Toxic Chemicals and Heavy Metals in the Spokane River

A Public Guide

Status of Toxic Chemicals & Heavy Metals


Description and Use

Polychlorinated biphenyls (PCBs) are human-made, chlorinated chemical compounds originally developed in 1929. Because they do not burn, break down or conduct electricity, they were used in electrical transformers, capacitors, lubricants, and many other commercial and household products, e.g.—fluorescent lighting fixtures and newsprint. Manufacturing of PCBs was banned in 1979.

Sources and Pathways to The Spokane River

Although banned, previous PCB releases still persist in the environment. Products with PCBs are still in use and may release this toxic chemical into the air, water, or soil. Current testing shows about 55% of PCBs enter the river through the City of Spokane combined sewer overflow and storm water system, 25% at the Idaho border, 15% through industrial and wastewater treatment discharges, and 5% from the Little Spokane River.

Possible Human Health Effects

PCBs can cause skin rashes, immune deficiencies, liver disease, reproductive disorders, and neurological and behavioral problems. They are also a probable human carcinogen. Their presence in Spokane River fish tissue led to an updated fish consumption and preparation advisory.

Cleanup and Restoration

In 2006, high concentrations of PCBs in sediments were “capped” behind Upriver Dam. Capping trapped PCBs and other contaminants on the river bottom by placing layers of coal (carbon), sand, and gravel on top of contaminated areas. A couple of miles upstream, PCB sediments were removed in an environmentally sensitive backwater area of Donkey Island and replaced with clean sand.

A draft PCB Total Maximum Daily Load (TMDL) report was released in 2006. Also called a water quality cleanup plan, the report calls for 95 to 99 percent reductions of all PCBs entering the river. 2007 studies helped determine storm drains releasing PCBs. A new draft report is expected in 2010.


Description and Use

Polybrominated diphenyl ethers (PBDEs) are chemical additives used in everyday household products to reduce death and injury from fires. Also called flame retardants, they are found in everyday items like cushions for chairs and couches, computer casings, carpet pads, and coatings for draperies.

Sources and Pathways to The Spokane River

PBDEs can leach out of products and enter the air, soil, and water. Specific pathways to the Spokane River are not yet known.

Possible Human Health Effects

In lab tests with animals, some PBDEs are linked with brain development (learning, memory and behavior) and thyroid problems. Most problems stem from pre-natal and newborn exposure. Further, the level of PBDEs in human bodies (including breast milk) is doubling every 2 to 5 years. If this rate continues, levels in humans could cause the same problems as those found in animals.

2005 testing showed fish in the Spokane River had the highest levels of PBDEs sampled in Washington State. Concentrations were highest in the Nine Mile area of the Spokane River. EPA recently adopted a reference dose, which is the maximum acceptable oral dose of a toxic substance, for PBDEs. For future advisories, this will help determine safe levels of fish consumption.

Cleanup and Study

In 2007, Washington banned many uses of Deca and all uses of Penta and Octa (the most popular PBDE compounds). Even though PBDEs are banned for use in Washington, products that contain them are still being used. Further, EPA estimates that most exposures to PBDEs (up to 80%) occur in the home and not from eating fish.

2007 studies helped determine storm drains releasing PCBs into the rivers. A 2009 study will track changes in PBDE levels in fish, and assess possible effects on osprey reproduction. The Urban Waters Initiative is using this data to investigate cleanup options.


Description and Use

Dioxins/furans refer to a group of toxic substances that share a chemical structure. They are mostly produced as a by-product of burning items such as municipal waste, sludge, medical waste, and wood. They can also be produced as part of manufacturing herbicides and pulp/paper products.

Sources and Pathways to The Spokane River

Dioxins/furans can be released into the air, soil, and water. Limited data has shown the presence of dioxins/furans in the Spokane River. Specific pathways to the Spokane River are not fully known at this time.

Possible Human Health Effects

Dioxins/furans are a probable human carcinogen. Non-cancer effects include neurological, immune, and reproductive issues. No state or federal standards currently exist to determine safe levels in fish for consumption.

Cleanup and Study

2007 studies helped determine storm drains releasing dioxins/furans.The Urban Waters Initiative is using this data to investigate cleanup options.



Lead, arsenic, cadmium, and zinc are part of a group of contaminating metals released into the environment as part of mining, milling, and ore processing. Metals concentrated in these wastes can be toxic.

Sources and Pathways to The Spokane River

Since the 1880’s, an estimated 100 million tons of mine wastes were released into the river system from the Upper Coeur d’Alene Basin in Idaho. Contaminants traveled downstream, moved through Lake Coeur d’Alene, and can be deposited in the Spokane River.

Possible Human Health Effects

Ingestion of lead and arsenic from shoreline sediments at recreational beaches from the Idaho border to Upriver Dam are of primary concern, particularly for children playing in the sand. Lead exposure can have multiple effects, including causing behavior and learning problems in children, nervous system damage, kidney damage, and reduced growth. Arsenic can also have multiple effects, including cardiovascular disease, stroke, and changes in the skin.

Elevated levels of lead are present in Spokane River fish tissue. The current fish advisory, see page 8, provides guidance for consumption.

Metals Cleanup and Restoration

Ecology-guided cleanup activities of metals-contaminated shorelines began in 2006. Cleanup of Island Complex, Starr Road, Murray Road and Harvard Road North locations are now complete. A combination of digging out (removal) of contaminants, capping (isolation) of contaminants, and general improvements to these shoreline recreational areas reduced public exposure to metals such as lead and arsenic, while improving public access and river habitat.

Between 2009 and 2013 cleanup of Barker Road South, Barker Road North, Flora Road, Myrtle Point, and Island Lagoon recreational areas is planned.

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