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All facilities in Minnesota are required to determine if they need an air permit. Small facilities should start by determining whether they qualify as an "insignificant facility," which has potential air emissions that are low enough that the MPCA does not require an air permit.

Use this spreadsheet to calculate emissions to determine eligibility as an "insignificant facility" under Minn. R. 7008.2600.

Common questions

What if my facility has air emission sources that aren’t listed in the calculator? Your facility may still qualify as an insignificant facility even if it has emission sources in addition to those listed in the calculator. Some emission sources are so small that they aren’t required to be part of the calculations. See the list in Minnesota Rule at 7007.1300, subpart 2.

My facility is an insignificant facility. What are the compliance requirements? Keep records of all emission units and the rule citation stating that each emission unit is an insignificant activity or conditionally insignificant activity. The calculator does this for you, so keep an electronic or printed copy of the completed calculator. You are not required to submit anything to the MPCA. If you are inspected you may be asked to prove that you don’t need a permit – your copy of the completed calculator can be used for that.

My facility doesn’t qualify as an insignificant facility. Now what? Consider whether you could make changes at the facility that would allow you to qualify as an insignificant facility. Certain types of facilities that meet specific requirements can also be exempt from permitting requirements, including auto body repair shops, small coating facilities, woodworking shops, concrete manufacturers, and gas stations. If your facility doesn’t qualify under any of these options, you will need to calculate the facility’s potential emissions to determine if a permit is needed. If you do need a permit, small facilities usually qualify for a registration air permit.

Do I have to use the calculator? No. You can calculate the potential emissions (PTE) of each air emission source at your facility to confirm that the facility is under air permit thresholds:

  • total hazardous air pollutant (HAP) emissions - 10 tons per year
  • NOx emissions - 100 tons per year
  • SO2 emissions - 50 tons per year
  • particulate matter emissions - 100 tons per year
  • PM-10 emissions - 25 tons per year
  • VOC emissions - 100 tons per year
  • CO emissions - 100 tons per year
  • Lead emissions - 0.5 tons per year
  • CO2e emissions - 100,000 tons per year