Section R18-2-205. Nitrogen Oxides (Nitrogen Dioxide)

A.      The primary ambient air quality standards for oxides of nitro- gen, measured in the ambient air as nitrogen dioxide, are:

1.        53 parts per billion – annual average concentration.

2.        100 parts per billion – one-hour average concentration.

B.       The secondary ambient air quality standard for nitrogen diox- ide is 0.053 (parts per million (100 micrograms per cubic meter) -- annual arithmetic mean.

C.      The levels of the standards shall be measured by a reference method based on 40 CFR 50, Appendix F or a federal equiva- lent method designated in accordance with 40 CFR 53.

D.      The annual primary standard is met when the annual average concentration in a calendar year is less than or equal to 53 ppb, as determined in accordance with 40 CFR, Appendix S for the annual standard.

E.       The one-hour primary standard is met when the three-year average of the annual 98th percentile of the daily maximum one-hour average concentration is less than or equal to 100 parts per billion, as determined in accordance with 40 CFR 50, Appendix S.

F.       The secondary standard is attained when the annual arithmetic mean concentration in a calendar year is less than or equal to

0.053 ppm, rounded to three decimal places, with fractional parts equal to or greater than 0.0005 ppm rounded up. To demonstrate attainment, an annual mean shall be based upon hourly data that is at least 75% complete or upon data derived from the manual methods, that is at least 75% complete for the scheduled sampling days in each calendar quarter.

Historical Note

Amended effective December 22, 1976 (Supp. 76-5). Former Section R9-3-206 repealed, new Section R9-3- 206 adopted effective May 14, 1979 (Supp. 79-1).

Amended effective October 2, 1979 (Supp. 79-5).

Amended effective August 29, 1980 (Supp. 80-4).

Amended by deleting subsections (B) through (D) effec- tive September 22, 1983 (Supp. 83-5). Former Section R9-3-206 renumbered without change as Section R18-2- 206 (Supp. 87-3). Former Section R18-2-205 renumbered to R18-2-204, new Section R18-2-205 renumbered from R18-2-206 and amended effective September 26, 1990 (Supp. 90-3). Amended by final rulemaking at 18 A.A.R.

1542, effective August 7, 2012 (Supp. 12-2).