§51.150. Classification of regions for episode plans.
40 C.F.R. § 51.150
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.
Priority I Regions means any area with greater ambient concentrations than the following:
Sulfur dioxide— 100 µg/m 3 (0.04 ppm) annual arithmetic mean; 455 µg/m 3 (0.17 ppm) 24-hour maximum.
Particulate matter— 95 µg/m 3 annual geometric mean; 325 µg/m 3 24-hour maximum.
Carbon monoxide— 55 mg/m 3 (48 ppm) 1-hour maximum; 14 mg/m 3 (12 ppm) 8-hour maximum.
Nitrogen dioxide— 100 µg/m 3 (0.06 ppm) annual arithmetic mean.
Ozone— 195 µg/m 3 (0.10 ppm) 1-hour maximum.
Priority IA Region means any area which is Priority I primarily because of emissions from a single point source.
Priority II Region means any area which is not a Priority I region and has ambient concentrations between the following:
Sulfur Dioxides— 60-100 µg/m 3 (0.02-0.04 ppm) annual arithmetic mean; 260-445 µg/m 3 (0.10-0.17 ppm) 24-hour maximum; any concentration above 1,300 µg/m 3 (0.50 ppm) three-hour average.
Particulate matter— 60-95 µg/m 3 annual geometric mean; 150-325 µg/m 3 24-hour maximum.
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).
Areas which do not meet the above criteria are classified Priority III.
Notes, amendments, and revision history
Amendments
[51 FR 40668, Nov. 7, 1986, as amended at 58 FR 38822, July 20, 1993]
Source
Source: 51 FR 40668, Nov. 7, 1986, unless otherwise noted.
Authority
Authority: 23 U.S.C. 101; 42 U.S.C. 7401-7671q.
Source
Source: 36 FR 22398, Nov. 25, 1971, unless otherwise noted.
Amendments
[51 FR 40668, Nov. 7, 1986, as amended at 58 FR 38822, July 20, 1993]