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Electronic Code of Federal Regulations

e-CFR data is current as of December 5, 2019

Title 40Chapter ISubchapter CPart 51Subpart CC → §51.1307


Title 40: Protection of Environment
PART 51—REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS
Subpart CC—Provisions for Implementation of the 2015 Ozone National Ambient Air Quality Standards


§51.1307   Determining eligibility for 1-year attainment date extensions for an 8-hour ozone NAAQS under CAA section 181(a)(5).

(a) A nonattainment area will meet the requirement of CAA section 181(a)(5)(B) pertaining to 1-year extensions of the attainment date if:

(1) For the first 1-year extension, the area's 4th highest daily maximum 8-hour average in the attainment year is no greater than the level of that NAAQS.

(2) For the second 1-year extension, the area's 4th highest daily maximum 8-hour value, averaged over both the original attainment year and the first extension year, is no greater than the level of that NAAQS.

(b) For purposes of paragraph (a)(1) of this section, the area's 4th highest daily maximum 8-hour average for a year shall be from the monitor with the highest 4th highest daily maximum 8-hour average for that year of all the monitors that represent that area.

(c) For purposes of paragraph (a)(2) of this section, the area's 4th highest daily maximum 8-hour value, averaged over both the original attainment year and the first extension year, shall be from the monitor in each year with the highest 4th highest daily maximum 8-hour average of all monitors that represent that area.

[83 FR 63033, Dec. 6, 2018]

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