The cleanup of the land at Willamette Cove has one goal: to make the entire site safe for people to visit and for plants and animals to thrive.
Metro and the Port of Portland are working together to achieve that goal. DEQ, Oregon’s Department of Environmental Quality, is overseeing the work and will determine when the goal has been met.
While Metro and the Port are at work, another cleanup is being planned to address contamination from the top of the riverbank down into the riverbed. While this includes Metro property, Metro is not part of the group leading this cleanup, though we stay in close touch. This is the in-water cleanup, part of the Portland Harbor Superfund Site and overseen by the federal Environmental Protection Agency.
While these are separate projects, each relies on the other for its success. It is important for both projects to coordinate their cleanup efforts.
Willamette Cove has two cleanups in the works. The in-water project starts at the top of the riverbank and goes out into the Willamette River. The upland cleanup starts at the top of the riverbank and goes in land.
What are the cleanup requirements?
At its simplest, Metro will clean up Willamette Cove by excavating and removing highly contaminated soil and covering the site with clean soil so people and animals can’t touch any remaining contamination. What has to be removed, where it goes and what replaces it is all part of the planning that is happening now and must follow the cleanup plan approved by DEQ. The cleanup will reduce risk to the point where no further cleanup action is necessary for a recreation site.
In 2021, DEQ laid out its guidelines for the cleanup. The main elements are:
- All contamination that is a high risk to human health – these are called hot spots – must be hauled to a DEQ-approved landfill.
- All contamination from metals that are a high risk to plants and animals – called ecological hot spots – must be hauled to a DEQ-approved landfill or covered with clean soil.
- At least one foot of clean topsoil will be placed over the entire site.
The guidelines also directed that much of the remaining contaminated soil had to be gathered in one spot and enclosed in a structure called a consolidated engineered cap. Because of significant testimony from the public and Tribal governments opposing the mound of contaminated soil, DEQ gave Metro the option to greatly reduce or eliminate the consolidation area by hauling excavated contaminated soil to a DEQ-approved landfill.
In 2022, the Metro Council decided to eliminate the consolidation cell and remove contaminated soil that is excavated from Willamette Cove to an off-site landfill.
Previous cleanups
Since Metro purchased Willamette Cove in 1996, four small cleanups have removed contamination that needed immediate attention
1999 An oil tank is discovered and removed.
2004 20 tons of oil-saturated soil removed.
2008 987 tons of soil with human health hot spot levels of lead and other metals removed.
2015 to 2016 5,000 tons of soil with human-health hot spot levels of dioxins/furans removed.
Since then, Metro, the Port and DEQ have been creating the detailed plans for a successful and safe cleanup. As part of this process, an extensive study was conducted and draft results were released in 2023. The study showed that contamination went down to at least three feet in depth across most of the site, which was deeper than the cleanup plan had assumed. Discovering this kind of new information is a normal part of the cleanup planning process, and why these studies are done. Metro, the Port and DEQ have been discussing how to incorporate this information into the cleanup plans.
Throughout its decision-making process, DEQ takes into account five balancing factors when choosing one course of action over another: effectiveness in achieving protection, long-term reliability, implementability, implementation risk and reasonableness of cost. In the areas where we can’t dig to clean, Metro and the Port will make sure the remaining contamination can no longer cause risk to humans, plants or animals by using layers of suitable materials to isolate the contamination. These materials usually include lots of clean soil and topsoil that keep contamination in place and keep people and animals away from the contamination.
But remember: the contamination that is a risk to people will be removed and there will not be a built-up mound of contaminated soil on the site.
After the cleanup
Following the cleanup, Metro plans to create the nature park at Willamette Cove. Along with building all the facilities and amenities for the park, Metro will plant hundreds of trees and tens of thousands of shrubs, bushes and other small plants. It’s likely literal tons of native grass and wildflower seeds will be scattered across the site. Over the coming years and decades, healthy natural areas with forests, prairie and riverside habitat will grow up in the nature park.
Making Willamette Cove safe, not pristine
A reality of cleaning up sites like Willamette Cove is that, unfortunately, they can’t be made pristine with zero contaminants. This is why it is so important to keep contaminants out of soil in the first place.
The goal is to make Willamette Cove safe, which means eliminating exposure pathways to the contamination. Exposure pathways are the ways people, plants and animals contact dangerous levels of contamination. DEQ’s cleanup plan will remove these exposure pathways to protect people, plants and animals just as effectively as digging out every trace of contamination.
There are multiple reasons why a cleanup can’t remove all of the contaminants at a site. For instance, some of the contaminants such as metals are found naturally in our local rocks and soil. Some chemicals travel deep into the ground or have been deeply buried over time. In this case, it may be impractical to dig out the contaminants, or it might be so destructive to the land that removing it is worse than leaving it.
In its record of decision for Willamette Cove, DEQ says, “The selected cleanup plan accomplishes equivalent protection to the full removal option, in terms of preventing people, plants and animals from being exposed to contamination. DEQ’s selected cleanup plan also has lower implementation risk because it requires less transportation, which reduces chance of accidents/spills of contaminated material through neighborhoods and across the state. It also minimizes environmental costs, also called carbon footprint.”
It can be scary to imagine any contaminants being left after a cleanup. It’s understandable. But when the cleanup is done, Willamette Cove will be safe for people, plants and animals to use as a nature park. There are other parks and natural areas in greater Portland that have gone through similar cleanups, including Cully Park, a neighborhood park with playgrounds and community and Native gardens, and Oaks Bottom Wildlife Refuge, which has become a flourishing marshland habitat including beavers and otters. Both were landfills before becoming parks. Willamette Cove will join these sites as safe places where you can connect with nature close to home.