It’s been an “interesting” spring up at the old Triumph mine site near Sun Valley – and not in a good way. The Wood River Valley saw above-average snowfall this winter, leading to a 199% of average snowpack going into May followed by above-average runoff this spring. For the Triumph area, that meant more water than usual on site and high groundwater tables, leading to local groundwater interacting with and leaching metals out of the mine tailings pile. This interaction caused bright orange water to percolate out of the ground in a ditch next to the tailings pile and higher volumes of other mine-related water being discharged near the East Fork Big Wood River.
Once ICL became aware of these issues in early May, we contacted the Idaho Department of Environmental Quality (IDEQ) and went out on site with their staff to discuss the ongoing water quality concerns. These issues were recently summarized in a front-page piece in the Idaho Mountain Express. Although the runoff issues observed on site this spring are quite troubling, the silver lining is that it puts a renewed spotlight on the need for accelerated cleanup efforts at Triumph. IDEQ did collect samples of both the discolored tailings water and potential discharge pond water near the East Fork; we are still waiting on those results.
To get a better handle on how water contamination is occurring on site, IDEQ is currently sampling an expanded network of groundwater monitoring wells on a quarterly basis for the next couple of years. The ultimate remediation solution at Triumph will likely require 1) significant source control measures to prevent clean groundwater in the area from interacting with the tailings pile and 2) a Clean Water Act discharge permit (known in Idaho as an IPDES permit) with enforceable limits for arsenic and other metals discharged into the East Fork. ICL compelled the State of Idaho to apply for a discharge permit through a legal settlement spurred on by a lawsuit ICL filed in 2018 alleging illegal pollutant discharges from the mine site without a permit. 
We’ve written about the ongoing contamination issues at Triumph several times before on our blog (e.g. in 2022 and 2021) and the site remains Idaho’s poster child for what can go wrong if mining projects don’t have sufficient financial assurance to pay for cleanup efforts if (or when) the mining company goes bankrupt.
ICL remains committed to holding the State accountable to remediating the Triumph site to ensure water quality is protected in the area. We will continue to advocate that IDEQ and the Idaho Department of Lands receive the funding they need in their annual budgets to complete this cleanup work in a timely and comprehensive manner.
If you are looking to take action right now against mining pollution, we urge you to speak up for strong repercussions for a mining company in the Silver Valley in North Idaho that has been discharging illegally high levels of arsenic into the South Fork Coeur d’Alene River.