Portland Harbor Superfund Site Risk Assessment

Evaluating risks to people and the environment along this crucial stretch of the Willamette River.

Nearly two centuries of industry along Oregon’s Willamette River has led to significant sediment contamination, especially near the watershed’s convergence with the Columbia River, near Portland. A 10-mile stretch of the Willamette, running through Portland Harbor, continues to be heavily contaminated by metals, pesticides, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and dioxins. Levels in the sediment were high enough for the Environmental Protection Agency (EPA) to designate this reach of the river as a Superfund site and add the site to their National Priorities List in 2000.  As responsible stewards of the river, the City of Portland called upon GeoEngineers’ risk assessment team to offer guidance on the Superfund process and provide their technical expertise to help ensure that the risk assessments supported the City’s goals to clean up and protect users of the river.

The EPA outlines the complex requirements of Superfund site characterization and cleanup. Our experienced environmental team understands the nuances of the state and federal regulations that apply to this site, and was there to help the City understand their options, every step of the way.

GeoEngineers’ toxicologists reviewed reports and helped the City understand the primary health risks from the site. Since Portland Harbor is used for industrial, commercial and recreational activities and also provides critical habitat to important fish, birds and mammals, this project involved a diverse range of stakeholders, including the City, the Port of Portland, tribes, federal and state agencies, and industries along the river. GeoEngineers was able to support the City by understanding the needs and mandates of all stakeholders, technical aspects of the project and the regulations governing the cleanup.


  • GeoEngineers participated in meetings between the City and other stakeholders, analyzing and reviewing technical reports, documents and methodologies to help the City understand their role in the cleanup. A primary goal of our document review was to evaluate whether the reports’ conclusions were fair and in line with the City’s goal of protecting the river’s ecosystem.
  • We managed the Portland Harbor database (including sediment, water and tissue data) for the City and added new sediment data from the studies conducted by the City. Performing statistical evaluations of the available data, we helped create GIS maps showing different views of the site data and areas of the site with potentially unacceptable risks to people and the environment.
  • The team assessed the food web model created by the Lower Willamette Group to illustrate potential areas of risk within the site’s ecosystem. An accurate model was crucial to determine necessary sediment cleanup levels. Our assessment allowed the City’s staff to better understand how the model would be used in the site cleanup process.


GeoEngineers’ risk assessment and counsel provided a roadmap to help the City of Portland understand their role in the cleanup process and the environmental realities of the site. Our team helped the City navigate complex federal and state regulations, and supported them with the technical information they needed to make critical planning decisions. Our input helped maintain the City’s status as a leading steward of the Lower Willamette River, while showing the path toward the most effective cleanup strategies.

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