The Department of Natural Resources is seeking comments, from Sept. 15 through Oct. 16, on two draft dam safety permits and a draft public waters work permit for the Poly Met Mining, Inc. (PolyMet) NorthMet mining project. The permits relate to a proposed copper-nickel mine near Hoyt Lakes in northeastern Minnesota.
This is the public’s opportunity to submit written comments on these draft permits.
One draft dam safety permit covers the proposed flotation tailings basin, which would receive tailings (a mixture of finely ground waste rock and water) after the commercially recoverable copper, nickel and other elements are removed. This proposed tailings basin would be on the site of the existing tailings basin of the historic LTV iron ore mine.
The second draft dam safety permit covers the proposed hydrometallurgical residue facility, which would receive residue (mostly gypsum) generated from a process that would use pressure and temperature reactions to extract additional precious metals beyond what can be achieved by the primary processing facility.
PolyMet initially submitted its dam safety permit applications in July 2016. Since then, the DNR, its external consultant Emmons Olivier Resources, Inc. (EOR), and a team of top geotechnical dam safety experts assessed the design, construction, operation, and maintenance of the proposed NorthMet dams. This team included experts in mining geotechnical engineering with both Minnesota and worldwide experience. The group included a member of the review panel that previously investigated the Mount Polley dam failure in British Columbia.
The DNR considered input from state, local, and tribal government technical experts. The applications have been used to create the two draft dam safety permits, which the DNR is now releasing for public comment.
The DNR dam safety permit program regulates the construction, operation, and maintenance of Minnesota dams to protect public health, safety and welfare. Minnesota rules establish standards and criteria for dams, which cover both initial permitting and ongoing regulatory oversight.
PolyMet also submitted an application for a public waters work permit in May 2017. The DNR recently completed its comprehensive review of this application, and considered input from state, local, and tribal government technical experts to create the draft public waters work permit.
The draft public waters work permit is for a culvert extension to widen Dunka Road, the connecting road between the proposed NorthMet plant site and mine site. It would extend the culvert on Unnamed Creek, which is a tributary to Wyman Creek, a public water.
The DNR public waters work permit program applies to public water basins, wetlands, and watercourses. A public waters work permit may be required for proposed projects that affect the course, current, or cross-section of public waters.
The DNR is seeking public comments on these three draft permits before making any permitting decisions. Commenters should include the words “NorthMet Dam Safety” or “NorthMet Public Waters” in the title of their comment emails or letters.
Written comments may be submitted no later than Oct. 16, by email to:
NorthMetPermitting.DNR@state.mn.us or by U.S. mail to:
MN Department of Natural Resources
ATTN: PolyMet NorthMet Project
500 Lafayette Road N, Box 45
St. Paul, MN 55155-4045
In addition to the two dam safety permits and the public waters work permit, the project would need nine additional DNR permits, as well as several other state, federal and local permits and approvals in order to proceed.
The DNR permits and approvals that are needed before the proposed NorthMet project could proceed, include the permit to mine (including financial assurance and wetlands replacement), water appropriation permits, dam safety permits, public waters work permit, burning permit, and an endangered species takings permit. A timeline of the permitting process is available from the DNR’s PolyMet website.
PolyMet’s dam safety and public waters work permit applications, along with DNR’s draft permits and fact sheets, are available on the State’s PolyMet Portal (click on the DNR link).