Saint Paul | Northern Iron

Northern Iron LLC operates an iron foundry that manufactures metal castings and machined parts at 867 Forest St. N. in Saint Paul’s Payne-Phalen neighborhood, an area of concern for environmental justice.

Air emission modeling showed that Northern Iron highly likely exceeded levels of lead and particulate matter emissions in February 2024.

The MPCA has given Northern Iron until May 8 to show compliance with air quality standards. If it does not, the MPCA will begin the process to revoke Northern Iron's air permit.

Our role  

Several state agencies, along with city and county governments, have regulatory roles over a facility like Northern Iron. The MPCA is responsible for issuing and enforcing Northern Iron's air permit, which is designed to limit emissions to federal and state health standards.

Northern Iron submitted an incomplete application to renew its air permit in January 2025. The MPCA has requested additional information to complete the permit.

• Northern Iron air permit application (aq5-39)
• Reference: National Ambient Air Quality Standards (U.S. EPA)

January 2025 supplemental submissions

• Cover letter (aq5-40a)
• Process flow diagram (aq5-40b)
• Hood evaluation and certification (aq5-40c)

  EQUI 23 revised
• Hood evaluation and certification (aq5-40d)

  EQUI 23 revised and EQUI 117 (MPCA edit)
• GI-07 and supporting calculations (aq5-40e)
• Disc sander filter info (aq5-40f)
• Air permit modification application (aq5-40g)
• GI-05F supplement (aq5-40h)
• CD-05 compliance plan for control equipment (aq5-40i)
• GI-05A pollution control equipment information (aq5-40j)

  (TREA45)
• GI-05F emission source associations (aq5-40k)

  (TREA 18)

The MPCA is committed to maintaining an ongoing dialogue with the Payne-Phalen community about our agency’s work in the neighborhood. In May 2024, the MPCA held a community meeting at the Saint Paul Eastside YMCA to discuss Northern Iron and address community questions. 

Air monitoring

The MPCA has installed a regulatory air monitor near Northern Iron to measure lead and fine particle concentrations. The air monitor continually measures pollutants to help the MPCA improve and protect outdoor air. With this data, the agency can track pollution trends over time to show whether outdoor air meets air quality standards and health benchmarks. Air monitors have strict requirements and are tested often to ensure high quality data.

This table shows the lead concentration values from samples collected by the Northern Iron monitor along with the wind direction on those days. The EPA's action level is 0.15 micrograms per cubic meter (µg/m³).

The MPCA also reviews air emission factors and preliminary air quality modeling data to estimate maximum potential pollution from Northern Iron. 

17156: Community air sensor data

Community air sensors

Sensors currently gather data on air quality near Northern Iron.

Real-time data

Guidance for residents  

No level of lead is safe for people, and elevated levels of lead can impact residents’ health. Children are most at risk for health impacts.

Minnesota Department of Health blood level screening guidelines recommend all children receive a blood lead test around 12 and 24 months of age. Older children and pregnant adults should be tested when additional risk factors are present.  

Timeline

• 2020: The MPCA found unauthorized changes at Northern Iron that resulted in increased particulate matter emissions.
• 2022: The MPCA conducted an announced inspection at Northern Iron.
• 2023: The MPCA fined Northern Iron $41,500 for air permit violations and negotiated a stipulation agreement which requires the company to conduct air quality modeling.
• February 2024: The MPCA received new air emission modeling, or computer estimates, that indicated the foundry’s lead and particulate matter emissions were highly likely exceeding national ambient air quality standards (NAAQS). The agency issued an administrative order on April 16 requiring Northern Iron to reduce these emissions to meet air quality standards within 30 days.
• May 21, 2024: The Ramsey County District Court ordered both parties into mediation. On June 21, the mediation ended. The MPCA cannot discuss the mediation due to a duty of confidentiality.
• June 27, 2024: Attorneys for MPCA and Northern Iron met with the Ramsey County District Court judge to discuss next steps. The judge laid out a scheduling order, requesting motions be filed in early July for a protective order from Northern Iron and a motion to dismiss from the MPCA.
• July 11, 2024: The Ramsey County District Court issued a temporary injunction that allows Northern Iron to increase its operations and lifted provisions of the MPCA’s administrative order that limited production to ensure it meets national ambient air quality standards.
• Aug. 28, 2024: The Ramsey County District court ordered Northern Iron install two additional regulatory monitors at their facility.
• Sept. 10, 2024: Northern Iron submitted an amended air permit application to the MPCA. The agency informed the court and Northern Iron on Sept. 13 that the application was deemed incomplete. Northern Iron submitted significant supplemental application materials on Sept. 16, and the MPCA has deemed the application administratively complete. The agency will now proceed with a thorough technical permitting process.
• October 2024: The MPCA began its technical review of Northern Iron’s air permit application and found that the application was incomplete.
• January 2025: Northern Iron submitted a new permit application that was missing important information. To address this delay in working on a revised permit, the MPCA requested that the court stay the case — or pause Northern Iron’s case against the MPCA — so the MPCA can focus on the permit over the coming weeks. To be clear, the MPCA is committed to write a permit that will protect the community from emissions from the facility and engaging with community to understand the needs and priorities of people who live near the facility. The court issued the stay on Feb. 21, 2025.
• March 2025: The MPCA sent a letter to Northern Iron requesting information related to its operations and emissions at the facility showing that it complies with a requirement to maintain 100 percent capture of emissions from the building.
• April 2025: A new air toxic monitor was placed outside Northern Iron, and the MPCA will monitor for 57 volatile organic compounds and seven carbonyls. The information will be posted on this page after the data has been reviewed and validated, which is how the MPCA ensures scientific soundness.
• April 2025: The MPCA issued a final notice to Northern Iron for information required to determine compliance and to write a permit. If the agency does not receive the requested information, it will begin the process to revoke the foundry's existing air permit.