Idaho reaches deal over abandoned silver-lead mine

The Sun Valley in central Idaho, where the Triumph Mine is located, as well as several ski resorts. Photo by Airman 1st Class Connor J. Marth, U.S. Air Force.

The state of Idaho and the Idaho Conservation League reached a tentative settlement around a lawsuit filed by the latter, whose members say Idaho officials are discharging arsenic and other pollutants from the abandoned Triumph silver and lead mine into the east fork of the Big Wood River.

Such actions would be in violation of the Clean Water Act.

This week, however, the activists and the regional government reached a deal that could see the state paying expensive cleanup costs for what’s left at the 60-acre site, located in the central Sun Valley. Rehabilitation work started 30 years ago after Asarco Mining filed for bankruptcy and paid the Department of Environmental Quality $1.7 million to take care of it.

Yet, according to the Associated Press, a mine tunnel and the tailings pond are both leaking. In addition to this, the EPA told the news agency that 1 million cubic yards of black sand left over from the defunct mine is laced with lead, arsenic, and zinc.

All of these situations would have to be solved by the state if the deal with the Conservation League is approved by a judge, following reviews by the EPA and U.S. Department of Justice. The agreement asks Idaho to apply for the federal permit, monitor the site, post several ‘no trespassing’ signs around a settling pond and possibly installing a treatment plant to treat the wastewater in perpetuity.