A newly released Washington Department of Ecology study on PCBs in the Spokane River concludes that significant reductions in polychlorinated biphenyls levels have occurred over the last two decades but concentrations still don’t meet state and Spokane Tribal standards.
The “Spokane River PCB Source Assessment” found that PCB levels in the Spokane River increase in successive reaches of the river from the Idaho border downstream to Long Lake Dam at the southern end of Lake Spokane.
Polychlorinated biphenyls are a family of human-made, chlorinated chemical compounds that were once widely used in a variety of applications such as insulating fluids for electric transformers and capacitors. The U.S Environmental Protection Agency banned all production of PCBs in 1979.
The Ecology data, collected between 2003 and 2007, indicate that substantial reductions in PCB levels have occurred in fish from most parts of the river since previous samples were collected in the 1990s. The reductions may be due to improvements made at industrial and municipal facilities over the past 10 to 15 years, in addition to natural break-down.
However, current levels in most parts of the Spokane River are still elevated compared to other freshwater areas in Washington.
“It’s true that PCBs do gradually break down over time and the river is receiving fewer PCBs than in the past,” said Rob Duff, who manages Ecology’s Environmental Assessment Program statewide. “However, PCBs break down slowly and the PCBs still entering the river continue to accumulate in fish. As time and nature work to reduce PCBs in the river, we can assist that process by finding the remaining PCB sources that are high in order to reach our goal of a cleaner, healthier Spokane River.”
The study indicates that to protect human health, all sources of PCBs would have to be reduced by more than 95 percent. This includes reductions in the river at the Idaho border and sediment deposits.
The study says that while it is unclear whether these drastic reductions will ever be realized, it is clear that further reductions of PCBs in the river is likely obtainable and is worth the effort.
Researchers found that PCBs in Washington reaches of the river come from the following sources: contaminated stormwater in the city of Spokane (44 percent); municipal and industrial discharges (20 percent); Idaho at the state line (30 percent) and from the Little Spokane River (six percent). PCBs deposited in sediments from historical discharges also find their way into fish.
The fact that concentrations in fish at the Mission Park reach have not declined like other reaches of the river is evidence that urban stormwater is a major source of PCBs.
State and local health officials have issued fish consumption advisories along the entire Spokane River, leading them to recommend that people avoid eating any fish taken from the Idaho border to Upriver Dam. Other advisories also are in effect. Go to: www.doh.wa.gov/fish
on the state Department of Health website for details.
“While fish consumption advisories may still be necessary in the future, it’s not right that people need advice on how to eat fish” Duff said. “They should be able to catch it and throw it in the pan. Reducing sources in a targeted way, informed by good data, needs to continue so that fish are safe to eat.”
PCBs can cause behavior and learning deficits in children exposed while in the womb, so meal limits of certain fish are especially important for women of child-bearing age and for young children.
Jim Bellatty who manages Ecology’s Water Quality Program in Eastern Washington said, “PCBs are everywhere and come from many diverse sources. We have to be creative and use all the tools we have. This is something water managers are facing all over the country, and the problem won’t go away overnight. All of who live and work near the Spokane River need to work together.”
The source assessment study serves as the basis of Ecology’s ongoing efforts to decrease toxics in the environment, specifically the Spokane River. The “Spokane River Toxics Reduction Strategy” outlines several actions the state is taking to reduce PCBs and other toxic chemicals in the river.
Some of Ecology’s actions include:
-- The Urban Waters team is tracing outlet pipes up from the river through the wastewater systems to find the sources of higher concentrations of PCBs. These investigations focus on identifying businesses and other activities that contribute PCBs to the wastewater system and reducing those contributions through cleanups and better business practices.
-- Ecology continues to eliminate historical sources through the state Toxics Cleanup Program.
-- Ecology is assessing the need for the further reduction of PCBs in effluent discharges and bringing dischargers to the table to identify ways to make improvements.
-- The 2011 discharge permits will be issued soon to the four Washington dischargers to the Spokane River. They will include PCB monitoring requirements to better understand from where they are coming. Future permits will have numerical limits on the PCBs that can be discharged.
The results of Washington’s study will be discussed at the Spokane River Forum, May 23-24, at the CenterPlace Regional Event Center in the Spokane Valley. See www.spokaneriver.net/conf
For more information go to the Spokane River Toxics Reduction Strategy at http://www.ecy.wa.gov/geographic/spokane/spokane_river_basin.htm