County Affected:

Parts of Gila County | View on a Map >

Nonattainment Area Designation Date:

Aug. 5, 2013

Learn more about the designation of the area in the Federal Register (FR) (78 FR 47191) | View >

Pollutant of Concern:

Sulfur Dioxide (SO₂) (2010 standard)

Summary: 

On Jan. 31, 2022, EPA determined that the Miami SO₂ Nonattainment Area failed to meet the 2010 1-hour SO₂ primary federal limit established in the federal National Ambient Air Quality Standards (NAAQS) by Oct. 4, 2018, based upon monitored air quality data from January 2015 to December 2017 | Learn More >

As a result, ADEQ is required to develop a revision to the State Implementation Plan (SIP) that includes an updated emissions inventory, a modeled attainment demonstration, a strategy for possible exceptional events demonstrations, and permanent and enforceable SO₂ control measures that will provide for swift attainment of the SO₂ NAAQS in the Miami SO₂ Nonattainment Area, no later than Jan. 31, 2027. ADEQ is currently working with permitted facilities, local government, and community stakeholders in a collaborative effort to develop a SIP revision to satisfy nonattainment area plan requirements under the Clean Air Act and to improve the air quality in this area.  

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