74 FR 122 pgs. 30469-30470 - Ambient Air Quality Surveillance
Type: RULEVolume: 74Number: 122Pages: 30469 - 30470
FR document: [FR Doc. E9-15326 Filed 6-25-09; 8:45 am]
Agency: Environmental Protection Agency
Official PDF Version: PDF Version
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 58
Ambient Air Quality Surveillance
CFR Correction
In Title 40 of the Code of Federal Regulations, Parts 53 to 59, revised as of July 1, 2008, on page 271, in appendix G to part 58, Table 2 is corrected to read as follows:
Appendix G to Part 58-Uniform Air Quality Index (AQI) and Daily Reporting
| These breakpoints | O 3 (ppm) 8-hour | O 3 (ppm) 1-hour1 | PM 2.5 (µg/m3 ) | PM 10 (µg/m3 ) | CO (ppm) | SO 2 (ppm) | NO 2 (ppm) | Equal these AQI's | AQI | Category |
|---|---|---|---|---|---|---|---|---|---|---|
| 0.000-0.059 | 0.0-15.4 | 0-54 | 0.0-4.4 | 0.000-0.034 | (3 ) | 0-50 | Good. | |||
| 0.060-0.075 | 15.5-40.4 | 55-154 | 4.5-9.4 | 0.035-0.144 | (3 ) | 51-100 | Moderate. | |||
| 0.076-0.095 | 0.125-0.164 | 40.5-65.4 | 155-254 | 9.5-12.4 | 0.145-0.224 | (3 ) | 101-150 | Unhealthy for Sensitive Groups. | ||
| 0.096-0.115 | 0.165-0.204 | 4 65.5-150.4 | 255-354 | 12.5-15.4 | 0.225-0.304 | (3 ) | 151-200 | Unhealthy. | ||
| 0.116-0.374 | 0.205-0.404 | 4 150.5-250.4 | 355-424 | 15.5-30.4 | 0.305-0.604 | 0.65-1.24 | 201-300 | Very Unhealthy. | ||
| (2 ) | 0.405-0.504 | 4 250.5-350.4 | 425-504 | 30.5-40.4 | 0.605-0.804 | 1.25-1.64 | 301-400 | |||
| (2 ) | 0.505-0.604 | 4 350.5-500.4 | 505-604 | 40.5-50.4 | 0.805-1.004 | 1.65-2.04 | 401-500 | Hazardous. | ||
| 1 Areas are generally required to report the AQI based on 8-hour ozone values. However, there are a small number of areas where an AQI based on 1-hour ozone values would be more precautionary. In these cases, in addition to calculating the 8-hour ozone index value, the 1-hour ozone index value may be calculated, and the maximum of the two values reported. | ||||||||||
| 2 8-hour O 3 values do not define higher AQI values (= 301). AQI values of 301 or greater are calculated with 1-hour O 3 concentrations. | ||||||||||
| 3 NO 2 has no short-term NAAQS, and can generate an AQI only above the value of 200. | ||||||||||
| 4 If a different SHL for PM 2.5 is promulgated, these numbers will change accordingly. | ||||||||||
[FR Doc. E9-15326 Filed 6-25-09; 8:45 am]
BILLING CODE 1505-01-D