NorthMet Supplemental Draft Environmental Impact Statement (SDEIS)

State and federal environmental review of the proposed PolyMet Mining Inc. project


A comprehensive environmental analysis of Minnesota’s first proposed copper-nickel mine has been released for public review and input. The Minnesota Department of Natural Resources, U.S. Army Corps of Engineers, and U.S. Forest Service are seeking public review and input on the SDEIS.


Review the SDEIS

Download complete SDEIS or individual chapters »

There are copies available for public review at several locations. Limited hard copy versions and CDs are also available.

Public Meetings and Commenting

The comment period closed on Thursday, March 13, 2014.

Comment period will not be extended.
Learn more »

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Fact Sheets

We've prepared the following Fact Sheets (downloadable PDFs) to assist you in the review of the SDEIS. More detailed information can be found in the accompanying links.

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Project and Land Exchange Overview

What is the Environmental Review Process?

What's Changed since the DEIS?

Effective Commenting

A Guide to the SDEIS Document

Threatened and Endangered Species

Land Exchange


Cumulative Effects


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Proposed NorthMet Mining Project and Land Exchange

Project Overview

Topics Reviewed for the NorthMet Environmental Impact Statement

Review of Topics

DNR News

01/13/2014: Duluth meeting provides opportunities for public comment on NorthMet Supplemental Draft EIS Full story

12/06/2013: State and federal agencies release NorthMet Supplemental Draft Environmental Impact Statement, opening public comment period Full story

08/23/2013: DNR announces publication date for draft NorthMet environmental review document Full story



The NorthMet Project would create an open pit copper, nickel, cobalt and precious metals mine with adjacent stockpile areas; refurbish a portion of the former LTV Steel Mining Company (LTVSMC) processing plant and construct a new hydrometallurgical facility at the plant site; construct a new tailings basin facility on the site of LTVSMC tailings facilities; and add to existing utility infrastructure and rail lines. The Land Exchange would consist of USFS conveyance of Superior National Forest Lands encompassing the NorthMet mine site and surrounding lands to PolyMet, and USFS acquisition from PolyMet of up to five tracts of private lands within the Superior National Forest proclamation boundary. 


Partner links


The Land Exchange legal notice, identifying requirements under 36 CFR 218, is available on the Superior National Forest website, The Biological Assessment and Biological Evaluation for the proposed NorthMet project are also posted on the Superior National Forest website.


The USACE public notice for the SDEIS and public meetings, and the public notice for the USACE Section 404 Clean Water Act Permit, are available on the Army Corps of Engineers, St. Paul District website,


Earlier stages in the development of the EIS

Read about the 2009 Draft EIS and supporting documents.