FOOTNOTES:

⁽¹⁾ This average is not to be exceeded more than once per year.

⁽²⁾ The lead standard was revised 10/15/2008.

⁽³⁾ The standard is attained when the 3-year average of the 98th percentile of the annual distribution of daily maximum 1-hour average concentrations is less than the standard.  The NO₂ standard was revised 1/22/2010.

⁽⁴⁾ The standard is attained when the expected number of days per calendar year with maximum hourly average concentrations above the standard is equal to or less than 1 over a three-year period, as determined by Appendix H of 40 CFR 50.

⁽⁵⁾ The standard is attained when the three-year average of the fourth-highest daily maximum 8-hour average is less than or equal to the standard.  The ozone standard was revised 3/27/2008.

⁽⁶⁾ The standard is attained when the expected annual arithmetic mean concentration, as determined in accordance with Appendix K to 40 CFR 50, is less than or equal to the standard.

⁽⁷⁾ The standard is attained when the 3-year average of the annual 99th percentile concentration is less than the standard.

⁽⁸⁾ The standard is attained when the 98th percentile concentration for the year is less than the standard.  The PM_2.5 standard was revised 10/17/2006.