In Response: Column critical of Twin Metals was just more anti-mining misinformation
From the column: "Suggesting concentrates from the Twin Metals mine could hypothetically create an acid mine drainage problem for someone else was nonsensical."
The Feb. 4 commentary in the News Tribune, “Magical thinking not a plan for Twin Metals, acid rock drainage,” was another example of the misinformation that continues to be spread by mining opponents about the copper-nickel industry and about the proposed Twin Metals Minnesota project.
(The commentary was in response to my column in the News Tribune on Jan. 14, headlined, “Acid rock drainage a nonissue with Twin Metals mine.”)
First, the suggestion in the Feb, 4 column that Twin Metals does not have a plan was both false and disrespectful to the communities, employees, and contractors the company has supported through its investment of $530 million to date. In fact, Twin Metals spent more than a decade developing a plan to mine, which was submitted to state and federal agencies in 2019.
Ironically, the actions of opponents have prevented the publication and evaluation of Twin Metals’ plans, as they would be available for all to review as part of the multiyear state and federal Environmental Impact Statement process. Opponents aim to prevent the very process designed to analyze all the scientific data for which the opponents are calling.
Implying that Twin Metals has no details about its mineral deposit was also misleading. The geochemical characterization program conducted to date of the ore, waste rock, and tailings is highly comprehensive and exceeds global guidelines. The purpose of the environmental-review process is for agencies to review this and all other data submitted by the company, in detail.
The column mentioned issues with tailings ponds, which is irrelevant for Twin Metals, because it will have no tailings ponds and no tailings dam. Instead, filtered tailings will be placed and compacted as an engineered landform, which eliminates the potential for tailings flow. This methodology meets the recommendations from the investigative panel that studied the Mount Polley tailings breach. Contrary to the column’s assertions, the design of the dry stack is considered “Maximum Credible Earthquake,” and the dry stack would not experience liquefaction or flow. Additionally, Twin Metals’ tailings do not have the potential for acid rock drainage generation.
Finally, suggesting concentrates from the Twin Metals mine could hypothetically create an acid mine drainage problem for someone else was nonsensical. The concentrates containing the sulfur are shipped off-site to processing facilities for refinement to ultimately be used as a commercial product.
The Twin Metals project and the copper-nickel industry have the potential to bring tremendous growth and benefits to northern Minnesota. Therefore, it is important for all of us to better understand the facts that show how modern mining can be done safely and responsibly.
Rens Verburg of Redmond, Washington, is a principal geochemist at Golder Associates USA (golder.com), with more than 30 years of experience in the geochemical evaluation of mining issues. He was project director for the development of the Global Acid Rock Drainage (GARD) Guide for the International Network for Acid Prevention. The GARD Guide (gardguide.com) is a worldwide reference for best practices in preventing acid rock drainage.