State of Oregon Department of Environmental Quality
Significant Air Quality Impact
Table 1 – OAR 340-200-0020
Pollutant | Averaging Time | Air Quality Area Designation | ||
Class I | Class II | Class III | ||
SO2 (µg/m3)* | Annual | 0.10 | 1.0 | 1.0 |
24-hour | 0.20 | 5.0 | 5.0 | |
3-hour | 1.0 | 25.0 | 25.0 | |
1-hour | --- | 8 | --- | |
PM10 (µg/m3) | Annual | 0.20 | 0.2 | 0.2 |
24-hour | 0.30 | 1.0 | 1.0 | |
PM2.5 (µg/m3) | Annual | 0.06 | 0.3 | 0.3 |
24-hour | 0.07 | 1.2 | 1.2 | |
NO2 (µg/m3) | Annual | 0.10 | 1.0 | 1.0 |
1-hour | --- | 8 | --- | |
CO (mg/m3)** | 8 hour | --- | 0.5 | 0.5 |
1-hour | --- | 2.0 | 2.0 | |
* micrograms/cubic meter **milligrams/cubic meter | ||||