carimmohelp: PolyMet Updates Status of Environmental Review

ST. PAUL, MINNESOTA, Feb 01, 2012 (MARKETWIRE via COMTEX –
PolyMet Mining Corp.

(«PolyMet» or the
«Company» today reported continued progress toward completion of the
environmental review of its NorthMet project. PolyMet controls 100%
of the development-stage NorthMet copper-nickel-precious metals
ore-body and the nearby Erie Plant, located near Hoyt Lakes in the
established mining district of the Mesabi Iron Range in northeastern
Minnesota.

The Minnesota Department of Natural Resources («DNR» and the U.S.
Army Corps of Engineers («USACE» published a draft Environmental
Impact Statement («EIS» on the project in November 2009. Since then,
several critical tasks have been completed, including:

          --  Evaluation of all comments on the draft EIS, including extensive             comments by the US Environmental Protection Agency ("EPA"         --  Incorporation of the proposed land exchange with the US Forest Service             ("USFS" into the project EIS process, with the USFS joining the DNR and             USACE as a Co-Lead Agency.         --  EPA participation in the review process as a Cooperating Agency         --  Changes to the project to reduce its impact on the environment and             enhance the economics

Asupplemental draft EIS («SDEIS» will describe in detail the project
that PolyMet plans to build, analyze the environmental impacts, and
demonstrate that the project complies with all current, relevant
state and federal environmental standards.

«The agencies are guiding an extremely rigorous environmental review
process, and we are committed to working with them to provide the
hard data they need to make decisions both for the EIS and for
subsequent permitting,» said Brad Moore, PolyMet’s Executive Vice
President of Governmental and Environmental Affairs.

Mr. Moore continued, «We believe the level of detailed engineering
being incorporated into the SDEIS will provide a clear and thorough
analysis of the project and its potential impact on the environment,
as well as supporting completion of project permitting.»

EIS Status Update

ERM, the Lead Agencies’ environmental consultant, has completed a
significant amount of work on the SDEIS, which will comprise nine
chapters. The first four chapters, comprising over 400 pages and
including more than 100 figures, have been drafted and are being
reviewed by the Lead Agencies.

Other important milestones already achieved include:

          --  Approval of air emission estimates.         --  Approval of cumulative visibility, acid deposition, and fiber impact             evaluation reports.         --  Completion of geotechnical stability modeling with results now under             review.         --  Completion of direct wetland impact evaluation and wetland mitigation             plans, which are now under review.         --  Completion of hazardous materials assessment; threatened, endangered and             sensitive species analysis; assessments of wildlife and heritage             resources; and wetland/floodplain analysis reports for the lands             involved in the land exchange, which have been delivered to the USFS for             review.         --  Delivery by PolyMet of updated project documents including the detailed             project description, mine plan, reclamation and waste disposal plans,             and extensive data packages.

As SDEIS preparation moves into the final stages, the Lead Agencies
have completed a detailed assessment of tasks outstanding and the
timeline. The key task is completion of detailed environmental
modeling, including quality assurance plans as well as generation,
verification, review, and documentation of modeling data.

The Lead Agencies expect that all aspects of modeling will be
completed in the spring of 2012, with the preliminary SDEIS available
for review by the Cooperating Agencies during the summer, and public
review and comment in the fall of 2012.

Frank Sims, Co-Chairman of the Board of PolyMet observed, «Completion
of the environmental review is a complex process. While the timeline
has been challenging, we are encouraged by the commitment of the
Agencies to produce a strong EIS and have growing confidence about
the path to completion.»

About PolyMet

PolyMet Mining Corp. (
www.polymetmining. com is a publicly-traded
mine development company that controls 100% of the NorthMet
copper-nickel-precious metals ore body through a long-term lease and
owns 100% of the Erie Plant, a large processing facility located
approximately six miles from the ore body in the established mining
district of the Mesabi Range in northeastern Minnesota. PolyMet
Mining Corp. has completed its Definitive Feasibility Study and is
seeking environmental and operating permits to enable it to commence
production. The NorthMet project is expected to require approximately
one-and-a-quarter million hours of construction labor and create
approximately 360 long-term jobs, a level of activity that will have
a significant multiplier effect in the local economy.

POLYMET MINING CORP.

Joe Scipioni, CEO

This news release contains certain forward-looking statements
concerning anticipated developments in PolyMet’s operations in the
future. Forward-looking statements are frequently, but not always,
identified by words such as «expects», «anticipates», «believes»,
«intends», «estimates», «potential», «possible», «projects», «plans»,
and similar expressions, or statements that events, conditions or
results «will,» «may,» «could,» or «should» occur or be achieved or
their negatives or other comparable words. These forward-looking
statements may include statements regarding our beliefs related to
the expected proceeds and closing of the registered direct offering,
exploration results and budgets, reserve estimates, mineral resource
estimates, work programs, capital expenditures, actions by government
authorities, including changes in government regulation, the market
price of natural resources, costs, or other statements that are not a
statement of fact. Forward-looking statements address future events
and conditions and therefore involve inherent risks and
uncertainties. Actual results may differ materially from those in the
forward-looking statements due to risks facing PolyMet or due to
actual facts differing from the assumptions underlying its
predictions. PolyMet’s forward-looking statements are based on the
beliefs, expectations and opinions of management on the date the
statements are made, and PolyMet does not assume any obligation to
update forward-looking statements if circumstances or management’s
beliefs, expectations and opinions should change.

Specific reference is made to PolyMet’s most recent Annual Report on
Form 20-F for the fiscal year ended January 31, 2011 and in our other
filings with Canadian securities authorities and the Securities and
Exchange Commission, including our Report on Form 6-K providing
information with respect to our operations for the year ended January
31, 2011 for a discussion of some of the risk factors and other
considerations underlying forward-looking statements. PolyMet’s
Quarterly Report for the three months ended April 30, 2011 included a
detailed description of the transition to IFRS.

The TSX has not reviewed and does not accept responsibility for the
adequacy or accuracy of this release.

          Contacts:         PolyMet Mining Corp. - Corporate         Douglas Newby         Chief Financial Officer         +1 (651 389-4105         dnewby@polymetmining.com          PolyMet Mining Corp.  - Media         LaTisha Gietzen         VP Public, Gov't  Environmental Affairs         +1 (218 471-2157         lgietzen@polymetmining.com          PolyMet Mining Corp. - Investors         Crystal Agresti         +1 (651 389-4104         cagresti@polymetmining.com          PolyMet Mining Corp. - Investors         Alex Macdougall         +1 (226 663-3000         amacdougall@polymetmining.com  www.polymetmining.com

SOURCE: PolyMet Mining Corp.

          mailto:dnewby@polymetmining. com         mailto:lgietzen@polymetmining.com         mailto:cagresti@polymetmining.com         mailto:amacdougall@polymetmining.com  http://www.polymetmining.com