Lead (2008) NAAQS Notes

More detailed design value data can be found at the Air Quality Design Value site

1. The level of the 2008 NAAQS for Pb is 0.15 micrograms per cubic meter (µg/m³) not to be exceeded in any 3-month quarter. The design value for the 2008 lead NAAQS is the maximum rolling 3-month lead-TSP average over a 3-year period.

2. 2008 Lead area designations were effective on December 31, 2010. Effective December 31, 2011, five additional areas were designated nonattainment. These areas were: Arecibo, PR; Belding, MI; Chicago, IL; Pottawattamie, IA; and Saline County, KS.

3. For Frisco, TX, the design value for each 3-year period listed here is based on data from monitors sited outside of the fence surrounding the dominate Pb source. When data from site 480850009 during the period in which it was located a few feet inside the fenced are considered, design values in many 3-year periods are higher.

4. Effective October 3, 2014, the Hayden, AZ area was designated nonattainment. Because of the form of the 2008 Pb NAAQS, one 3-month average ambient air concentration over 0.15 mg/m3 is enough to cause a violation of the Pb NAAQS. ADEQ's Globe Highway monitor registered four violations in 2011; however, at the time of designation the data had not been quality assured and certified and therefore was not relied upon as the basis for a nonattainment designation.