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The Minnesota State Implementation Plan (SIP) is focused on the six criteria air pollutants regulated by national ambient air quality standards (NAAQS): ground-level ozone, fine particles, lead, nitrogen dioxide, carbon monoxide, and sulfur dioxide. Any regulation or program that the state or EPA believes is necessary to attain and maintain the NAAQS is included in the SIP. Air toxics, or hazardous air pollutants, are regulated under other portions of the Clean Air Act and are not included in the SIP.

EPA must review each NAAQS every five years to ensure they adequately protect human health and the environment. Recent reviews have resulted in more stringent federal standards. When EPA standards change, states must designate which areas within their borders are in "attainment" with the standards. Areas where air quality doesn't meet standards are in “nonattainment.”

If a state doesn't submit its SIP on time or leaves out mandated information, the EPA may create a federal implementation plan that lays out how the state will meet the NAAQS and other requirements.

Global: Criteria pollutant data explorer (Tableau)
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Criteria pollutant data explorer

Minnesota monitoring data for six common air pollutants compared to national standards set by U.S. EPA.

Site- or area-specific plans

In the SIP, the state denotes nonattainment areas that don't comply with the standards, which must encompass the ambient air that exceeds the standard and all the sources of air pollution that contribute to the nonattainment. If all or part of a state is in nonattainment, the state must submit a SIP detailing how it will achieve attainment.

Minnesota currently has one nonattainment area in Dakota County; refer to State implementation plan for lead.

Permitting and the SIP

As part of the SIP, states must have programs for reviewing new or changing major sources of air emissions. The programs must:

  • review new sources of air pollution in nonattainment areas.
  • prevent significant deterioration of air quality in attainment or maintenance areas.

Learn about Minnesota's SIP-approved programs:

The MPCA includes federally enforceable limits in its air permits in the state. Limits set under Minnesota’s Title I SIP authority are noted in permits as a “Title I Condition: SIP for (pollutant name) NAAQS." Title I conditions never expire, regardless of the status of the permit.

State implementation plan for lead

In 2009, the EPA significantly decreased the NAAQS limit for lead air pollution. When federal standards are changed, states must review monitoring data to determine if they still meet the standard.

Based on 2007-2009 monitoring data, the MPCA recommended a nonattainment designation for an area surrounding Gopher Resource Corporation, a lead smelter and battery recycling company in Eagan in Dakota County. That means that the area is not meeting the federal standard for lead air pollution.

The MPCA submitted a SIP for the nonattainment area in Eagan in June 2012. The MPCA has been working with Gopher Resource on controls that will allow the area to attain the new lead standard. The area must meet the standards for three years before it can be redesignated to attainment.