- Environmental Site Assessment & Remediation
Market
- Development
Location
- Seattle, Washington
Overview
This private family foundation funds education, health and development programs around the world. The family envisioned building a new world headquarters for the Foundation on urban land in Seattle, Washington. GeoEngineers was fortunate to be involved from the very beginning—long before a site was selected—and remained on the project through the environmental cleanup, building design and construction phases.
In 2004, the holding company that the Foundation had created to select and develop their campus asked GeoEngineers to assess potential development risks associated with six different properties being considered as the headquarters site. GeoEngineers undertook a thorough review of the sites, weighing geological and geotechnical factors as well as critical area considerations and potential environmental risk to narrow the list of possible sites.
The most desirable site was a 12-acre city block located in the heart of Seattle’s lower Queen Anne neighborhood, next to Seattle Center. Historically, a streetcar and bus barn, dairy, dry cleaning plant and other light industrial businesses had occupied portions of this block and its neighboring properties. These uses had contaminated the soil and groundwater, and the large land parcel had become an under-developed parking lot in the middle of a vital city neighborhood.
GeoEngineers’ studies, analyses, and extensive experience with brownfields projects gave the Foundation information they needed to purchase the site with confidence that its many environmental issues could be resolved. Once the parcel was identified and secured, we developed an overall site cleanup strategy and coupled it with the Foundation’s long-term, multiphase redevelopment plan to manage and/or reduce environmental risk.
The Foundation selected a “dream team” of the best environmental and geotechnical experts, structural engineers, architects, legal and land-use specialists and builders in the Northwest to work on the project. The laudable scope and vision of this project—to revitalize an underutilized property and further the Foundation mission and community—captured the imagination of everyone involved.
Our environmental teams were on the scene to monitor the cleanup, which included segregating and removing approximately 620,000 tons of contaminated soil from the site and designing and monitoring installation of one of the largest vapor barrier systems in the world. The barrier encapsulates the entire subsurface portion of the campus structures and guards against residual chemical vapors from remaining contaminated soil and groundwater undergoing ongoing treatment.
GeoEngineers’ geotechnical experts also collaborated with the integrated project team from the conceptual phases to final design for the Foundation’s campus development. The final design for the 12-acre site consisted of a parking garage and three six-story office buildings that will offer a combined 1.3 million square feet of office space once the third building is finished. For a full discussion of the GeoEngineers’ geotechnical work on the Foundation project, see the related project profile.
GeoEngineers developed an environmental approach that regulators praised as a model of effective collaboration between architectural and engineering design teams, general contractors, regulators and the community. The end result validated the Foundation’s vision of “a hub for innovation.” That innovation began with the Foundation’s decision to develop on underutilized urban land and to establish a cleanup approach that created a healthy place for those who visit or work at the campus.
Approach
- In the initial Environmental Site Assessment (ESA), GeoEngineers evaluated subsurface soil and groundwater conditions associated with historical uses at and adjacent to the property.
- Identified areas that contained contaminants–including polycyclic aromatic hydrocarbons (PAHs), metals, gasoline and solvents
- Estimated the costs and risks associated with dealing with the contaminants the construction team would likely encounter or disturb during construction.
- Developed a detailed cleanup action plan and remediation cost estimates for each phase of redevelopment
- Liaised with client and regulators regarding the site’s environmental cleanup issues
- Designed and oversaw installation of a large, complex chemical vapor barrier under the campus buildings
- Led a complex identification and contaminated soil segregation process that separated contaminated soil from clean soil while not delaying tight construction schedules
- Obtained regulatory approval and then oversaw installation of a protective cap in areas within the property where residual contaminated soil remained outside the construction footprint
- Developed post-construction soil and groundwater handling plans and implemented a groundwater monitoring program
Results
The Seattle private family foundation’s 1,100-space parking garage built for the Seattle Center was completed in 2008. Two of the three six-story Phase 1 Campus buildings were completed in June 2011, providing the Foundation with 900,000 square feet of office space. The Campus was awarded LEED©-NC (Leadership in Energy and Environmental Design for New Construction) Platinum certification from the United Stated Green Building Council, and is the largest, non-profit LEED©-NC Platinum building in the world.
GeoEngineers:
- Helped the Foundation fulfill its vision of creating a lively, environmentally friendly urban headquarters rooted in the Seattle community
- Reduced the owner’s environmental risk with minimal impact to the redevelopment process
- Won kudos from the State of Washington Department of Ecology for Remediation Investigation/ Feasibility Study, Clean-Up Action Plan and disproportionate-cost analyses, called among the most significant completed in the state
- Oversaw the safe removal of a large volume of solvent- and gasoline-contaminated soil from the property during construction
- Reduced urban blight by reclaiming and redeveloping urban land for uses that enhance and engage the neighborhood and maximize existing infrastructure
- Continues to work with the developer and the Foundation to develop the third building, which will add an additional 400,000 square feet of office space to the 900,000 square feet already completed
Related Staff
Related Projects
