US Army Corps of Engineers
St. Paul District

Public Notices

Special Public Notice Regarding Clean Water Act Section 404 Public Hearing and Submission of Public Comments for the PolyMet Project (1999-05528-JKA)

NOTE: Public Notice extended to December 31, 2015

This is a Notice of Availability of Final Environmental Impact Statement and Supplemental Notice for Section 404 Permit Application providing additional information regarding opportunities for public comment on the proposed discharge of dredged and fill material into waters of the U.S. associated with the PolyMet Mining Inc. proposed NorthMet Project.

Project Description and Purpose: A joint federal/state Final Environmental Impact Statement has been prepared by the U.S. Army Corps of Engineers, St. Paul District; the U.S. Forest Service, Superior National Forest; and the Minnesota Department of Natural Resources that describes the anticipated environmental and socioeconomic impacts of the proposed PolyMet Mining, Inc. NorthMet Project and Land Exchange.

Polymet Mining – Section 404 permit status

The U.S. Army Corps of Engineers, St Paul District, completed its Record of Decision and issued an individual permit to PolyMet Mining, Inc., for its NorthMet project March 21, 2019. The permit authorizes the discharge of dredged and fill material into 901 acres, and indirect impacts to 27 acres, of waters of the United States in association with the construction and development of the NorthMet mine, which is located in St Louis County, Minnesota.

The Corps' evaluation of the project was for construction-related impacts to wetlands, specifically the discharge of dredged or fill material into waters of the U.S.

The applicant purchased 1,278 credits from the Lake Superior Wetland Bank to offset wetland loss. 

The Corps, and its co-lead agencies, U.S. Forest Service and Minnesota Department of Natural Resources, worked to ensure the project complies with all applicable laws.  The agency is confident in its decision, having identified an appropriately balanced alternative and proffered a permit that will allow access to an important mineral resource while maximizing protection to natural resources including wetlands.

Application process/history

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The Corps of Engineers, St. Paul District, and its partners – the U.S. Forest Service and the Minnesota Department of Natural Resources – worked together to develop a comprehensive, robust Final Environmental Impact Statement, or FEIS, for the proposed PolyMet mining project near Hoyt Lakes, Minnesota.

The agencies reviewed and responded to public comments from three public meetings, to include a Corps public hearing in Duluth, Minnesota. In addition, the Corps, and its partners, collectively received more than 58,000 submissions and thematically responded to approximately 17,000 unique comments from the public engagement and Supplemental Draft EIS review.   

The agencies have publicly released the NorthMet Mining and Land Exchange FEIS. Completion of the nearly 3,000-page environmental document signifies a major step forward in the review process, which has been thoughtful, independent and thorough. Despite the FEIS being released, no permit decisions have been made.  After the environmental review process is complete, the project will still need to receive local, state and federal approvals and permits in order to proceed. This includes the Corps’ Department of the Army permit.
The PolyMet Mining Company is proposing to develop a copper-nickel mine. The open pit mine, waste rock stockpiles and other mine-site facilities would disturb around 1,400 acres. The least reactive waste rock would be stored in a permanent stockpile adjacent to the mine. The most reactive waste rock would be stored temporarily in lined surface stockpiles and then backfilled into the mine pit and permanently stored under water. Ore processing would take place at the former LTV Steel Mining Company’s taconite ore processing plant. The plant would need to be refurbished and modified to process base and precious metal sulfide ore. PolyMet has estimated the project would have direct impacts on about 900 acres of wetlands. Most of these wetlands at the mine site abut the Partridge River, which is part of a tributary system to Lake Superior. The potential for elevated levels of sulfate and metals in drainage water from the open pits, stockpiles and tailings basin is a concern.
PolyMet Mining, Inc., has proposed to construct and operate an open pit mine approximately 6 miles south of Babbitt in St. Louis County, Minnesota. The ore from this mine would be hauled approximately 8 miles west on an existing railroad line for processing in an idle taconite ore processing plant. The processing plant is approximately 6 miles north of Hoyt Lakes, Minnesota. The ore would be crushed and processed to extract copper, nickel, cobalt and precious metals by flotation, dissolution and precipitation. The waste from the mine, or tailings, would be discharged into an existing taconite tailings basin. 

PolyMet News Releases

Corps of Engineers issues permit for PolyMet’s NorthMet mine project
3/22/2019
ST. PAUL, Minn. – The U.S. Army Corps of Engineers, St Paul District, completed its Record of Decision and issued an individual permit to PolyMet Mining, Inc., for its NorthMet project late yesterday,...
Corps of Engineers, partners, complete PolyMet Mining EIS
11/6/2015
ST. PAUL, Minn. – The U.S. Army Corps of Engineers, St. Paul District, in partnership with the U.S. Forest Service and the Minnesota Department of Natural Resources, have completed the PolyMet Mining...
Corps of Engineers reminds everyone that public comments for the proposed PolyMet project closes March 13
2/27/2014
ST. PAUL, Minn. – The U.S. Army Corps of Engineers, along with the U.S. Forest Service and the Minnesota Department of Natural Resources, are reminding everyone that the NorthMet Mining Project and...
Corps of Engineers to host public hearing and meetings on PolyMet Mining environmental documents
12/16/2013
ST. PAUL, Minn. – The U.S. Army Corps of Engineers, St. Paul District, assisted by the U.S. Forest Service and the Minnesota Department of Natural Resources, is hosting a public hearing for the...
Corps of Engineers, partners nearly complete with PolyMet environmental impact statement
8/23/2013
ST. PAUL, Minn. – The U.S. Army Corps of Engineers, St. Paul District; the U.S. Forest Service; and the Minnesota Department of Natural Resources, or DNR, announced today, Aug. 23, that the they will...

Contact information

U.S. Army Corps of Engineers
St. Paul District, Regulatory Branch
180 5th Street E, Suite 700
Saint Paul, MN 55101

Phone: (800) 290-5847
Email: mvp-reg-inquiry@usace.army.mil 

Related Sites

Minnesota Department of Natural Resources
(includes fact sheets, maps and additional MnDNR information)

U.S. Forest Service