40 C.F.R. § 51.150

Current through September 30, 2024
Section 51.150 - Classification of regions for episode plans
(a) This section continues the classification system for episode plans. Each region is classified separately with respect to each of the following pollutants: Sulfur oxides, particulate matter, carbon monoxide, nitrogen dioxide, and ozone.
(b)Priority I Regions means any area with greater ambient concentrations than the following:
(1) Sulfur dioxide-100 [MICRO]g/m3 (0.04 ppm) annual arithmetic mean; 455 [MICRO]g/m3 (0.17 ppm) 24-hour maximum.
(2) Particulate matter-95 [MICRO]g/m3 annual geometric mean; 325 [MICRO]g/m3 24-hour maximum.
(3) Carbon monoxide-55 mg/m3 (48 ppm) 1-hour maximum; 14 mg/m3 (12 ppm) 8-hour maximum.
(4) Nitrogen dioxide-100 [MICRO]g/m3 (0.06 ppm) annual arithmetic mean.
(5) Ozone-195 [MICRO]g/m3 (0.10 ppm) 1-hour maximum.
(c)Priority IA Region means any area which is Priority I primarily because of emissions from a single point source.
(d)Priority II Region means any area which is not a Priority I region and has ambient concentrations between the following:
(1) Sulfur Dioxides-60-100 [MICRO]g/m3 (0.02-0.04 ppm) annual arithmetic mean; 260-445 [MICRO]g/m3 (0.10-0.17 ppm) 24-hour maximum; any concentration above 1,300 [MICRO]g/m3 (0.50 ppm) three-hour average.
(2) Particulate matter-60-95 [MICRO]g/m3 annual geometric mean; 150-325 [MICRO]g/m3 24-hour maximum.
(e) In the absence of adequate monitoring data, appropriate models must be used to classify an area under paragraph (b) of this section, consistent with the requirements contained in § 51.112(a) .
(f) Areas which do not meet the above criteria are classified Priority III.

40 C.F.R. §51.150

51 FR 40668, Nov. 7, 1986, as amended at 58 FR 38822, July 20, 1993