The kokanee salmon stocked in Mountain Lake more than 30 years ago contain two persistent organic pollutants: polychlorinated biphenyls (PCBs) and dioxin, according to the Washington State Department of Ecology Water Quality Assessment website.
The PCBs present are listed as a Category 5, the highest impairment category, since 2004, meaning samples taken from salmon’s tissue exceeded Washington state’s fish tissue-equivalent concentration — a concentration of 5.3 parts per billion of PCBs in fish tissue.
Washington has some of the more progressive standards in dealing with water toxicology than other states, DOE biologist Keith Seiders said.
But the numbers are confusing, according to DOE staff. Ecology Water Quality Unit Supervisor Chad Brown said the last time Mountain and Cascade lakes were sampled was in 2004 and 2008. However, every two years, the DOE is lawfully required to submit water quality assessment data to the Environmental Protection Agency, regardless of whether or not the data comes from new samples. If there is no new data, the same listing status is kept.
“The data gets reviewed every two years,” Brown said. “These tissue samples from Mountain Lake are part of a state toxic review from biologists around the state, which are separate from but used for a water quality assessment. The Department of Ecology is not going out and searching for specific data every two years, but we do have to submit to the EPA.”
Paul Kamin, general manager of the Eastsound Water Users Association, said that the water systems using water from Mountain Lake do infrequently test for PCBs and dioxins, and the results have been non-detect.
“It doesn’t mean that there’s not anything there. It means there’s not a public health risk associated with the potable water supplies [Doe Bay and Olga] that are using water from Mountain Lake, despite the fact that years ago they found higher than normal concentrations of PCBs in fish in the lake,” Kamin said. “But these toxins are real and persistent, which means they don’t break down. They accumulate up the food chain.”
Due to the cost variations in testing, technological limitations, a lack of resources at the state level and the fact that different species accumulate contaminants differently, measuring a chemical in both water and fish tissue is challenging.
“We cannot measure down to zero, because in any instrument in any kind of measurement one tries to make, when you get down to a small enough increment, there’s always going to be some background noise,” Seiders said. “You can measure down to some level of uncertainty. So for the samples taken from Mountain Lake and Cascade Lake in 2008, we couldn’t distinguish below 4.8 parts per billion in the measuring system. Our results came from one analytical method — measuring PCB Aroclors (a PCB mixture produced from approximately 1930 to 1979).”
“Using that method, everything came back non-detect. However, we also used a much more sensitive method to measure PCBs in fish only in Mountain Lake. That was the PCB congener method, which is a much more expensive method. Those levels in Mountain Lake were 10-11 parts per billion, which is above the 5.3 parts per billion threshold.”
The Department of Ecology and Department of Health use different parts per billion thresholds to help protect public health. The DOH typically doesn’t issue fish advisories until levels exceed 20ppb, whereas Ecology’s threshold for a Category 5 listing is 5.3ppb, used to regulate pollution in a water body.
In order to fulfill requirements in the federal Clean Water Act, the DOE must periodically assess the status of water quality in state water bodies to develop a water quality assessment for the EPA. The Clean Water Act also requires that states provide a list of impaired waters that are not meeting water quality standards. These are classified as Category 5, or a 303(d) listing, and require a water improvement project.
Mountain Lake is not alone. Ninety percent of fish sampled in Washington exceed the PCB levels allowed, triggering a 303(d) water quality listing under the Clean Water Act. The waters off of Friday Harbor and in Horseshoe Lake on Blakely Island also hold Category 5 listings on the Ecology website; the waters off of Friday Harbor for dissolved oxygen and Horseshoe Lake for total phosphorus.
Yet PCBs and dioxins, much like lead, are the most widespread contaminant nationally, as both are extremely persistent compounds that break down very slowly. Thus, they can pollute via atmospheric deposition, the process whereby precipitation particles, aerosols and gases move from the atmosphere to the earth’s surface. Although PCBs were banned in the U.S. by 1979, a large part of the current exposure is due to releases that occurred decades ago.
“They have molecules that like to cling to something. They are everywhere,” Seiders said. “Our Puget Sound orcas have some of the highest levels of PCBs than any other animal anywhere. Seals, polar bears, aboriginal peoples in the arctic — the PCB levels they have in their systems are the highest across the world because of high concentrations of fish in their diet.”
However, the state’s water and fish assessment model criteria indicates the risk level for eating fish is low.
“The idea is if the average human ingests one ‘dose’ of PCBs every day for 70 years, it will increase your risk of getting cancer one in a million. You have a higher risk of getting in a car accident than from getting cancer from eating fish.”
According to the Department of Health, there are health benefits to eating fish that outweigh the risk.
Seiders said, “We’re able to measure contaminants in fish because we’re authorized to under the Clean Water Act. If we were to go out and measure for PCBs in beef, pigs beans, we would certainly find the same amounts or more.”
Washington state’s goal is to reduce and phase-out persistent, bioaccumulative, and toxic chemicals such as mercury, PCBs, DDT, and dioxins which threaten human health and the health of the environment.
One of the ways the DOE seeks to do so is by developing water cleanup plans for Category 5s and reduce pollution sources throughout the surrounding watershed.
According to a site ranking for the 2004 Washington state fish tissue contaminant results, Mountain Lake was prioritized 20th out of 47 listings for clean up. Sites with the highest scores would be the highest priority for follow up actions.
“We assume it’s likely that due to Mountain Lake’s elevation, these contaminants are entering through the atmosphere,” Seiders said. “There’s no point source into the lake from a factory. However, if there’s a power line that runs through there and a transformer failed, that transformer could leak into the lake. It could come from runoff from car exhaust or illegal burning. As far as I know, no one has investigated that more fully. We’re not saying it is atmospheric deposition. It could be something else but it seems unlikely without further research.”
Kamin also posturized as to how PCBs are accumulating in fish tissue in Mountain Lake. “My theory is it might be partially due to the fact that Cascade Lake is heavily stocked with 6,000 fish each year. The life expectancy of a fish is much longer in Mountain Lake than it is in Cascade Lake.”
An email from a regional ecologist steward Julie Morse stated “there’s not much to do management wise, though it’s good for people fishing to be aware of this.”