Water 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.

MPCA water quality permits establish specific limits and requirements to protect Minnesota's surface and groundwater quality for a variety of uses, including drinking water, aquatic life and recreation. These are also known as NPDES/SDS permits (National Pollutant Discharge Elimination System/State Disposal System).

Individual Wastewater NPDES/SDS Permit

PolyMet's NorthMet mining project would need an individual wastewater NPDES/SDS permit from the MPCA to authorize any discharge of industrial process wastewater.

The MPCA typically follows the process below for processing individual water quality permit applications. The PolyMet process may vary.

Water permit process with marker showing current status as completeness review

* includes coordination with EPA

Current status

Preparing proposed revised permit documents

The public comment period for the draft water quality permit for PolyMet’s NorthMet project closed on March 16, 2018. The MPCA has reviewed all comments and information received and is in the process of finalizing response to comments. This process has resulted in changes to the draft permit that the MPCA proposes to issue including additional permit limits and new requirements related to the construction and operation of engineering controls (such as seepage capture and wastewater treatment systems).

The revised 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.

Revised permit and accompanying fact sheet:

PDF icon PolyMet NPDES/SDS Draft Permit - Revised Oct 2018 (public notice format) (wq-wwprm1-51z)
PDF icon PolyMet NPDES/SDS Draft Permit - Revised Oct 2018 (updated format) (wq-wwprm1-51aa)
PDF icon PolyMet NPDES/SDS Draft Permit - Fact Sheet with Attachments Revised Oct 2018 (wq-wwprm1-51cc)

We are providing the revised permit in two formats; one in the same format as the draft permit placed on public notice in January, and one in the format consistent with our updated permitting database. Although the two formats are different in appearance, both formats are identical with respect to permit contents and requirements. Should the MPCA decide to issue the permit, it will be in the updated format. Both versions are being provided here for ease of reference.

This is not a final decision of the MPCA, nor is this a public comment period. Sending the revised permit to EPA is a normal step in the water 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 revised permits online.

Next steps

The EPA will be reviewing the revised permit in the coming weeks. Following consideration of any feedback provided by EPA during this review, the MPCA Commissioner will make a decision on issuance of the permit. The intent of the MPCA is to make final permit decisions by the end of this calendar year.

Previous steps

Permit application

On July 11, 2016, PolyMet submitted an application to the MPCA for an NPDES/SDS water quality permit for its proposed NorthMet mining project in northeastern Minnesota. MPCA staff processed the application and began preparing a draft permit. This process 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 October 2017.

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 17, 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.

Previous supporting documents

Public notice draft permit, fact sheet, and fact sheet attachments

PDF icon Draft NPDES/SDS Permit (wq-wwprm1-51j)

PDF icon Draft NPDES/SDS Permit Fact Sheet (wq-wwprm1-51k)

PDF icon Draft NPDES/SDS Permit Fact Sheet, Attachment 1 (wq-wwprm1-51l)

PDF icon Draft NPDES/SDS Permit Fact Sheet, Attachment 2 (wq-wwprm1-51m)

PDF icon Draft NPDES/SDS Permit Fact Sheet, Attachment 3 (wq-wwprm1-51n)

PDF icon Draft NPDES/SDS Permit Fact Sheet, Attachment 4 (wq-wwprm1-51p)

PDF icon Draft NPDES/SDS Permit Fact Sheet, Attachment 5 (wq-wwprm1-51q)

Public meeting fact sheets

PDF icon NPDES permit and PolyMet requirements (wq-wwprm1-51s) (Jan 2018)

PDF icon PolyMet permit highlights (wq-wwprm1-51t) (Jan 2018)

PDF icon NPDES/SDS permit and sulfate (wq-wwprm1-51u) (Jan 2018)

PDF icon Reverse osmosis (wq-wwprm1-51v) (Jan 2018)

October 2017 updated NPDES/SDS permit application

PDF icon NPDES/SDS Permit Application - Vol I: Introduction (wq-wwprm1-50u) (Oct 2017)

NPDES/SDS Permit Application - Vol II: Mine Site (wq-wwprm1-50v) (pdf 145.3 mb) (Oct 2017)

PDF icon NPDES/SDS Permit Application - Vol III: Waste Water Treatment System (wq-wwprm1-50w) (Oct 2017)

PDF icon NPDES/SDS Permit Application - Vol IV: Plant Site Sewage Treatment and Stormwater (wq-wwprm1-50x) (Oct 2017)

PDF icon NPDES/SDS Permit Application - Vol V: Tailings Basin and Beneficiation Plant (wq-wwprm1-50y) (Oct 2017)

PDF icon NPDES/SDS Permit Application - Vol VI: HRF and Hydrometallurgical Plant (wq-wwprm1-50z) (Oct 2017)

PDF icon NPDES/SDS Permit Application - Vol VII, Transportation and Utility Corridors (wq-wwprm1-51a) (Oct 2017)

The initial July 2016 permit application and November 2016 update:

PDF icon NPDES-SDS Permit App - Vol I – Introduction v1 JUL2016.pdf

PDF icon NPDES-SDS Permit App - Vol II - Mine Site v1 JUL2016.pdf

PDF icon NPDES-SDS Permit App - Vol III - Waste Water Treatment System v1 JUL2016.pdf

PDF icon NPDES-SDS Permit App Vol IV-Plant Site Sewage Treatment and Stormwater v1 JUL2016.pdf

PDF icon NPDES-SDS Permit App - Vol V – Tailings Basin and Beneficiation Plant v1 JUL2016.pdf

PDF icon NPDES-SDS Permit App Vol VI–HRF and Hydrometallurgical Plant v1 JUL2016.pdf

PDF icon NPDES-SDS Permit App Vol VII - Transportation and Utility Corridors v1 JUl2016.pdf

PDF icon NorthMet Project NPDES/SDS Permit: Application Update Nov. 30, 2016 (wq-wwprm1-50r)

Key references cited in application

Wastewater Treatment System:  Design and Operation Report v2 (wq-wwprm1-51b) (108.9 mb) (Oct 2017)

PDF icon Water Management Plan - Plant (wq-wwprm1-50a) updated July 2016

PDF icon Flotation Tailings Management Plan (wq-wwprm1-50b)

PDF icon Geotechnical Data Package Vol 2.pdf

PDF icon Adaptive Water Management Plan.pdf

PDF icon Installation and Monitoring Plan for Wells N of Mine Site.pdf

PDF icon Mercury Overview.pdf

PDF icon Mine Plan.pdf

PDF icon NorthMet Project Description.pdf

PDF icon Plant Site Wastewater Treatment Plant Pilot testing.pdf

PDF icon Reclamation Plan.pdf

PDF icon Residue Management Plan.pdf

PDF icon Surface water and groundwater quality data collected 2014 2015.pdf

PDF icon Waste Water Treatment System Design and Operation Report.pdf

PDF icon Water Management Plan - Mine (wq-wwprm1-50p) updated July 2016)

PDF icon Wetland Residence Time.pdf

Correspondence related to permit application

PDF icon MPCA Application Completeness letter (Aug. 2, 2016)

PDF icon PolyMet response to EPA letter (Nov. 9, 2016)

PDF icon November 9, 2016 Comment Letter Response

Construction Stormwater General NPDES/SDS Permit

When a project includes land-disturbing activities totaling an acre or more, a Construction Stormwater Permit must be obtained from the Minnesota Pollution Control Agency. Land-disturbing activities are common practices related to construction. Some examples include removing vegetation, like grass or trees, changing the topography by using a bulldozer to level a slope, digging holes to examine the characteristics of the soil at the project site, or installing monitoring wells. These routine activities must be regulated by this permit because they have the potential to allow stormwater—runoff caused by rain and snowmelt—to carry dirt and pollutants into our lakes, rivers and streams.

Virtually all types and sizes of construction projects involve the same types of land-disturbing activities. Whether the project is building an apartment building, a new road or bridge, or digging holes to examine soil characteristics, similar actions involving land disturbance take place. All of these actions increase the potential for soil to runoff from the site and stormwater management practices can be used to reduce that potential. These practices are required by the Construction Stormwater General permit. Because the land disturbing activities on these various types of construction projects are similar, the appropriate regulatory mechanism is a general permit. General permits are used by the MPCA when a category of permittees has activities, operations, and discharges that are substantially similar. The Construction Stormwater General Permit has requirements that address all types of land-disturbing construction activity. Because the activities regulated by the permit are similar, land disturbing construction activities, the permit does not need to be modified for each project. Each permittee covered by the general permit must develop a Stormwater Pollution Prevention Plan (SWPPP), specific to the project, which details how the requirements of the permit will be met. The SWPPP takes into account the specific characteristics of the project and identifies the practices that will be implemented at the project to meet the requirements of the general permit. The SWPPP becomes an enforceable part of the permit.

The current Construction Stormwater General Permit was issued and became effective in August 2013. Prior to its issuance the permit went through a public-notice and comment process. When an applicant seeks coverage under this permit, there is no additional public comment period.  Since the permit became effective, nearly 7,000 projects have been covered by this permit. When an applicant has submitted a complete and accurate application in accordance with the requirements of the general permit, they can be authorized to discharge stormwater associated with construction activity under the general permit.

Current status

On February 7, 2017, PolyMet submitted an application for a Construction Stormwater General Permit for geotechnical investigations at the NorthMet Project plant site and tailings basin. Geotechnical investigations are very common prior to construction of commercial buildings, apartments, road projects; examples include the Vikings stadium, the Saint Croix River Bridge and the Highway 53 project near Virginia. Since these activities disturb more than one acre of land, a Construction Stormwater General Permit is required before commencing the activity.

The purpose of PolyMet’s geotechnical work is to investigate and characterize geological conditions at the site prior to construction and mining operations. This includes such activities as borings and test pits to determine soil characteristics and depth to bedrock and installation of monitoring wells.

Coverage under the February 7, 2017, permit application was effective on March 9, 2017. Coverage under this application only authorizes activities related to geotechnical work; it does not authorize construction or operation of the processing facility, mine pits, or other construction activities. MPCA approved PolyMet’s SWPPP, which is now an enforceable part of the permit.

On March 13, 2017 and November 7, 2017, PolyMet submitted applications for a Construction Stormwater General Permit for additional geotechnical work; specifically mine site geotechnical investigation work and monitoring well installation. As with the February 7, 2017 application, coverage under this application only authorizes activities related to geotechnical work; it does not authorize construction or operation of the processing facility, mine pits, or other construction activities. Coverage under these permit actions was effective on April 12, 2017 and December 7, 2017 respectively. MPCA approved PolyMet’s SWPPP for each of these actions, which are now enforceable parts of the permits.

Coverage information for both permits is available at the following link: https://cf.pca.state.mn.us/water/stormwater/csw/search.cfm

Future construction stormwater permits

The applications received on February 7, March 13, 2017, and November 7, 2017 for coverage under the Construction Stormwater General Permit are related to geotechnical investigation and monitoring well installation in a portion of the project area. Additional geotechnical investigation, as well as land-disturbing construction activity related to other aspects of the project, will require additional future applications for coverage under the Construction Stormwater General permit.

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