Seattle Public Utilities
After years of study, one of the region’s toxic hot spots just got a major make over. It didn’t come cheap. The total cost was a cool $8 million. But the clean up demonstrated that an urban waterway can be home to both industry and nature.
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The barge, DB Anchorage, navigates a bend in the river. A 75 ton crane it carries has dredged three and half acres of contaminated mud from Slip 4, a pier on the Lower Duwamish River. The toxic hot spot which for more than a century was a berthing area for Boeing and other companies, is now a lot closer to being a river that nurtures salmon and bull trout. It’s taken a long time.
“But we couldn’t really start clean up until the ongoing sources of pollution, especially PCB into this area, were controlled.” BJ Cummings with the Duwamish River Clean Up Coalition. PCBs or polychlorinated biphenyls, found in coolants, lubricants, and plasticizers, were banned in the U.S. in 1979 but are extraordinarily persistent. “It turned out there was PCB in the caulking at Boeing Field that was then seeping into the soil and getting into the storm water pipes and then flowing out right here into Slip 4.”
The river was designated a Superfund site in 2001. The EPA worked with Boeing, the city, county, and port for years on a clean up plan. Finally in 2007 a plan to clean up this particular bend in the river was in place. But the project was delayed. The Department of Ecology determined storm water discharges from North Boeing Field would likely re-contaminate the river unless they were controlled. The Environmental Protection Agency waited for Boeing to take action. “After about five years I was tired of waiting,” Karen Keeley is Superfund Project Manager for EPA Region 10.
She and the Department of Ecology worked with Boeing to install a state-of-the-art storm water treatment system. “It wasn’t the process of how to do the clean up; it really was just ensuring that we had controlled sources of contamination in the slip enough that we could move forward and not have re-contamination down the road.”
The heavy lifting began last fall. Seattle Public Utilities and local contractor, General Construction Company, had a short window — October through February when salmon don’t migrate. By all accounts the Slip 4 clean up has been a success — on time, on budget, with a local company and local employees.
In addition to dredging the river’s contaminated muddy bottom, shoreline has been restored. Jennie Goldberg with Seattle Public Utilities: “We cut back the banks to create a more natural flow so that we could create another acre of inter-tidal riparian habitat for the Chinook salmon and the bull trout that are the protected species that cruise through here in the waterway.” An otter has even been sighted. Those who know the river well say otters were already in residence, but at least the work didn’t scare them away.
So is that the end of the story for this toxic hot spot on the Duwamish waterway? With an $8 million tab, 67 percent paid by Boeing and 33 percent by the City of Seattle, one might think so. But urban storm drains don’t just carry legacy contaminants like PCBs. They also carry a toxic stew of petroleum and copper from vehicles, phthalates, pet waste, and flame retardants.
There are thousands of storm drains and outfalls in King County alone, many which empty into the Duwamish. Storm water permits determine how cities and industries will curb this pollution and are issued by the Department of Ecology every five years. New permits are expected this summer. But the current draft, says Heather Trim with People for Puget Sound, is full of loopholes. “We don’t want to spend all this money to do the clean-up and then turn around and have contamination continuing to come in and re-contaminate the whole river."
The draft permit fails to recognize the power of low-impact development and green infrastructure to curb pollution spread by storm water, says Trim. “The term feasibility was used way too much in the whole permit.”
Cities and urban enclaves including Seattle, Bremerton, and the Port of Tacoma, have been proactive with green infrastructure such as porous pavement to absorb pollution. Storm water permits throughout the state need to be held to the same bar, says Trim. Legislation has been proposed to delay implementation on new runoff controls. “And we argue that it’s way more cost effective to do those techniques and it’s important to clean up the Sound. We can’t delay this.”
The EPA’s proposal for cleaning up the rest of the Duwamish waterway Superfund site is scheduled for public review in August.
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