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Hot mix asphalt plants in Minnesota must follow federal and state air standards. They may also be required to get a state air permit.

Federal standards

Use the EPA's regulation navigation tool to determine your requirements.:

State standards

Operations

  • Use only the materials, fuels, and additives allowed in Minn. R. 7011.0913.
  • Operate control equipment according to manufacturers’ specifications.
  • Run an accumulating hour meter on the dryer burner.
  • Do not exceed the demonstrated compliance throughput from your most recent performance test unless allowed by Minn. R. 7011.0922, Subpart 2.
  • If you choose to use the control efficiency rule to limit your actual emissions for particulate matter, fabric filters must have a control efficiency of at least 99% for PM and 93% for PM10, and scrubbers (Venturi) must have a control efficiency of at least 94% for PM and 84% for PM10.
  • If you burn fuel oil that contains more than 0.7% sulfur, conduct SCREEN3 air modeling.

Inspections, maintenance, monitoring, and testing

Daily

  • Check control equipment monitoring devices.
  • For fabric filters, check exterior cleaning system equipment.
  • Record pressure drop, liquid flow rate, and water pressure for wet scrubbers and other wet control devices.
  • If you have non-self-cleaning ponds for wet scrubbers and other wet control devices, check sediment level in the ponds to confirm that sediment is less than half the pond depth.
  • Read the fuel pressure gauge of the dryer burner, except when burning natural gas or propane.
  • Check whether there is a negative draft on the dryer burner inlet, except when burning natural gas or propane.

Weekly

  • Check that the pH of water leaving wet scrubbers and other wet control devices is between 5 and 10.

Monthly

  • Inspect control equipment ducts, connections, and housings for leaks.
  • For fabric filters, check the clean-air side of bags for leaks and check interior cleaning equipment.
  • Check for wear on accessible dampers, spray bars, nozzles, and demisters on wet scrubbers and other wet control devices.

Yearly

  • Thoroughly inspect all control equipment, including structural components.
  • Calibrate control equipment monitoring devices.
  • Tune dryer burner.
  • Conduct a performance test on the baghouse.

If you have a registration option D air permit:

Performance test schedules for wet scrubbers and other wet control devices depend on production volume. (Minn. R. 7011.0920)

If your production in tons per year is:Test the performance of wet scrubbers and other wet control devices:
No more than 35,000 tons in any of last 3 years and manufacturer-rated capacity is 100 tons/hour or less at 5% moistureAt least once since 1991
Less than 100,000 tons in any of last 3 yearsOnce every 3 years
Between 100,000 and 200,000 tons in any of last 3 yearsOnce every 2 years
More than 200,000 tons in the previous yearWithin 60 days of start-up in the following year

Recordkeeping

Retain all records for five years.

Daily

  • Plant’s hours of operation as indicated by the hour meter, and total tons of hot mix asphalt produced.
  • Production throughput by dividing the total tons of hot mix asphalt produced by the hours of operation.
  • Baghouse pressure drop.
  • Any corrective actions to the dryer burner.
  • Fuel pressure of the dryer burner, except when burning natural gas or propane.
  • Whether there is a negative draft on the dryer burner inlet, except when burning natural gas or propane.

Yearly

  • Materials, fuels, and additives used, and amounts used.
  • Date the dryer burner was tuned.
  • Control equipment checks, inspections, and calibrations, date, and any repairs.
  • All maintenance to baghouses or wet scrubbers and other wet control devices, date, and any repairs.
  • If you do SCREEN3 modeling, keep a record of the sulfur content of the fuel modeled, the site modeled, the model output file, and supporting calculations.

Reporting

Report control equipment deviations that are outside the manufacturers’ specifications or the most recent performance test range, whichever is more restrictive. Use deviations reporting form DRF-2.

Air permit due dates

SubmittalDue date
Emission inventory fees for previous reporting yearMailed to permitees between February and April, due within 30 days
Emission inventory reportApril 1
Emissions summary review periodBegins in August/September
January 30
July 30