15A NCAC 02D .0405      OZONE

The ambient air quality standard for ozone measured by a reference method based on Appendix D of 40 CFR Part 50 and designated according to 40 CFR Part 53 shall be 0.070 parts per million (ppm), daily maximum eight-hour average. The standard shall be deemed attained at an ambient air quality monitoring site when the average of the annual fourth-highest daily maximum eight-hour average ozone concentration is less than or equal to 0.070 parts per million (ppm) as determined by Appendix U of 40 CFR Part 50, or equivalent methods established under 40 CFR Part 53.


History Note:        Authority G.S. 143-215.3(a)(1); 143-215.107(a)(3);

Eff. February 1, 1976;

Amended Eff. January 1, 2010; April 1, 1999; July 1, 1984; July 1, 1979; December 1, 1976;

Readopted Eff. January 1, 2018.