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Controlling Air Emissions Under the FARR

The information on this page is for owners and operators of air pollution sources regulated under EPA's Federal Air Rules for Reservations (FARR) in Idaho, Oregon, and Washington.
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Estimating your air emissions

When you register your facility under the FARR, you may need to provide estimates of the following emissions:

  • PM10 and PM2.5 particulate matter
  • Sulfur oxides
  • Nitrogen oxides
  • Carbon monoxide
  • Volatile organic compounds
  • Lead and lead compounds
  • Ammonia
  • Fluorides
  • Sulfuric acid mist
  • Hydrogen sulfide
  • Total reduced sulfur
  • Reduced sulfur compound source emissions

Generally accepted emissions estimating procedures include:

  • Source-specific emissions tests
  • Mass balance calculations
  • Published emissions factors
  • Engineering calculations

The basis of all calculations and the calculation itself must be included with your application.

For assistance, please call the FARR Hotline at 1-800-424-4372 and ask to speak with the FARR Registration Rule Coordinator.

Emission factors and calculators:

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Managing fugitive particulate matter

Owners and operators of air pollution sources may be required to control emissions of fugitive particulate matter according to the requirements below.

What is fugitive particulate matter?

Particulate matter is a mixture of solid particles and liquid droplets in the air. Fugitive particulate matter is particulate matter that has not passed through a stack (such as a chimneys, pipe, vent, or duct) before being released to the air.

"Fugitive dust" is a type of fugitive particulate matter released into the air by wind or other similar forces.

Why is it important?

High levels of particulate matter in the air can affect human health. It can reach deep into the lungs and cause respiratory problems. Particulate matter is linked to aggravated asthma, chronic bronchitis, and premature death.

Am I required to control fugitive particulate matter?

If your facility is located within the jurisdiction of the FARR and produces fugitive particulate matter, and if your source is not listed in the exemptions below, then you are required to comply with the requirements for fugitive particulate matter listed below. Owners and operators performing materials handling or storage, construction, or demolition activities must also comply.


The following sources are not required to comply with the FARR requirements for fugitive particulate matter:

  • Open burning
  • Single family homes or residential buildings that have four or fewer apartments or housing units
  • Agricultural activities
  • Forestry and silvicultural activities
  • Non-commercial smokehouses
  • Sweat houses or lodges
  • Public roads that are owned or maintained by any federal, tribal, state, or local government.

What are the requirements?

Owners and operators must:

1. Take actions to prevent and minimize fugitive particulate matter emissions. Examples include (but are not limited to):

  • Using water or chemicals to control dust during building demolition, construction, road grading, or land clearing.
  • Using asphalt, oil (not used oil), water, or other chemicals on unpaved roads, materials stockpiles, and other surfaces that can release dust into the air.
  • Enclosing materials stockpiles if using oil, water, or chemicals is not effective.
  • Using good housekeeping methods to reduce the build-up of dusty materials that can enter the air. Clean up spilled or materials already built-up promptly.
  • Installing hoods, fans, and fabric filters to enclose and vent dusty materials.
  • Containing fugitive particulate matter when performing sandblasting or similar activities.
  • Covering open-bodied trucks when the truck is carrying materials that can be released into the air.
  • Removing earth or other material that can be carried into the air promptly from paved streets.

2. Perform an annual survey to see if any fugitive particulate matter emissions are being produced.

  • The survey must be performed each year. For new air pollution sources or new operations, a survey must be performed within 30 days of the start of the operations.
  • The survey must be performed during typical operating and weather conditions.
  • The survey results, date and time of the survey, and sources of any fugitive particulate matter that is found must be documented.

3. Prepare a written implementation plan if fugitive particulate matter emissions sources are found during the initial or annual survey. The plan must:

  • List the actions that will be taken to prevent the fugitive particulate matter emissions.
  • Include monitoring and recordkeeping procedures.
  • Be kept onsite and updated after each annual survey.

You should also:

  • Maintain your records that document the yearly surveys and the actions taken to prevent the emissions.

For construction or demolition activities, the written plan must be prepared before beginning operations.


FARR rule for fugitive particulate matter

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