Beneath the beautiful waves of tourist attraction Coeur d’Alene Lake lies a hundred years of toxic metal pollution. This pollution’s source is the historic mining communities of Silver Valley, the number one producer of silver in the United States. According to Kootenai Environmental Alliance (KEA), Coeur d’Alene Lake contains about 83 million tons of contaminated sediments.
“It’s important to understand that it’s from many, many mines,” NIC Environmental Science Professor Julie Van Middlesworth said. “I don’t think it’s going to go away.”
Between 1880 and 1980 the silver mining projects dumped tons of toxic materials, including cadmium, arsenic, lead and zinc, into surrounding water bodies.
Cadmium, arsenic and lead are poisonous to humans and animals, while zinc is toxic to aquatic organisms., according to Betty Kramer, environmental reporter, Spokesman Review.
“My dad has done projects to improve the quality of the water going into Coeur d’Alene Lake,” Caralina
Fischer, 22, Nursing, said. “I do think it poses a risk, because water is everywhere; it goes everywhere in the ground and people consume it.”
Despite its magnitude the pollution does not pose much of a problem during most of the year.
“The only time is a major problem is during the spring when it floods and there are a lot of suspended sediments,” Van Middlesworth said. “If it can stay down there at the bottom, undisturbed, and conditions don’t change, it’ll eventually be buried without health concerns.”
According to Idaho Department of Environmental Quality (DEQ), a major cleanup method is removing contaminated soil to replace it with clean. Idaho DEQ has an annual budget of $1 million to monitor the toxin levels in Coeur d’Alene Lake.
“It’s about containing the waste that’s already been produced,” Van Middlesworth said. “Right now there are no serious health effects because the pollution is generally associated with the sediments, you can still swim.”
Students who were unaware that the pollution existed were uneasy upon hearing about it.
“I can’t say I know much. There’s blue-green algae, I think, but I don’t know if that’s really pollution,”
Amber Stotz, 28, Accounting, said.
Hearing that it was specifically metal pollution brought greater concern.
“I never was a swimmer, but now I’d feel worse about swimming,” John “Risky” Boltz, 27, Film, said. “It could be a big problem.”
As Van Middlesworth explained, while the lake is rich in oxygen, the pollutants remain in the sediment.
But excess phosphorus and nitrogen nutrients can cause too much plant growth, which reduces the water’s oxygen concentration causing the toxins to become suspended in the water.
“People tend to get complacent and think they’re not directly affecting the lake, but they are,” Van Middlesworth said. “You’re not supposed to be mucking around in the sediment for a reason.”
Van Middlesworth recommends that those enjoying the lake should try not to disturb the sediments and wash up afterward.
The metal pollution is here to stay, but with caution and awareness, Coeur d’Alene can continue to use its lovely lake.
