Written by Brynn O’Donnell
Edited by Alison M Jones, NWNL Director
All images © Alison M Jones
Brynn O’Donnell is a freshwater ecosystem scientist, with a focus on urban biogeochemistry. She also believes in the importance of science accessibility, and practices this by telling stories of the human relationship with water through her podcast, Submerge.
Multnomah Channel of Willamette River, Oregon
Were you to walk alongside the Lower Willamette River on any given day in Portland OR, you would find a bustling river. On this important Columbia River Tributary, you’d likely see boaters and other recreationists paddling around after a day of work, or fishermen angling for stocked trout. The Portland Harbor of the Lower Willamette River hosts an international port for ocean-going vessels and industry.1 The cultural resource of the river is important to multiple local tribes; and overall, the Lower Willamette River is extremely valuable to local residents
Yet the value and importance of the river did not protect it from environmental degradation and pollution. For decades, river-side industry has discharged toxic chemicals and contaminating byproducts into the Portland Harbor. These included PCBs, mercury, DDT, heavy metals, pesticides and others. Before many of these were banned from use, regulations were imposed to mitigate direct discharging into waterways. These contaminants then sank to the bottom and became trapped in sediment, producing a slow-leaching toxic benthos (river bottom) that still haunts Portland, these many decades later. This 10-mile stretch of the Lower Willamette River was so polluted by 2000 that the EPA listed it as a hazardous US Superfund Site.2
Industry on Willamette River (below Mt. St Helens), Portland
Superfund sites represent some of the most polluted parts of the United States. Sites receive ‘Superfund’ designations from the EPA when their contamination via toxins and hazardous waste is so extreme that it poses serious threats to human and environmental health. A ‘Superfund’ designation stresses urgency in the need for cleanup.3 Currently, 1,338 active sites are on the EPA Superfund list. Thus far, 412 Superfund sites have been removed because their clean-up has been effective.4
When a site is labeled as a Superfund, that title draws awareness to its environmental conditions that have gone awry and a plan is formed. The cost of instituting a cleanup plan is largely the responsibility of parties complicit in rampant pollution. The Portland Harbor Superfund site has an extensive history of industry and stakeholders contributing to the river’s pollution.
Tanner Springs Park an urban constructed wetlands, Portland
Industry has been discharging toxic contaminants into this stretch of river for decades. Pesticides, heavy metals, DDT, PCBs and PAHs are some of the contaminants shuttled off from local industrial factories and into the river.5 Although long banned, these contaminants are still found buried within sediments that sank in the river over time. They are a stark reminder of past industrial pollution.6 Once these historical contaminants sink into the sediment, they become much harder to remove and require very large clean-up campaigns to filter river sediment. Thus these toxins have not yet been completely removed. Additionally, some studies have shown that it is possible that these banned toxins are leaching into the river water,7 where they have the potential to do much more damage.
“These toxins have been banned for thirty years. But they still show up. They are still here. They are still in the river.”
— Brent Foster , Exec. Dir., Columbia River Keeper in 2007
Tanner Springs Park, an urban constructed wetlands, Portland
The persistence of toxins in the ecosystem has led to multiple health warnings and ecological ramifications. This is habitat for many fish species that are unfortunately constantly exposed to these toxins. Moreover, the toxins bioaccumulate in the fish, meaning the fish absorb these pollutants faster then they break them down or excrete them.8
As a result, PCB, pesticide and mercury contamination were found to be significant in fish taken from this harbor site.9 Additionally, they had high levels of mercury and DDT,10 banned in 1972, largely a result of awareness raised by Rachel Carson’s Silent Spring. However, although DDT was banned over 40 years ago, it is still found in fish. If there are no active attempts to clean and restore Superfund sites, the decadal persistence of these contaminants will create ongoing threats.
The EPA has determined that the greatest threat to humans within the Portland Harbor Superfund Site is the consumption of fish that live there year-round, since they have been most exposed to these toxins.11 In 2007, Brent Foster, then the Executive Director of Columbia RiverKeeper, noted in an interview with NWNL that human cancer rates can rapidly increase when eating fish with high levels of DDT and PCP’s. He explained that in 2002, the Columbia River Intertribal Fish Commission stated that tribal members who consumed fish along some polluted parts of the river were exposed to a jarring 1-in-50 risk of cancer.
Sign on green infrastructure, Tanner Springs Park, Portland
The risk of cancer is not exclusive to fish consumption.12 The Portland Harbor pollution is also a risk for those who frequently recreate in the river’s most polluted parts. However recreation is supposedly safe in most of the Willamette River.13
The clean-up task seems daunting. How to clean up an environmentally-polluted site that’s held onto toxic contaminants for decades? The EPA has suggested an extensive clean-up plan. However, once this historic abuse in this stretch of the Willamette has been addressed, it is essential that the City of Portland ensures future protection of the health of the river. Only through watershed-scale initiatives can the Lower Willamette River be kept healthy.
Fortunately, Portland takes its commitment to watershed health seriously. The city has become a leader in urban implementation of green infrastructure. The city’s recent instillation of swales and constructed wetlands helps slow down and filter its urban runoff. Addressing ways to reduce pollutants or excessive nutrients while they are still on city land stops many of these toxins from ever reaching the Willamette River itself – and the Columbia River just a few miles downstream from Portland.