The massive mine-waste cleanup in the Coeur d’Alene River Basin will be broadened to make sure ecological contamination is addressed along with human health risks, officials from the U.S. Environmental Protection Agency said Tuesday.
In 1983, the EPA listed the Bunker Hill mining site in the Silver Valley – a 21-square-mile area referred to as “the Box” – as a Superfund site because of heavy metals contamination resulting from a century of mining activities.
In 2002, the agency issued a “record of decision” – essentially a roadmap for the cleanup – to address areas beyond the Box, throughout the 1,500-square-mile Coeur d’Alene Basin.
“In the Box, we’ve completed a lot of cleanup there. Most of that cleanup is related to human health,” said Angela Chung, the EPA’s basin cleanup team leader. “We called that Phase I. We are now looking at what we’re going to do as part of Phase II. (It) is meant to address more of the eco-concerns, specifically, dissolved zinc contamination in groundwater and surface water.”
Part of the reason for the wider focus was a 2005 recommendation from the National Academy of Sciences calling on the EPA to treat the basin cleanup more holistically – that is, as an entire, interconnected area. The record of decision will be changed to reflect that new goal, Chung said.
“The source of a lot of the problems in the lower basin come from the upper basin,” said Terry Harwood, executive director of the Basin Environmental Improvement Project Commission, created by state legislation in 2001 to oversee the cleanup. “This high water we had this year? The (contaminated) material came down again. It’s just pervasive. It’s all over in the whole basin.”
Recreation sites that have been cleaned include boat launches and parking areas along the Coeur d’Alene River, and at Rose, Anderson, Thompson and Killarney lakes, said Ed Moreen, an EPA environmental protection specialist in the Coeur d’Alene field office.
Moreen said that in Phase II of the project, the EPA will try to better understand the ecosystem in the lower river basin, stretching west from the Silver Valley to Lake Coeur d’Alene, to determine what cleanup projects should take priority.
The EPA collected sediment samples this spring, he said, after high waters receded, and found high levels of metals contamination.
“The material coming in at the confluence of the South Fork and the North Fork (of the Coeur d’Alene River) was contaminated,” Moreen said.
“But we also found that we had higher levels of contamination that were further downstream. It’s getting picked up and transported. … That’s really the focus of that lower basin … we want to enhance our understanding of that system.”
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