Willamette

Polychlorinated biphenyl
Polycyclic aromatic hydrocarbonDioxin

Top image from the Oregon DEQ, their website is here, with information about progress on improving the water quality in the Willamette

Link to Willamette Riverkeeper here

As they note on their website, some of the current problems (including habitat modification and pollution) facing the river include the following:

The Willamette is on the Clean Water Act 303 (d) list for violations of water quality standards.

• The Willamette currently violates temperature, bacteria, and mercury standards.
• A large section of the river, some 40-miles known as the Newberg Pool, is home to resident fish (those that don't migrate such as the northern pikeminnow) that exhibit high percentages of skeletal deformities. For example, in some samples in this area over 50% of the juvenile fish were deformed. This section of the river, as well as others, contains PCBs, dioxin, and PAH among others.
• A six-mile stretch of the river in Portland is now a federally designated Superfund site. This site is highly polluted with all manner of toxic pollution, heavy metals, and other substances. It is now going through a cleanup process that will likely push a decade to complete.
• Spring Chinook and steelhead, the Willamette's native salmonids, are listed as threatened under the Federal Endangered Species Act.
• Other species such as lamprey eel and white sturgeon have been found to contain significant concentrations of man made chemicals in their tissues.
• There is a fish consumption advisory for people that eat ANY species of resident fish. This is pretty much any fish other than salmon, lamprey, and sturgeon.
• New studies are underway that are looking into additional impacts from toxic and other pollution on the Willamette River and the species that inhabit it.