401 Certification for NorthMet

Public comment period has closed

The public comment period for the draft air quality permit, draft water quality permit, and draft 401 water quality certification for PolyMet’s NorthMet project closed on March 16, 2018. The MPCA is currently reviewing all comments and information received.

Since Polymet proposes to alter (fill and/or excavate) protected wetlands for the NorthMet project, the company has 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 follows the general process below for processing 401 certification requests.  

401 certification process with marker showing request submitted

Current status

Reviewing public comments

The public comment period for the draft 401 water quality certification for PolyMet’s NorthMet project closed on March 16, 2018. The MPCA is currently reviewing all comments and information received and will be preparing responses to comments. This process may result in changes to the draft certification prior to the MPCA’s decision whether to issue the certification.

Links to the draft certification, preliminary antidegradation determination, and the technical support document are provided below:

Draft 401 Certification documents:

PDF icon Draft 401 Certification (wq-wwprm1-51e)
PDF icon Preliminary Antidegradation Determination for 401 Certification (wq-wwprm1-51f)
PDF icon 401 Certification Fact Sheet (wq-wwprm1-51g)


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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