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Air Quality System (AQS)

Please note that the AQS User Support Process has changed. View here.

The Air Quality System (AQS) contains ambient air pollution data collected by EPA, state, local, and tribal air pollution control agencies from over thousands of monitors.  AQS also contains meteorological data, descriptive information about each monitoring station (including its geographic location and its operator), and data quality assurance/quality control information.  AQS data is used to:
  • assess air quality,
  • assist in attainment/non-attainment designations,
  • evaluate State Implementation Plans for non-attainment areas,
  • perform modeling for permit review analysis, and
  • prepare reports for Congress as mandated by the Clean Air Act.