Each area designated nonattainment for ozone pursuant to
section 7407(d) of this title shall be classified at the time of such designation, under table 1, by operation of law, as a Marginal Area, a Moderate Area, a Serious Area, a Severe Area, or an Extreme Area based on the design value for the area. The design value shall be calculated according to the interpretation methodology issued by the Administrator most recently before
November 15, 1990. For each area classified under this subsection, the primary standard attainment date for ozone shall be as expeditiously as practicable but not later than the date provided in table 1.
TABLE 1 |
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Area class | Design value* | Primary standard attainment date** |
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*The design value is measured in parts per million (ppm). |
**The primary standard attainment date is measured from November 15, 1990. |
Marginal | 0.121 up to 0.138 | 3 years after November 15, 1990 |
Moderate | 0.138 up to 0.160 | 6 years after November 15, 1990 |
Serious | 0.160 up to 0.180 | 9 years after November 15, 1990 |
Severe | 0.180 up to 0.280 | 15 years after November 15, 1990 |
Extreme | 0.280 and above | 20 years after November 15, 1990 |