Section R18-2-405. Special Rule for Major Sources of VOC or Nitro- gen Oxides in Ozone Nonattainment Areas Classified as Serious or Severe

A.      Applicability. The provisions of this Section only apply to sta- tionary sources of VOC or nitrogen oxides in ozone nonattain- ment areas classified as serious or severe. Unless otherwise provided in this Section, all requirements of Articles 3 and 4 of this Chapter apply.

B.       “Significant” means, for the purposes of a major modification of any major stationary source of VOC or nitrogen oxides, or for determining whether an otherwise minor source is major under the definition of major source in R18-2-401, any physi- cal change or change in the method of operations that results in net increases in emissions of either pollutant by more than 25 tons when aggregated with all other creditable increases and decreases in emissions from the source over the previous five consecutive calendar years, including the calendar year in which the increase is proposed.

C.      For any major source that emits or has the potential to emit less than 100 tons of VOC or oxides of nitrogen per year, a physical or operational change that results in a significant increase in VOC or oxides of nitrogen, respectively, from any

Department of Environmental Quality – Air Pollution Control

discrete operation, unit, or other pollutant emitting activity at the source shall constitute a major modification, except that the increase shall not constitute a major modification, if the owner or operator of the source elects to offset the increase by a greater reduction in emissions of VOC or oxides of nitrogen, as applicable, from other operations, units or activities at the source at an internal offset ratio of at least 1.3 to 1. If the owner or operator does not make such an election, the change shall constitute a major modification but BACT shall be sub- stituted for LAER when applying R18-2-403(A)(1) to the major modification.

D.      For any stationary source that emits or has the potential to emit 100 tons or more of VOC or oxides of nitrogen per year, a physical or operational change that results in any significant increase in VOC from any discrete operation, unit or other pol- lutant emitting activity at the source or oxides of nitrogen, respectively, shall constitute a major modification except that if the owner or operator of the source elects to offset the increase by a greater reduction in emissions of VOC or oxides of nitrogen, as applicable, from other operations, units or activities within the source at an internal offset ratio of at least

1.3 to 1, R18-2-403(A)(1) shall not apply to the change.

E.       For any new major source or major modification that is classi- fied as major because of emissions or potential to emit VOC or nitrogen oxides in an ozone nonattainment area classified as serious, the increase in emissions of these pollutants from the source or modification shall be offset at a ratio of 1.2 to 1. The offset shall be made in accordance with the provisions of R18- 2-404.

F.       For any new major source or major modification that is classi- fied as such because of emissions or potential to emit VOC or nitrogen oxides in an ozone nonattainment area classified as severe, the increase in emissions of these pollutants from the source or modification shall be offset at a ratio of 1.3 to 1. These offsets shall be made in accordance with the provisions of R18-2-404.

Historical Note

Former R9-3-405, Other industries, renumbered R9-3- 406, new Section adopted effective September 17, 1975 (Supp. 75-1). Former Section R9-3-405 repealed, new Section R9-3-405 adopted effective May 14,1979 (Supp. 79-1). Amended effective October 2, 1979 (Supp. 79-5). Former Section R9-3-405 renumbered without change as Section R18-2-405 (Supp. 87-3). Section R18-2-405 renumbered to R18-2-605, new Section R18-2-405 adopted effective November 15, 1993 (Supp. 93-4).

Amended by final rulemaking at 5 A.A.R. 4074, effective September 22, 1999 (Supp. 99-3). Amended by final

rulemaking at 18 A.A.R. 1542, effective August 7, 2012

(Supp. 12-2).