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1-Hour Ozone (1979) Section 185A Nonattainment Areas - NAAQS Revoked

As of June 15, 2005

Areas Listed Alphabetically Design
Values
(ppm)
Avg
Expected
Exceedences
No.
NAA
Counties
2000
Pop.
(1000's)
EPA
Region
State Located
in
MSA/
CMSA
Chico, CA 0.100 0.0 1 203 9 CA msa
Imperial Co, CA 0.110 0.0 1 142 9 CA no
Yuba City, CA 0.120 1.0 2 114 9 CA msa
 
3 Total Areas 4 459  
 

"Section 185A" was previously called "Transitional". Prior designation retained by operation of law in 1991 but without measured violation based on 1987-89 data. Totals were adjusted to account for multiple areas in a single county. The former 1-Hour Ozone designations and classifications as of June 15, 2004, are being retained in subpart C of Part 81 for purposes of the anti backsliding provisions of 40 CFR 51.905. 40 CFR 51.905(c) references subpart C of part 81 for the areas affected by the anti-backsliding regulation.


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