401 Certification for NorthMet

MPCA issues PolyMet final air and water quality permits and 401 certification

On December 20, 2018, the MPCA made final regulatory decisions to issue the PolyMet air emission permit, water quality permit, and 401 certification.  The decisions were reached after comprehensive regulatory and technical analysis, extensive public participation, and review by other state/federal agencies and independent third-party experts.
This notification is the MPCA’s final progress report on the status of the PolyMet air emission permit, water quality permit, and 401 certification.

Since Polymet proposed to alter (fill and/or excavate) protected wetlands for the NorthMet project, the company applied for a permit under Section 404 of the federal Clean Water Act (CWA), governing placement of dredged or fill material into wetlands.  Section 404 permits are issued by the US Army Corps of Engineers, which oversees such activities. 

The 404 permit requires the applicant to also request a water quality certification from the state under CWA Section 401. This allows the state (in this case the MPCA) to review the proposed activity in order to determine if it will comply with applicable water quality standards, and identify any conditions needed to ensure compliance. If the review finds that water quality will be protected, the 401 certification is issued and the certification and conditions become part of the 404 permit.

The MPCA issued the final Polymet 401 certification on December 20, 2018.  

401 certification process with marker showing request submitted

Current status

The public comment period for the draft 401 certification for PolyMet’s NorthMet project closed on March 16, 2018. The MPCA reviewed all comments and information received. MPCA issued the final 401 certification on December 20, 2018.

PDF icon FINAL PolyMet 401 Certification (wq-wwprm1-51hh)
PDF icon FINAL PolyMet 401 Antidegradation Determination (wq-wwprm1-51ii)
PDF icon FINAL PolyMet 401 Certification Fact Sheet (wq-wwprm1-51jj)
PDF icon FINAL PolyMet 401 Findings of Fact (wq-wwprm1-51kk)
PDF icon FINAL PolyMet 401 CCH RTC (wq-wwprm1-51ll)
PDF icon FINAL PolyMet 401 Themed Comments & Responses (wq-wwprm1-51mm)

Public meetings

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.

The following 401 certification fact sheets were available at the public meetings:

PDF icon Clean Water Act Section 401 water quality certification (wq-gen2-19) (Jan 2018)
PDF icon 401 Water Quality Certification for PolyMet (wq-wwprm1-51r) (Jan 2018)

Certification request and supporting documents:

PDF icon 401 Reinitiation Cover Letter 2016-08-02
PDF icon Summary of NorthMet Project Modifications since Publication of the SDEIS
PDF icon Wetland Permit Application v2 AUG2013 w application
PDF icon 401 Resubmittal Letter (7-21-2017) (wq-wwprm1-50s)
PDF icon 401 Resubmittal Response Letter (7-28-2017) (wq-wwprm1-50t)
PDF icon Antidegradation Assessment - NorthMet Project Section 401 Certification (wq-wwprm1-51c)
PDF icon NorthMet Project Wetland Replacement Plan (wq-wwprm1-51d)
PDF icon Cross-Media Analysis (wq-wwprm1-51i)
PDF icon MPCA Conclusions on Cross-Media Report (wq-wwprm1-51h)
PDF icon 401 Resubmittal Letter (7-11-2018) (wq-wwprm1-51y)


401 certification requests include a description of:

  • Size and location of the aquatic resources, such as wetlands and streams, that will be excavated or filled
  • How aquatic resources near the project footprint might be negatively affected
  • Plan to replace lost aquatic resources
  • Plan to monitor nearby aquatic resources in case additional resources are lost and must be replaced  

Public input will be solicited if a draft 401 certification is developed. The MPCA encourages public participation during the formal public notice and comment period.

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