The Montana DEQ wants to know more about the proposed Black Butte Mine operation and tailing facilities and their potential to contaminate surface water, ground water, and harm the Smith River.
In late 2015, Canadian Tintina Resources applied for a permit to develop the Black Butte Copper Mine, a large copper mine directly adjacent to and underneath Sheep Creek at the headwaters of the Smith River in central Montana. After a 90-day initial review of tests and studies performed by Tintina the Department of Environmental Quality (DEQ) has issued a ‘deficiency letter’ outlining a number of matters to be corrected or clarified and where further data is required in support of its effort to open a new copper mine.
In a good faith effort to both assist DEQ in a thorough review and to ensure critical, missing data and science is identified and required before the permit process moves any farther, Upper Missouri Waterkeeper partnered with American Rivers in hiring expert scientists to review the mining plan and potential impacts to geochemistry, water quality and quantity, and fisheries.
Our expert found incomplete data on water rights, groundwater modeling, long-term treatment of tailings, and the discharge potential of harmful effluent from the mine.
Notably, Tintina’s data collection did not follow appropriate protocols, and information was not provided on the value of Sheep Creek as a spawning tributary to the Smith River/Missouri River. Missing too, is data for aquatic communities and their habitats for significant streams put at risk from spills or otherwise affected by hauling of copper concentrate to rail heads, including Deep Creek and the Shields River.
Acid Mine Drainage
The proposed mine will have to dig into sulfide minerals, which when exposed to air and water, can react to form sulfuric acid in a process known as acid mine drainage. Acid mine drainage is highly toxic to fish and other aquatic life. Nearly half the tailings left over from the proposed mine will be kept down in the mine.
It appears the tailings impoundment will be excavated below the groundwater table, increasing risk to impoundment stability and potentially accelerating leaching of metals and acid if groundwater infiltrates the liner system. Information is absent regarding extra engineering precautions that prevent groundwater infiltration of the impoundment. Tintina’s application provided insufficient data to determine whether acid mine drainage and metals leaching from mine waste stored in the tailings facility and underground tunnels will be effectively prevented and/or contained in perpetuity.
Impacts on Water Table
Groundwater pumping from the proposed mining activities could potentially lower the water table, and create a “cone of depression” that extends to the Sheep Creek alluvium – posing a threat to adjacent stream flows. The Smith River, and Sheep Creek, already suffer from low flows during most years, putting pressure on downstream aquatic life and agricultural activities. Tintina’s groundwater modeling contains major errors and is insufficient to estimate mine dewatering rates or determine impacts to stream flows. Because the groundwater hydrology is so complex, there aren’t enough monitoring wells to provide sufficient information on groundwater flows or quality to determine impacts after mine development.
Steps Moving Forward
Once DEQ receives a response from Tintina, they will have just 30 days to review all of the new data as opposed to the 90 days allotted for initial review. The 30-day timeframe is far too short a period for DEQ to thoroughly review the big missing pieces because of data complexity and the breadth of information that must be considered. These abbreviated timetables are the unfortunate result of special interest group lobbying in our state legislature and speak to the strong need for citizens to speak up at every turn on behalf of their favorite rivers.
Following the technical completeness review, the next step is specific scrutiny of potential environmental impacts pursuant to the Montana Environmental Policy Act (MEPA). There will be further opportunities for public and scientific input during the MEPA scoping and drafting process.
Wrong for Montana
Tintina claims to be creating wealth for society stating, “We all need this. Anytime we can get a hold of an opportunity to advance it to the point where it’s creating wealth, that’s great for everyone.” In reality, the Black Butte Mine would create just 200 jobs and operate 11 to 14 years, and many of those jobs are specialized, meaning out-of-state workers would likely be hired.
Tintina owns multiple mineral deposits in several other sites in the same watershed and has projected 50 years of mining in Central Montana. This means the proposed copper mine could very well be the tip of the iceberg, where one short-term, risky mine turns out to be the beginning of a new mining district in the Little Belt Mountains.
Montana has a long legacy of mining projects that have degraded our rivers and streams, and cost taxpayers millions of dollars in ongoing clean-up. The Smith River is too special a place to put at any risk from any type of mine.