Minnesota Department of Transportation

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Project development

Environmental process | Environmental review

Air Quality

Purpose

The purpose of the Clean Air Act (CAA) legislation and National Environmental Policy Act (NEPA) is to protect health and welfare by attaining and maintaining the National Ambient Air Quality Standards (NAAQS). These air quality guidelines implement CAA & NEPA and advise the project manager in complying with the regulations throughout the environmental review process.

When to use this subject

Is the Project type listed under Exempt Projects in 40 CFR 93.126, 40 CFR 93.127,or 40 CFR 93.128?

Projects that are exempt from air analysis

The Project type is listed under Exempt Projects in 40 CFR 93.126, 40 CFR 93.127,or 40 CFR 93.128.

  • NAAQS analysis is not required
  • MSAT analysis will need to be addressed, see the Prepared statements section for suggested language
  • CO and PM10 conformity determination is not applicable if project is listed under 93.126 or 93.128
    • Projects listed under 93.127 are not exempt from a project-level conformity determination
  • Greenhouse Gas Analysis Guidance

Projects that require air analysis or determination

The Project type is not listed under Exempt Projects in 40 CFR 93.126, 40 CFR 93.127,or 40 CFR 93.128, and is therefore Non-Exempt.

  • NAAQS analysis is required
  • A project-level conformity determination is required
  • MSATs must be addressed in the environmental document
    • See Mobile Source Air Toxics Analysis in the Detailed Requirements section and the Prepared statements section for suggested language
  • Go to Air Quality process ┬áto determine if CO Hot Spot or PM10 analysis is required based on project location
  • Greenhouse Gas Analysis Guidance

How this subject fits into the overall project development process

Begin working on air quality analysis during the scoping process by preparing the Early Notification Memo. You must complete the analysis by the time you prepare the environmental document.

Organizations involved