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Hayden | PM-10 Nonattainment Area

County Affected:

Parts of Pinal County | View on a Map >

Nonattainment Area Designation Date:

Oct. 31, 1990
(55 FR 45799)

Classification Level: 


Pollutant of Concern:

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


The concentration of PM10 in the air in Hayden has recently triggered violations of the 1987 PM10 National Ambient Air Quality Standards (NAAQS). ADEQ is developing a redesignation request so that EPA will reclassify the area to attainment. As part of this request, ADEQ must include an updated emissions inventory, modeling demonstration and a strategy for Exceptional Events. ASARCO is making numerous improvements to the Hayden smelter as part of a $180 million converter retrofit project which will further reduce PM10 concentrations. Some of the controls implemented at the copper smelter include:

  • Ventilation hooding over furnaces
  • Baghouses for flash furnace and anode furnace
  • Paved road cleaning
  • Chemical dust suppressants for unpaved roads
  • Enclosed and ventilated storage of acid plant scrubber blowdown solids
  • Wind fences for byproduct storage‚Äč

Sources of Pollutant: 

  • Copper smelter
  • Open burning and wildfires
  • Windblown dust

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