County Affected:

Parts of Maricopa and Pinal County | View on a Map >

Nonattainment Area Designation Date:

May 10, 1996
(61 FR 21372)

Classification Level:

Serious

Pollutant of Concern:

PM₁₀ (particulate matter 10 microns or less in diameter; 1987 standards)

Summary: 

The concentration of PM₁₀  in the air in Phoenix is occasionally above federal standards. Often this is the result of large scale dust storms, which cannot be controlled. In 2012, Maricopa Association of Governments (MAG), in conjunction with Maricopa County Air Quality Department (MCAQD) and ADEQ, submitted an updated State Implementation Plan (SIP) that demonstrates a reduction of PM₁₀  by 5 percent each year until the Maricopa County nonattainment area meets standards. EPA finalized its approval of the 2012 plan on June 10, 2014 (79 FR 33107). 

Sources of Pollutant: 

• Unpaved roads
• Paved roads
• Construction
• Windblown dust
• Unpaved parking lots
• Agricultural activities 

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