Counties Affected:

Parts of Pinal and Gila Counties  | View on a Map >

Nonattainment Area Designation Date:

Oct. 31, 1990
(55 FR 45799)

Classification Level: 

Moderate

Pollutant of Concern:

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

Summary: 

The concentration of PM₁₀ in the air in Miami has been below federal standards for several years. ADEQ is developing a redesignation request so that EPA will reclassify the area as an attainment area. As part of this request, ADEQ must include an updated emissions inventory, modeling demonstration and a strategy for Exceptional Events. Freeport-McMoran made numerous improvements to the Miami smelter as part of a $250 million expansion project that will further reduce PM₁₀ concentrations. Some of the controls implemented at the copper smelter include:

• Baghouses for materials storage bins
• Baghouse for anode furnace
• Wet electrostatic precipitator for furnace
• Ventilation system over furnace
• Water suppression for material piles and unpaved roads
• Paved road cleaning

Sources of Pollutant:

• Manufacturing of metal
• Open burning and wildfires
• Windblown dust

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