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EPA Proposes Changes to the Portland Harbor Superfund Cleanup Plan

New science finds lower risk for one pollutant

Contact Information: 
Suzanne Skadowski (

PORTLAND – The U.S. Environmental Protection Agency is proposing changes to the cleanup plan for the Portland Harbor Superfund site, a 10-mile stretch of the Lower Willamette River in Portland, Oregon. The proposed changes are based on updated research on one of the chemicals targeted for cleanup. The changes will result in reduced cleanup costs and a slightly smaller cleanup area where benzo[a]pyrene (BaP) is the risk driver. EPA is taking public comment on the proposed changes through December 21, 2018.

“Today’s proposal ensures that the cleanup plan is current with the latest science to protect people’s health and the environment,” said Acting EPA Administrator Andrew Wheeler. “Working with tribal nations, the state, other partners, and the responsible parties, we are moving the cleanup forward to return the Lower Willamette to a healthier working waterway for all.”

New Research

In 2017, EPA updated the estimated health risk for BaP based on over five years of national research that showed that it is less toxic for people who contact or ingest the chemical than previously thought. BaP is one of a group of contaminants called carcinogenic polycyclic aromatic hydrocarbons (cPAHs) that are targeted for cleanup in Portland Harbor. The updated health risk information for BaP is available in EPA’s Integrated Risk Information System:

Proposed Cleanup Changes

Based on the updated health risk information, EPA is proposing to change the cPAH cleanup levels in the river’s beaches and nearshore sediments. The new cleanup levels will require less sediment dredging and capping. Due to these changes, the cleanup area is expected to be reduced by about 17 acres out of the total 2,200 acres, and cost about $35 million less than the original $1 billion cleanup estimate. The proposed changes to the 2017 cleanup plan are described in an Explanation of Significant Differences document. A fact sheet summarizing the proposed changes is available at:  

Cleanup Progress

EPA is working with multiple responsible parties to conduct site-wide baseline sampling, delineate Sediment Management Areas, and design the cleanup. Negotiations for sampling and cleanup design are also ongoing with other responsible parties. EPA continues to engage with communities, tribal nations, state and local governments, and stakeholders through community forums and other public opportunities. A fact sheet on the site cleanup progress is available at:

The Oregon Department of Environmental Quality (DEQ) is investigating and cleaning up riverside properties, both along Portland Harbor and upriver, to reduce pollution sources that could re-contaminate the site. DEQ has assessed nearly 500 upland sites, identified over 170 sites as potential sources, and completed cleanup and/or source control at 110 sites. DEQ has also cleaned up contaminated sediment at five areas upriver, and more cleanup work is expected in 2019. DEQ’s goal is to sufficiently control sources by the time EPA’s in-water cleanup begins.


The Portland Harbor Superfund site covers approximately 2,200 acres of the Willamette River from river mile 1.9 to river mile 11.8. The site was listed on the Superfund National Priorities List in 2000, due to high levels of contaminants in the river sediments, water, and fish, which pose a risk to people’s health, especially for subsistence and tribal fishers. 

In 2017, EPA issued a cleanup plan for the Portland Harbor Superfund Site. Active cleanup construction, including dredging, capping, and natural recovery of contaminated sediments, is expected to take about 13 years. EPA expects the cleanup to result in a 100-fold reduction in contamination-related cancer risk and other serious risks, and the river’s natural recovery process will further reduce these risks.

Public Information and Comment Opportunities

Public comments on the proposed Explanation of Significant Differences can be submitted by November 21 via email to:

EPA is hosting two public events to present information and answer questions about the proposed Explanation of Significant Differences. EPA will host an online webinar on November 1 and an in-person community information session on November 20. Event times and location information will be available at:

View the Explanation of Significant Differences at:

Superfund Task Force. In May 2017 EPA established a task force to restore the Superfund program to its rightful place at the center of the Agency's core mission to protect health and the environment.