The Idaho Department of Environmental Quality (DEQ) has released a five-year report on the status of an abandoned mine near Triumph, an unincorporated town southeast of Ketchum, home to about 65 people.
A silver, zinc and lead mine operated there last century, and since the mid-1990s, DEQ has led a cleanup effort.
The greatest concerns on the site have historically been contaminated soils, tailings and minerals like arsenic in waterways.
In the announcement of the standard, five-year review, for which it is seeking public comment until November 8, the department said it conducted the report "because hazardous substances remain on site above levels that permit unlimited use and unrestricted exposure."
Since the last report was released five years ago, the department's work has included installing another plug on the mine tunnel to slow the flow of contaminated water. It also stabilized a collapsed section of a tunnel in 2018.
Contaminated water around the mine site continues to be an issue. Last fall, the Idaho Conservation League filed a lawsuit against DEQ and the Idaho Department of Lands that said mine pollutants were flowing into wetlands near the East Fork of the Big Wood River. The nonprofit argued this violated the Clean Water Act. The groups reached a settlement a month later.
The agreement, in part, increased attention to water monitoring in the area. Since 2014, DEQ has increased groundwater monitoring and has also tested several wells at nearby homes.
In an emailed statement to Boise State Public Radio, the Idaho Conservation League wrote, "We believe that the settlement agreement ICL reached with DEQ and IDL last October has put the state on the right path to remediating the Triumph mine site."
The organization pointed out that the state departments have applied for an EPA permit for the discharge of mining-impacted waters. "We have confidence that those additional remediation measures are a significant step in the right direction at Triumph."
Last year, DEQ secured $1.5 million from the state to continue work at the Triumph mine site over the next decade. Don Carpenter, a Senior Mining Scientist at DEQ, said more money may be needed to stabilize the tunnel in the long term, and to possibly add a third plug.
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