Minnesota PCA Posts PolyMet Draft Air Emission Permit

Draft permit is last state permit required for public meeting

ST. PAUL, Minn.–(BUSINESS WIRE)–The Minnesota Pollution Control Agency has informed Poly Met Mining
Inc., a wholly-owned subsidiary of PolyMet Mining Corp. (together
“PolyMet” or the “company”) TSX: POM; NYSE AMERICAN: PLM – that it has
posted the draft air emission permit and supporting permit documentation
on its website for the NorthMet copper-nickel-precious metals project.

The draft air emission permit is the last state permit required for the
upcoming public meetings in February.

The agency released the draft air emission permit to tribes and PolyMet
and posted it on its website for public review. As previously announced
by the MPCA, public meetings on the draft air and water permits and the
draft Permit to Mine will be held jointly with the Department of Natural
Resources on February 7 and 8, 2018, in Aurora and Duluth, respectively.
The public comment period for MPCA’s draft air emission and water
permits will begin prior to the February public meetings. The draft
Permit to Mine was released for public comment by the DNR on January 5,
2018.

The draft air emission permit describes how PolyMet will meet federal
and state air quality regulations and contains conditions that are
enforced by both the state and federal governments. It identifies the
sources on the site that could generate air emissions, details the
conditions under which the company must operate to control emissions,
and sets emission limits, monitoring and reporting requirements.

“We are delighted to see the last of the major state permits we have
applied for released as draft permits by the state, along with the draft
Section 401 Certification,” said Jon Cherry, president and CEO. “It has
been a long and difficult road, and we look forward to receiving the
agencies’ final decisions on these permits.”

The draft air emission permit posted by the MPCA, including related
conditions and other permit documentation, are found at https://www.pca.state.mn.us/northmet.

About PolyMet

PolyMet Mining Corp. (www.polymetmining.com)
is a publicly traded mine development company that owns 100 percent of
Poly Met Mining, Inc., a Minnesota corporation that controls 100 percent
of the NorthMet copper-nickel-precious metals ore body through a
long-term lease and owns 100 percent of the former LTV Steel Mining
Company site, a large processing facility located approximately six
miles from the ore body in the established mining district of the Mesabi
Iron Range in northeastern Minnesota. The NorthMet Final Environmental
Impact Statement was published in November 2015, preparing the way for
decisions on permit applications. NorthMet is expected to require
approximately two million hours of construction labor, create
approximately 360 long-term jobs directly, and generate a level of
activity that will have a significant multiplier effect in the local
economy.

PolyMet Disclosures

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 the ability to receive
environmental and operating permits, job creation, and the effect on the
local economy, or other statements that are not a statement of fact.
Forward-looking statements address future events and conditions and
therefore involve inherent known and unknown 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 risk factors and other considerations
underlying forward-looking statements discussed in PolyMet’s most
recent Annual Report on Form 40-F for the fiscal year ended January 31,
2017, and in our other filings with Canadian securities authorities and
the U.S. Securities and Exchange Commission, including our Report on
Form 6-K providing information with respect to our operations for the
three and nine months ended October 31, 2017.

The Annual Report on Form 40-F also contains the company’s mineral
resource and other data as required under National Instrument 43-101.

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

Click
here to subscribe to Mobile Alerts for PolyMet Mining Corp.

Contacts

PolyMet Mining Corp.
Media
Bruce Richardson, +1
651-389-4111
Corporate Communications
[email protected]
or
Investor
Relations
Tony Gikas, +1 651-389-4110
Investor Relations
[email protected]