| AMBIENT AIR QUALITY STANDARDS | |||
|---|---|---|---|
| Pollutant | Standard | Unit | Comments | 
| Particulate Matter | |||
| PM10 - 24 hour | 150 | ug/m3 | Primary and Secondary Standard: Maximum 24-hour average concentration with not more than one expected exceedance per year. | 
| PM2.5 - 24 hour | 35 | ug/m3 | Primary and Secondary Standard: based upon the annual 98th percentile averaged over a three year period. | 
| PM2.5 - Annual | 9 | ug/m3 | Primary and Secondary Standard: Maximum expected annual arithmetic mean averaged over three years. | 
| Sulfur Dioxide | |||
| Annual | 10 | ppb | Secondary Standard: 10 ppb, averaged over a three year period. | 
| 1 hour | 75 | ppb | Primary Standard: based upon the annual 99th percentile averaged over a three year period. | 
| Carbon Monoxide | |||
| 8 hour | 9.0 | ppm | Primary Standard: (10 milligrams per cubic meter of air), maximum 8-hour average concentration not to be exceeded more than once per year. | 
| 1 hour | 35.0 | ppm | Primary Standard: (40 milligrams per cubic meter of air), maximum 1-hour average concentration not to be exceeded more than once per year. | 
| Ozone | |||
| 8 hour
                                     (2015 std)  | 
                                0.070 | ppm | Primary and Secondary Standard: Fourth highest maximum 8-hour average concentration averaged over a three year period. | 
| Nitrogen Dioxide | |||
| Annual | 53 | ppb | Primary and Secondary Standard: maximum annual arithmetic mean concentration. | 
| 1 hour | 100 | ppb | Primary Standard: based upon the annual 98th percentile averaged over a three year period. | 
| Lead | |||
| Rolling 3 month average | 1.5 | ug/m3 | Primary and Secondary Standard: annual maximum rolling 3 month average averaged over a three year period. |