which resolved Superfund contamination issues in waterway sediments. In this role, Floyd|Snider provided technical assistance and informed the City and contractor on all environmental issues, evaluated results from water quality, sediment and soil quality, and waste characterization monitoring associated with environmental compliance. The $60 million construction effort involved creating an off-site nearshore confined disposal facility, hydraulic and mechanical dredging, placement of capping materials, construction of marinas and associated temporary tenant relocations, and the creation of habitat mitigation sites. 

Since 2006, we have supported the City in the completion of the Remedial Action Construction Completion Report and in development and initial execution of Operation, Maintenance and Monitoring Plans (OMMP) for the sediment cleanup, confined disposal facility, and constructed aquatic habitat areas. Execution of the OMMP has included working closely with City staff and the City laboratory to execute chemical, physical, and biological monitoring of the completed cleanup and confined disposal facility.   

Floyd|Snider continues to provide technical services for the City to manage this project’s OMMP activities under the City of Tacoma On-call contract. The OMMP activities include confined disposal facility monitoring, statistical evaluation and reporting, subtidal hydrographic surveying, benthic recolonization monitoring, and ongoing sediment cap monitoring.


  • Preliminary Design Evaluation
  • Complex Program Management and Master Planning Facilitation
  • Environmental Permitting
  • Design and Bid Package Preparation
  • Construction Management
  • Agency Coordination and Negotiation
  • Remedy Slope Cap Maintenance
  • Long-term Monitoring
  • Sediments and Confined Disposal Facility

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