1. a) 1978 Primary and Secondary Quarterly Average NAAQS for Lead

   BOARD NOTE: Derived from 40 CFR 50.12. USEPA designated Granite City as nonattainment with the 2008 primary and secondary three-month average NAAQS for lead effective December 31, 2010 and an area of Chicago effective December 31, 2011. See 76 Fed. Reg. 72097, 79108 (Nov. 22, 2011); 75 Fed. Reg. 71033, 71042 (Nov. 22, 2010). Thus, this subsection (a) was obsolete on December 31, 2012, and the Board removed it.

2. b) 2008 Primary and Secondary Three-Month Average NAAQS for Lead

   1. 1) The 2008 primary and secondary three-month average NAAQS for lead and its compounds is 0.15 µg/m³, arithmetic mean concentration over a three-month period, measured in the ambient air as lead by either of the following:

      1. A) An FRM based on appendix G of 40 CFR 50, incorporated by reference in Section 243.108, and designated by USEPA and listed in the List of Designated Methods, incorporated by reference in Section 243.108; or
      2. B) An FEM designated by USEPA and listed in the List of Designated Methods, incorporated by reference in Section 243.108.

   2. 2) The 2008 primary and secondary three-month average NAAQS for lead are met when the maximum arithmetic three-month mean concentration for a three-year period, as determined in accordance with appendix R of 40 CFR 50, incorporated by reference in Section 243.108, is less than or equal to 0.15 µg/m³.

      BOARD NOTE: Derived from 40 CFR 50.16.

(Source: Amended at 44 Ill. Reg. 14223, effective August 18, 2020)