In October 2008, the U.S. Environmental Protection Agency (EPA) revised the existing National Ambient Air Quality Standard (NAAQS) for Lead (Pb). U.S. EPA's final rule for Pb, effective January 12, 2009, stated that the county in which violations of the Pb NAAQS had occurred would be the default boundary for Pb nonattainment areas within a State. On December 15, 2009, Governor Janice K. Brewer sent Arizona's recommendations to U.S. EPA asking that all of the State, except the Hayden Area, be designated at attainment/unclassifiable for the 2008 Pb NAAQS. As for the Hayden Area, the Governor asked that U.S. EPA hold off making a premature, legal designation of "non-attainment" under the federal Clean Air Act in order to allow the State to negotiate an improved permit with ASARCO for the Hayden complex. If such an improved air permit is not entered or if the area records further violations of the lead standard, U.S. EPA could designate the existing Hayden Sulfur Dioxide (SO2) Nonattainment Area, excluding Indian Country, as a non-attainment area for lead. This recommendation follows careful consideration of the new Pb standard, requirements for designation of nonattainment areas, and options available for implementing the standard. On November 08, 2011, U.S. EPA designated the Hayden area as unclassifiable for the Pb NAAQS and the remainder of Arizona as unclassifiable/attainment.
For more information please visit U.S. EPA: Lead Air Quality Standards
The following information and Technical Analysis for Lead Boundary Designation is available for review: