Mining

Mining has a long history in Minnesota. Iron ore has been mined here since the 1800s, and the taconite industry is an important sector in our state’s economy. Today, the state’s extensive copper and nickel deposits are just being proposed to be mined. While many activities related to mining are regulated by other state and federal agencies, including the Minnesota Department of Natural Resources (DNR), the MPCA plays an important part in the state’s mining sector as well.

Minnesota’s mining history - Minnesota DNR

Where are metallic mining activities located in Minnesota?

Minnesota state agencies collect data on the locations of metallic mining activities and sites. Agencies collect different data because regulatory authority over each type of activity varies between regulatory agencies.

MPCA’s role in mining

Environmental review

The MPCA participates in environmental review for mining projects where, most commonly, the DNR is the responsible governmental unit.

Permitting

Permits the MPCA issues for mining operations include air emissions, wastewater, and activity involving fill of surface waters, including wetlands (Section 401 certification). MPCA’s permitting authority is described in Minnesota Statutes Chapters 116.07 (air quality), Minnesota Rules Chap. 7001.1000 – 7001.1150 (water quality), and Minnesota Rules Chap. 7001.1400 – 7001.1470 (wetlands/401 certification).

Responsibilities for permitting include:

Air quality
Water quality
Solid waste
Hazardous waste storage and transportation
Above- and below-ground storage tanks
Section 401 certification

Air permitting

MPCA air quality permits are issued to mining facilities to identify the units at each facility that generate air pollutants and, where applicable, place limits on those emissions. In some cases air permits may also authorize construction or modification of a facility. Permits issued to mining facilities control air emissions from crushing and handling of rock, combustion sources such as furnaces, and fugitive dust.

All air permits, including those issued to mining facilities, are posted on the MPCA webpages listing air permits issued in Minnesota.

For more information on air quality permits, check these publications on the MPCA website:

Water permitting

MPCA water quality permits establish specific discharge limits and requirements to protect Minnesota's surface and groundwater quality for a variety of designated uses, such as drinking water, fishing and recreation. For links to more information on MPCA wastewater permitting, visit the Water Permits and Rules page.

Section 401 certification

MPCA also uses the Section 401 certification program to protect water quality standards. Any project with a discharge that needs a federal permit, such as a permit to dredge or fill wetlands or surface waters, also needs a Section 401 certification. The 401 certification is part of a larger water quality protection effort that is an integral part of the Federal Clean Water Act. The program often works closely with other agencies that play a role in water quality protection, including the U.S. Army Corps of Engineers, DNR, Minnesota Board of Soil and Water Resources, and local government agencies.

Mining projects

Polymet’s NorthMet project

Environmental review is complete (See the DNR’s website) and the project can proceed with permitting. The State launched a web portal dedicated to Minnesota’s permitting process for the NorthMet project at www.mn.gov/polymet. Permitting this project is expected to be very complex. It will need permits from several state agencies; the portal will provide information about those permits and direct users to agency websites with more detail. To stay informed, we encourage interested parties to sign up on the web portal to receive the latest news and updates on the permitting processes as they become available. Information about MPCA permits for the project will be made available through the portal.

Minntac tailings basin NPDES permit

The draft permit for Minntac's tailings basin was open for public comment through Dec. 23, 2016. Revisions were made to the draft permit based on received comments, and a proposed permit was sent to EPA for final review on Nov. 14, 2018. The final permit is effective Dec. 1, 2018.

Silica sand

Visit MPCA's silica sand page for activities and sites related to silica sand or other nonmetallic mining in Minnesota.