Thank you for the opportunity to comment on the Draft Environmental Assessment for exploration activities at the Black Butte Copper Project. Please accept these comments on behalf of Earthworks, a non-profit conservation organization.
The proposed project is at the headwaters of the Smith River, one of the most treasured streams in Montana for its premier recreational opportunities, beautiful scenery and renowned trout fishing.
Given the acid-generating qualities of this ore-body and the value of the downstream resource, the proposed Black Butte exploration project merits rigorous review and the most protective measures.
Our most significant concern is the lack of detail in how wastewater from the site will be managed and treated. The EA provides various options for how water might be managed, but there isn’t a specific detailed plan. Furthermore, the EA states that “kinetic humidity cell tests are ongoing and water treatment systems are under design, so Tintina cannot quantitatively predict the chemistry of water that would be land applied using the LAD system” (EA p. 53). Without this information, the EA can’t effectively evaluate potential water quality impacts, mitigation measures, or determine whether impacts are significant.
We’re also concerned that the EA doesn’t provide specifics for how wastewater will be managed in the event that Tintina seeks an operating permit after the decline is complete. The permit application and EIS process may take years to complete. During this time the exposed decline walls and waste rock will likely be an ongoing source of acid or metals leaching, which will require management and treatment.
It appears that the LAD systems may ultimately discharge to wetlands/surface water. What hydrologic analysis has been done to determine whether these discharges will ultimately report to surface water, and whether surface water quality will be impaired? Additional analysis should be done to evaluate the capacity of the LAD systems to manage flows and various contaminants. A mile-long underground tunnel into acid generating rock at the headwaters of the Smith River is a significant proposal. Water quality impacts from hardrock mines are notoriously difficult to predict. Montana mines with acid mine drainage have resulted in severe impacts to surface and groundwater quality.1 The State of Montana needs to do a better job of identifying these impacts up front rather than after the impact has occurred. For these reasons, we believe an Environmental Impact Statement (EIS) is warranted.
The EIS should include a thorough analysis of the potential impacts to water quality, and detailed plans for water management and treatment that extends over a 3-5 year timeframe to account for managing seepage in the event the company files for an operating permit.
We support the agency-mitigated alternatives that include a geotextile liner for the NAG stockpile and the additional water quality monitoring of water discharging to the LAD systems, but we believe that those should be incorporated within the alternatives analysis of the EIS process.
We also ask that MDEQ include the bond calculation in the EIS. Given Tintina’s lack of financial resources, the bond amount needs to ensure that the cost of all aspects of exploration, reclamation and long-term water treatment are covered. The public ultimately bears the liability for these costs, therefore the public should have the opportunity to comment on the bond amount as part of the EIS process.
Thank you again for the opportunity to comment. More detailed comments are below.