Air quality permit for NorthMet

MPCA sends PolyMet revised permit documents for EPA review

The MPCA considered the nearly 700 public comment submittals which resulted in the addition of numerous conditions to the draft permits to ensure compliance with air and water regulations. The revised permit documents have been sent to EPA for review in accordance with applicable permitting rules and agreements.

The revised permits are not open for public comment. This notification is intended to serve only as a progress report on the current status of the MPCA draft air quality and water quality permits.

An air emission permit is a regulatory document that contains legally enforceable requirements. A permit identifies the units at each facility that generate air pollutants, details the conditions under which the facility must operate to comply with rules and regulations and, where applicable, sets limits on those emissions.

The MPCA follows the general process below for processing air permits applications:

Air permit process timeline showing current status as completeness review

Current status

The public comment period for the draft air quality permit for PolyMet’s NorthMet project closed on March 16, 2018. The MPCA has reviewed and considered all comments. This process has resulted in changes to the draft permit that the MPCA proposes to issue including clarification of fugitive dust control management and recordkeeping and additional monitoring and recordkeeping requirements.

The proposed permit and support documents were sent to the Environmental Protection Agency (EPA) for review on October 25 as part of the regular federal oversight of the state permitting program. The comments including responses, proposed permit, and Technical Support Document can be viewed at the following links:

PDF icon Air Quality Proposed Permit and Appendices - PolyMet (aq5-36u)
PDF icon Air Quality Proposed Technical Support Document (TSD) and Attachments - PolyMet (aq5-36v)
PDF icon Comments and Response to Comments on the Public Notice of PolyMet Air Permit (aq5-36t)

This is not a final decision of the MPCA, nor is this a public comment period. Sending the proposed permit to EPA is a normal step in the air permitting process as part of the federal oversight of the state permitting programs. In the interest of ensuring transparency for this high-interest project, MPCA is taking the additional step of posting the proposed permit online.

Next steps

As part of the federal oversight for the State's Title V air permitting program, the EPA has 45 days to review the permit and make an objection. The EPA review period will conclude on December 10, 2018. Title V program allows the public to petition the EPA Administrator to object to specific permits. Petitions must be filed with the EPA administrator within 60 days after the EPA review period concludes. The 60-day petition period for the PolyMet air permit begins on December 11, 2018 and ends on February 11, 2019.

Previous steps

Public notice and public meetings

MPCA staff completed their review of the updated permit application and supporting materials and prepared a draft permit and supporting fact sheet for the proposed project. The draft permit and fact sheet were provided to the interested Tribes, the EPA, and the Permittee for an early review and comment period on January 24, 2018. The public notice period for the draft permit ran from January 31, 2018 to March 16, 2018. The MPCA held two public meetings on the draft permits jointly with the Minnesota Department of Natural Resources on Wednesday, February 7, 2018 in Aurora and Thursday February 8, 2018 in Duluth.

Public notice, draft permit, and technical support documents:

PolyMet Air Quality Permit Public Notice
PDF icon Draft Air Emissions Permit No. 13700345-101
PDF icon Draft TSD for Air Emissions Permit No. 13700345-101
PDF icon Draft TSD Attachments for Air Emissions Permit No. 13700345-101

Permit application submitted

On August 24, 2017, PolyMet submitted an air permit application to the Minnesota Pollution Control Agency (MPCA) for its proposed NorthMet project in northeastern Minnesota. The information contained in these documents helps the MPCA determine which state and federal requirements apply and develop conditions for a permit that ensures the project can meet applicable laws and requirements. During this process it is normal for MPCA technical staff to request additional information from the applicant.

Previous supporting documents

Public meeting fact sheets

PDF icon Overview of PolyMet’s air permit (aq5-36q) (Feb 2018)
PDF icon PolyMet’s mercury air emissions (aq5-36r) (Feb 2018)
PDF icon Fiber requirements in the PolyMet air permit (aq5-36s) (Feb 2018)

Air Modeling Protocol Review

Before PolyMet can submit an air permit application, they must conduct air quality modeling to estimate potential air quality impacts. Before an applicant completes the modeling, they must have a modeling protocol approved by the MPCA. The air quality modeling protocol describes the modeling approach and data that will be used to predict pollutant concentrations. The modeling results must be submitted with a permit application.

Class I Air Modeling

Class I areas are places where air quality is given special protections. PolyMet is near four Class I areas: Boundary Water Canoe Area Wilderness, Voyageurs National Park, Isle Royale National Park, and Rainbow Lake Wilderness. Class I modeling is conducted to estimate the potential impact on these areas.

PDF icon Class I Modeling Protocol (Plant Site and Mine Site).pdf
PDF icon Class I Modeling Protocol Approval (Plant Site and Mine Site).pdf

The results of the Class I modeling, based on the modeling protocol, are included in a permit application.

Class II Air Modeling

Class II areas are places where the air quality meets all standards and moderate increases in air quality impacts are allowed. All of Minnesota, except for the Boundary Water Canoe Area Wilderness and Voyageurs National Park, is designated as Class II. Class II modeling is conducted to estimate the potential impact in Class II areas near the proposed facility.

PDF icon Class II Modeling Protocol (Mine Site).pdf
PDF icon Class II Modeling Protocol (Plant Site).pdf
PDF icon Class II Modeling Protocol Approval (Plant Site and Mine Site).pdf

The results of the Class II modeling, based on the modeling protocol, are included in a permit application.

Air Emissions Risk Analysis (AERA) Modeling

An AERA uses a scientific process to estimate the potential human health risks from air toxics, pollutants that may cause cancer, other serious health effects, or environmental and ecological effects. The quantitative risk estimates and qualitative information, for both the facility and the surrounding area, are meant to describe risks to individuals who, as a result of where they may live and what they do, may experience the highest level of exposure within a reasonable set of situations.

PDF icon AERA Workplan (Mine Site).pdf
PDF icon AERA Workplan (Plant Site).pdf
PDF icon AERA Workplan Approval (Plant Site and Mine Site).pdf

The results of the AERA modeling, based on the work plan, are included in a permit application.

Permit application documents submitted by Polymet

PDF icon Application for a Permit to Construct and Operate v1 AUG2016-1.pdf
PDF icon Application for a Permit to Construct and Operate v1 AUG2016-2.pdf
PDF icon Application for a Permit to Construct and Operate v1 AUG2016-3.pdf
PDF icon PolyMet Air Permit Application v2-Part 1 (aq5-35t) (1-11-2018)
PDF icon PolyMet Air Permit Application v2-Part 2-Appendices (aq5-35u) (1-11-2018)
PDF icon PolyMet Air Permit Application v2-Part 3-Appendices (aq5-35v) (1-11-2018)
PDF icon PolyMet Air Permit Application v2-Part 4-Appendices (aq5-35w) (1-11-2018)
PDF icon PolyMet Air Permit Application v2-Part 5-Appendices (aq5-35x) (1-11-2018)

Air quality permit applications include a description of:

  • equipment at the facility that will generate air pollutants
  • pollution control equipment that will be used to reduce emissions
  • type and quantity of air pollutants that will be emitted
  • potential air quality impacts near the facility

In addition to the application documents above, PolyMet submitted the studies, reports, and other documents referenced in the application and air modeling output files. Because of the volume, size, and format of these files they are not posted online but are available by request at https://www.pca.state.mn.us/about-mpca/information-requests

PDF icon PolyMet Class I report erratum (aq5-35) (12/23/2016)
PDF icon PolyMet AERA report erratum (aq5-35a) (1/10/2017)
PDF icon PolyMet Class I modeling approval (2/8/2017)
PDF icon PolyMet Mine Site Fugitive Emissions Control Plan (aq5-35c) (4/14/2017)
PDF icon PolyMet Plant Site Fugitive Emissions Control Plan (aq5-35d) (4/14/2017)
PDF icon PolyMet Fiber Monitoring and Quality Assurance Project Plan (aq5-35e) (8/31/2017)
PDF icon PolyMet AERA Emissions Technical Memo Update V2 (aq5-35f) (09/17/2017)
PDF icon PolyMet AERA Emissions True-Up Technical Memo v1d2 (aq5-35g) (10/5/2017)
PDF icon PolyMet AERA Errata and Response to Comments (aq5-35h) (12/19/2016)
PDF icon PolyMet AERA Forms v1 NOV 2016 (aq5-35i) (08/24/2016)
PDF icon PolyMet AERA Mine Site Update v1 NOV 2017 (aq5-35j) (11/15/2017)
PDF icon PolyMet AERA Proposed Verification v1 FEB 2017 (aq5-35k) (02/22/2017)
PDF icon PolyMet AERA Risk Analysis and Respirable Fraction of Dust Based Emissions v2 JUL 2012 (aq5-35l) (07/18/2012)
PDF icon PolyMet AERA Verification Runs v1 MAY 2017 (aq5-35m) (05/30/2017)
PDF icon PolyMet AERA MDH MPCA Memo NOV 2014 (aq5-35n) (11/20/2014)
File PolyMet AERA 1Hr Results value Cu Ni fix with As (aq5-35o) (12/06/2017)
File PolyMet AERA 2017 RASS Mine Site multipathway year 8 (aq5-35p) (2/06/2017)
File PolyMet AERA 2017 RASS Mine Site multipathway year 13 (aq5-35q) (12/06/2017)
File PolyMet AERA 2017 RASS Plant Site Inhale RME Cancer Chronic CuNiFix (aq5-35r) (12/06/2017)
File PolyMet AERA 2017 RASS Plant Site Inhale RME Non Cancer Chronic CuNiFix (aq5-35s) (12/06/2017)
PDF icon PolyMet Class II 1 Hour NO2 NAAQS Cumulative Results (aq5-36l) (12/01/2017)
PDF icon PolyMet Class II 1 Hour PM2.5 NAAQS Cumulative Results-Year 8 (aq5-36m) (12/01/2017)
PDF icon PolyMet Class II 1 Hour SO2 NAAQS Cumulative Results (aq5-36n) (12/01/2017)
PDF icon PolyMet Class II 24-Hour PM2.5 NAAQS Cumulative Results-Year 13 (aq5-36o) (12/01/2017)
PDF icon PolyMet Class II 24-Hour PM10 NAAQS Cumulative Results-Year 8 (aq5-36p) (12/01/2017)
PDF icon PolyMet Class II 24-Hour PM10 NAAQS Cumulative Results-Year 13 (aq5-35y) (12/01/2017)
PDF icon PolyMet Class II Annual PM2.5 NAAQS Cumulative Results-Year 8 (aq5-35z) (12/01/2017)
PDF icon PolyMet Class II Annual PM2.5 NAAQS Cumulative Results-Year 13 (aq5-36a) (12/01/2017)
PDF icon PolyMet Class II AQDM Results Form DEC 2017 (aq5-36b) (12/01/2017)
PDF icon PolyMet Class II AQDM Results Review Form DEC 2017 (aq5-36c) (12/14/2017)
PDF icon PolyMet Class II Cumulative NAAQS Receptor Grid (aq5-36d) (12/01/2017)
PDF icon PolyMet Class II Mine Site Model Source Layout-Year 8 (aq5-36e) (12/01/2017)
PDF icon PolyMet Class II Mine Site Model Source Layout-Year 13 (aq5-36f) (12/01/2017)
PDF icon PolyMet Class II Modeling Analysis Memo-DEC 2017 (aq5-36g) (12/01/2017)
PDF icon PolyMet Class II Process Plant Model Source Layout (aq5-36h) (12/01/2017)
PDF icon PolyMet Class II Tailings Basin Model Source Layout (aq5-36i) (12/01/2017)
PDF icon PolyMet Class I Air Quality Dispersion Modeling Report JAN 2018 (aq5-36j) (12/23/2016)
PDF icon PolyMet Class I Air Quality Dispersion Modeling Report Review Form JAN 2018 (aq5-36k) (02/01/2017)

Completeness review

On September 1, 2016, MPCA provided PolyMet with a letter indicating that the air quality permit application for its proposed NorthMet project was determined to be ‘complete enough for processing.’ MPCA staff may have additional questions during the development of the permit to clarify information contained in the application and may request additional information from PolyMet to address these questions. These requests will not invalidate the determination of completeness for this application. This letter is not an approval to construct, modify, or operate the facility.

PDF icon Application Completeness Review.pdf

Public input will be solicited if a draft permit is developed. The MPCA encourages public participation during the formal public notice and comment period.

Tribal and Permittee Review

On August 24, 2016, PolyMet submitted an application to the MPCA for an air quality permit for its proposed NorthMet mining project in northeastern Minnesota. MPCA staff processed the application and began preparing a draft permit. This resulted in additional information and clarifications being made to the Agency. To reflect this additional information, PolyMet submitted an updated version of the permit application in January 2018.

MPCA staff have completed their review of the permit application and supporting materials and have prepared a draft permit and supporting technical support document for the proposed project. The draft permit and technical support were provided to the interested Tribes and PolyMet for their review. A formal public notice and comment period, during which the public meetings identified above will take place, will follow. The MPCA encourages public participation during the formal public notice and comment period.

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