County Affected:

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

Nonattainment Area Designation Date:

2008 National Ambient Air Quality Standard
May 4, 2016

2015 National Ambient Air Quality Standard
June 4, 2018

Classification Level: 

Moderate, classification under the 2008 ozone standard. Marginal classification under the 2015 ozone standard.

Pollutant of Concern:

• Ozone (2008 standard; 75 ppb)
• Ozone (2015 standard; 70 ppb)

Summary: 

The concentration of ozone in the air in Phoenix is above the 2008 and 2015 ozone standard. Maricopa Association of Governments (MAG) submitted a plan to EPA in January 2017 for the 2008 ozone standard.

Key controls in the plan include:

• Summer fuel reformulation
• Emissions testing
• Federal Tier 2 and Tier 3 vehicle fuel standards
• Coordinated traffic signal systems

MAG submitted a plan to EPA on July 8, 2020 for the 2015 ozone standard.

Sources of Pollutant: 

• Industrial solvents and coating use 
• Residential/industrial fuel combustion
• Open burning/wildfires
• Cars and trucks

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